In general, a solar battery device includes a configuration shown in FIG. 1. In FIG. 1, the reference numeral 1 represents a p-type semiconductor substrate formed in a plate-like shape, and having a size ranging from 100 to 150 mm square and a thickness ranging from 0.1 to 0.3 mm. The p-type semiconductor substrate herein includes a polycrystalline or monocrystalline silicon and the like and is doped with a p-type impurity such as boron and the like. A manufacturing method for the solar battery device will be hereinafter described. First, this substrate is doped with an n-type impurity such as phosphorus and the like to form an n-type diffusion layer 2. Next, an antireflection film 3 such as silicon nitride (SiN) and the like is provided. Then, a conductive aluminum paste is printed on a backside of the substrate by a screen printing method. Thereafter, by drying and firing the conductive aluminum paste, a backside electrode 6 and a BSF (Back Surface Field) layer 4 are formed simultaneously. Successively, a conductive silver paste is printed on a front-side of the substrate. Then, the conductive silver paste is dried and fired to form front-side electrodes 5. With regard to the solar battery device manufactured in such a manner, the front-side electrodes 5 include busbar electrodes and current-collecting finger electrodes. The busbar electrodes are for taking out light-generating current generated by the solar battery device to the outside thereof. The current-collecting finger electrodes are connected to these busbar electrodes. Hereinafter, while a surface of the substrate which is to be a light receiving surface side of the solar battery is referred to as a front-side, a surface of the substrate which is to be the opposite side of the light receiving surface is referred to as a backside.
With regard to the solar battery device manufactured in such a manner, the electrodes are generally formed by the screen printing method and firing as mentioned above. In the screen printing method, in order to form the finger electrodes and the busbar electrodes on the light receiving surface of the solar battery cell, for example, a conductive paste containing a silver powder, an organic vehicle, and a glass frit is generally used. Solids of various types of inorganic oxides or conductive materials and the like may be added to this conductive paste to improve performance thereof. When applying this conductive paste to a predetermined position of the semiconductor substrate by the screen printing method and firing the paste, the silver powder sinters each other under high-temperature to form silver electrodes. At the same time, the glass frit is softened to melt the antireflection film and reach the n-type diffusion layer, and the silver electrodes are electrically connected to the n-type diffusion layer. In general, such a method is called Fire Through, which is adopted as a method for forming electrodes of various solar battery cells.
With regard to the aforementioned method for forming electrodes, in order to fire the electrodes, the semiconductor substrate should be subjected to high-temperature treatment at 600° C. or more. Due to this high-temperature treatment, the semiconductor substrate is damaged by heat. Alternately, a contaminant which is a lifetime killer gettering upon the diffusion layer may be released inside the semiconductor substrate, which decreases a lifetime of the semiconductor substrate. Furthermore, the electrodes formed by Fire Through are obtained by sintering the conductive particle for a short time. Therefore, the following electrodes may be easily formed, which is a problem. That is, electrodes which have small density compared to electrodes formed by plating and have plenty cavities in front-sides or insides of the electrodes, and each area of those electrodes connected to the semiconductor substrate is not uniform and is easily peeled off, for example. Such a decrease in the lifetime and abnormality in the electrodes may cause problems in performance or long-term reliability of the solar battery cell so that solutions to these problems are demanded.
In order to solve the problems, for example, Patent Document 1 discloses a method where a solar battery cell formed by firing electrodes is subjected to heat treatment under an atmosphere including at least hydrogen gas to improve contact resistance of the electrodes. However, in the method disclosed in Patent Document 1, a process is added after firing, which leads to increase costs. Furthermore, there is a problem in safety of the process since hydrogen gas, which is difficult to handle, is used. Therefore, a much simpler method to solve the problems is demanded.


This invention relates generally to the field of collapsible reusable shipping containers of the type disclosed in my prior U.S. Pat. No. 3,443,737 granted Apr. 13, 1969; and more particularly to an improved sliding door construction which may be incorporated into a vertical wall of such container to impart greater structural rigidity thereto under fluid loads which tend to exert a hydraulic outward pressure against the inner surfaces of the container.
In the container disclosed in the above patent, the door is supported in a through opening in a side wall by a pair of extrusions of generally H-shaped cross section, each of which define opposed recesses engaging a vertically disposed edge of the door opening, and a corresponding vertical edge on the door. While this arrangement does guide the door smoothly during opening and closing movement, the pressure on the edges of the abutting wall is entirely frictional in nature, and when the container is loaded, for example, with a relatively heavy particulate load, resistance to outward deformation of the wall and the door depends almost entirely upon the engagement of the wall at the lower edges thereof with the rigid pallet, and the engagement of the upper edges thereof beneath the rim of the detachable lid. Depending upon the height and thickness of the walls of the container, and the density of the fluid load, this construction has at times proven inadequate. It is, of course, possible to rigidly interconnect the extrusions to the edges of the wall, but since the door edges must remain free to move in order to selectively open the door, this expedient has but limited utility.


1. Field of the Invention
The present invention relates to a clock processing part and more particularly to an internal clock generating circuit and a method for the same.
2. Description of the Related Art
Typically, a central processing unit (CPU) and a semiconductor memory device are interconnected through a signal bus. In such a case, the CPU and the semiconductor memory device function as master and slave, respectively. The CPU master transmits data including address, command, writing data, and a clock required for sampling data to the memory device slave.
An external clock transmitted through the signal bus may be a clock aligned or centered to the data as shown in FIGS. 1 and 2. The slave memory receives the external clock and generates an internal clock needed for sampling data. In order to correctly sample data, the internal clock should be a data-centered clock as shown in FIG. 1b. If an external clock is a data-aligned clock, it is relatively difficult to generate a data centered internal clock. However, a gradual increase in the data rate/pin decreases the number of valid data windows. If the data and clock have slightly different paths in the system, there may be a bigger skew between the clock and pin that will be applied to the slave. The problem gets worse in a double data rate (DDR) product, which receives two pieces of data at one clock cycle as shown in FIG. 2b, compared to a single data rate (SDR) product as shown in FIG. 2a.
When an external clock is centered or aligned to data, a system designer desires to adopt to the slave a function of intentionally pushing or pulling the timing of a clock on a time axis as shown in FIG. 3 in order to use an internal clock adjusted to a valid window of data. At this time, the slave memory performs a setup/hold centering function of a data sampling clock by pushing or pulling the timing of a clock on the time axis in response to a setting signal.
Typically, a delay line or delay chain is constructed with an inverter chain having a plurality of inverters as internal delay elements. The inverter chain is constructed with inverters connected in at least more than two levels having a relatively large amount of a unit delay. Therefore, it is not adequate to a case that requires a more precise delay.
What is needed is a delay line or delay chain providing improved resolution degree by decreasing the amount of unit time delay and providing more precise control of the delay while minimizing skew in the clock signal.
Therefore, the present invention is disclosed to solve the aforementioned problems and it is an object of the invention to provide an internal clock generating circuit to generate an internal clock precisely controlled as much as the necessary amount of delay in an improved resolution degree and a method for the same.
It is another object of the present invention to provide an internal clock generating method and the related circuit that can precisely sample data even when there is a skew between clock and data to be applied to a semiconductor memory.
It is a still another object of the present invention to provide an internal clock generating method and the related circuit that can control the delay time in response to an external signal.
It is a further another object of the present invention to provide an internal clock generating method and the related circuit that can minimize skew of an output clock, but in an improved resolution degree.
In order to accomplish the aforementioned objects in accordance with an aspect of the present invention, disclosed is an internal clock generating circuit of a semiconductor device comprising a delay chain having a plurality of delay units for generating multi-phase clocks by adjusting an input clock, a thermometer converter for outputting a thermometer code value in response to an input selection data, and a multiplexer for selectively outputting one of a plurality of clocks input from the delay chain in response to the thermometer code value.
In another aspect of the invention the multiplexer selectively outputs one of the plurality of clocks applied from the delay chain by dividedly multiplexing the thermometer code value into two stages of upper and lower bits.
In another aspect of the invention the delay chain additionally includes regenerators to restore a pulse form of a clock.
In another aspect of the invention the delay unit of the delay chain is constructed with RC delays.
In another aspect of the invention the regenerator is a short type pulse generator.
In another aspect of the invention a pulse regenerator is additionally included to restore a pulse form of a clock output from the multiplexer.
In another aspect of the invention the pulse regenerator is a short type pulse regenerator.
In another aspect of the invention the regenerators are respectively positioned in symmetry at positions where +/xe2x88x92 delay of the delay units against the thermometer code value changes non-linearly.
In another aspect of the invention the selection data is a binary code data applied from outside.
In another aspect of the invention the delay unit of the delay chain is constructed with path gates.
Disclosed is a method of generating clock signals in a semiconductor device comprising the steps of generating multi-phase clock signals by adjusting an input clock signal through a delay chain having a plurality of delay units, decoding a thermometer code value in accordance with selection data, outputting one of the plurality of clock signals in response to the thermometer code value, and restoring a pulse shape of the output clock signal into its original state and outputting it as a delay-controlled internal clock signal.
Disclosed is a semiconductor clock signal circuit, comprising means for generating multi-phase clock signals by adjusting an input clock signal through a delay chain having a plurality of delay units, means for decoding a thermometer code value in accordance with selection data, means for outputting one of the plurality of clock signals in response to the thermometer code value, and means for restoring a pulse shape of the output clock signal into its original state and outputting it as a delay-controlled internal clock signal.


In digital modulation schemes, data symbols are transmitted by modulating the amplitude and/or phase of a carrier wave having a certain frequency. For example, a data symbol typically represents an M-bit fragment of data, resulting in N=2M possible symbols. The set of N possible symbols are mapped to a set of N respective fixed complex numbers, which are referred to as constellation points and may be represented in the complex plane in the form of a constellation diagram. In order to transmit a given symbol, a complex carrier wave is multiplied by the value of the constellation point corresponding to the symbol, thereby modulating the amplitude and phase of the carrier by amounts corresponding respectively to the amplitude and phase of the constellation point.
Various constellations designs are used in various modulation schemes, including N-Quadrature Amplitude Modulation (QAM) in which the constellation comprises a square lattice of N regularly-spaced constellation points, and N-Phase Shift Keying (PSK) in which the constellation comprises a circular lattice of N regularly-spaced constellation points. Various other constellation designs are also known.
In order to measure the performance of a given constellation or between different constellations, various metrics may be used.
For example, capacity is a measure of the maximum rate of information that can be reliably transmitted over a communications channel. The maximum theoretical capacity of a channel is given by a well-known formula derived by Shannon. The Coded Modulation (CM) capacity is the maximum capacity achievable using a fixed non-uniform constellation without any coding constraints. The Bit Interleaved Coded Modulation (BICM) capacity is the maximum capacity achievable using a certain binary Forward Error Correction (FEC) scheme and fixed non-uniform constellation.
In addition, when comparing two systems, the difference in Signal-to-Nose Ratio (SNR) required achieving the same Bit Error Rate (BER) may be referred to as the SNR gain.
In contrast to uniform constellations, a non-uniform constellation is a constellation in which the constellation points are not regularly spaced. One advantage of using a non-uniform constellation is that performance may be increased, for example for SNR values below a certain value. For example, the BICM capacity may be increased by using a non-uniform constellation, when compared to an equivalent uniform constellation. Using a non-uniform constellation may also achieve a SNR gain over an equivalent uniform constellation.
A constellation may be characterised by one or more parameters, for example specifying the spacing between constellation points. Since constellation points of a uniform constellation are regularly spaced, the number of parameters needed to characterise a uniform constellation is typically equal to 1. For example, for a QAM type constellation, the constellation is characterised by the (constant) lattice spacing. For a PSK type constellation, the constellation is characterised by the (constant) distance of each constellation point from the origin. On the other hand, since the spacing between constellation points in a non-uniform constellation varies, the number of parameters needed to characterise a non-uniform constellation is relatively high. The number of parameters increases as the order of the constellation (i.e. the number of constellation points) increases.
One problem with designing a non-uniform constellation is that a relatively high number of parameters need to be searched to find the optimum constellation. This problem is increased in the case of constellations of higher order. In the case of high-order constellations (e.g. constellations comprising more than 1024 constellation points), an exhaustive search across all parameters may be unfeasible.
Therefore, what is desired is a technique for designing non-uniform constellations, and in particular, for designing non-uniform constellations for optimising performance (e.g. capacity and SNR performance). What is also desired is a technique for designing non uniform constellations using an algorithm having a relatively low complexity and relatively high computational efficiency.


The present invention relates to a yarn carrier, and a method and apparatus for manufacturing the same, and wherein the carrier is characterized by the ability to accommodate the tail of the yarn to be wound thereon between the carrier and the base plate of the winding machine, without severing the yarn tail during winding of the package.
Yarn carriers of the described type are designed to be wound with a yarn, and with a yarn tail extending from the carrier to permit the trailing end of the yarn on an exhausted carrier to be tied to the leading end of the yarn on a succeeding fully wound carrier. The yarn tail is typically formed at the beginning of the yarn winding operation by taking a length of yarn and extending it over the open large end of the carrier. The carrier is then mounted into a cradle of the winding machine which includes a base plate which fits into the large end of the cone and holds the yarn tail. A nose plate secures the small end of the carrier for proper rotation about a fixed axis in the machine, and the carrier is rotated by a rotating drum which engages the surface of the carrier and which feeds the yarn onto the rotating carrier in a predetermined reciprocating pattern.
Such yarn carriers are commonly manufactured from a sheet of paper which is wound about a mandrel to form a frusto-conical tubular member composed of several layers of the paper sheet. Both ends of the resulting tubular member are trimmed during the winding operation to provide even end surfaces, and the carrier is then finished to provide a rounded nose at the small end. The above end trimming operation is conventionally effected by a knife blade which moves radially inwardly against the paper sheet as it is being wound, and this operation inherently produces a rather sharp, annular burr at the intersection of the inner wall surface and the cut end surface at the large end of the tubular member. The annular burr at the large end is undesirable, in that it acts to sever the yarn tail when the yarn tail is positioned between the large end of the carrier and the base plate of a winding machine in accordance with the above described winding procedure. More particularly, the carrier often rotates relative to the base plate during the starting and stopping of the winding operation, and this relative movement causes the annular burr to sever the yarn tail.
To alleviate the severance problem, it has been proposed to polish the inside wall at the large end of the tubular member, to eliminate the burr. More particularly, this prior polishing operation has been performed with the use of a chuck having a profile matching the desired profile of the large end of the carrier, and it resulted in a slightly beveled edge on the inside of the large end of the carrier, and with the paper material at the large end being compressed to form a relatively hard inner surface.
While the polishing of the inner end of the carrier has been a generally satisfactory method of removing the sharp annular burr and thereby avoiding the severance of the yarn tail during the winding process, modern winding machines have been designed with a universal base plate which is adapted to receive carriers of various angles of taper, to thereby avoid the expense of changing base plates whenever a different style of carrier is being wound. While such universal base plates are efficient from this point of view, they create a further problem in that the yarn tail is often pinched by a non-flush fit between the inside end surface of the carrier and the base plate, and such pinching in turn often results in the severance of the yarn tail. This problem is particularly acute where the carrier includes a hardened inner end surface as described above, since the hardened nature of the inner end surface tends to aggravate the severity of the pinching problem.
Other solutions for the problem of severing the yarn tail have been proposed, note for example, U.S. Pat. Nos. 4,700,834 and 4,700,904, both issued to Martinez. These prior patents suggest the formation of spaced apart grooves, or grooves of crisscross configuration, or forming a ring of loose non-woven fibrous material of substantial thickness on the inside surface of the large end of the carrier. However, these rather elaborate constructions do not address the problem associated with the sharp annular burr as discussed above.
It is accordingly an object of the present invention to provide a yarn carrier, and a method and apparatus for manufacturing the same, which effectively avoids the above noted problem of severance of the yarn tail during the winding operation.


Portable handheld devices such as smartphones and tablet computing devices are widely distributed around the globe. In some markets, nearly every potential consumer carries their own device and uses it to send and transmit information. Devices are configured to use phone networks, like 3G and 4G networks, as well as data networks such as Internet connections accessed through Wi-Fi. Accordingly, these devices can offer their users the ability to access content almost constantly while they are turned on.
This ubiquitous and persistent connectivity of consumers offer obvious opportunities for gaming, marketing, news, communication, entertainment, and other electronic media. However, sophisticated and interactive electronic media such as interactive apps and games, group chats or “tweeting”, social networking apps with frequent updates, streaming music sites, or internet auction sites can quickly burden server capability as the volume of users increases. Further, old paradigms, such as creating a web page and posting it or giving people an app to play with on their phone, are being replaced by demand for continuous active content delivery such as games, apps, or media players that involve a person with real-time events, other parties, and new information on-the-fly.
The volume of content now involved in electronic media, the number of connected users, and the resulting demands on existing content delivery technologies leads to lag-times and increased latencies, as well as slow and sometimes stopped or broken data connections. Content preparation and delivery methods are poorly suited to the demands now being placed on them. As a result, users experience delays in obtaining access to content. Also, certain kinds of content requiring quick interactivity among high numbers of users is difficult to distribute at optimal rates.


The present invention relates to a tamper-resistant information processing device. It is particularly very effective when applied to cards such as the IC card.
An IC card is a device used for such purposes as to hold personal information which should not be altered without permission, to encrypt data by use of a cryptographic key (which is secret information), or to decrypt ciphertext. The IC card does not have any power source therein, but when it is inserted in a,reader/writer for IC cards, the IC card is supplied with power and becomes operable. When the IC card is in the operable state, it receives a command transmitted from the reader/writer, and carries out a process such as transfer of data according to the command.
FIG. 1 shows a basic conceptual configuration of an IC card in which an IC card chip 102 is mounted on a card 101. As shown in the figure, an IC card generally has disposed thereon a supply voltage terminal Vcc, a ground terminal GND, a reset terminal RST, an input/output terminal I/O, and a clock terminal CLK. The positions of these terminals are specified in ISO International Standard 7816. The IC card receives power from the reader/writer and exchanges data with the reader/writer. Such communication between the IC card and the reader/writer is described, for example, on page 41 of a book entitled xe2x80x9cSMARTCARD HANDBOOKxe2x80x9d authored by W. Rankl and W. Effing and published by John Wiley and Sons in 1997.
The configuration of the semiconductor chip mounted on an IC card is basically the same as that of the ordinary microcomputer. FIG. 2 is a block diagram showing the basic configuration of the semiconductor chip mounted on an IC card. As shown in FIG. 2, the semiconductor chip for cards has a central processing unit (CPU) 201, a memory device 204, an input/output (I/O) port 207, and coprocessor 202. Some systems do not employ the coprocessor. The CPU 201 is a device for performing logic and arithmetic operations, while the memory device 204 stores programs and data. The input/output port is a device for communicating with the reader/writer. The coprocessor performs cryptographic processing itself or operations necessary for cryptographic processing at high speed. For example, types of coprocessors employed include a particular operation device for performing a residue operation for RSA and a cryptographic device for performing a rounding process for DES. There are many IC card processors which do not have any coprocessors. A data bus 203 is a bus connecting one device to another.
The memory device 204 includes such memories as a ROM (Read Only Memory), a RAM (Random Access Memory), and an EEPROM (Electric Erasable Programmable Read Only Memory). Information stored in a ROM cannot be altered, and therefore ROMs are used to store mainly programs. Information stored in a RAM, on the other hand, can be freely rewritten, but the stored information disappears once the power supply is interrupted. That is, since the power supply to an IC card is interrupted when the IC card is removed from the reader/writer, the RAM can no longer hold its contents after that. The EEPROM, in contrast, can continue holding its contents even if its power supply is interrupted. Therefore, the EEPROM is used for storing data which it is necessary to rewrite, and hold even when the IC card is removed from the reader/writer. For example, the number of the remaining call units of a prepaid telephone card is rewritten each time the card is used, and the call unit data must continue to be held even after the card is removed from the reader/writer. This is why the call unit data of the prepaid card is held in an EEPROM.
The present invention provides a tamper-resistant information device for use with cards having high security.
Specifically, an object of an embodiment according to the present invention is to reduce the correlation between the contents of data processing operations and consumed currents in a card component such as the IC card chip. Reducing the correlation between the contents of the data processing operations and the consumed currents in the chip makes it difficult to estimate what is being processed in the IC card chip and how, and to derive the cryptographic key from the observed waveforms of the consumed currents. Thus, the present invention provides cards with high security.
Since IC cards have an IC card chip mounted thereon which is capable of holding programs and important information, they are used to store important information or internally perform cryptographic processing. It has been conventionally considered that the difficulty of breaking a code stored in an IC card is the same as the difficulty of deriving its encryption algorithm. However, it is pointed out that the details of the encryption processing operation and the cryptographic key may be derived by observing and analyzing the current consumed during the encryption process in the IC card, which may be easier than deriving of the encryption algorithm. The consumed current is obtained by measuring the current supplied from the reader/writer to the IC card. The details of this attack and its danger are described, for example, on page 263 (8.5.1.1 Passive Protective Mechanisms) of the book xe2x80x9cSMARTCARD HANDBOOKxe2x80x9d authored by W. Rankl and W. Effing and published by John Wiley and Sons. The following specifically describes the attack. Each CMOS constituting an IC card chip consumes a current when its output state switches from xe2x80x9c1xe2x80x9d to xe2x80x9c0xe2x80x9d or vice versa. Particularly, a large current flows through the data bus 203 when the bus value changes from 1 to 0 or vice versa. The current of the bus driver, the wiring employed, and the capacitance associated with transistors connected to the wiring cause such a current to flow. Therefore, it is possible to identify what is operating in the IC card chip by observing the consumed current.
FIG. 3 shows single-cycle waveforms of currents consumed in an IC card chip. The current waveforms are different from one another as indicated by reference numerals 301 and 302, depending on the processed data. More specifically, such a difference occurs depending on data flowing through the bus 203 and data processed in the central processing unit 201.
The coprocessor 202 can perform, for example, 512-bit modular multiplication in parallel with the CPU processing. This means that it is possible to observe the waveform of a current different from that in the CPU for a long time. Therefore, the number of operations performed by the coprocessor can be measured by observing its particular current waveform. If the number of operations performed by the coprocessor has some relationship to the cryptographic key, it might be possible to derive the key from the number of the operations.
Further, if which operation is performed or what is operated by the coprocessor changes depending on the cryptographic key, the dependency might be found by observing the corresponding change in the consumed current, and the cryptographic key might be derived.
Similarly, in the CPU, the influence of each bit value of the cryptographic key on processed data might be obtained by changing the data a plurality of times and observing the corresponding change in each consumed current. It might be possible to derive the cryptographic key by statistically processing the waveforms of these consumed currents.
The ideas on which embodiments of the present invention are based include: dividing a process performed in an IC card so that attackers cannot specify the process as a whole; and inserting a dummy process. These methods make it difficult to identify the original process and derive the cryptographic key from the waveforms of the consumed currents.
A tamper-resistant device as represented by the IC card chip is regarded as an information processing device having one or more data processing means which each comprise: a program storage unit for storing a program; a memory unit having a data storage unit for storing data; and a central processing unit (CPU) for performing a predetermined process to process data according to the program; wherein the program is composed of process instructions for giving an execution direction to the CPU.
A method according to an embodiment of the present invention for scrambling the correlation between processed data and consumed currents in an IC card chip is to divide the data into pieces, and instead of performing a given operation(s) on the entire data as a whole, perform another different operation(s) on each piece of the divided data so as to still produce the same results as those that will be obtained if the given operation is performed on the entire data as a whole. As a result, the essential operation(s) can be concealed.
Specifically, pieces of scramble data R1, R2, . . . , and Rn are prepared. Original data D1 to be processed is divided into data blocks D1[1], D1[2], . . . , and D1[n].
The data blocks and scramble data are used to produce scrambled data blocks x[1], x[2], . . . , and x[n] by employing, for example, one of the following methods.
(1) logical AND operation
(2) x[1]=0, x[2]=xxe2x88x92v
(3) x[1]=x AND R, x[2]=x AND xcx9cR, where xcx9cR is the inverse of R
That is, by using the scramble data R1, R2, . . . , and Rn, where R1 XOR R2 XOR . . . XOR Rn=2{circumflex over ( )}Lxe2x88x921 (L is the bit length of D1), the data block (original data) D1 is divided so that D2[1]=D1 AND R1, D2[2]=D1 AND R2, . . . , and D2[n]=D1 AND Rn, where n is an integer. In this case, the equation D2[1]+D2[2]+ . . . +D2[n]=D1 holds. In addition to the above logical AND operation, an ordinary addition operation or subtraction operation can be used for this purpose. A ring multiplication operation is performed on values obtained as a result of the above addition operation or subtraction operation to produce the final proper value. Since the randomly divided data blocks D2[1], D2[2], . . . , and D2[n] are used instead of directly using the original data D1, it is difficult to determine the original data D1 from information included in the observed current waveform alone. When a plurality of waveforms are statistically processed (for example, averaged to remove noise components from them), the characteristics of each waveform are eliminated, which further makes it difficult to determine original data (effectively hiding original information). It should be noted that the above randomly divided data may be produced through a division operation using pseudorandom numbers.
Another method for reducing the correlation between the contents of the data processing operation and the consumed current is to change the original data to be processed, and instead of performing a given operation on the original data, perform another different operation on the changed data so as to still produce the final proper results but consume a current different from that which will be consumed if the given operation is performed on the original data.
Specifically, random scalar data R for scrambling other data is prepared. Then, by using the prepared random scalar data R and a particular element V, the element to be processed is changed from x to x+R*V, where the symbols xe2x80x9c+xe2x80x9d and xe2x80x9c*xe2x80x9d denote ordinary addition and multiplication operations, respectively. The element V has the characteristic that whether or not the element V is added to data, an operation on the data produces the same results as if the element V were not added to the data. The above x+R*V can be used as an exponent or a scalar to scramble statistical processing of waveform observation data of consumed currents. It should be noted that the above element V acts as a number of 1 in a multiplication operation, and 0 in an addition operation. For example, when N=pq, where N is the modulus of a public key in the RSA cryptosystem, the element V is a multiple of (pxe2x88x921) (qxe2x88x921). When a scalar multiple of a base point on an elliptic curve is used, the element V is a multiple of the order of the base point.
Further, randomly determining the order in which each piece of the divided data is processed further makes it difficult to find the correlation between the contents of the data processing operation and the consumed current.
Still further, combining all the above methods for scrambling encrypted data is effective in further reducing the correlation between the contents of the data processing operation and the consumed current.
The present invention can be applied to information hiding for modular multiplication and modular exponentiation in the RSA cryptography. Furthermore, in the elliptic curve cryptography, it can be applied to information hiding for multiplication and division in underlying fields, and the calculation of a scalar multiple of a base point. In modular multiplications, the logical AND operation described above is used to divide data, and then the distributive law is used to obtain the final proper result from the divided data. In the modular exponentiation and the calculation of a scalar multiple of a base point, the exponent is divided by means of ordinary subtraction, then modular exponentiation is performed on each piece of the divided exponent, and the product of the operation results is calculated to obtain the final result (proper answer). These operations are effective in scrambling encrypted data. It should be noted that the above modular multiplications include multiplication in a prime field.


1. Field of the Invention
The present invention relates generally to an antenna assembly, and more particularly to an antenna assembly with a moveable antenna assembling on an electronic device, such as notebook.
2. Description of the Prior Art
Since the wireless communication technology of using electromagnetic wave to transmit signals has the effect of remote device transmission without cable connection, and further has the mobility advantage, therefore the technology is widely applied to various products, such as moveable phones, notebook computers, intellectual home appliance with wireless communication features. Because these devices use electromagnetic wave to transmit signals, the antenna used to receive electromagnetic wave also becomes a necessity in the application of the wireless communication technology. An antenna almost requires to receive and send signals in different directions. But the radiating performance of antennas inside the electronic devices is dissatisfactory due to the influence of components in the electronic devices. Outer antennas can eliminate the trouble, but the outer antennas can not achieve the handsome requirement of present designs of the electronic devices.
Hence, an improved antenna assembly with a moveable antenna is desired to overcome the above-mentioned shortcomings of the existing antennas.


When purchasing steel from multiple sources, quality of the steel may not be as dependable and as stable as when purchasing steel from a single source. Also, some steel has unusual composition such as alloying components like Boron, which reduces import duty but affects the behavior of the metal and requires different welding. When this chemical composition becomes hidden in the steel supply chain, the steel can be dangerous.
Originally, only chemical analysis could determine metallurgical components of the steel, and specialty steel suppliers employed metallurgists with laboratory equipment to test the steel. With the rapid availability of high performance microcomputers, heavy stand-alone machines use an arc for spectrographic analysis of a metal sample. Newer test equipment uses Energy Dispersive X-ray Fluorescence (ED-XRF) technology for spectral analysis of steel, although they are expensive and not practical for steel processing workshops.
Plasma cutters have become common for metalworking, including working with steel, aluminum, and other metals. In plasma cutting, a plasma formed of a gas heated by an electric arc serves to conduct electricity into, and remove melted metal from, a metal workpiece. Plasma cutters may be used with “numerically controlled” (NC), computer controlled cutting machines, or may be handheld.


1. Field of the Invention
The present invention relates to a semiconductor package and a fabrication method thereof, and more particularly to semiconductor packages each with an extra plurality of electrical connecting points and a fabrication method thereof.
2. Description of the Prior Art
Owing to the trend toward multi-function, high-performance, and high-speed electronic products, semiconductor manufacturers nowadays are devoted to research and development of semiconductor devices integrated with multiple chips or packages with a view to meeting the requirement for today's electronic products.
Referring to FIG. 1, U.S. Pat. No. 5,222,014 discloses a stack structure of a semiconductor package, and a method for fabricating the stack structure of a semiconductor package involves providing a first ball grid array (BGA) substrate 11 having bonding pads 110 disposed thereon, mounting a semiconductor chip 10 on the first BGA substrate 11, forming an encapsulant 13 on the first BGA substrate 11 such that the encapsulant 13 encapsulates the semiconductor chip 10, mounting and electrically connecting a second BGA substrate 12 (which has been packaged like the first BGA substrate 11) to the bonding pads 110 via solder balls 14.
However, in the stack structure of the semiconductor package described above, the number of the bonding pads 110 electrically connecting the second BGA substrate 12 with the first BGA substrate 11 is restricted by the size of the encapsulant 13, thus limiting the type of semiconductor packages to be stacked and the number of I/O connections that can be formed, such that the type of semiconductor packages to be stacked and I/O connection layout on the second BGA substrate 12 would be restricted by the bonding pad 110 arrangement on the first BGA substrate 11. Moreover, due to the height limitation of the solder balls 14, the height of the encapsulant 13 disposed on the first BGA substrate 11 must be minimized (typically below 0.3 mm), which increases the difficulty of fabrication. Other stack structures of semiconductor packages such as that disclosed in U.S. Pat. Nos. 6,025,648 and 6,828,665 also experienced the same problem.
Besides, in accordance with the foregoing known stack structures of semiconductor packages, electrical connecting points for forming electrical connections with external devices rely totally on the circuits on the substrate surface, while the encapsulant which occupies the majority of space in a package, however, is incapable of providing extra electrical connecting points, such that not only the overall electrical performance of the semiconductor product cannot be improved, the usage of the package would also be limited.
Thus, there is an urgent need to develop a semiconductor package and a method for fabricating the same, for providing an extra plurality of electrical connecting points, thereby solving the problem of package usage limitation, improving the electrical performance of electronic products and overcoming the stacking limitation in terms of size and type of semiconductor packages and the number of I/O connections.


For the purpose of conveying loose materials such as bulk materials, that is, rock/stones, mineral resources, excavation material, agricultural products, et cetera, use has long been made of troughed conveyor belts, which receive the conveyable material at a receiving location on their carrying side and discharge the same at a discharge location. Since the conveyable material is open to the environment as it is being transported, contaminants and environmental weathering influences can act on the conveyable material, and the latter can pollute the environment and also pose a risk to the environment. It is also the case, on account of their configuration, that troughed conveyor belts can be used to realize curves and gradients only to a limited extent. It is thus not usually possible, in conventional belt systems, to exceed an angle of inclination of 20° in gradient. If this is the limit of feasibility, it is necessary to connect a plurality of inter alia specific conveying belts with transfer locations. This increases the complexity for, and therefore the costs of, the conveyor system to a considerable extent.
In order to eliminate these disadvantages, conveyor belts which are closed during operation and are referred to as tube belts, tubular conveyor belts, pipe belts or mega pipes, were developed in the 1980s. The tube belts are rolled together between the receiving location and discharge location to give a closed tube, by virtue of the outer belt flanks overlapping and thus fully enclosing the conveyable material. This means that the conveyable material in the tube belt and the environment are completely separated from one another, since the tube belt remains closed over the conveying route. It is only for the purposes of receiving and discharging the transportable material that a tube belt widens and assumes the form of a conventional troughed conveyor belt. This rules out contamination of the bulk material along the conveying route and the associated environmental pollution. It is also the case that the conveyable material cannot be influenced by the environment during transportation. Further essential advantages of the tube belts in relation to the conventional troughed conveyor belts reside in the possibility of realizing very narrow three-dimensional curves and in the relatively high angles of inclination of up to 35° in gradient, which means that complicated three-dimensional curved routes can be realized by a single system. Since tube belts usually have a smooth surface on their carrying side, the angles of inclination are nevertheless limited to a gradient of up to 35°, depending on the bulk material properties.
In order to eliminate these disadvantages, conveyor belts which are closed during operation and are known as SICON®conveyor belts or pocket (conveyor) belts have also been developed. A pocket conveyor belt comprises two textile-reinforced profiles each with a steel cable vulcanized therein as a tension member. The profiles run over the sets of rollers and carry the pocket which accommodates the conveyable material. This droplet-shaped pocket consists of highly flexible rubber and is connected to the profiles by means of hot vulcanization. The profiles are arranged one above the other during transportation, and the belt is therefore closed off in a dust-tight manner. The belt is carried, and guided, by specific sets of rollers which, for the closed state of the belt, comprise a carrying roller and a guide roller. Further sets of rollers, each comprising a carrying roller and one to three guide rollers, are available for loading and unloading the belt and for curves and gradients.
In a manner similar to tube belts, the essential advantages of the pocket conveyor belt in relation to the conventional troughed conveyor belts reside in the possibilities of realizing very narrow three-dimensional curves and in the relatively high angles of inclination of up to 35°; in the case of conventional belt systems, the angle of inclination cannot usually exceed 20°. This makes it possible to realize complicated three-dimensional curved routes by a single system, without any transfer locations on the conveying route. In addition, the material in the pocket conveyor belt and the environment are completely separated from one another, since the pocket conveyor belt remains closed over the conveying route. For loading purposes, the pocket conveyor belt is opened with the aid of a specific set of rollers for opening and closing the belt. The belt can be unloaded at an overhead discharge point or an S-shaped discharge station. At the S-shaped discharge station, it is possible optionally for the belt to be emptied or for the conveyable material to be poured into the belt again.
A pocket conveyor belt differs from the conventional tube belt not just in construction, but also in functioning and areas of application. It is thus possible for a pocket conveyor belt, depending on the profile size, to negotiate radii of 0.6 m or 1.0 m, which cannot be realized by a conventional tube belt. The minimum curve radius which can be realized by a tube belt is approximately 30 m. In contrast to the tube belt, the conveyor length, the conveyor cross section and the associated conveyor capacity and maximum possible material particle size of a pocket conveyor belt are very limited. All of this predestines a pocket conveyor belt for an “in-plant closed” transport of industrial bulk materials, while a tube belt is considered in practice to be more akin to an “out-plant closed” conveying principle for the entire range of particle sizes.
For a number of application cases, the advantages of the tube belts or the pocket conveyor belts and the steep conveyor belts are required at the same time, that is, a tube belt or pocket conveyor belt which can be used even at angles of inclination above 35°.
U.S. Pat. No. 6,170,646, GB 1197700, U.S. Pat. No. 5,351,810, JP 480 48 385 U, JP 580 83 314 U, United States patent application publication 2012/0000751 A1, FR 14 968 97 A, GB 88 76 98 A, JP 582 16 803 A, U.S. Pat. No. 3,392,817 A and WO2005/085101 A1 disclose a number of technical solutions in this respect for increasing the angle of inclination of tube belts and pocket belts by differently shaped profiles having been applied to the carrying-side cover panel of a tube belt or pocket belt. The core idea of these approaches has been in each case, for elastic rubber or plastic-material strips connected to the conveyor belt to be fitted transversely to the longitudinal direction of the conveyor belt and to be offset at certain intervals from one another in the longitudinal direction. It is possible here for the transverse strips to span both the entire belt width and just part of the belt width. It can be established from these documents that the transverse strips may be configured both in a continuous state, in the form of ribs or wave-like strips, and in a divided state, for example, at right angles, in sawtooth form or in trapezoidal form. The divided transverse strips here are configured such that, when the tube belt or pocket belt is deformed in tube or pocket form, the flanks of the strip butt more or less against one another or overlap and thus form partition walls spaced apart in the longitudinal direction. Depending on the height, that is, radial formation, of the transverse strips, the conveyable material is retained in a force-fitting and form-fitting manner during transportation, and it is therefore possible to prevent the conveyable material from sliding back in the conveyor belt and thus to realize relatively large gradients. In the case of the transverse strips being virtually closed, it is even possible to realize vertical conveying directions, wherein purely form-fitting force transmission takes place.
It is a disadvantage of the above-described tube belts or pocket belts that they involve very high outlay, and are therefore expensive to produce. It is thus necessary for the transverse strips, on account of their size, in particular their radial extent, to be produced in the form of separate elements and to be applied subsequently to the conveyor belt for example by means of adhesive bonding, that is, by cold vulcanization. This requires the further operating steps of the transverse strips being separately produced and subsequently installed on the conveyor belt. Single-piece production of conveyor belts with transverse strips, that is, simultaneously with the vulcanization of the conveyor belt, is ruled out in production terms on account of the size of the transverse strips. It may also be necessary for the transverse strips to be installed on the conveyor belt for the first time at the site of use of the conveyor belt, so that there is no increase in the volume of the conveyor belt for transportation purposes. Furthermore, the adhesive-bonding locations constitute a weak point which, over time, will fail sooner than other constituent parts of the conveyor belt.
It is also disadvantageous that, if the known tube belts or pocket belts are suitable for relatively large angles of inclination, that is, above 35° in gradient, the conveyable material is retained in a form-fitting manner by the transverse strips and the latter are subjected to corresponding loading. This requires a corresponding stable and radial formation of the transverse strips with higher material and production costs than in the case of flatter profilings, although the latter do not allow such gradients. It is also the case that the higher transverse strips increase the transportation costs of the conveyor belts, because the latter cannot be wound as tightly for transportation purposes, that is, less belt length per rolled together belt drum can be transported in one journey. At the same time, this means that the pieces of belt which can be transported per drum in one journey are shorter, and there is therefore an increase in the outlay for installing the endlessly closed conveyor belts in the conveyor-belt system. As is also the case with conventional tube belts, the pocket conveyor belts have a smooth surface, as a result of which it is possible to realize the angles of inclination of up to 35°, depending on the bulk-material properties.


The present invention relates to control systems of the type having a plurality of remotely located process control units connected together through a communications link and, more particularly, to a control system in which one or more redundant control units each serve as a back-up for a plurality of the remotely located process control units.
Many system type industrial installations, for example, those related to industrial process-type manufacturing and electrical power generation, employ a large number of physically distributed controlled-devices and associated sensors for effecting coordinated operation of the overall system. In the past, coordinated control of the various devices has been achieved by manual operation and various types of semi-automatic and automatic control systems including electromagnetic relay systems, hardwired solid-state logic systems, and various types of computer control systems. The computer systems have included central systems in which the various sensors and controlled devices are connected to a central computer; distributed control systems in which a remotely located computer is connected to each of the controlled devices and to one another, and hybrid combinations of the central and distributed systems. The successful functioning of the control system is vital to any industrial process, and, accordingly, distributed systems have generally been preferred over central systems because the failure of one of the remotely located control computers generally does not cause a system wide failure as in the case of the failure of the central computer in the central system. In copending application Ser. No. 115,161, filed Jan. 14, 1980, invented by Michael E. Cope and assigned to the assignee of this application, there is disclosed a distributed control system. The preferred embodiment of the present invention is employed in a distributed control system as disclosed in this copending application.
In the control system disclosed in application Ser. No. 115,161, U.S. Pat. No. 4,304,001, a plurality of remote process control units R.sub.n (remotes) are connected to various controlled devices and sensors and communicating with one another through a communications link, which transmits data serially. Each remote is assigned a unique succession number or position in a predetermined succession order with each remote unit assuming supervisory communication control of the communications link on a revolving or master for the moment basis in accordance with the remote's relative position in the succession order. Information transfer including process data and command control information is accomplished between a source remote R.sub.s and a destination remote R.sub.d by successively transmitting information blocks over the communications link with the destination remote R.sub.d testing the validity of the blocks and, if valid, responding with an acknowledgement signal (ACK), and, if invalid, a non-acknowledgement signal (NAK) is sent by the destination remote R.sub.d. The source remote R.sub.s will retransmit the information blocks in response to a non-acknowledgement signal from a destination remote.
In accordance with the present invention, one or more of the remotes connected to the communications link is a redundant remote. Each redundant remote is designed to monitor a plurality of other remotes which are referred to as primary remotes and each of which may perform active control operations. The redundant remote detects whether or not any one of the primary remotes has failed and if it has failed, it then will take over operation of the inputs and outputs of that remote by sending instructions or commands over the communications link to the failed remote .


Data sources are currently scanned for a variety of purposes. For example, files can be scanned for viruses at predetermined locations. One example is the McAfee Vitran™ solution which combines heuristics and virus detection at predetermined locations and provides for isolation of suspect files. However, this solution is limited to virus scanning only.
In other solutions, specific data streams can be scanned for inappropriate content. For example, Microsoft's Internet Explorer™ provides for a Content Advisor that filters content based on user pre-selected criteria and rating placed on a web site. The Content Advisor in this case can filter content that creates fear, depicts drug or alcohol use, shows sexuality or nudity, among others. The filtering can be complete or limited based on the context of the web site. Other content scanning solutions include Net Nanny™ or Surfwatch™.
These solutions are, however, limited to one type of scanning and typically are performed on a specific data stream or file.


Tn U.S. Pat. No 3,612,793 issued on Oct. 12, 1971, to John O. Roeser and entitled "Electrical Switch Components And Switches Formed Thereby," there is shown and described a unitary combination switchblade and contact means For compact switch mechanisms. As can be seen from FIGS. 8, 9 and 10 of the '793 patent, the combination switchblade and contact means 16 comprises a pair of identical members 109a (109b) each being formed of a first end portion 110 a mid-portion 116 and a curvilinear second end portion 118. The first end portion 110 consists of a pair of spaced apart legs 112 and 114. The legs are spaced apart by a dimension D so as to receive therebetween a tension spring 120, as illustrated in FIG. 5. A combination strut and attachment means 124 is shear formed in the curvilinear second end portion 118 and includes a reverse curve portion 131 for mating with the end of the tension spring 120 (FIG. 5).
The curvilinear second end portion 118 further includes an upper contact portion 128 and a lower contact portion 130 which is separated from the upper contact portion 128 by means of the reverse curve portion 131. The legs 112 and 114 are provided with sharpened edges 132 for pivoting within opposed V-shaped notch portions 106 formed within an elongated metal member 74 of the actuating means 114. The lower contact portion 130 is located within the same plane as the first portion 110 and the mid-portion 116 However, the upper contact portion 128 is off-set from that same plane. The lower and 15 upper contact portions 128 and 130 define movable contact members which are adapted to be snapped between opposed fixed contact portions upon upper terminal members 134 and lower terminal members 136, as illustrated in FIG. 5.
The upper portions of the upper terminal members 134 are formed with an off-set transverse portion 116 having a depending upper fixed contact 148 (FIGS. 14 and 15). The upper fixed contacts 148 serve to make electrical contact engagement with the upper contact portions 128 of the movable contact members. The lower terminal members 136 are provided with portions 156 which serve as lower fixed contacts for electrical contact engagement with lower contact portions 130 of the movable contact members.
The combination switchblade and contact means 16 is assembled with other components so as to form a compact precision, snap-action push-button switch 10 and is illustrated in FIGS. 2, 5 and 6. In operation, when the button 72 of the actuator means 14 is depressed so as to move downwardly, this causes the elongated metal member 74 to also more downwardly against the bias of the return springs 76 and 78. Initially, the combination 15 switchblade and contact means is restrained by means of the lower fixed contact portions 156 so that the lower contact portions 130 of the movable contact members remain in contact therewith.
This contact continues until the pivot points 106 pass the center line of the tension spring 120. At that time, the movable contact members will snap overcenter and the upper contact portions 130 thereof will become engaged with the upper fixed contacts 148. This engagement continues until such time when the pressure upon the top of the button 72 is released, thereby causing the return springs 76 and 78 to return the metal member 74 and button 72 to their rest positions shown in FIGS. 1 and 2. As the metal member 74 returns past the center line of the tension spring 120, the movable contact members will snap overcenter again in the reverse direction.
The present invention represents an improvement over the combination switchblade and contact means described above in connection with the '793 patent. The upper contact portion 128 and the lower contact portion 130 upon the second end portion 118 of the switchblade and contact means 16 in the aforenoted patent experience a high degree of stress during the switching operations which tends to shorten the service lives of such components. It would therefore be desirable to provide a novel and improved switch butterfly assembly for use in precision snap action switches which has a unique configuration so as to reduce the stresses upon the movable contact portions, thereby prolonging the service lives thereof.


Heretofore, reactive liquid polymer (RLP) epoxy adducts have been used for many years for toughening composites and adhesives. They provide outstanding improvement at room temperature, but are only minimally effective at lower temperatures. An epoxy adduct using CTB can improve low temperature performance, but the CTB, with no or low bound acrylonitrile content, is not miscible in uncured epoxy and will separate upon aging.


In the context of growing product functionalities of component carriers equipped with one or more electronic components and increasing miniaturization of such components as well as a rising number of components to be mounted on the component carriers such as printed circuit boards, increasingly more powerful array-like components or packages having several components are being employed, which have a plurality of contacts or connections, with ever smaller spacing between these contacts. In particular, a low loss electric connection of embedded components is desired. For example, component carriers with high I/O count and/or high-frequency signal transmission may be critical in this respect. Moreover, there is a strong tendency in the field of component carriers of continued miniaturization. In particular, it is desired to form electrically conductive connections with smaller and smaller dimensions. Thus, conventional procedures of contacting different layers of stacked layer-type component carriers reach their limits.


Endoscopes are increasingly being used in medical diagnosis and therapy When used as directed the endoscope becomes grossly soiled and massively infected with microorganisms which are present in body cavities, on the mucous membrane, and in the blood. Accordingly the instruments must be thoroughly cleaned and disinfected after each use. Endoscopes are precision instruments which are made from a combination of materials. They are difficult to clean in view of the sensitivity of the materials involved to chemical attack and because they have narrow lumens making access to and cleaning of interior surfaces difficult.
Until the last decade, it was common for soiled instruments to be placed on a towel or in a covered pan until they were sent to a centralised service where they were scrubbed, washed and either sterilised in a steam autoclave (if not heat sensitive) or chemically (e.g. with formaldehyde). In the last decade, there has arisen a particular concern to avoid transmission of very serious and sometimes fatal diseases such as may be carried in blood and tissue, for example hepatitis B, HIV, and other infections.
Nowadays, contaminated endoscopes and other medical instruments are typically treated in a first bath (“presoak” or “cleaning” bath) containing one or a combination of anionic and non ionic surfactants. The first bath may optionally include one, or a combination of enzymes, adapted to digest biological contaminants including cellular material, blood and other body fluids. Enzyme containing pre-soaking liquids are significantly more efficient in removing water insoluble and protein soils and are now considered the industry standard. In the case of surgical instruments requiring to be sterilised, the instruments are typically then removed from the first bath, washed free of enzyme solution and other residues, and then deposited in a second bath containing a chemical sterilizing agent (for example, glutaraldehyde). The first bath container is subsequently washed and then furnished with a fresh enzyme solution so that the process may be repeated. The necessity for separate cleaning and sterilizing baths arises since enzymes are denatured by all known sterilizing agents and since sterilizing agents are deactivated by enzymes (as enzymes are proteins). Accordingly it has to date proved impossible to provide a “single bath” cleaning and sterilizing treatment, although a two part system involving an enzyme treatment followed by addition of a phenolic disinfectant in the same bath has been proposed.
Sterilisation protocols are followed to prevent cross infection and therefore instruments used with one patient are not combined with those which may have been used with another in the presoak bath. It is noteworthy that the presoak is not passive. Staff are instructed to syringe detergent liquor through all the lumens, to brush biopsy channels, etc. A colonoscope requires up to 14 manual brushing-syringing-plugging-unplugging operations. It is usual for staff to wear latex gloves when handling instruments into or out of the baths and when performing such like operations.
The present inventor has observed that currently used procedures, while effective for preventing crossinfection between patients, in fact exposes medical and/or hospital staff to hitherto unrecognised health and safety risks. By virtue that the enzymes of the first bath digest the biological secretions holding the microorganisms, thus releasing them within the bath, and surfactants efficiently disperse them, the fluid content of the first bath is itself readily contaminated to high levels with infectious material. Contrary to the belief of some hospital staff, enzymes do not kill bacteria but rather release them. The present inventor has measured bacterial counts in excess of 1×109 colony forming units (“cfu”) per sq. cm. on instruments entering the first bath
Staff are therefore at risk of infection (i) from splashes from the first bath either during scrubbing to release contaminants or during draining the first bath (or from splashes if an instrument is accidentally dropped into the bath), (ii) from glove failures (latex gloves have a “pinhole” failure rate of about 12%), (iii) from accidental glove immersion above the wrist line, (iv) from finger stick incidents in the bath resulting in glove and sometimes dermal penetration, (v) from aerosols created by brushes and syringes. In addition the wall surface of the first bath remains contaminated after the bath has been emptied and if not itself disinfected may be handled by unprotected staff. The last mentioned risk may be minimised by performing the sterilisation step immediately after the digestion step in the same container, but this does not avoid any of the other hitherto unrecognised risks and is wasteful in use of excess sterilant.
In some cases instruments may not be required to be sterilised, for example with spatulas, and holders which do not penetrate the body tissue, hair dressing implements and the like, it may be sufficient to disinfect the instruments to an appropriate standard. In such cases it would be desirable to provide a cleaning and disinfecting treatment capable of meeting the required standards with a single composition.
Any discussion of the prior art herein is not to be construed as indicative of the state of the common general knowledge in the field.
It is the object of the invention to avoid or ameliorate the above discussed disadvantages of prior art, or at least provide a commercial alternative to the prior art.
It is an object of preferred embodiments of the present invention to avoid or at least ameliorate the risk of infection to persons cleaning medical instruments by such procedures.
It is a further object of at least some of the preferred embodiments to provide a single step cleaning and disinfecting composition for use in cleaning medical instruments.
Preferred embodiments of the invention also address the risk of cross infection of instruments by virtue of multiplication of microorganisms, if any, which remain on the bath walls after each cycle of instrument cleaning.
It is an object of some embodiments of the invention to provide simple means for cleaning and disinfecting surfaces which require to be disinfected


In electrostatographic imaging and recording processes such as electrophotographic printing, an electrostatic latent image is formed on a primary image-forming member such as a photoconductive surface and is developed with a thermoplastic toner powder to form a toner image. The toner image is thereafter transferred to a receiver member, e.g., a sheet of paper or plastic, and the toner image is subsequently fused or fixed to the receiver member in a fusing station using heat and/or pressure. The fusing station includes a heated fuser member which can be a roller, belt, or any surface having a suitable shape for fixing thermoplastic toner powder to the receiver member. Fusing typically involves passing the toned receiver member between a pair of engaged rollers that produce an area of pressure contact known as a fusing nip. In order to form the fusing nip, at least one of the rollers typically includes a compliant or conformable layer. Heat is transferred from a heated roller fuser member to the toner in the fusing nip, causing the toner to partially melt and attach to the receiver member.
Normally included in a compliant heated fuser member roller is a resilient or elastically deformable base cushion layer (e.g., an elastomeric layer). The base cushion layer is usually covered by one or more concentric layers, including a protective outer layer. The base cushion layer is typically bonded to a core member included in the roller, with the roller having a smooth outer surface. Where the fuser member is in the form of a belt, e.g., a flexible endless belt that passes around the heated roller, it commonly has a smooth outer surface which may also be hardened. Similarly, a resilient base cushion layer can be incorporated into a deformable pressure roller used in conjunction with a relatively hard fuser roller.
Simplex fusing stations attach toner to only one side of the receiver member at a time. In this type of station, the engaged roller that contacts the unfused toner is commonly known as the fuser roller and is a heated roller. The roller that contacts the other side of the receiver member is known as the pressure roller and is usually unheated. Either or both rollers can have a compliant layer on or near the surface. It is common for one of these rollers to be driven rotatably by an external source while the other roller is rotated frictionally by the nip engagement.
In a duplex fusing station, which is less common, two toner images are simultaneously attached, one to each side of a receiver passing through a fusing nip. In such a duplex fusing station there is no real distinction between fuser roller and pressure roller, both rollers performing similar functions, i.e., providing heat and pressure.
It is known that a compliant fuser roller, when used in conjunction with a harder or relatively non-deformable pressure roller, e.g., in a Digimaster 9110 machine made by Heidelberg Digital L.L.C., Rochester, N.Y., provides easy release of a receiver member from the fuser roller, because the distorted shape of the compliant surface in the nip tends to bend the receiver member towards the relatively non-deformable unheated pressure roller and away from the much more deformable fuser roller. On the other hand, when a conformable or compliant pressure roller is used to form the fusing nip against a hard fuser roller, such as in a DocuTech 135 machine made by Xerox Corporation, Rochester, N.Y., a mechanical device such as a blade is typically necessary as an aid for releasing the receiver member from the fuser roller.
A conventional toner fuser roller includes a rigid cylindrical core member, typically metallic such as aluminum, coated with one or more synthetic layers usually formulated with polymeric materials made from elastomers. An elastically deformable or resilient base cushion layer, which may contain filler particles to improve mechanical strength and/or thermal conductivity, is typically formed on the surface of the core member, which core member may advantageously be coated with a primer to improve adhesion of the resilient layer. Roller cushion layers are commonly made of silicone rubbers or silicone polymers such as, for example, polydimethylsiloxane (PDMS) polymers disclosed, e.g., by the Chen, et al., patent (U.S. Pat. No. 6,224,978, assigned to Eastman Kodak Company, Rochester, N.Y.).
The most common type of fuser roller is internally heated, i.e., a source of heat is provided within the roller for fusing. Such a fuser roller generally has a hollow core member, inside of which is located a source of heat, usually a lamp. Surrounding the core member can be an elastomeric layer through which heat is conducted from the core member to the surface, and the elastomeric layer typically contains fillers for enhanced thermal conductivity [see for example the Fitzgerald patents (commonly assigned U.S. Pat. Nos. 5,292,606 and 5,336,539) and the Fitzgerald, et al., patent (commonly assigned U.S. Pat. No. 5,480,724)]. An internally heated fuser roller can be made using a condensation-polymerized silicone rubber material including solid filler particles, such as for example used in a NexPress 2100 digital color press (manufactured by NexPress Solutions LLC, Rochester, N.Y.).
Less common is an externally heated fuser roller, which fuser roller is typically heated by surface contact with one or more heating rollers. An externally heated fuser roller can be made using an addition-polymerized silicone rubber material including solid filler particles. Externally heated fuser rollers are for example disclosed by the O'leary patent (U.S. Pat. No. 5,450,183, assigned to Eastman Kodak Company, Rochester, N.Y.), the Derimiggio, et al., patent (commonly assigned U.S. Pat. No. 4,984,027), the Aslam, et al., patent (commonly assigned U.S. Pat. No. 6,567,641), and the Chen, et al., patent (commonly assigned U.S. Pat. No. 6,490,430). Inclusion of thermal-conductivity-enhancing fillers enhances heat transfer from one or more external heating rollers typically used for the external heating of the fuser roller. Moreover, the thermal-conductivity-enhancing fillers enable intermittent use of an auxiliary heating device located within the roller.
Some fuser rollers rely on film splitting of a low viscosity oil to enable release of the toner and (hence) receiver member from the fuser roller. The release oil is typically applied to the surface of the fuser from a donor roller coated with the oil provided from a supply sump. A donor roller is for example disclosed in the Chen, et al., patent (commonly assigned U.S. Pat. No. 6,190,771) which is hereby incorporated by reference.
Release oils (commonly referred to as fuser oils) are composed of, for example, polydimethylsiloxanes. When applied to the fuser roller surface to prevent the toner from adhering to the roller, fuser oils may, upon repeated use, interact with PDMS material included in the resilient layer(s) in the fuser roller, which in time can cause swelling, softening, and degradation of the roller. To prevent these deleterious effects caused by release oil, a thin barrier layer made of, for example, a cured fluoroelastomer and/or a silicone elastomer, is typically formed around the resilient cushion layer, as disclosed in the Davis, et al., patent (U.S. Pat. No. 6,225,409, assigned to Eastman Kodak Company, Rochester, N.Y.) and the Chen, et al., patents (U.S. Pat. No. 5,464,698, and 5,595,823, assigned to Heidelberg Digital L.L.C., Rochester, N.Y.). A fluoro-thermoplastic random copolymer outermost coating can also be used for this purpose, as disclosed in the Chen, et al., patents (commonly assigned U.S. Pat. Nos. 6,355,352 B1 and 6,361,829 B1).
To rival the photographic quality produced using silver halide technology, it is desirable that electrostatographic multicolor toner images have high gloss. To this end, it is desirable to provide a very smooth fusing member contacting the toner particles in the fusing station. A gloss control outer layer (which also serves as a barrier layer for fuser oil) can be provided as disclosed in the Chen, et al., patent application (commonly assigned U.S. patent application Ser. No. 09/608,290). A fluorocarbon thermoplastic random copolymer useful for making a gloss control coating on a fuser roller is disclosed in the Chen, et al., patent (commonly assigned U.S. Pat. No. 6,429,249).
In the fusing of the toner image to the receiver member, the area of contact of a conformable fuser roller with the toner-bearing surface of a receiver member sheet as it passes through the fusing nip is determined by the amount of pressure exerted by the pressure roller and by the characteristics of the resilient cushion layer. The extent of the contact area helps establish the length of time that any given portion of the toner image will be in contact with and heated by the fuser roller. It is generally advantageous to increase the contact time by increasing the contact area so as to result in a more efficient fusing process. However, unless the effective modulus for deforming a compliant roller in the nip is sufficiently low, high nip pressures are required to obtain a large nip area. Such high pressures can be disadvantageous and cause damage to a deformable roller, e.g., such as pressure set or other damage caused by edges of thick and/or hard receiver members as they enter or leave the nip. Hence a low modulus deformable roller is desirable.
It is known from the Chen, et al., patent (commonly assigned U.S. Pat. No. 5,716,714) that use of a relatively soft deformable fusing-station roller (e.g., a deformable pressure roller having a low effective modulus for deformation) can advantageously reduce the propensity of a fusing station nip to cause wrinkling of receiver members passing through the nip.
One way to try to create a low modulus fusing-station roller is to use a foamed material, e.g., a cured material having an open-cell or a closed-cell foam structure, with the material inclusive of suitable strength-enhancing and/or thermal-conductivity-enhancing fillers. Attempts to utilize such foamed materials, for example as base cushion layers, have not generally been successful, for a number of reasons. The thermal conductivity of closed-cell structures tends to be disadvantageously low, even when squeezed in a fusing nip. Although an open-cell structure can be squeezed relatively flat in a fusing nip, the resilience typically becomes compromised because opposite walls within the foam tend to stick together under the heat and pressure of the nip. Moreover, foamed polymeric materials generally have poor tear strength, and shear strength also tends to be low. As a result, fusing-station rollers incorporating foamed base cushion layers are quite susceptible to damage and tend to age rapidly.
In particular, attempts to make fusing-station rollers with fluoroelastomer foamed materials, which have desirable low surface energy and high thermal stability, have not been successful because of the tendency to incur a “pressure set” under the high loading typically present in fusing station nips. For example, foam rollers made with VITON® fluoroelastomers are susceptible to “pressure set”.
Suitable thermal conductivity of synthetic layers used in fusing-station rollers is attainable by the use of one or more suitable particulate fillers, the thermal conductivity being determined by the filler concentration. The thermal conductivity of most polymers is very low and the thermal conductivity generally increases as the concentration of thermally conductive filler particles is increased. However, if the filler concentration is too high, the mechanical properties of a polymer are usually compromised. For example, the stiffness of the synthetic layers may be increased by too much filler, e.g., so that there is insufficient compliance to create a wide enough nip for proper fusing. Moreover, too much filler will cause the synthetic layers to have a propensity to delaminate or crack or otherwise cause failure of the roller. Because the mechanical requirements of fusing-station rollers require that the filler concentrations generally be moderate, the abilities of the layers to transport heat are thereby limited. In fact, the total concentration of strength-enhancing and thermal-conductivity-enhancing in prior art internally heated compliant fuser rollers has reached a practical maximum. As a result, the number of copies that can be fused per minute is limited, and this in turn can be the limiting factor in determining the maximum throughput rate achievable in an electrostatographic printer.
An auxiliary internal source of heat may optionally be used with an externally heated fuser roller, e.g., as disclosed in the Aslam, et al., patent (commonly assigned U.S. Pat. No. 6,567,641) and in the Chen, et al., patent (commonly assigned U.S. Pat. No. 6,490,430). Such an internal source of heat is known to be useful when the fusing station is quiescent and/or during startup when relatively cold toned receiver members first arrive at the fusing station for fusing therein. In order for such an auxiliary internal source of heat to be effective (when intermittently needed) the fuser roller must have a sufficiently large thermal conductivity. However, this requirement conflicts with a need to keep heat at the surface of an externally heated fuser roller, i.e., so as not to unnecessarily conduct heat into the interior which would compromise the fusing efficiency of the roller. On the other hand, it is important to have a high enough thermal conductivity at the surface of the fuser roller to ensure efficient transfer of heat to the fuser roller from one or more heating rollers contacting the surface. Moreover, in order to have high efficiency, externally heated fuser rollers rely to a certain extent on thermal conduction of heat around the surface of the roller.
Ways to improve upon the above-described limitations associated with externally heated elastically deformable fuser rollers (including an optional auxiliary internal source of heat) are disclosed in the Chen, et al., patent applications (commonly assigned U.S. patent application Ser. Nos. 10/139,486 and 10/139,464). In the Chen, et al., U.S. patent application Ser. No. 10/139,486, an externally heated fuser roller having improved efficiency includes a core member, a base cushion layer around the core member, a relatively thin heat storage layer around the base cushion layer, and an outer gloss control layer around the heat storage layer, wherein the heat storage layer is loaded with more thermally conductive filler than is the base cushion layer and hence has a higher thermal conductivity. In the Chen, et al., U.S. patent application Ser. No. 10/139,464, a thin heat distribution layer is further included between the heat storage layer and the outer gloss control layer. While the fusing efficiencies relating to U.S. patent application Ser. Nos. 10/139,486 and 10/139,464 are much improved, the fuser rollers (respectively having three-layer and four-layer structures around the core member) are relatively expensive to manufacture, and may be susceptible to delamination with prolonged use.
It is known that instead of solid fillers, certain hollow fillers can be included in an addition-polymerized silicone rubber for the purpose of lowering rather than increasing the thermal conductivity of a deformable fuser roller, as disclosed in the Meguriya patent (U.S. Pat. No. 6,261,214, assigned to Shin-Etsu Chemical Company, Ltd., Tokyo, Japan). In particular, the Meguriya patent discloses incorporation into the silicone rubber of hollow filler particles (also known as microballoons) manufactured under the tradename EXPANCEL® available from Expancel, Sundsvall, Sweden, and Duluth, Ga.
Hollow microballoons are well known and are disclosed for example in the Morehouse, et al., patent (U.S. Pat. No. 3,615,972, assigned to Dow Chemical Company, Midland, Mich.). Microballoons are made from thermoplastic microspheres which encapsulate a liquid blowing agent, typically a hydrocarbon liquid. Such microspheres are made in unexpanded form. The walls of the unexpanded microspheres are generally impermeable to the liquid blowing agent, i.e., diffusion of molecules of the liquid blowing agent through the walls is typically negligible. An expanded form of a microsphere, i.e., a microballoon, is obtained by heating an unexpanded microsphere to a suitable temperature so as to vaporize the blowing agent, thereby causing the microsphere to grow to a much larger size. Too high of a heating temperature can result in some loss of internal vapor pressure and a shrinking of the microballoon. Methods for expanding microspheres are disclosed in numerous patents, such as, for example, the Gunderman, et al., patent (U.S. Pat. No. 3,914,360, assigned to Dow Chemical Company, Midland, Mich.), the Edgren, et al., patent (U.S. Pat. No. 4,513,106, assigned to KemaNord AB, Stockholm, Sweden) and the Morales, et al., patent (U.S. Pat. No. 6,235,801 B1). Expansion is generally irreversible after cooling, and the expanded microballoon form is stable under normal ambient conditions and can be sold as a dry powder or alternatively as a slurry in a liquid vehicle. Expanded microspheres or microballoons which are available commercially can be incorporated into various materials, such as for example to make improved paints or lightweight parts. Unexpanded microspheres are also available commercially for incorporation into various types of materials (e.g., expandable inks) or for manufacture of solid parts, e.g., by thermal curing in a mold so as to expand the microspheres. The shell material of certain microsphere particles can include finely divided inorganic particles, e.g., silica particles.
The use of microspheres in a compressible layer of a digital printing blanket carcass is disclosed in the Castelli, et al., patent (U.S. Pat. No. 5,754,931, assigned to Reeves Brothers, Incorporated, Spartanburg, S.C.). The microspheres are uniformly distributed in a matrix material which includes thermoplastic or thermosetting resins.
The Dauber, et al., patent (U.S. Pat. No. 5,916,671, assigned to W.L. Gore & Associates, Incorporated, Newark, Del.) discloses a resilient gasket made of a composite of polytetrafluoroethylene and resilient expandable microspheres.
There remains a need to provide for an electrostatographic machine an improved fusing station having high productivity which includes fusing-station members that are simple in construction, are very durable, and are made of material that can resist gouges or pressure damage from edges of receiver members moving through a high pressure fusing nip.
Specifically, there remains a need for a tough, long lasting fuser roller which can have only one layer coated on a core member, and which is thereby simple in structure by comparison with multi-layer prior art fuser rollers. This layer is required to be chemically unreactive, stable at high temperatures, and impervious to fuser oil. Moreover, there remains a need for an improved pressure roller having a similarly simple structure and which has similar properties.
A crosslinked fluoroelastomer is a desirable material for making fuser rollers and pressure rollers, because of low surface energy, chemical inertness, imperviousness to fuser oil, and high-temperature stability.


Digital storage oscilloscopes are well known and have many capabilities for displaying waveforms of interest to a user and information related to those waveforms. For example, the envelope of a waveform is sometimes of interest to a user. Oscilloscopes exist which have an operating mode, termed `envelope mode`, in which the minimum and maximum excursions of a signal (termed the envelope of the signal) over a predetermined number of preceding signal acquisition periods is displayed. At each acquisition, the acquired signal is analyzed to determine the new envelope waveform, and that waveform is displayed on the screen. During display of the envelope waveform, the oscilloscope is unable to display the waveform of the underlying signal. In such an oscilloscope, the envelope waveform is occasionally reset, and the signal being monitored is briefly displayed to provide the user an idea of the underlying signal. Such oscilloscopes display the envelope waveform as a fully filled-in waveform. Such a display, however, provides no information concerning the underlying signal.
For example, FIG. 1 is a display screen 2 of a prior art oscilloscope screen displaying the envelope waveform 4 of an underlying signal (not shown). In FIG. 1, the background 5 of the display screen is dark, and the displayed signal 4 is represented by a white display, in the known manner. The signal being monitored has the envelope 4 illustrated in white on in FIG. 1. As can be seen, the fully filled-in displayed waveform 4 gives no indication of the underlying signal, but only displays the minimum and maximum excursions of that signal over the period of time over which the underlying signal is enveloped.
Oscilloscopes also have the ability to rasterize an acquired waveform using sparsely populated vectors with pixels displayed at a reduced display intensity. For example, see U.S. patent application Ser. No. 09/026 185, filed <<filing date>> by Sullivan et al., incorporated by reference herein. By rasterizing using sparse vectors, and with reduced intensity, the rasterizer can process more acquisitions, giving a more accurate representation of the signal being observed.
Though the envelope mode is useful, a user may wish simultaneously to view the underlying signal and its envelope. An oscilloscope which can display the envelope waveform, while simultaneously displaying sufficient acquisitions of the underlying signal to provide an accurate indication of that signal is, thus, desirable.


SAR (specific absorption rate) for users of portable wireless devices (PWDs) is a matter of increasing concern. RF radiation to the user's head results from the free-space generally omnidirectional radiation pattern of typical current PWD antennae. When PWDs equipped with such an antenna are placed near the user's head, the antenna radiation pattern is no longer omnidirectional as radiation in a large segment of the azimuth around the user is blocked by the absorption/reflection of the user's head and hand. An antenna system for PWDs that greatly reduces radiation to the body and redirects it in a useful direction is also desirable.
Prior art antennas for PWDs may cause audio noise in a hearing aid of the user. Referring to FIG. 16, a diagrammatic view of a prior art PWD 400 (in the form of a cellphone) used in the vicinity of a hearing aid 402 is illustrated. Cellphone 400 has a speaker on the keyboard surface near the top of the phone, which is normally aligned with the center of the user's ear 404 during use. Hearing aid 402 may be any type, including in-ear and behind-ear variations. Hearing aid 402 has an amplified audio output port 406, which is inserted into the ear canal of the ear 404. During operation, an electromagnetic field 408 is generated around cellphone 400 by omnidirectional antenna 440. In operation, electromagnetic field 408 illuminates the hearing aid 402, user's ear 404, and the user's head. RF noise is induced in the hearing aid by the field 408, resulting in excessive audio noise being presented to the user.
The planar inverted F antenna or PIFA is characterized by many distinguishing properties such as relative lightweight, ease of adaptation and integration into the device chassis, moderate range of bandwidth, omni directional radiation patterns in orthogonal principal planes for vertical polarization, versatility for optimization, and multiple potential approaches for size reduction. Its sensitivity to both vertical and horizontal polarization is of practical importance in mobile cellular/RF data communication applications because of the absence of the fixed antenna orientation as well as the multi-path propagation conditions.
To assist in the understanding of a conventional PIFA, a conventional single band PIFA assembly is illustrated in FIG. 17. FIG. 17 illustrates a prior art single-band PIFA antenna 440 located on the rear side 442 of a personal wireless device 444. PIFA 440 consists of a radiating element 446, a ground plane 448, a feed conductor 450, and a grounding conductor 452. PIFA 440 is typically positioned near an upper edge of ground plane 448 with the free end of radiating element 446 being closer to a user's hand than the feed conductor 450 and grounding conductor 452. The feed conductor 450 serves as a feed path for radio frequency (RF) power to the radiating element 446. The feed conductor 450 is electrically insulated from the ground plane 448. The grounding conductor 452 serves as a short circuit between the radiating element 446 and the ground plane 448. The resonant frequency of the PIFA 440 is determined by the length (L) and width (W) of the radiating element 446 and is slightly affected by the locations of the feed conductor 450 and the grounding conductor 452. The impedance match of the PIFA 440 is achieved by adjusting the dimensions of the conductors 450, 452, and by adjusting the separation distance between the conductors 450, 452. In operation, ground plane 448 radiates RF energy which is absorbed by a user's hand. Antenna 440 can be configured to reduce the SAR value to 1.6 mw/g with the PWD 444 transmitting at the 0.5 watt cw level. However, even at this level audio noise may be generated in a user's hearing aid by operation of PWD 444. Another limitation of the PIFA is its relatively low front-to-back ratio. Front-to-back ratios of typically PIFAs range from 0 to 2 dB. A 5 dB front-to-back ratio may be achieved by substantially increasing the distance between radiating element 446 and ground plane 448. A need exists for an antenna exhibiting substantially greater front-to-back ratios.
FIG. 18 illustrates a prior art dual-band PIFA antenna 462, which is located on the rear of a personal wireless device 464, and electrically connected to ground plane 466 at one end and capacitively coupled to ground plane 466 at another end. PWD 464 further includes a battery pack 470 positioned away from antenna 462. In normal operation, PWD 464 is oriented in an upright manner so that end 472 is generally above end 474. Ground plane 466 is provided by the ground traces of the printed wiring board (PWB). The portion of antenna 462 indicated by numeral 476 resonates over a higher frequency band, while the entire portion 476, 478 of antenna 462 resonates over a lower frequency band. PIFA antenna 462 is grounded at its upper end at location indicated as numeral 480 to ground plane 466. PIFA antenna 462 is capacitively coupled at pad 482 in a direction away from upper end 472 of PWD. This type of antenna provides some reduction in SAR, but has limited ability to reduce hearing aid noise from a digital PWD.
Despite all of the desirable properties of a PIFA, the PIFA has the limitation of a rather large physical size for practical application. A conventional PIFA should have the semi-perimeter (sum of the length and the width) of its radiating element equal to one-quarter of a wavelength at the desired frequency. With the rapidly advancing size miniaturization of the radio communication devices, the space requirement of a conventional PIFA is a severe limitation for its practical utility.


This invention relates to pens which utilize a fluid ink and whose writing tips are axially positionable with respect to an outer sheath.
Various types of pens using an aqueous or non-aqueous fluid are in widespread use for writing, drawing, painting or marking purposes, and may collectively be referred to as marking pens. Said fluids, which may be inks having soluble dyes, or paints having dispersed pigments, may be generically referred to as marking fluids. Many of such pens are provided with protective caps which prevent evaporation of the fluid and prevent accidental contact of the fluid with the clothing or skin of the user or with other objects. However, the placement and removal of the cap is troublesome, and the cap is frequently misplaced.
Marking pens which avoid the need for a protective cap are well known and generally employ a mechanism whereby the tip of the pen can be retracted into a protective enclosure within an elongated sheath comprising the outer body of the pen. Marking pens of such construction are disclosed for example in U.S. Pat. Nos. 4,218,154; 3,652,172; and 4,540,300. The protective enclosures and associated retracting mechanisms are, however, generally of complex, expensive construction and do not endure long term use.
Accordingly, it is an object of the present invention to provide a retractable capless marking pen having a protective enclosure within the body of the pen that prevents evaporation of marking fluid from the tip of the pen.
It is a further object of this invention to provide a marking pen as in the foregoing object of rugged and durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.