The present invention relates to a tilt-adjustable seat cushion for a vehicle seat having an underframe for receiving an upholstered seat part, this seat cushion having two frame parts which are arranged laterally of the underframe. The seat cushion includes a swiveling shaft for the underframe disposed in the frame parts and extends in transverse direction of the vehicle. Each frame part carries at least one row of teeth for interaction with two pinion gear teeth. An adjusting shaft carries the pinion gear teeth and has on one end a handwheel.
In a known seat cushion of the above type, shown in German Published Unexamined patent application No. 3,316,618, the adjusting shaft with the handwheel and the pinion gear teeth is disposed in the underframe and, for this purpose, on both sides, is guided in a respective longitudinal slot in the underframe. The rows of teeth that ascend in the direction of the swiveling shaft of the underframe, penetrate through openings in the floor of the underframe. For assembly, first the underframe is inserted into the frame parts. Then, the adjusting shaft is guided through one longitudinal slot in the underframe, through two recesses in the frame parts, of which one is in each case directly opposite one row of teeth, and then through the other longitudinal slot in the underframe, until two pinion gear teeth engage in the assigned row of teeth.
Because of the tolerances of the underframe and of the components for the tilt adjustment, the above-described assembly is not too easy. However, the assembly becomes significantly more difficult because it can only be carried out at the upholstered seat cushion, in other words, with the seat upholstery part that is firmly connected with the underframe. An objective of the present invention is to significantly facilitate the mounting of the underframe and of the tilt-adjusting mechanism in a seat cushion having an underframe for receiving an upholstered seat part.
This and other objectives are achieved in the present invention by providing a tilt-adjustable seat cushion for a vehicle seat having an underframe for receiving an upholstered seat part, the seat cushion having two frame parts which are arranged laterally of the underframe, swiveling shaft means for the underframe disposed in the frame parts that extends in transverse direction of the vehicle, each frame part carrying at least one row of teeth for interaction with at least two pinion gear teeth, and an adjusting shaft carrying the pinion gear teeth having at one end a hand wheel, with bearing block means. The adjusting shaft is disposed in the bearing block means, this bearing block means being connected to and forming a separate assembly with the frame parts and the adjusting shaft. This separate assembly is then connected with the underframe by fastening means. In certain preferred embodiments, the fastening means are screws or clips.
By disposing the adjusting shaft in a separate bearing block that is separate from the underframe, the tilt-adjusting mechanism comprising the frame part and the adjusting shaft can be assembled completely and only then be connected with the upholstered seat cushion. Because the underframe and the seat upholstery part are absent during the assembly of the tilt-adjusting mechanism, there is more free space and better accessibility so that assembly times are considerably shortened. After the pre-assembly of the tilt-adjusting mechanism is completed, the upholstered underframe is placed without difficulty and connected with the adjusting mechanism.
In certain preferred embodiments, the bearing block or at lest the bearing points of the adjusting shaft in the housing block are made of plastic, to prevent the development of noise caused by rattling, etc.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.


The method most commonly used to produce iron oxides used as pigments employs, as its source material, pickling liquids that contain ferrous sulfate or chloride originating from the iron industry or from the process for producing titanium dioxide.
The acid aqueous solution of ferrous salts is first neutralized by dissolving iron scrap and is then treated in conditions of oxidation with sodium hydroxide to precipitate FeOOH nuclei which are then pumped into a reactor that contains iron scrap and is maintained in air stream.
The resulting ferric sulfate (chloride) hydrolyzes forming FeOOH or Fe2O3; the sulfuric or hydrochloric acid that is released reacts with the iron to form ferrous sulfate or chloride, which are then oxidized to ferric salts. The reaction time varies from a few days to several weeks, depending on the reaction conditions and on the type of pigment that is sought.
The advantage of the method, with respect to others, is the limited use of alkali and of ferrous sulfate or chloride. The small quantity of ferrous salt that is required initially is renewed continuously during the process by the dissolving of the iron by the sulfuric or hydrochloric acid released in the reaction.
The disadvantage of the method is the difficulty in eliminating, even after thorough washing, the impurities of sulfate and chloride anions that are present in the oxides, which have a negative effect on the quality of the pigments.
For example, in order to reduce these anions to values that are acceptable for the production of high-quality red pigments, it is necessary to treat the precipitated oxides with concentrated solutions of NaOH (U.S. Pat. No. 5,614,012).
GB 1226876 describes a method for producing highly pure FeOOH suitable for producing ferrites for use in electronic devices, wherein electrolytic iron with average dimension between 20 and 140 microns is reacted, in conditions of oxidation with air made to flow at high speed in order to maintain a uniform aqueous suspension of the iron particles, with an acid chosen among sulfuric acid, hydrochloric acid, nitric acid and acetic acid, used at a molar concentration of less than 0.01 and in a molar ratio with the iron of more than 0.02 and preferably between 0.26 and 0.55. Iron is used in an amount not exceeding 25 g/l and the weight ratio between the solution and the iron is at least 40.
The reaction temperature is between 50 and 70° C.: at temperatures above 70° C., there is an undesirable production of oxides such as spinel, which also form at temperatures below 70° C. if the iron concentration is higher than 25 g/l.
At temperatures below 50° C., the oxide particles that form are too fine and difficult to filter and wash in order to achieve values of impurities due to acid radicals of less than 0.1% by weight.
The sought dimensions of FeOOH are a few microns in length and more than 0.3 and 0.1 microns in width and thickness, respectively.
If the concentration of the acid is too high (more than 0.25 mol in the case of sulfuric acid), the FeOOH yield decreases even considerably due to the dissolving of iron ions in the mother liquor. The productivity of the method is 20-26 g of FeOOH per liter of suspension per hour.


JPEG as described in W. Pennebaker and J. Mitchell, “JPEG still image data compression standard,” Kluwer Academic Publishers, 1993, (hereinafter “reference [1]”), G. Wallace, “The JPEG still-image compression standard,” Commun. ACM, vol. 34, pp. 30-44, April 1991 (hereinafter “reference [2]”), is a popular DCT-based still image compression standard. It has spurred a wide-ranging usage of JPEG format such as on the World-Wide-Web and in digital cameras.
The popularity of the JPEG coding system has motivated the study of JPEG optimization schemes—see for example J. Huang and T. Meng, “Optimal quantizer step sizes for transform coders,” in Proc. IEEE Int. Conf. Acoustics, Speech and Signal Processing, pp. 2621-2624, April 1991 (hereinafter “reference [3]”), S. Wu and A. Gersho, “Rate-constrained picture-adaptive quantization for JPEG baseline coders,” in Proc. IEEE Int. Conf. Acoustics, Speech and Signal Processing, vol. 5, pp. 389-392, 1993 (hereinafter “reference [4]”), V. Ratnakar and M. Livny, “RD-OPT: An efficient algorithm for optimizing DCT quantization tables”, in Proc. Data Compression Conf., pp. 332-341, 1995 (hereinafter “reference [5]”) and V. Ratnakar and M. Livny, “An efficient algorithm for optimizing DCT quantization,” IEEE Trans. Image Processing, vol. 9 pp. 267-270, February 2000 (hereinafter “reference [6]”), K. Ramchandran and M. Vetterli, “Rate-distortion optimal fast thresholding with complete JPEG/MPEG decoder compatibility,” IEEE Trans Image Processing, vol. 3, pp. 700-704, September 1994 (hereinafter “reference [7]”), M. Crouse and K. Ramchandran, “Joint thresholding and quantizer selection for decoder-compatible baseline JPEG,” in Proc. IEEE Int. Conf. Acoustics, Speech and Signal Processing, pp. 2331-2334, 1995 (hereinafter “reference [8]”) and M. Crouse and K. Ramchandran, “Joint thresholding and quantizer selection for transform image coding: Entropy constrained analysis and applications to baseline JPEG,” IEEE Trans. Image Processing, vol. 6, pp. 285-297, February 1997 (hereinafter “reference [9]”). The schemes described in all of these references remain faithful to the JPEG syntax. Since such schemes only optimize the JPEG encoders without changing the standard JPEG decoders, they can not only further reduce the size of JPEG compressed images, but also have the advantage of being easily deployable. This unique feature makes them attractive in applications where the receiving terminals are not sophisticated to support new decoders, such as in wireless communications.
Quantization Table Optimization
JPEG's quantization step sizes largely determine the rate-distortion tradeoff in a JPEG compressed image. However, using the default quantization tables is suboptimal since these tables are image-independent. Therefore, the purpose of any quantization table optimization scheme is to obtain an efficient, image-adaptive quantization table for each image component. The problem of quantization table optimization can be formulated easily as follows. (Without loss of generality we only consider one image component in the following discussion.) Given an input image with a target bit rate Rbudget, one wants to find a set of quantization step sizes {Qk:k=0, . . . , 63} to minimize the overall distortion
                    D        =                              ∑                          n              =              1                                      Num                            _                            Blk                                                                    ∑                              k                =                0                            63                                                                  D                                  n                  ,                  k                                                                          (                                  Q                  k                                )                                                                        (        1        )            subject to the bit rate constraint
                    R        =                                            ∑                              n                =                1                                            Num                                _                                Blk                                                                                R                n                                                          (                                                      Q                    0                                    ,                  …                                                                                ,                                      Q                    63                                                  )                                              ≤                      R            budget                                              (        2        )            where Num_Blk is the number of blocks, Dn,k(Qk) is the distortion of the kth DCT coefficient in the nth block if it is quantized with the step size Qk, and Rn(Q0, . . . , Q63) is the number of bits generated in coding the nth block with the quantization table {Q0, . . . , Q63}.
Since JPEG uses zero run-length coding, which combines zero coefficient indices from different frequency bands into one symbol, the bit rate is not simply the sum of bits contributed by coding each individual coefficient index. Therefore, it is difficult to obtain an optimal solution to (1) and (2) with classical bit allocation techniques. Huang and Meng—see reference [3]—proposed a gradient descent technique to solve for a locally optimal solution to the quantization table design problem based on the assumption that the probability distributions of the DCT coefficients are Laplacian. A greedy, steepest-descent optimization scheme was proposed later which makes no assumptions on the probability distribution of the DCT coefficients—see reference [4]. Starting with an initial quantization table of large step sizes, corresponding to low bit rate and high distortion, their algorithm decreases the step size in one entry of the quantization table at a time until a target bit rate is reached. In each iteration, they try to update the quantization table in such a way that the ratio of decrease in distortion to increase in bit rate is maximized over all possible reduced step size values for one entry of the quantization table. Mathematically, their algorithm seeks the values of k and q that solve the following maximization problem
                              max          k                                              max            q                                                                                -                  Δ                                                                                D                                                          |                                                      Q                    k                                    ->                  q                                                                                Δ                                                                                R                                                          |                                                      Q                    k                                    ->                  q                                                                                (        3        )            where ΔD|Qk→q and ΔRQk→q are respectively the change in distortion and that in overall bit rate when the kth entry of the quantization table, Qk, is replaced by q. These increments can be calculated by
                                                                                Δ                                                                                D                                                          |                                                      Q                    k                                    ->                  q                                                      =                                          ∑                                  n                  =                  1                                                  Num                                    _                                    Blk                                                                          [                                                                            D                                              n                        ,                        k                                                                                (                      q                      )                                                        -                                                            D                                              n                        ,                        k                                                                                (                                              Q                        k                                            )                                                                      ]                                                                                and                                    (        4        )                                                      Δ                                                                          R                                          |                                          Q                k                            ->              q                                      =                              ∑                          n              =              1                                      Num                            _                            Blk                                                      [                                                            R                  n                                                                  (                                                            Q                      0                                        ,                    …                                                                                ,                    q                    ,                    …                                                                                ,                                          Q                      63                                                        )                                            -                                                R                  n                                                                  (                                                            Q                      0                                        ,                    …                                                                                ,                                          Q                      k                                        ,                    …                                                                                ,                                          Q                      63                                                        )                                                      ]                                              (        5        )            The iteration is repeated until |Rbudget−R(Q0, . . . , Q63)|≦ε where ε is the convergence criterion specified by the user.
Both algorithms aforementioned are very computationally expensive. Ratnakar and Livny—see references [5] and [6]—proposed a comparatively efficient algorithm to construct the quantization table based on the DCT coefficient distribution statistics without repeating the entire compression-decompression cycle. They employed a dynamic programming approach to optimizing quantization tables over a wide range of rates and distortions and achieved a similar performance as the scheme in reference [4].
Optimal Thresholding
In JPEG, the same quantization table must be applied to every image block. This is also true even when an image-adaptive quantization table is used. Thus, JPEG quantization lacks local adaptivity, indicating the potential gain remains from exploiting discrepancies between a particular block's characteristics and the average block statistics. This is the motivation for the optimal fast thresholding algorithm of—see reference [7], which drops the less significant coefficient indices in the R-D sense. Mathematically, it minimizes the distortion, for a fixed quantizer, between the original image X and the thresholded image {tilde over (X)} given the quantized image {circumflex over (X)} subject to a bit budget constraint, i.e.,
                              min                                ⌊                                          D                                                  (                                      X                    ,                                          X                      ~                                                        )                                            |                              X                ^                                      ⌋                                                                        subject                                                              to                                                                          R                                      (                              X                ~                            )                                      ≤                  R          budget                                    (        6        )
An equivalent unconstrained problem is to minimize
                              J                                (            λ            )                          =                              D                                      (                              X                ,                                  X                  ~                                            )                                +                      λ                                                                                R                                            (                                  X                  ~                                )                                                                        (        7        )
A dynamic programming algorithm is employed to solve the above optimization problem (7) recursively. It calculates J*k for each 0≦k≦63, and then finds k* that minimizes this J*k, i.e., finding the best nonzero coefficient to end the scan within each block independently. The reader is referred to reference [7] for details. Since only the less significant coefficient indices can be changed, the optimal fast thresholding algorithm—see reference [7]—does not address the full optimization of the coefficient indices with JPEG decoder compatibility.
Joint Thresholding and Quantizer Selection
Since an adaptive quantizer selection scheme exploits image-wide statistics, while the thresholding algorithm exploits block-level statistics, their operations are nearly “orthogonal”. This indicates that it is beneficial to bind them together. The Huffman table is another free parameter left to a JPEG encoder. Therefore, Crouse and Ramchandran—see references [8] and [9]—proposed a joint optimization scheme over these three parameters, i.e.,
                                          min                          T              ,              Q              ,              H                                                                    D                                            (                                  T                  ,                  Q                                )                                                                                subject                                                                          to                                                                                R                                            (                                  T                  ,                  Q                  ,                  H                                )                                                    ≤                  R          budget                                    (        8        )            where Q is the quantization table, H is the Huffman table incorporated, and T is a set of binary thresholding tags that signal whether to threshold a coefficient index. The constrained minimization problem of (8) is converted into an unconstrained problem by the Lagrange multiplier as
                              min                      T            ,            Q            ,            H                                            [                                    J                                            (                λ                )                                      =                                          D                                                  (                                      T                    ,                    Q                                    )                                            +                              λ                                                                                R                                                        (                                          T                      ,                      Q                      ,                      H                                        )                                                                                ]                                    (        9        )
Then, they proposed an algorithm that iteratively chooses each of Q, T, H to minimize the Lagrangian cost (9) given that the other parameters are fixed.
JPEG Limitations
The foregoing discussion has focused on optimization within the confines of JPEG syntax. However, given the JPEG syntax, the R-D performance a JPEG optimization method can improve is limited. Part of the limitation comes from the poor context modeling used by a JPEG coder, which fails to take full advantage of the pixel correlation existing in both space and frequency domains. Consequently, context-based arithmetic coding is proposed in the literature to replace the Huffman coding used in JPEG for better R-D performance.


1. Field of the Invention
The present invention generally relates to debugger systems for computer software.
2. Description of the Prior Art
During the coding of computer programs, the inadvertent production of errors, or bugs, is typically unavoidable. Debugging systems help identify, and thus eliminate, these bugs from a computer program.
One tool used with debuggers are breakpoints. Breakpoints are stopping locations in a computer program under test. The computer program will run until it reaches a predetermined breakpoint address; control is then returned to the debugger. At this point, the debugger can examine the memory locations used by the computer program under test. By examining these memory locations, the user can locate and eliminate bugs in the computer program under test.
There are difficulties with breakpoints, however. For example, some computer systems are parts of systems in which the computer system under test provides and receives data from another part of the system within a certain time restriction. The breakpoints can thus cause timing problems. Sometimes it is not feasible for the computer user to be around during the testing of the computer system. For example, if a breakpoint is set at a location where it is unlikely for the program to hit, it would not make sense for the computer user to sit at the computer screen waiting for such an unlikely event. Additionally, some testing of the computer system can occur late at night when the software engineers are not available.
One way to avoid these problems is through the use of tracepoints. Tracepoints are similar to breakpoints, but unlike breakpoints, they do not stop the program indefinitely. Once the program reaches a tracepoint, data in predetermined memory locations are stored. Control is then returned to the computer program under test. After the computer program has run, a xe2x80x9chex dumpxe2x80x9d of all the data obtained by the tracepoints is provided to the user. The user sifts through the hexadecimal representation of the data in order to determine the bugs in the computer system. It is desired to have an improved tracepointing system for examining a computer program under test.
One embodiment of the present invention relates to the use of programming abstractions to represent the tracepoint output as well as the data to collect at each tracepoint event. This makes it easier for the user of the debugging system to collect and evaluate the tracepoint event data. The user does not have to sift through the hexadecimal representations in order to determine the locations of and contents of memory. For example, if a variable, X, is used in the source code of the computer program under test, the debugger system can interpret the user""s command xe2x80x9ccollect Xxe2x80x9d at a given tracepoint to collect the data stored in the memory location associated with the variable, X. Later, an instruction to xe2x80x9cprint Xxe2x80x9d will cause the debugging software to display the value of X. The user need not look up the address of variable X, then look at the contents of that address; the debugger system does this automatically for the user.
In a preferred embodiment, the system can collect data from the stack and then produce an output indicating what subroutine called which, and with what arguments, at the time of the tracepoint event.
In a preferred embodiment, the debugger system uses a programming abstraction, such as a variable used in the source code of the program under test, and checks the address and symbol table created during the compiling of the computer program under test to determine some indication of the addresses of the required data. This indication is sent to a debugger agent (a subprogram running on the target system that provides services for the debugger on the host computer) along with the computer program under test. The debugger agent in the target system collects the desired data and stores the data into a buffer when a tracepoint is executed. After the computer program under test has run, the debugger system can send a request to the debugger agent on the target to obtain the data in the buffer. The debugger can then represent the data using programming abstractions. In a preferred embodiment, both the collection and display representations of the data uses the symbol and address table created by the compiler for the compiled program under test.
In another embodiment of the present invention, the system includes bytecode expressions that are run as part of the tracepoint collecting of data at the target system. The target system can evaluate expressions in order to determine the data to collect. For example, consider an array Q[n] which has 100 elements. If the user wants to collect the data in the location Q[X+Y], where X and Y are both program variables, the present invention can evaluate X+Y in order to determine the address location of the array value Q[X+Y] in order to obtain this value and store it in the buffer. In this way, less data need be stored. For example, if only the element Q[X+Y] is required, the system need not store all 100 elements of the array each time the tracepoint is hit. This is an important consideration because the data storage capacity of the buffer at the target system is an important limiting factor. A given tracepoint could be hit a large number of times. By using bytecode expressions, the buffer is not filled with unwanted data. and thus filled prematurely.
Having the arithmetic expression evaluated at the target system rather than at the debugger is important. In breakpoint systems, typically the evaluation of expressions is done at the debugger. This is undesirable when using tracepoints that operate in real time because the arithmetic calculations of the expressions at the target system can occur much faster than the data transfer between the target system and the host system. For the same reason, the debugger agent stores the data into a buffer, rather than sending the data directly to the host system at the time of a tracepoint event.


Many disabled and elderly persons are inhibited or precluded from playing golf due to various aspects of their conditions. Some may have trouble getting into position to swing a golf club, such as those who rely on a wheelchair for mobility. Others may not be able to effectively grip and/or move their body to swing the club, such as persons suffering from certain paralysis. Still others may be physically able, but lack the cognitive ability to swing a golf club in a traditional manner, such as some mentally disabled or autistic persons.
Additionally, many persons seek to improve their golf swing through the use of training apparatuses. Training apparatuses physically manipulate a person's movement or the movement of their club to teach certain swing mechanics. Many persons learn more effectively by witnessing visual demonstrations of certain techniques including, but not limited to, the pendulum-like swing motion often used in chipping and putting.


Force control in robotics is conventionally implemented using either impedance control or admittance control. One example of an impedance control feedback loop is illustrated in FIG. 1. With impedance control, positions of the joints of the robot are inputted into the controller and joint torques for controlling movement of the robot are outputted and applied. In other words, the impedance controller determines position and applies (or commands) force/torque. In FIG. 1, the impedance controller applies specific joint torques to the joints. If the robot experiences external force acting on one of the joints, for example, the impedance control system does not calculate or measure such force. Instead, the impedance controller merely re-determines the robot position and re-calculates the requisite force to be applied.
Conventional impedance control may provide stable control when contacting rigid environments and may provide a light feel when engaging soft environments. However, impedance control can give the robot an unstable loose feel and may introduce errors when interacting with stiff virtual constraints, such as haptic boundaries, which limit movement of the robot.
Admittance control, on the other hand, is the inverse of impedance control. One example of an admittance control feedback loop is illustrated in FIG. 2. With admittance control, rather than determining position and commanding force, the controller instead determines applied force/torque and commands position. A force-torque sensor or joint torque measurements are used to detect input force to the system. Based on the detected input force, and knowing a current position of the joints based on measured joint angles, the admittance controller commands a new position of the joints by applying determined joint torques to move the joints accordingly.
Conventional admittance control can give the robot stable rigid feel and may reduce errors when interacting with virtual constraints, such as haptic boundaries. However, a robot subject to admittance control may feel heavy to a user and may overreact when contacting rigid environments. As significantly, using a single admittance controller that utilizes either the force/torque sensor or the joint torques to measure external force(s) acting on one or more of the joints provides significant challenges. Mainly, when the robot experiences such external forces, the location(s) (e.g., the joint(s)) to which the external forces are applied are unknown thereby potentially resulting in undesired dynamic behavior of the robot.


1. Field of the Invention
This invention relates to a circuit arrangement for producing high voltages by means of a voltage multiplier, e.g. of the Cockcroft-Walton type, that is fed from an alternating current source.
2. Description of the Related Technology
It is known per se to provide high-voltages e.g. for discharge tubes, including X-ray tubes, by means of voltage multipliers of the kind concerned.
In the case of X-ray tubes it is generally desired to earth the anode because this makes it easier to obtain the necessary dispersion of heat from the anode. In order to avoid extremely high potentials in relation to earth, it is a frequently chosen solution, however, to supply the anode and cathode of the X-ray tube from high-voltage sources of opposite polarities each at half of the full anode-cathode voltage of the tube.
In either case, the filament of the tube will attain a high voltage relative to earth and due to the fact that the magnitude of the filament current determining the intensity of the X-radiation shall, moreover, generally be adjustable, certain difficulties arise, in particular as regards fulfilment of the demands for insulation, whereby the means for supplying and controlling the filament current become excessively voluminous and heavy, meaning a considerable increase of the total volume and weight of the X-ray tube. This is particularly inadvantageous in case of mobile X-ray devices for radiological tests of materials.
This applies also to other parts of the tube, e.g. a bias grid, the voltage of which deviates by only a small amount from the cathode voltage of the tube.
Similar problems occur also in other devices than X-ray tubes, which are supplied from a circuit arrangement of the type in question, and where it is desirable to produce small amplitude voltages lying at the voltage level of the high voltage.


The invention relates to controllably dissolving a composite.
Controlled release of medication in vivo is the subject of much research. Various methods and release agents have been suggested, tested and marketed. Calcium sulfate has been utilized as filler for bone cavities as it is capable of being spontaneously adsorbed and replaced by bone. Calcium sulfate, formed from the hemihydrate, has been used as a controlled release agent alone for the filling of bone cavities and in combination with additives such as medicaments and pesticides. As a carrier for medicaments, it has been useful in vivo because it is biocompatible and is progressively resorbed by the body, thereby eliminating the need for secondary surgical procedure.
One application for a calcium sulfate controlled release agent is the local delivery of medicaments in vivo. The ideal characteristics of a local medicament delivery system are (1) biodegradability, (2) biocompatibility, (3) prolonged pharmaceutical release (e.g., over a period of at least 4 to 6 weeks), (4) reproducibility, (5) predictable pharmacokinetics, and (6) controllability.
One of the disadvantages to the use of calcium sulfate as a carrier is that, for some medicaments, the medicament is eluted from the calcium sulfate matrix at too rapid of a rate.


(1) Field of the Invention
The present invention relates generally to aligning wafers, and in particular, to aligning wafers independent of the layers formed therein in the manufacture of integrated circuits.
(2) Description of the Related Art
Alignment marks and aligning wafers with respect to those marks are an important part of the process of manufacturing semiconductor devices and integrated circuits. As is known in the art, integrated circuits are fabricated by patterning a sequence of masking layers, and the features on successive layers bear a spatial relationship to one another. Thus, as a part of the fabrication process each level must be aligned to the previous levels. Alignment of one pattern layer to previous layers is done with the assistance of special alignment patterns designed on to each mask level. When these special patterns are aligned, it is assumed that the remainder of the circuit patterns are also correctly aligned. Since each layer must have alignment marks for proper registration with respect to the next layer, each alignment or registration then becomes layer dependent.
The tools that are used to pattern the various layers in a wafer are known as photomasks or masks and reticles. The patterns on the mask or the reticle are defined by a combination of opaque and translucent areas. A light source through the mask or the reticle projects the patterns onto the surface of a wafer, and depending upon the material that is being exposed to the light, the pattern is transferred on to the surface where the light arrives or not. A mask contains patterns that can be transferred to an entire wafer in one exposure. A reticle, on the other hand, contains a pattern image which must be stepped and repeated in order to expose an entire substrate.
The adjustment of the image of the mask being exposed to the previously produced patterns was originally performed by human operators, who compared the image locations under a microscope and adjusted the position of the mask to bring it into alignment with wafer patterns. Decreasing feature sizes, and the increasing number of alignments per wafer with step-and-repeat projection aligners, have been the impetus for developing automatic alignment systems. The principle of one type of automatic alignment procedure is illustrated on page 476 of S. Wolf's book, "Silicon Processing for the VLSI Era," vol. 2, Lattice Press, Sunset Beach, Calif., 1990. Alignment marks consisting of two rectangular patterns, each set at a 45.degree. angle to the directions of the motion an xy-stage table are fabricated on a wafer. Two corresponding rectangular patterns are located on the reticle of an optical aligner, and their image is projected onto the wafer. The superimposed alignment target and the reticle image are reflected back into the main optical element of the aligner, and then into an on-axis microscope. The image from the microscope is focused onto the face of a TV camera, and is subsequently digitized into a form that can be analyzed by a computer. When alignment is achieved, a signal is generated. The 45.degree. orientation of the alignment marks makes it possible to obtain both x an y registration information from the horizontal scan-lines of the video camera. The relative position of the wafer marks with respect to the reticle windows determines the registration of the two images.
Registration and alignment in wafer steppers are performed globally and locally. Global alignment performs rotational and translational alignment of the entire wafer, while local alignment provides alignment to a target within a particular region of a pattern image on the wafer. Global alignment is usually accomplished at a remote alignment station before a wafer is moved under the projection lens for exposure. An apparatus for global aligning is disclosed in U.S. Pat. No. 4,046,985, though for a different purpose other than for aligning masks. The aforementioned apparatus aligns the wafer to a fixed reference position, inverts the aligned wafer to expose its backside and transfers it with controlled motion to a set position under a laser apparatus. The laser beam scans the backside of the wafer to create in a kerf area between chip sites on the wafer an easily breakable cut for the purpose of subsequently separating and removing the chips. This method of aligning differs from the method that will be disclosed in the present invention.
U.S. Pat. No. 3,752,589 discloses a method of aligning the pattern of a photomask on one side of a wafer to the patterns placed on the underside of the wafer. The alignment of the mask with respect to the wafer is achieved by optically superimposing the images present on the mask and on the underside of the wafer and adjusting the mask relative to the wafer until the relative positions of the combined images are corrected to a predefined set of conditions. This method requires two viewing apparatus: one for the mask facing the wafer and the other on the opposing side facing the underside of the wafer, which is superfluous in the present invention as disclosed later in a preferred embodiment.
Cade, in U.S. Pat. No. 4,534,804, on the other hand, teaches a method of forming a laser alignment mark such that same mark now extending, after heat treatment, to both the front and the back of the wafer can be used to align photoresist photomasks to both the front and the back side of a silicon wafer. The alignment mark that is formed is actually a defect planted into the wafer by means of a laser beam. The wavelength of the laser beam is chosen such that it passes through the lightly doped wafer without absorption but is absorbed by a following heavily doped semiconductor layer to generate therein heat and resulting defect. The semiconductor wafer is then heated to cause the defects to migrate through a lightly doped epitaxial layer to the front surface thereof in which there is formed an identically positioned image of the mark scribed on the back side. It will be appreciated, however, that this method is limited to contiguous semiconductor materials without any intervening other types of layers.
Generally, the process of aligning masks in fabricating semiconductor devices in a substrate, and, subsequently, in "metallizing" or wiring the devices together to form integrated circuits on the substrate require different considerations. Up to the level where devices are fabricated, the alignment of masks is accomplished by projecting infrared rays from the underside of the wafer while observing the patterns by an infrared microscope. But this method is not applicable when metallized layers are present because metallic films are opaque to infrared rays. Similarly, the method of U.S. Pat. No. 4,534,804 cannot applied since the metallized layer would preclude the migration of a laser defect through it.
The process of metallization, or "personalization" requires the patterning of the metal layers to form the desired circuit pattern. This is accomplished by masking the metal layer with a photosensitive emulsion and then positioning a photographic mask thereon. The emulsion is next exposed to ultraviolet rays though the photographic mask and then the emulsion is developed and the unexposed emulsions is washed away with solvent. The exposed metal areas are then etched to form wiring patterns corresponding to those on the mask. Certain predetermined areas on the metal layer do also contain alignment marks for registration with the next level of metal layer to be deposited.
Before the next metal layer is deposited, however, an interlevel layer of a dielectric insulator is first blanket deposited over the wiring layer. An interlevel layer usually will form a relatively rough topography conforming to the geometrical features of the underlying layer. Since the depth-of-field limitations of submicron optical-lithography tools require surfaces to be planar within .+-.0.5 micrometers (See S. Wolf and R. N. Tauber, "Silicon Processing for the VLSI Era," vol. 2, Lattice Press, Sunset Beach, Calif., 1990, p. 203), planarization, as is well known in the field, of the dielectric layer will also be required if optical lithography is to be usable for fabricating integrated circuits with submicron feature sizes of today. Conventionally, planarization is performed in any number of ways including mechanical polishing, or a combination of mechanical and chemical polishing, called CMP. It will be appreciated that as more layers of metal and interlevel dielectric are deposited, the surface topography of each layer will vary because of the cumulative effect of the number of underlying features that are disposed on top of each other. Hence, the photographic alignment of masks of each layer to the preceding layer will depend upon the nature of the planarized surfaces of each layer, and therefore will vary accordingly. A method is disclosed in this invention where the layer dependency of alignment is eliminated.
To appreciate the layer dependency of alignment and its effects thereof, FIGS. 1a and 1b show a conventional system where wafer (20) is disposed between a movable xy-stage (30) and an alignment source (10). The rays emanating from source (10) are shown by numeral (15) in both FIGS. 1a and 1b. In FIG 1a, wafer (20) is provided with one level of metal (40), or wiring layer, and in FIG. 2a, with two levels of metal, where the second wiring layer is denoted by numeral (50). First and second metal layers, (40) and (50), respectively, are separated by an interlevel dielectric layer (45), and second layer (50) has on it dielectric layer (55). As is commonly used in the manufacture of semiconductor wafers, the interlevel dielectric layers (45) and (55) shown in FIGS. 1a and 1b are spin-on-glass, or SOG. For the reasons given earlier, both of the dielectric layers are subjected to planarization by means of chemical-mechanical polishing before the respective metals layers are deposited thereon. However, it will be noted that the roughness or non-planarity of second dielectric layer (55) is more pronounced than that of the first layer (45). This is because, as the number of metal interconnect levels are increased, the stacking of additional layers on top of one another produces a more and more rugged topography as mentioned earlier. Although polishing creates more planarity, nonetheless, the remaining non-planarity varies from one layer to another depending upon the cumulative effect on the topography of the underlying layer. As a result, the patterns on layer (50) visible through the second interlevel layer (55), for example, are more diffused and not as clear as the patterns on layer (40) are through layer (45). Furthermore, the depth-of-field varies from layer to layer on the optical-lithography tools that are used for aligning masks over different layers. Consequently, the signals generated by the edges of the patterns on metal layers vary depending upon the planarity of the layer over which a mask is placed. In other words, the signals for aligning masks over patterns and alignment marks on a wafer are layer dependent, and are sometimes weak, and at other times not distinct so as to cause misalignment and therefore product defects. What is needed, therefore, is a method whereby the aligning and alignment signals are independent of a particular layer over which a mask is positioned and that the alignment signal strength is invariant throughout the manufacture of a semiconductor substrate.


1. Field of the Invention
The present invention relates to an actuator for lifting device and more particularly, to such an actuator, which comprises a linking rod assembly for moving a lifting device, and a transmission gear set and a brake module arranged at one side of the linking rod assembly and rotatable by a motor to move the linking rod assembly in extending out or retracting an extension tube.
2. Description of the Related Art
A lifting device is a mechanism for changing the elevation of an object. Different lifting devices differently configured to fit different application requirements.
FIG. 11 illustrates an actuator A for use in a lifting device. As illustrated, the actuator A comprises an electric motor A1 having a worm A11 fixedly connected to the output shaft thereof, a worm gear A2 meshed with the worm All, a spiral spring A3 sleeved onto the gear shaft of the worm gear A2, and a retractable rod A4 coupled to the worm gear A2. According to this design, the retractable rod A4 and the worm gear A2 are on the same axis. When starting the electric motor A1, the worm A11 is driven to rotate the worm gear A2, the retractable rod A4 is moved axially subject to rotation of the worm gear A2, and the spiral spring A3 is wound tightly on the periphery of the gear shaft of the worm gear A2.
The aforesaid prior art actuator provides a braking effect to prevent an accident, however it still has drawbacks as follows:
1. Because the retractable rod A4, the spiral spring A3 and the worm gear A2 are arranged on one same path, the worm bear A2 occupies a part of the reciprocating path of the retractable rod A4. Thus, the length of the retractable rod A4 is limited, lowering the performance of the actuator.
2. The worm gear A2 is directly connected in series to one end of the retractable rod A4. When the retractable rod A4 receives an external pressure, the pressure will be directly transferred by the retractable rod A4 to the worm gear A2. If the worm gear A2 is held down by the spiral spring A3 at this time, direct transfer of the external pressure by the retractable rod A4 to the worm gear A2 may damage the worm gear A2 and the spiral spring A3.


1. Field of the Invention
The present invention relates to a method for producing powder and a fluidized bed pulverizing apparatus.
2. Description of the Related Art
A toner used for an electrophotographic image forming apparatus is formed of fine particles having relatively uniform particle sizes of micron order. As an apparatus for producing such fine particles (powder) of micron order, a fluidized bed pulverizing apparatus (also called as an air flow pulverizing apparatus) is known. The fluidized bed pulverizing apparatus is constituted with a pulverization chamber (fluidized bed container), in which pulverization of a powder material is performed by allowing the powder material to collide against each other, a plurality of fluid jetting nozzles for jetting fluid in the pulverization chamber so as to entrain the powder material in the fluid, followed by colliding against each other so that the powder material entrained therein also collide each other, and then forming a fluidized bed in which the powder material further collide and are pulverized, and a centrifugal classification rotor which classifies the finely-pulverized powder, and is provided at the upper part of the pulverization chamber. In a typical fluidized bed pulverizing apparatus, the powder material supplied into the pulverization chamber are entrained in air flows which are jetted from a plurality of pulverizing nozzles, respectively, so as to collide against each other, and the powder material along with the air flow collide against each other, and then are pulverized. The air flow entirely fluidizes the powder material in the pulverization chamber, so as to accelerate pulverization caused by collision between the powder materials. Part of the powder material which has been pulverized and fluidized is guided to the area near a rotating rotor provided at the upper part of the pulverization chamber, and the particles of powder material each having a certain particle size or smaller are guided inside the rotor along with the fluid flow, and then powder as a final product (hereinafter referred to as product powder) is taken out from an outlet. The particles of the powder each having a certain particle size or larger are returned back to the outer periphery of the rotor by the centrifugal separation effect of the rotating roller, and are again returned back to the pulverization chamber, and then subjected to pulverization therein.
FIG. 1 shows a cross-sectional view of a conventional fluidized bed pulverizing apparatus. With reference to FIG. 1, a structure of the conventional fluidized bed pulverizing apparatus and a method for producing powder will be described below. In FIG. 1, 1 denotes a powder material supply inlet, from which a powder material is supplied, 2 denotes an outlet which discharges pulverized powder as a product along with exhaust air, 3 denotes a centrifugal classification rotor which classifies the pulverized powder, 4 denotes a pulverization chamber in a fluidized bed container, 5 denotes fluid jetting nozzles whose jetting openings are arranged inside the pulverization chamber 4, and which face each other and jet fluid, 6 denotes a motor driving the centrifugal classification rotor 3. The external appearance of the main body of the entire fluidized bed pulverizing apparatus is a substantially cylindrical housing.
The operation of the fluidized bed pulverizing apparatus shown in FIG. 1 is as follows. At first, before operation of the apparatus, inside the pulverization chamber 4 a certain amount of the powder material is charged. Next, compressed air is jetted from each of the two fluid jetting nozzles 5 facing each other, the air jetted from each of the two fluid jetting nozzles 5 forms jetted air flow. The jetted air flow entrains the powder material which is present in the pulverization chamber 4, so as to transport the powder material. The two jetted air flows entraining the powder material collide against each other near the center of the pulverization chamber 4, so as to form air flow upward, downward, leftward and rightward directions inside the pulverization chamber 4. These air flows further entrain the powder material in the pulverization chamber 4, so as to form a fluidized bed of the powder material in the pulverization chamber 4. On the other hand, the powder material entrained in the jetted air flows collide against each other along with the collision of a plurality of jetted air flows, and are pulverized. Further, in the fluidized bed, the collision and pulverization of the powder material are repeated.
Air in the pulverization chamber 4 passes from the outer periphery of the centrifugal classification rotor 3 located at the upper part of the pulverization chamber 4, through a gap between the rotors provided in the centrifugal classification rotor 3, and is guided to the outlet 2 connected to the centrifugal classification rotor 3, and then discharged from the outlet 2 to the outside. The powder material forming the fluidized bed is raised along with the exhaust air to the upper part inside the pulverization chamber 4, and enter the gap between the rotors from near the outer periphery of the centrifugal classification rotor 3. The centrifugal classification rotor 3 rotates at a certain rotating speed, among the powder material along with the air flow which reach the gap between the rotors, the powder material each having a certain particle size or larger is blown away to the outside of the centrifugal classification rotor 3 by centrifugal force. The particles of powder material each having a particle size smaller than a certain particle size along with the air flow are guided from the centrifugal classification rotor 3 to the outlet 2, and then discharged to the outside. The particles of powder material each having a certain particle size or larger are blown away to the outside of the centrifugal classification rotor 3, fall down in the pulverization chamber 4, and then are pulverized again in the fluidized bed.
From the powder material supply inlet 1, the powder material in an amount corresponding to the amount of powder discharged from the outlet 2 are supplied to the pulverization chamber 4, and the amount of the powder material in the pulverization chamber 4 is kept constant. Thus, in the fluidized bed pulverizing apparatus, the particles of powder material each having a desired particle size can be continuously produced. Meanwhile, the particle sizes of the particles of the powder material discharged from the outlet 2 can be controlled by adjusting the rotating speed of the centrifugal classification rotor 3. The pulverizing speed of the powder material, namely production speed of the pulverized powder material can be controlled by adjustment of the speed and flow rate of the air flow jetted from the fluid jetting nozzle 5.
In the fluidized bed pulverizing apparatus, the powder material is repeatedly pulverized in the pulverization chamber, in order to obtain the particles of product powder each having a desired particle size. In this case, when the production speed of the product powder is intended to increase, it is necessary to increase air flow rate jetted from the fluid jetting nozzle 5 so as to increase the pulverization efficiency of the powder material. However, in the case where the air flow rate jetted from the fluid jetting nozzle 5 is increased, the amount of exhaust air is increased, decreasing the classification efficiency of the centrifugal classification rotor 3. As a result, the average particle size of the product powder may become large, or the particles of powder material each having a large particle size may be easily mixed in the product powder. The average particle size of the particles of product powder can be controlled by adjustment of the rotating speed of the centrifugal classification rotor 3 to some degree. However, it is not easy to prevent the large size particles of the powder material from being mixed in the product powder. Therefore, as a countermeasure for the problem of the mixture of the large size particles of the powder material in the product powder, there has been known a method of providing a baffle plate at the upper part of the pulverization chamber 4, by which the course particles are prevented from mixing in the product powder. However, this method may decrease pulverization efficiency, probably causing decrease in production speed.
Moreover, there has been proposed a fluidized bed pulverizing apparatus (also referred to as “an air flow pulverizing apparatus”), for the purpose of improvement of pulverization efficiency of the fluidized bed pulverizing apparatus, adjustment of particle size of the product powder, and stabilization of product quality.
For example, Japanese Patent Application Publication (JP-B) No. 07-4557 discloses an air flow pulverization method, in which the pulverization efficiency of the powder material is improved by using a pulverization medium having a relatively large particle size.
Japanese Patent Application Laid-Open (JP-A) No. 2002-126560 discloses an air flow pulverizer, in which the pulverization efficiency is improved by adjusting the internal pressure of a pulverization chamber to negative pressure, or rising temperature in the pulverization chamber.
Japanese Patent (JP-B) No. 4025179 discloses an air flow pulverizer, in which a secondary collision unit for powder material which has collided by jetted air flow is provided so as to increase probability of collision between the powder materials, thereby increasing the pulverization efficiency.
JP-B No. 4291685 discloses an air flow pulverizer, in which compressed air jetted from a jetting nozzle is heated so as to improve the pulverization efficiency of the powder material, and the particle size of the product powder is optimized.
JP-A No. 2006-297305 discloses an air flow pulverizer, in which a space blocking member is provided in the inner wall of the pulverization chamber, particularly around a jetting nozzle, so as to decrease a dead space in the fluidized bed during the formation of the fluidized bed, thereby increasing the pulverization efficiency.
JP-B No. 2503826 discloses an air flow pulverizing method, in which a bypass directly leading from the pulverization chamber to the channel for discharging the final powder is provided so as to control the particle size distribution of the product powder.
JP-A No. 05-146704 discloses an air flow pulverizing method, in which a load current value of a motor for driving a classification rotor of a classifier is calculated as an integrated value of a predetermined time, and based on the value the supply amount of the powder material is adjusted so as to stabilize the particle size of the product powder.
JP-A No. 3995335 discloses an air flow pulverizer which controls the quality of the product powder in such a manner that the density of fluidized powder material in the pulverization chamber of the air flow pulverizer and the amount of powder material deposited in the lower part of the pulverization chamber are measured, and according to the density and the amount, the taking out of the deposited powder material and the supply of the raw material of the powder are controlled.
By using the above-described fluidized bed pulverizing apparatuses (air flow pulverizing apparatuses) or the fluidized bed pulverization methods, a certain effect is obtained for the purpose of improvement of pulverization efficiency, adjustment of product quality, product quality stabilization. However, any of the fluidized bed pulverizing apparatuses (air flow pulverizing apparatuses) and the fluidized bed pulverization methods aims to improve pulverization efficiency, and adjust and stabilize of product quality only during steady operation. Therefore, they still have problems in terms of the adjustment of product quality and the stabilization of quality during the initial operation of the fluidized bed pulverizing apparatus.
At the beginning of the operation of the fluidized bed pulverizing apparatus, a powder material is entirely in non-pulverized state. When air is jetted from a jetting nozzle, the powder material present in the pulverization chamber is whirled up in the air jetted from the jetting nozzle, and the powder material is started to collide and form a fluidized bed. In the unsteady state during the initial formation of the fluidized bed, not only the abundance ratio of the pulverized particles of powder material each having a certain particle size or smaller is low, but also the ratio of the non-pulverized particles of the powder material each having a large particle size introduced into a centrifugal classification rotor provided at the upper part of the pulverization chamber is high. In such unsteady operation state, the particle size of the product powder discharged from the outlet along with the exhaust air from the centrifugal classification rotor tends to be large. Thus, during the initial operation of the apparatus, the quality of product powder is not stable. In the case where the quality of the product powder is emphasized, the discharged product powder is discarded or recycled as an off-specification product for a certain time during the initial operation of the fluidized bed pulverizing apparatus, until the quality of the product powder finally becomes stable. In the fluidized bed pulverizing apparatus which is expected to produce a large number of product lots, every time when operation restarts for changing a product lot, off-specification products are formed, causing significant decrease in the production efficiency.


The chemical, materials handling, and transportation fields preferably require containers having only a minimal number of ports and other openings thereon for safety, cost and other reasons. It is therefore advantangeous to provide containers such as cargo and storage tanks and bulk shipping containers having single openings which can be used for multiple purposes such as for filling and cleaning, for venting or relieving normally occurring pressure and vacuum conditions, and also for preventing dangerous pressure build-up in the container in the event of fire and the like. Government regulations can also require tanks, vessels and other containers for the transportation and storage of chemicals and other substances to have means providing prescribed flow rates for pressure and vacuum relief under predetermined pressure conditions, and also means providing temperature actuated pressure relief and depressurization at or above predetermined temperature conditions. Such relief means should be rugged and durable so as to be able to withstand abuse in industrial environments, should operate under severe adverse conditions, and should also be leak-resistant even in the event the container tips or overturns.
The device disclosed in U.S. Pat. No. 5,165,445, referenced above, mounts on or over a single opening or orifice on a container and can provide both pressure relief and vacuum relief for the container through the container opening. Such device, however, provides no means for temperature actuated pressure relief. Furthermore, such device does not include mounting means adapted for replacing container caps and covers and so does not readily facilitate using the same port or opening for alternative purposes such as for filling and cleaning the container.
Numerous other devices attempting to satisfy one or more of the above discussed requirements are also known in the art. Reference is made to U.S. Pat. No. 5,031,790, which discloses a removable vented cap for fuel tanks including a self-actuating valve for pressure relief, an open vent for vacuum relief, and fusible plugs for temperature actuated pressure relief. Reference is also made to U.S. Pat. No. 3,385,468, which discloses a safety vent device for mounting over the vent hole of a gasoline tank, which device has passages for pressure and vacuum relief venting and a releasable member held in place with a thin band of fusible alloy to provide emergency pressure relief at a particular temperature. Such prior art devices are limited, however, as they include open passages and fusible means which can leak and allow contamination and such devices may also be damaged if the tank is overturned. Such devices can also expose the interior of a tank and the contents thereof to toxic fusible substances such as a solder substance containing lead alloy or like substances.
Contrasted to the relatively limited prior art devices discussed above, the subject invention relates to a durable and leak-resistant relief vent apparatus which mounts as a removable cover or cap over an opening on a container and can provide pressure relief and vacuum relief for the container at precise predetermined pressure and vacuum conditions and rapid fusible pressure relief at and above a precise predetermined temperature.


1. Field of the Invention
Aspects of the present invention relate to a fluorine-containing compound and an organic light-emitting device employing the same. More particularly, aspects of the present invention relate to a fluorine-containing compound that has electrical stability, good charge transport capability, and a high glass transition temperature and that can prevent crystallization. Aspects of the present invention further relate to an organic light-emitting device employing an organic layer including the fluorine-containing compound.
2. Description of the Related Art
Electroluminescent (EL) devices are self-emitting devices that have advantages such as a wide viewing angle, good contrast, and a rapid response time. EL devices are classified into inorganic EL devices, which include an emitting layer formed of an inorganic compound, and organic EL devices, which include an emitting layer formed of an organic compound. Organic EL devices show better brightness, driving voltage, and response speed characteristics compared to inorganic EL devices, and can create polychromatic light. Thus, extensive research into organic EL devices has been conducted.
Generally, organic light-emitting devices have a stacked structure including an anode, an organic light-emitting layer, and a cathode. A hole injection/transport layer or an electron injection layer may be further disposed between the anode and the organic light-emitting layer or between the organic light-emitting layer and the cathode to form an anode/hole transport layer/organic light-emitting layer/cathode structure, an anode/hole transport layer/organic light-emitting layer/electron transport layer/cathode structure, or the like.
A polyphenyl hydrocarbon and an anthracene derivative have been described as material for forming a hole transport layer (U.S. Pat. Nos. 6,596,415 and 6,465,115).
However, organic light-emitting devices including hole transport layers formed of currently available hole transport layer materials have disadvantages in terms of lifetime, efficiency, and power consumption characteristics, and thus, there is room for improvement in conventional organic EL devices.


Radiation is extensively used for the treatment of cancer and other diseased cells and tissues. Radiation therapy consists of exposing part or all of the body to a field of ionizing electromagnetic radiation. Often performed at 1 MeV or higher, the goal is to damage diseased cells. Although healthy cells frequently receive high radiation doses during such treatment, the healthy cells, ideally, are better able to repair the damage and remain viable while the diseased cells die.
The effectiveness of conventional radiation therapy is limited by insufficient radiation dosing due to the need to reduce radiation to normal cells and tissues. In many cases, the radiation dose to a tumor is the same as the dose to other tissues, especially surrounding tissues. This leads to significant toxicity in healthy cells. In order to increase the ratio of the dose to the intended target versus normal tissue (non target), radiation is often introduced to the tumor from different angles to reduce injury to skin and overlying tissue. However the x-rays also spread beyond the tumor and overshoot the target. The result is significant toxicity to an organism due to dosing of normal tissues.
Contrast agents are used to enhance the effect of x-rays for treatment of aberrant tissue. (U.S. Pat. Nos. 6,125,295 and 6,366,801). For example, a contrast agent is normally delivered to a tumor mass prior to delivering the radiation dose. These contrast agents have, as a component, an element with a high atomic number (Z), such as iodine or gold. The interaction between the ionizing radiation and the greater cross-section of the high Z material creates additional ionizations that result in greater cell toxicity at the site of the tumor.
Contrast agents also improve the accuracy of assessing a disease state. To be useful, the contrast material must be delivered to the area where a suspected abnormality may be present for radiation exposure to result in high enough contrast for a successful diagnosis
However, conventional contrast agents have the disadvantage that they lack affinity for the cells and tissues to be treated so that the residence time of the agent in the targeted tissue is short. The poor uptake of the conventional contrast agent by a tumor means that the agent needs to be applied directly into the tumor. Furthermore, the contrast agents migrate out of the tumor quickly and delivery of the radiation is required very soon after administering the contrast agent, often within one hour. If delivered by intravenous administration, common contrast agents often require relatively large volumes of contrast agent solution to be administered within a short period of time e.g., 100 ml within one minute. This creates a risk of rapid allergic reaction and can cause discomfort to the patient.
To achieve more specific cellular and tissue targeting with these agents, they are typically modified using a biological carrier such as a protein, or a monoclonal antibody, or fragments thereof. Thus a monoclonal antibody combined with a payload of iodine or other heavy element can be used to more selectively deliver high Z atoms to a tumor. These agents have been shown to be useful for the treatment (when the elements themselves are radioactive isotopes) and diagnosis of cancers. However, the biodistribution of these systems is unfavorable to enhance radiation therapy when the elements are not radioactive. In addition, the retention time of the dose in blood when radioactive elements are used is long, and usually only a small portion of the dose is observed at the site of the tumor. Unfortunately, the density of antigen sites that the tumor can present is low and so the potential amount of high Z material that can be delivered is relatively low. Better agents are needed to enhance the effect of radiation at tumor sites.


This invention relates to a picture frame and a picture frame assembly, in particular, a one-piece picture frame made from a suitably-foldable material for framing material to be framed wherein the material to be framed comprises at least one flat, planar object.
In the past, there have been many foldable frames made from foldable material. However, many of those frames had pictures pre-printed on the front surface of the back piece of the frame, or had the object to be framed adhered to the front surface of the back piece of the picture frame.
Moreover, the prior art picture frames were either too simple in that they did not provide a suitable frame into which the material to be framed could be inserted. Rather, the material to be framed was merely placed on the frame and attached to the frame. Such frames were not suitable for framing combined material comprising the object to be framed, such as a picture, photograph or postcard, plus a suitable viewing sheet over the object to be framed through which the object to be framed could be viewed, a suitable backing material and perhaps even matting.
On the other hand, other of the prior art picture frames were too complicated to be easily and cheaply manufactured and to be readily used. This is because many of these prior art picture frames utilized a plurality of intricate tabs and tab receiving areas. As a consequence, the picture frame required too many cuts, folds and insertions.
Also, none of the prior art provided a suitable frame incorporating as part of the frame a supporting means to support the frame on, for example, a desk top.


This section is intended to provide a background or context to the invention that is, inter alia, recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section. Thin film materials of metal-metal oxides of nanocomposites can have many applications, including resistive layers for electronic applications, such as, for example, electron multipliers like microchannel plates, resistive memories, electro-chromic devices, biomedical devices and charge dissipating coatings on micro-electromechanical systems. A related application, U.S. Ser. No. 13/011,645, which is incorporated by reference herein, describes microchannel plate fabrication by atomic layer deposition (“ALD” hereinafter), which provide an example of how one can benefit from the tunable resistance coatings and methods of preparation described herein.


The shipping industry is comprised of various types of shippers, including small package carriers, less-than-a-load (“LTL”) carriers, and truck load carriers. Small package carriers usually transport packages or boxes from multiple consignors, while truck load carriers typically transport entire trailer loads from a single consignor. LTL carriers, on the other hand, generally transport freight that falls in between small packages and trailer loads. For example, LTL carriers may move freight from multiple consignees in a single trailer load, such as crates, scrap metal banded together, vehicle parts, pallets of boxes, drums, and the like. This freight is usually consolidated into a single trailer and transported through a carrier's transportation network. To track the freight and provide carrier personnel with routing and handling instructions, LTL carriers currently use paper bills of lading. The use of paper bills of lading decreases the efficiency and throughput of carrier transportation networks—relying almost solely on the efficiency of carrier employees—and does not provide for real-time visibility of freight progressing through a transportation network.
In addition to using paper bills of lading to track freight, LTL carriers often use the weight and shipping classifications on the bills of lading (provided by consignors) to appropriately charge consignors and/or consignees for transporting the freight. And although many carriers have internal audit mechanisms to verify the weight and shipping classifications provided on the bills of lading, the audit procedures are generally paper-driven and manual in nature. The paper-driven and manual nature of the current audit procedures limit the carriers' ability to efficiently and cost-effectively audit much of the freight they transport. For instance, carriers often have personnel who are specifically employed to audit freight shipments. Typically, the personnel manually verify the shipping classifications and weight provided on the bills of lading by personally inspecting the freight. This methodology usually enables carriers to only audit select freight shipments, leaving the majority of freight shipments unaudited and possibly incorrectly classified.


This invention relates to a food cutting apparatus and particularly to apparatus for dividing a block of cheese into a plurality of relatively small chunks suitable for grating.
The mass marketing of various food products has resulted in development of automatic food forming apparatus. For example, pizzas which are mass marketed may advantageously be constructed with various automatic machinery. A highly satisfactory automated system is disclosed in Applicant's recently issued U.S. Pat. No. 3,779,205, which generally discloses an in-line processing line including means for delivering blocks of cheese to an automatic slicer which divides the block into a plurality of smaller pieces which are fed to a power-driven shredder. The shredded cheese is fed to an automatic depositing apparatus for depositing of the grated cheese upon the crust or dough bases in combination with automatic apparatus for depositing of meat, sauce and the like. Such a structure may provide a high speed, mass production of pizzas which are frozen and then shipped to various marketing outlets. The automated forming not only improves the quality of the product but significantly reduces the per unit cost.
In all of such automatic apparatus, very stringent requirements are established with respect to the construction of the apparatus to ensure high degrees of sanitary conditions. Generally, the apparatus will be made of stainless steel and must be made to permit convenient, complete cleaning of the apparatus.
The cheese cutting and grating or shredding means must correspondingly be constructed to permit complete and reliable cleaning. A practical, automated apparatus has not been commercially available which has a large capacity and a convenient construction suitable for high level sanitary application.


The present invention relates generally to lockers and more particularly to locker door retrofit assemblies. The present invention is designed to replace existing metallic door or other assemblies with a locker door assembly comprised of a more suitable material.
Lockers for storing clothing, articles of merchandise, etc., are commonly constructed. Storage lockers are found in many different settings. For example, athletic facilities have lockers to allow athletes to store their possessions while participating in athletic events. Community swimming pools typically have lockers for storing street clothes while a person swims. Lockers are also found in industry where they are used for several purposes, such as the storage of equipment, work clothes, chemicals, and other items which are preferably kept in such a concealed environment when not in use. Lockers are also commonly found in airports, hospitals, school hallways, prisons, and many other sites too numerous to mention.
Most commonly steel sheet metal is used as a primary construction material with metal fasteners used to assemble the finished locker. Metallic lockers suffer from several disadvantages. They are easily damaged or marred in some way such as by dents, scratches and graffiti. Moreover, the metal is subject to damage from rust, odors, delamination and fading.
Attempts have been made to solve the above-mentioned problems by wholly replacing these metallic lockers with plastic or wood lockers. Some storage lockers were built into either an existing wall of a building or into a building wall while under construction. These in-wall lockers may be expensive to replace with plastic lockers. These problems prevent many from taking advantage of the properties that plastic offers over steel sheet metal.
A need exists for a locker that is designed to overcome the aforementioned disadvantages. The present invention is a locker door retrofit assembly comprised of a material designed to overcome the above disadvantages, such as a plastic or a composite material. The following disclosure describes a plastic locker door retrofit assembly. However, it must be understood that any non-metal material that exhibits the desired characteristics may be utilized for the present invention.
In the present invention existing metallic doors and metallic jams or doors of other materials, such as wood, may be replaced with the plastic locker door assembly. Due to the plastic construction of the door assembly, the locker face will be resistant to many forms of abuse that lockers commonly receive. The locker doors will not dent as will metal lockers. The locker door of the present invention will maintain its color throughout its entire cross-section. Due to the preferred homogeneous nature of the plastic door assembly, the lockers of the-present invention will not delaminate. Furthermore, most materials used in the application of graffiti are readily removed from plastic panels to return the locker doors to the original surface appearance. The remaining metallic body of the locker system is hidden behind the plastic face and is thus protected. Moreover, the substitution with a plastic door assembly provides many cosmetic and aesthetically pleasing attributes to the locker system. These plastic lockers may carry almost any color scheme desirable. Colors may be chosen to match the surrounding decor, to provide a color coding scheme and/or to provide a medium for an organizational theme.
Other features and advantages of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which show preferred features of the present invention and the principles thereof.


This invention generally relates to information retrieval, and more specifically, to assembling answers from multiple documents. Even more specifically, embodiments of the invention relate to Question Answering systems and methods implementing parallel analysis for providing answers to questions and in which candidate answers may be assembled from multiple documents.
Generally, question answering (QA) is a type of information retrieval. Given a collection of documents (such as the World Wide Web or a local collection), a QA system should be able to retrieve answers to questions posed in natural language. QA is regarded as requiring more complex natural language processing (NLP) techniques than other types of information retrieval such as document retrieval, and QA is sometimes regarded as the next step beyond search engines.
QA research attempts to deal with a wide range of question types including: fact, list, definition, how, why, hypothetical, semantically-constrained, and cross-lingual questions. Search collections vary from small local document collections, to internal organization documents, to compiled newswire reports, to the world wide web.
Closed-domain question answering deals with questions under a specific domain (for example, medicine or automotive maintenance), and can be seen as an easier task because NLP systems can exploit domain-specific knowledge frequently formalized in ontologies. Alternatively, closed-domain might refer to a situation where only a limited type of questions are accepted, such as questions asking for descriptive rather than procedural information. Open-domain question answering deals with questions about nearly everything, and can only rely on general ontologies and world knowledge. Open-domain Q/A systems, though, usually have much more data available from which to extract the answer.
Access to information is currently dominated by two paradigms: a database query that answers questions about what is in a collection of structured records; and a search that delivers a collection of document links in response to a query against a collection of unstructured data (text, html etc.).
One major challenge in such information query paradigms is to provide a computer program capable of answering factual questions based on information included in a large collection of documents (of all kinds, structured and unstructured). Such questions can range from broad such as “what are the risk of vitamin K deficiency” to narrow such as “when and where was Hillary Clinton's father born”.
User interaction with such a computer program could be either a single user-computer exchange or a multiple turn dialog between the user and the computer system. Such dialog can involve one or multiple modalities (text, voice, tactile, gesture etc.). Examples of such interaction include a situation where a cell phone user is asking a question using voice and is receiving an answer in a combination of voice, text and image (e.g. a map with a textual overlay and spoken (computer generated) explanation. Another example would be a user interacting with a video game and dismissing or accepting an answer using machine recognizable gestures or the computer generating tactile output to direct the user.
The challenge in building such a computer system is to understand the query, to find appropriate documents that might contain the answer, and to extract the correct answer to be delivered to the user. Currently, understanding the query is an open problem because computers do not have human ability to understand natural language nor do they have common sense to choose from many possible interpretations that current (very elementary) natural language understanding systems can produce.
Being able to answer a factual query in one or multiple dialog turns is of great potential value as it enables real time access to accurate information. For instance, advancing the state of the art in question answering has substantial business value, since it provides a real time view of the business, its competitors, economic conditions, etc. Even if QA is in a most elementary form, it can improve productivity of information workers by orders of magnitude.
U.S. patent application Ser. No. 12/152,441, the disclosure of which is hereby incorporated herein by reference in its entirety, describes a QA system involving the generation of candidate answers and selecting a final answer (or ranking a list of final answers) from among the set of candidate answers.
Current information retrieval and question answering systems attempt to satisfy a user's information need by identifying the single document segment (e.g., entire document, contiguous sequence of one or more sentences, or a single phrase) that is most likely to contain relevant information. There are many information needs, however, that cannot be satisfied by a single document segment.


Breastmilk pumps are well known and are generally comprised of a hood that fits over the breast, a vacuum pump connected to the hood for generating an intermittent vacuum within the hood, and a receptacle for the expressed milk. Manually driven vacuum pumps as well as those that are driven by a motor are ordinarily used. The vacuum pumps of these devices, as a rule, intermittently generate a vacuum or negative pressure within the hood, with the hood encompassing the nipple and a substantial amount of the breast. The intermittent suction action of the pump serves to pull on the breast and thereby extract milk in an action reminiscent of suckling. The milk so extracted typically flows from the hood into a collection container, e.g., a bottle, for storage and later use. A breastpump of the foregoing type is shown in U.S. Ser. No. 07/053,055, filed May 22, 1987, now U.S. Pat. No. 4,857,051.
Apart from the purely hygienic requirements for such equipment, there are also certain technical problems to consider. One such significant problem is that varying degrees of vacuum can be generated as the milk receptacle fills, which must then be compensated for. A solution to this problem is to provide a valving mechanism which serves to regulate the negative pressure applied.


1. Field of the Invention
This invention relates to EEPROM devices and more particularly to bit erasing as well as block erasing therein.
2. Description of Related Art
In the past in EEPROM devices, erasure has been performed groups of eight bits known as a byte, byte by byte, but one cell needs 2 1/8 transistors and tunneling window, so the cell size is large. See FIG. 1B where a cell includes a cell transistor Tc, a bit select transistor T.sub.bit, and share the byte select transistor T.sub.byte with seven other cells.
An alternative to the EEPROM which solves part of the problem of large cell size is the flash EPROM. While the flash EPROM has the advantage that the cell size is small, the problem is that the flash EPROM has the disadvantage that it erases block by block, and one can not use it to erase bit by bit or byte by byte.
FIG. 1A shows a cross section of a prior art device known as a FLOTOX (Floating-Gate Tunneling Oxide) EEPROM cell known as an E.sup.2 PROM cell which requires a tunnel oxide window and a select transistor, not shown in FIG. 1A, so the cell size is large. The FLOTOX cell is described in Samachisa et al of SEEQ Technology Inc. and U of C, Berkeley for "A 128k Flash EEPROM Using Double-Polysilicon Technology", IEEE J. Solid-State Circuits Vol. 8C-22, No. 5, pp 676-683 (Oct. 1987.) In FIG. 1A the device includes a P-substrate 10 containing a drain region 11 connected to V.sub.d voltage source, a source region 12 connected to V.sub.s voltage source, a tunnel oxide 14, gate oxide layer 15, a field oxide (FOX) 16, a floating gate 17 composed of polysilicon 1 first dielectric layer 18, a control gate 19 composed of polysilicon 2 connected to V.sub.g voltage source, and a second dielectric layer 20. The tunnel oxide 14 is located between the floating gate 17 and the N+ drain region 12.
FIG. 1B shows a prior art E.sup.2 PROM cell array (in accordance with FIG. 1A) and shows the connection lines required for its operation. Referring to Table 1 an operation table shows how an E.sup.2 PROM can program and erase in groups of cells, by the byte (8 bits.)
TABLE 1 ______________________________________ PROGRAM ERASE READ ______________________________________ SELECTED WORD LINE 20 V 20 V 5 V UNSELECTED WORD 0 V 0 V 0 V LINE PROGRAM LINE 17 V 0 V 0 V BIT LINE 0 (ERASED) 0 V 17 V 1.6 V BIT LINE 7 0 V 0 V 2.0 V (PROGRAMMED) ______________________________________
FIG. 2A shows a prior art flash memory cell structure know as an ETOX.RTM. flash memory comprising a flash memory cell with tunnel oxide TO below the floating gate FG. The device includes source S and drain D in the substrate and a control gate CG above the floating gate FG separated therefrom by a dielectric layer, with the erase E function from floating gate FG to source indicted and the programing P function from drain to floating gate FG indicated.
FIG. 2B shows a cell array of the prior art device of FIG. 2A. The array is controlled by bit lines BL1, BL2, BL3 and BL4 which extend vertically to the cells. The bit lines are connected to the S/D circuits of the cells, which are connected at the opposite ends to one of a plurality of voltage supply sources represented by V.sub.ss1, V.sub.ss2, and V.sub.ss3. Word lines WL1, WL2, and WL3 are the horizontally directed lines connected to the cells. In particular, the word lines WL1, WL2, and WL3 are connected to the control gates of the cells. FIG. 2B along with TABLE 2 which is a flash memory operation table shows how such an ETOX flash memory device operates. In particular, Table 2 below shows the operation table for the ETOX flash memory of FIGS. 2A and 2B is unable to program and erase by byte (8 bits.) Referring to Table 2, one can program or read a single bit (cell,) but one can not erase a single bit, because the word lines WL1, WL2, . . . WLn and V.sub.ss1, V.sub.ss2. . . V.sub.ssn lines are parallel with each other (i.e. are oriented in the same direction. )
TABLE 2 ______________________________________ PROGRAM ERASE READ ______________________________________ SELECTED WORD LINE 12 V 0 V 5 V (WL2) UNSELECTED WORD 0 V 0 V 0 V LINE (WL1, WL3) SELECTED BIT LINE (2) 7 V 0 V 1.6 V UNSELECTED BIT 0 V 0 V 0 V LINE 1, 3, 4 SELECTED V.sub.ss (2) 0 V 12 V 0 V UNSELECTED V.sub.ss (1, 3) 0 V 0 V 0 V ______________________________________


Coordinated multi-point (CoMP) is an interference avoidance concept that can be used to improve system spectral efficiency and cell edge user throughput performance. CoMP may be used to avoid interference to other cells by coordination of the transmissions across multiple eNBs.


For the production of perchlorate, various anode materials have been used commercially, including smooth massive platinum, platinized titanium or tantalum (despite a tendency to produce excess oxygen) and lead dioxide coated on titanium or graphite, although these lead dioxide anodes have a high overvoltage and wear rapidly.
Some proposals have already been made to combine platinum group metals and tin dioxide in electrode coating materials. For example, U.S. Pat. No. 3,701,724 mentioned an anode for chlorine production having a coating consisting essentially of a minor amount of a platinum group metal and/or platinum group metal oxides with a major amount of SnO.sub.2, Sb.sub.2 O.sub.5, Sb.sub.2 O.sub.3 or GeO.sub.2 and mixtures thereof. However, the claims and examples of this patent are directed solely to such coatings containing platinum group metal oxides and there is no enabling disclosure of a coating containing a platinum group metal. Also, U.S. Pat. No. 3,882,002 proposed an anode for chlorine production having a valve metal substrate coated with an intermediate layer of tin dioxide which was covered with an outer layer of a platinum group metal or oxide thereof. Neither of these proposals was directed to improving electrolytic performance in the production of percompounds.