In general, a communication conference system is configured such that audio of conference participants is collected by a plurality of microphones, and is mixed and then transmitted. On the reception side, the audio is reproduced from all of loudspeakers at an equal level of sound volume and phase. In the case of such a communication conference system, the audio data is reproduced with a same sound image regardless of who is speaking among the conference participants. As a result, it is difficult on the reception side to identify who spoke.
Moreover, on the reception side, since the sound volume of a loudspeaker is fixed, the sound volume from the loudspeaker significantly fluctuates when there is a plurality of conference participants on the transmission side, due to differences in the audio sound volume of the respective participants and in the distance between microphones and the participants.
Based on such circumstances, there has been proposed a voice telephone conference device that determines a speaker and the position of the speaker based on the temporal waveform and the frequency spectrum of a microphone input signal (for example, refer to Patent Document 1).                Patent Document 1: Japanese Unexamined Patent Application, First Publication (JP-A) No. H09-261351
The voice telephone conference device disclosed in Patent Document 1 determines a speaker and the position of the speaker based on the temporal waveform and the frequency spectrum of a microphone input signal, and transmits position information along with audio data. The reception side controls the sound volume of each loudspeaker based on the received position information. Moreover, there is provided a switch for switching to select audio data with a highest input level among the respective microphones, and the reception side is set so that the audio is emitted from the loudspeaker that corresponds to the microphone that collected the audio.
However, a sound field with a high level of presence (for example, a feel of depth) can not be realized by only controlling the sound volumes of the respective loudspeaker (stereo loudspeaker units) based on the position information.
Furthermore, each of the microphones is provided with the switch for switching to select audio data with a highest input level among the respective microphones. However, there is an issue in that when a plurality of speakers start speaking simultaneously, this switching needs to be performed in a short period of time, and accurate audio data cannot be transmitted as a result.


1. Field of the Invention
The present invention relates to a retractor for use in a vehicle seat belt system and particularly, to a seat belt retractor adapted to inhibit extraction of a seat belt in emergency situations such as collision.
2. Description of the Related Art
A motor vehicle conventionally includes a seat belt system mounted to a passenger's seat to protect a vehicle occupant in emergency situations such as collision. In such a seat belt system, an emergency lock type retractor is attached to a rigid member to take up a seat belt.
Such a retractor is designed to allow extraction of a seat belt when the seat belt is fastened around a vehicle occupant. The seat belt can also be extracted in non-emergency situations so as not to restrain movement of the occupant. In emergency situations such as collision, impact or sudden acceleration is sensed to actuate a reel lock mechanism so as to lock a reel around which the seatbelt is being wound. This allows the seat belt to restrain the vehicle occupant so as to inhibit sudden movement of the occupant or to protect the occupant.
The reel lock mechanism is operable to securely stop the reel per se around which the seat belt is wound. However, the seat belt may be extracted in the event that it is loosely wound around the reel. To prevent this, there has previously been proposed a seat belt retractor as shown in FIGS. 3 to 6.
As shown in FIGS. 3 and 4, a frame 10 includes a pair of parallel side walls 12 and 14, and a rear wall 16 extending between the side walls 12 and 14. A reel 20 and an emergency lock mechanism 22 are mounted to the lower portion of the frame 10 to take up a seat belt 18. A belt lock mechanism 24 is mounted to the upper portion of the frame 10 to inhibit extraction of the seat belt 18 at the time of emergency.
The reel lock mechanism 22 will now be described with reference mainly to FIG. 4.
The side walls 12 and 14 include coaxial support openings 26 and 28 through which a reel shaft 30 extends while passing through a bushing 32 made of synthetic resin and is rotated about its own axis.
A return spring 34 is connected at a central end to one end of the shaft 30. A cover 36 is disposed over the return spring 34 to secure one side of the return spring 34 to the side wall 12. Extraction of the seat belt 18 causes the reel 20 to rotate in a direction to store energy in the return spring 34. When the occupant releases his hand from the seat belt 18, the reel 20 is rotated under the biasing force of the return spring 34. Then, the seat belt 18 is automatically wound around the reel 20. It will be understood that the reel 20 and the reel shaft 30 are rotated in the direction of the arrow A.sub.1 when the seat belt 18 is extracted.
The reel lock mechanism 22 is mounted to the outer surface of the side wall 14.
The reel lock mechanism 22 includes a ratchet wheel 38 integral with the other end of the reel shaft 30. The ratchet wheel 38 includes a pin 40 coaxial with the shaft 30. A tie plate 42 has an opening 43 fitting around the pin 40. A lock ring 44 has a central opening 48 in which the pin 40 is loosely fit. An arcuate spring element 50 has one end engaged with a central hole (spring hanger) 52 of the tie plate 42 and the other end engaged with a hole (spring hanger) 54 of the lock ring 44. The lock ring 44 has internal teeth 56. The spring element 50 extends between the spring hanger 54 of the lock ring 44 and the spring hanger 52 of the tie plate 42 and provides a biasing force to rotate the lock ring 44 in the direction of the arrow A.sub.2.
A control lever 58 has a base end pivotally connected to the side wall 14 of the frame 10 by a pivot pin 60. The other, free end of the control lever 58 is engageable with the ratchet wheel 38. A pin 62 extends from one side of the control lever 58. The pivot pin 60 extends through an opening 64 which is formed in the front end of the tie plate 42.
The lock ring 44 has a pair of diametrically opposite integral tabs 66 and 68. The tab 66 is designed to rotate the control lever 58, whereas the tab 68 is designed to operate the belt lock mechanism 24.
The tab 66 of the lock ring 44 has an elongate hole 70 to receive the pin 62 of the control lever 58.
A hook retainer 72 is secured to the pin 40 of the shaft 30 which in turn, extends through the central opening 48 of the lock ring 44. A pair of diametrically opposite projections 76 and 78 extend from the peripheral edge of the hook retainer 72 to support a hook 74. The hook 74 has two openings 80 and 82 to receive the projections 76 and 78. This arrangement allows the hook 74 to reciprocate on a line extending between the projections 76 and 78 (shown by the arrows B.sub.1 and B.sub.2).
A compression coil spring 84 is disposed between the hook retainer 72 and the hook 74 to urge the hook 74 in the direction of the arrow B.sub.1. A pawl 86 extends from the outer peripheral edge of the hook 74 to engage with the internal teeth 56 of the lock ring 44. A connecting pin 88 extends from one side of the hook 74.
The hook 74 is normally urged in the direction of the arrow B.sub.1 by the compression coil spring 84. That is, the hook 74 is shifted to the left as shown in FIG. 4. This results in separation of the pawl 86 from the internal teeth 56.
A frictional engagement member 90 is substantially in the form of a ring. An opening 92 is formed adjacent to the outer peripheral edge of the frictional engagement member 90 to receive the connecting pin 88. A flywheel 96 is fit over the frictional engagement member 90 and includes a ratchet 94. The flywheel 96 has a central opening within which the pin 40 of the shaft 30 is loosely fit. The flywheel 96 is short and cylindrical in shape. The frictional engagement member 90 is fit within the flywheel 96. An arcuate spring 98 is fit on the outer periphery of the frictional engagement member 90 and urged against the inner periphery of the flywheel 96. Friction between the flywheel 96 and the frictional engagement member 90 enable sliding rotary motion of the flywheel 96. A hole 40A is formed in the leading end of the pin 40 to receive a rivet 96. This holds the flywheel 99 in place.
As shown in FIG. 3, an actuator 100 is mounted to the side wall 14 of the frame 10 and generally includes a case 104 fixed to the side wall 14, an operating element or barrel 106 loosely received in the case 104, an operating piece 110 having a protrusion 108 in contact with the upper surface of the operating barrel 106, and a support 112 by which the base end of the operating piece 110 is pivotally supported.
As shown in FIG. 3, a cover 114 surrounds the reel lock mechanism assembled in a manner shown in FIG. 4.
With the retractor of the seat belt thus constructed, the operating piece 110 is disengaged from the flywheel 96 when the seat belt is extracted by the vehicle occupant. This permits rotation of the reel 20 and the shaft 30 and thus, extraction of the seat belt 18. If the seat belt 18 is released, then the shaft 30 is rotated under the influence of the return spring 34 within the cover 36 so that the seat belt 18 may be wound around the reel 20.
If the speed of the vehicle is substantially changed due, for example, to collision, then the actuator 100 is rendered operative to inhibit extraction of the seat belt 18. Specifically, the operating barrel 106 is inclined when a substantial amount of acceleration is exerted on the actuator 100. This causes the protrusion 108 to push up the operating piece 110. A free end of the operating piece 110 is then brought into engagement with the ratchet 94. As a result, the flywheel 96 is prevented from rotating.
Stoppage of the flywheel 96 results in corresponding stoppage of the frictional engagement member 90. A vehicle collision causes extraction of the seat belt 18. This would result in rotation of the reel shaft 30 and thus, the hook retainer 72 and the hook 74 rotate in the direction of the arrow A.sub.1. However, the hook 74 can not be rotated since the frictional engagement member 90 is prevented from rotating as a result of engagement with the pin 88. The hook 74 is slid in the direction of the arrow B.sub.2 to the extent corresponding to the rotation of the hook retainer 72 in the direction of the arrow A.sub.1. The pawl 86 is then brought into engagement with the internal teeth 56 of the lock ring 44.
Consequently, the lock ring 44 is rotated in the direction of the arrow A.sub.1. Rotation of the tab 66 in the direction of the arrow A.sub.1 causes the control lever 58 to rotate in the direction of the arrow C.sub.1 since the pin 62 is engaged with the elongate hole 70. The free end of the control lever 58 is then brought into engagement with the ratchet wheel 38 of the reel shaft 30 so as to firmly lock the reel shaft 30 and the reel 20.
The construction of the belt lock mechanism 24 will next be described with reference to FIGS. 3, 4 and 5.
A first gripping member 120 is attached to the rear wall 16 of the frame 10 and includes a holder 123 vertically movable along the rear wall 16, a receiver 124 held by the holder 123, and a spring 126 disposed to urge the receiver in a downward direction. The receiver 124 has a rugged front surface.
122 is a guide member for guiding the seat belt 18. As shown in FIG. 6, the guide member or frame 122 has upper and lower slots 127 and 129 and is made of synthetic resin.
A pair of openings 130 and 132 are coaxially formed in the side walls 12 and 14 of the frame 10 to receive the shaft 134. A second gripping member 136 has a hole 137 through which the shaft 134 extends. Thus, the second gripping member 136 is rotatably mounted to the frame 10.
As shown in FIG. 5, a semicylindrical pusher 138 is attached to the free end of the second gripping member 136 and has a rugged surface in a face-to-face relation to the receiver 124. The seat belt 18 extends between the pusher 138 and the receiver 124.
A pin 140 (FIG. 3) extends from one side of the second gripping member 136 into an elongate hole 142 which is formed in the side wall 14 of the frame 10.
A rocker arm 146 is pivotally mounted to the outer side of the wall 14 of the frame 10 by a pivot pin 144. The rocker arm 146 is L-shaped and has a notch 148 at one end to receive the pin 140. The other end of the rocker arm 146 is pivotally connected to the upper end of a lever 150 to form a joint 152. The lever 150 is connected to the joint 152 of the rocker arm 146 in a manner to allow slight angular movement in a direction as indicated by E.
The lower end of the lever 150 is overlapped with the tab 68 of the lock ring 44. A pin 154 extends from the lower end of the lever 150 into an elongate hole 156 of the tab 68.
A spring 158 is mounted to the pivot pin 144 and has one end engaged with a hole 160 of the side wall 14 of the frame 10 and the other end engaged with a hole 162 of the rocker arm 146. The spring 158 urges the rocker arm 146 in the direction of the arrow G.sub.1.
Operation of the belt lock mechanism 24 thus constructed is as follows.
In a non-emergency situation, the rocker arm 146 is urged in the direction of the arrow G.sub.1 under the action of the spring 158 to push the pin 140 in the same direction. This causes the pusher 138 of the second gripping member 136 to separate from the receiver 124 so as to allow passing of the seat belt 18 between the pusher 138 and the receiver 124.
In emergency situations such as collision, the operating barrel 106 of the actuator 100 is inclined to cause the operating piece 110 to engage with the ratchet 94 of the flywheel 96 as mentioned earlier. As a result, the lock ring 44 is rotated in the direction of the arrow A.sub.1. Then, the seat belt 18 will be locked in the following steps 1 to 5.
1 Rotation of the tab 68 of the lock ring in the direction of the arrow A.sub.1 results in downward movement of the pin 154 within the elongate hole 156, and thus, rotation of the lever 150 in a direction as indicated by E.
2 The rotation of the lever 150 causes the free end 150a to engage with the ratchet wheel 38.
3 When the ratchet wheel 38 is rotated, the lever 150 is moved upwards. The rocker arm 146 is then rotated about the pivot pin 144 in a direction as indicated by G.sub.2. The pin 140 is pushed in a direction as indicated by G.sub.2 (The elongate hole 70 is so shaped that when the pin 140 is pushed in such a direction, the control lever 58 must not engage with the ratchet wheel).
4 As a result, the second gripping member 136 is moved toward the first gripping member 120 so as to grip or sandwich the seat belt 18 between the pusher 138 and the receiver 124.
5 Once the seat belt 18 is sandwiched between the pusher 138 and the receiver 124, extraction of the seat belt 18 urges the pusher 138 and the receiver 124 toward one another. As a result, the seat belt 18 is firmly gripped between the pusher 138 and the receiver 124 and can no longer be extracted.
In the prior art seat belt retractor, the seat belt 18 tends to slightly slide between the two gripping members 120 and 136 when the first gripping member 120 and the second gripping member 136 begin to grip the seat belt 18.
To present sliding motion of the seat belt 18, the pusher 138 or the receiver 124 could have a serrated surface to contact the seat belt. However, such a serrated surface presents a problem that the seat belt is rubbed to create a rough nap.


Hoses are often reinforced with continuous yarn to improve physical performance characteristics, such as burst strength. For example, radiator hoses for automobiles and trucks are generally reinforced with continuous yarn reinforcing elements. Continuous yarn reinforcements are typically used to improve the burst strength of such hoses. Even though building such fiber-reinforced hoses is a labor-intensive operation which results in a substantial amount of material waste, such techniques have been required to meet the demands of the automotive industry.
Building fiber reinforcements into hoses is a labor-intensive operation. After such hoses are built, they are typically trimmed to the exact size required. The fiber reinforcement containing material trimmed from such hoses generally has to be scrapped since it is not typically possible to recycle such fabric containing material.
Hoses have been made by extruding rubber compositions into the form of a tube which is subsequently shaped into the desired form and cured. Such techniques are advantageous in that they reduce labor costs, in-process inventory and waste. However, hoses made utilizing such extrusion techniques have typically not had the physical strength demanded by the automotive industry for radiator hose. More specifically, such hoses have had low burst strength.
By utilizing the technique disclosed in U.S. Pat. No. 5,268,134, hose which exhibits a burst strength of about 115 pounds per square inch can be made without utilizing fabric reinforcements. This process specifically comprises (1) extruding a rubber composition into the form of a tube, wherein the rubber composition is comprised of (a) an EPDM alloy comprised of (i) functionalized EPDM rubber, (ii) an EPDM rubber having thermoplastic side chains grafted thereto and (iii) dispersed thermoplastic wherein the thermoplastic is selected from the group consisting of nylons, polyesters and polyphenylene oxides, (b) an EPDM rubber, (c) carbon black, (d) at least one curative, (e) zinc oxide, (f) a processing oil and (g) stearic acid; (2) shaping the tube into the geometric form desired for the hose; and (3) curing the rubber composition at a temperature within the range of 130.degree. C. to 210.degree. C. to produce the hose.
U.S. Pat. No. 5,268,134 also discloses a process for manufacturing hose which comprises injection molding a rubber composition into the desired geometric form for the hose at a temperature which is within the range of 130.degree. C. to 210.degree. C., wherein the rubber composition is comprised of (a) an EPDM alloy comprised of (i) functionalized EPDM rubber, (ii) an EPDM rubber having thermoplastic side chains grafted thereto, and (iii) dispersed thermoplastic wherein the thermoplastic is selected from the group consisting of nylons, polyesters, and polyphenylene oxides, (b) an EPDM rubber, (c) carbon black, (d) at least one curative, (e) zinc oxide, (f) a processing oil, and (g) stearic acid; (2) shaping the tube into the geometric form desired for the hose; and (3) curing the rubber composition at a temperature within the range of 130.degree. C. to 210.degree. C. to produce the hose.


As part of the rapid growth of Internet and World Wide Web use, there has been an ever increasing growth in the availability of online services. Such online services include, for example, online banking and financial services, online email services, online retail services, online dating services and online social networks. A given online service provider may provide a number of such services, which users of the online services typically access using a username and password, or other user login credentials that may be used by a provider as a mechanism for verifying users of the provider's services.
Accessing online services using such login credentials is, however, subject to fraud and abuse. For example, malicious actors may obtain user login credentials using improper means. Such improper means may include the use of malicious software, such as could be installed on publicly available computers (e.g., in libraries, Internet cafes or other locations), to monitor keystrokes on an affected computer to capture users' login credentials. User credentials could also be improperly obtained using brute force attacks by trying various combinations of usernames and passwords through an automated trial and error process. These techniques for improperly obtaining login credentials are provided by way of example and a number of other approaches for improperly obtaining user credentials may be used. For example, login credentials may be improperly obtained from a user through a process referred to as phishing. Phishing may be accomplished by malicious actors that masquerade as a trustworthy entity (e.g., a bank or credit card company) by sending, for example, a fraudulent email message that appears to be from a trustworthy entity. These phishing messages may include a request that deceives a user into providing login credential information to a malicious actor.
Once a malicious actor has acquired a user's login credentials for a given online service provider, the malicious actor may then gain access to the user's account with that provider. Depending on the specific provider and online services provided by that provider, the malicious actor could then make fraudulent purchases using the user's financial information, gain access to the user's bank accounts, or perform other acts of identity fraud, posing as the legitimate user for whom the malicious actor has obtained login credentials.


1. Field of the Invention
The present invention relates to a method for forming self-assembled colloidal photonic crystals on a selected area of a substrate or forming self-assembled colloidal photonic crystals having different diameters on the same substrate using an electric field, and a method for fabricating three-dimensional photonic crystal waveguides of an inverted-opal structure using the self-assembled colloidal photonic crystals patterned by the patterning method.
2. Description of the Related Art
Photonic band gap structures in photonic crystals composed of dielectrics having a three-dimensional periodicity have become a matter of increasing interest. The photonic band gap structures are highly applicable to diverse optoelectronic devices such as microlasers, filters, high-efficiency LEDs, optical switches, low-loss waveguides, etc. In an initial stage of investigation, a three-dimensional photonic band gap in a microwave range was realized by providing periodicity to the dielectric constant of a dielectric-air structure by making small holes in a parallel direction on a silicon wafer or by stacking bar-shaped dielectrics in piles. However, in the wavelength ranges of infrared rays and visible light, it was only possible to form a two-dimensional photonic band gap. This is because it was very difficult to form a three-dimensional photonic band gap due to the need for scaling-down the etching space. In the case of a three-dimensional photonic band gap, the holographic lithography of laser light was used. Recently, research for methods of self-assembling small spheres (colloids) having a diameter of several hundred nanometers (nm) has been conducted.
In particular, diverse methods for fabricating self-assembled colloidal photonic crystals have been studied. One of the methods most frequently used is a dip-coating method for fabricating photonic crystals which utilizes capillary force exerted among a colloidal fluid, a substrate and colloidal particles. This dip-coating method is easy to carry out, and can form photonic crystals having a high crystallization in a wide area. However, it is difficult to selectively control the colloidal particles, and many semiconductor processes such as the lithography are required for patterning the photonic crystals. Additionally, in the case of forming photonic crystal of different kinds of colloidal particles or colloidal particles having different sizes, a template is required. Also, in the case of forming colloidal photonic crystals using three or more kinds of colloidal particles or colloidal particles having three or more sizes, the fabricating processes become complicated with limitations in design.
The most frequently used method for fabricating waveguides using photonic crystals comprises forming a transmission line from two-dimensional photonic crystals formed by periodically etching fine holes onto a silicon substrate. The two-dimensional photonic crystal has a photonic band gap and therefore results in no photonic loss in a two-dimensional light-traveling direction, but does suffer photonic loss in other light-traveling directions.
Meanwhile, because the three-dimensional photonic crystal of an inverted-opal structure has a photonic band gap in all three-dimensional light-traveling directions, a waveguide using these three-dimensional photonic crystals can greatly reduce photonic loss in comparison to a two-dimensional photonic crystal. The fabrication of a waveguide having the three-dimensional photonic band gap requires a high-grade etching technique such as e-beam lithography, a high fabricating cost and considerable manufacturing time, and it is difficult to implement the waveguide in a wide area. Accordingly, there has been an increasing demand for and interest in a method for fabricating three-dimensional photonic crystal waveguides of an inverted-opal structure through self-assembly of colloidal particles that can easily allow for fabricating photonic crystals in a wide area.
Conventional methods for fabricating three-dimensional photonic crystal waveguides of an inverted-opal structure have been proposed as follows.
First, the method described in “Multi-Photon Polymerization of Waveguide Structures within Three-Dimensional Photonic Crystals”, Advanced Materials, vol. 14, 2003, pp 271-294 by W. Lee et al. has problems due to material and area limitations. Second, the method described in “Micromolding of Three-Dimensional Photonic Crystals on Silicon Substrates”, Nanotechnology, vol. 14, 2003, pp 323-326 by P. Ferrand et al. also has problems in that its process is complicated and the photonic crystals are broken with the occurrence of cracks during an artificial piling up of the photonic crystals.


Field
The application relates to a medical apparatus, and more particularly, relates to a medical apparatus for delivering radiotherapy.
Description
Radiotherapy is a method which transmits radioactive rays such as α-rays, β-rays, or γ-rays, generated by radioisotopes, X-rays, electron beams, proton beams or other particles, to diseased tissue (e.g., a cancerous tumor). The rays kill cells of the tissue by causing ionizations within the cells or other cell damage.
A linear accelerator is a particle accelerator commonly used for radiotherapy. A linear accelerator comprises a radiation head in which a radiation source is arranged for radiating a radioactive beam toward diseased tissue. The radiation source may include an accelerating tube, an electron gun, a moving target, a magnetic biasing system, a collimator, and a flattening filter. The radiation head also includes a high-density lead shielding layer to prevent extraneous radioactive rays from harming bystanders during use of the linear accelerator. The above components, and others, contribute to the substantial mass of the radiation head.
Conventional radiotherapy is typically performed in conjunction with a computed tomography (hereinafter, “CT”) imaging apparatus or a magnetic resonance (hereinafter, “MR”) imaging apparatus to determine a specific position of the diseased tissue and to thereby properly position the diseased tissue relative to the emitted rays of the linear accelerator. As is known in the art, a CT imaging apparatus is particularly suited for imaging bone and an MR imaging apparatus is particularly suited for imaging soft tissue.
In one example, a patient is positioned within an imaging apparatus to image the diseased tissue and refine the patient's position, and the patient is then moved to the linear accelerator to radiate the diseased tissue. Since both the linear accelerator and the imaging apparatus occupy a large volume, the patient is moved over a substantial distance therebetween, thereby complicating the procedure and increasing the risk and extent of positioning errors.
FIG. 19 illustrates a prior combined medical apparatus 100. The medical apparatus 100 comprises a radiation therapy assembly 102, an imaging assembly 104, and a couch assembly 106. More particularly, the radiation therapy assembly 102 is a common radiotherapy apparatus, which comprises a gantry 1022 in which a through-hole 1024 extending along a horizontal direction is defined. One end of an arm 1026 is secured to the gantry 1022 and the other end thereof extends outwardly. A radiation head 1028 is fixed to the other end of the arm 1026. The imaging assembly 104 is a common CT imaging apparatus, which comprises a gantry 1042 defining a through-hole 1044 extending along a horizontal direction. An X-ray tube 1046 and a detector 1048 are arranged oppositely on a rotatable mechanism (not shown) surrounding the through-hole 1044. The couch 106 comprises a base 1062 and a patient support 1064 arranged on the base 1062.
In order to image a patient, the patient is placed on the patient support 1064, and the patient support 1064 is moved through the through-holes 1024 and 1044 in order to position the patient between the X-ray tube 1046 and the detector 1048. The X-ray tube 1046 and the detector 1048 are then operated as is known in the art to acquire an image of the patient. To radiate the patient, the patient support 1064 is moved such that the target volume, determined from the acquired image, is positioned in the beam field of the radiation head.
The length spanned by the through-holes 1024 and 1044 or, more particularly, the distance from the isocenter of the radiation therapy assembly 102 to the imaging plane of the imaging assembly 104, is quite long. The resulting movable distance of the patient support 1064 is directly related to the likelihood that deformation of the couch assembly and/or the patient support will introduce errors in imaging and/or radiation delivery. Additionally, as recited above, the large volume occupied by the combined medical apparatus 100, consisting of the radiation therapy assembly 102 and the imaging assembly 104, poses a significant challenge to any institution (e.g., a hospital) employing the apparatus 100.
FIG. 20 illustrates another prior combined medical apparatus 200. The medical apparatus 200 comprises a radiation therapy assembly 202, an imaging assembly 204 and a couch assembly 206. The radiation therapy assembly 202 comprises a gantry 2021 defining a through-hole 2022 extending along the horizontal direction. One end of an arm 2023 is secured to the gantry 2021 and the other end thereof extends outwardly. A radiation head 2024 is fixed on this other end of the arm 2023. The imaging assembly 204 is a CT imaging assembly which comprises a gantry 2041 defining a through-hole 2042 along the horizontal direction. An X-ray tube 2043 and a detector 2044 are oppositely arranged around through-hole 2042 on a rotatable mechanism (not shown). The couch assembly 206 comprises a base 2061 and a rotatable platform 2062 which is coupled to the base 2061 and rotatable about a vertical axis 2063. A patient support 2064 is slidably secured to the platform 2062, and a patient P is shown positioned on the patient support 2064.
In contrast to the combined medical apparatus 100 as shown in FIG. 19, the radiation therapy assembly 202 and the imaging assembly 204 of the medical apparatus 200 are separately arranged, and the couch assembly 206 is arranged between the radiation therapy assembly 202 and the imaging assembly 204. Accordingly, during the transition between an imaging mode and a radiating mode, the movement of the patient support 2064 differs from the movement of the patient support 1064 as shown in FIG. 19, i.e., the patient support 2064 rotates to change between the two modes but the patient support 1064 translates linearly to change modes.
The movable distance of the patient support 2064 is shorter than that of the patient support 1064 in FIG. 19, and thus, the apparatus 200 attempts to address the problem of flexible deformation of the patient support 2064. However, since the apparatus 200 requires sufficient distance between the radiation therapy assembly 202 and the imaging assembly 204 such that the patient support 2064 can be rotated without interference with the radiation therapy assembly 202 and the imaging assembly 204, the space occupied by the medical apparatus 200 is unsuitably large.
Thus, technical solutions are desired in radiotherapy to reduce complications, increase efficiency of resource usage, and decrease positioning error.


1. Field of the Invention
The present invention relates to alerting devices, and more particularly to a temperature based alerting device for obtaining a user""s attention upon the occurrence of a predetermined event.
2. Description of the Related Art
The use of wireless communication is increasing at an exponential rate, and as such there have been many attempts among the service providers and manufacturers of the hardware implemented in the wireless systems to provide options to the users that enable more convenient and more user friendly and discrete access to the services. Among these attempts have been the implementation of other methods for alerting the user of the occurrence of a particular event and more specifically, the occurrence of an incoming communication signal. For example, with radio paging devices, the user generally has two options for setting the alert type when an incoming page is received; (i) an audible tone to indicate the presence of an incoming page or alternatively, (ii) a vibration mode to vibrate the device when the incoming page is being received. The vibration mode of the radio pager serves the same function of obtaining the user""s attention when an incoming page is received but does so in a silent manner so as to not disturb the user or persons surrounding the user when the page is received.
Some wireless telephones also provide a similar vibration mode for indicating the presence of an incoming telephone call. The vibration mode has been implemented into these devices primarily to provide the user with the option of turning off the audible tones generated by the radio pager or wireless telephone to prevent inconvenient audible disturbances in a variety of different places. Examples of these places would be office meetings, libraries, and any other place or circumstance that the user deems appropriate to eliminate the audible tones generated by the respective devices.
U.S. Pat. No. 5,861,686 to Lee discloses a device for generating waking vibrations or sounds. The device is implemented into alarm watches or in communications equipment such as cellular pagers or phones. The device utilizes an electromagnet, a element and a first and second set of vibration members in a ring case. These elements are connected to the printed circuit board PCB of the device (e.g. watch, phone or pager) and together enable the selective generation of vibratory motion when the device receives an incoming call, or in the case of a watch for providing an alarm function.
U.S. Pat. No. 5,619,181 to Murray discloses a vibratory alerting device with audible sound generator. The alerting device simultaneously generates a vibration alert and an audible alert to notify the user as to the presence of an incoming call on a portable communication device such as a pager or wireless telephone.
As mentioned previously, the use of an audible alert signal can be undesirable when the user is located in place where an audible alert signal would be considered an interruption. In addition, the devices used to implement a vibratory alert signal in a communication device are generally bulky in nature and have mechanical moving parts which require additional space within the device and thereby increases the overall size of the device.
Furthermore, all of the existing alerting devices (e.g., audible and vibratory) are contained within the communication device (i.e., phone or pager) and therefor require the user to be carrying the same in order to receive the alerting signal.
It would be advantageous to provide a more discrete alerting device that is not physically connected or disposed within the user""s communication device. This would enable the user to be alerted as to the presence of an incoming communication signal without requiring them to carry the communication device.
In accordance with a preferred embodiment of a invention, the method for generating a temperature based signal for alerting a user to the occurrence of a predetermined event comprises: providing a temperature based alerting device having at least one heating element in contact with the user""s skin; initializing the temperature based alerting device to a predetermined temperature; setting a temperature change limit for the temperature based alerting device; changing the temperature of the heating element of the temperature based alerting device upon occurrence of the predetermined event; and resetting the temperature of the heating element of the temperature based alerting device when the user has responded to the occurrence of the predetermined event.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.


Many companies and other organizations operate computer networks that interconnect numerous computing systems to support their operations, such as with the computing systems being co-located (e.g., as part of a local network) or instead located in multiple distinct geographical locations (e.g., connected via one or more private or public intermediate networks). For example, distributed systems housing significant numbers of interconnected computing systems have become commonplace. Such distributed systems may provide back-end services to servers that interact with clients. Such distributed systems may also include data centers that are operated by entities to provide computing resources to customers. Some data center operators provide network access, power, and secure installation facilities for hardware owned by various customers, while other data center operators provide “full service” facilities that also include hardware resources made available for use by their customers. As the scale and scope of distributed systems have increased, the tasks of provisioning, administering, and managing the resources have become increasingly complicated.
The advent of virtualization technologies for commodity hardware has provided benefits with respect to managing large-scale computing resources for many clients with diverse needs. For example, virtualization technologies may allow a single physical computing device to be shared among multiple users by providing each user with one or more virtual machines hosted by the single physical computing device. Each such virtual machine may be a software simulation acting as a distinct logical computing system that provides users with the illusion that they are the sole operators and administrators of a given hardware computing resource, while also providing application isolation and security among the various virtual machines. With virtualization, the single physical computing device can create, maintain, or delete virtual machines in a dynamic manner.
While embodiments are described herein by way of example for several embodiments and illustrative drawings, those skilled in the art will recognize that embodiments are not limited to the embodiments or drawings described. It should be understood, that the drawings and detailed description thereto are not intended to limit embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning “having the potential to”), rather than the mandatory sense (i.e., meaning “must”). Similarly, the words “include,” “including,” and “includes” mean “including, but not limited to.”


This present invention relates to a hydrocarbon conversion process. More particularly, this invention relates to the catalytic hydrocracking of hydrocarbons.
The hydrocracking of hydrocarbons is old and well-known in the prior art. These hydrocracking processes can be used to hydrocrack various hydrocarbon fractions such as reduced crudes, gas oils, heavy gas oils, topped crudes, shale oil, coal extract and tar extract wherein these fractions may or may not contain nitrogen compounds. Modern hydrocracking processes were developed primarily to process feeds having a high content of polycyclic aromatic compounds, which are relatively unreactive in catalytic cracking. The hydrocracking process is used to produce desirable products such as turbine fuel, diesel fuel, and middle distillate products such as naphtha and gasoline.
The hydrocracking process is generally carried out in any suitable reaction vessel under elevated temperatures and pressures in the presence of hydrogen and a hydrocracking catalyst so as to yield a product containing the desired distribution of hydrocarbon products.
Hydrocracking catalysts generally comprise a hydrogenation component on an acidic cracking support. More specifically, hydrocracking catalysts comprise a hydrogenation component selected from the group consisting of Group VIB metals and Group VIII metals of the Periodic Table of Elements, their oxides or sulfides. These hydrocracking catalysts contain an acidic support comprising a crystalline aluminosilicate material such as X-type and Y-type aluminosilicate materials. This crystalline aluminosilicate material is generally suspended in a refractory inorganic oxide such as silica, alumina, or silica-alumina.
Regarding the hydrogenation component, the preferred Group VIB metals are tungsten and molybdenum; the preferred Group VIII metals are nickel and cobalt. The prior art has also taught that combinations of metals for the hydrogenation components, expressed as oxides and in the order of preference, are: NiO--WO.sub.3, NiO--MoO.sub.3, CoO--MoO.sub.3, and CoO--WO.sub.3. Other hydrogenation components broadly taught by the prior art include iron, ruthenium, rhodium, palladium, osmium, indium, platinum, chromium, vanadium, niobium, and tantalum.
There is a myriad of catalysts or catalyst systems known for hydrocracking whose properties vary widely. A catalyst suitable for maximizing naphtha yield may not be suitable for maximizing the yield of turbine fuel or distillate. Further, various reactions; i.e., denitrogenation, hydrogenation, and hydrocracking must be reconciled in a hydrocracking process in an optimum manner to achieve the desired results.
For instance when a feedstock having a high nitrogen content is exposed to a hydrocracking catalyst containing a high amount of cracking component the nitrogen serves to poison or deactivate the cracking component. Thus, hydrodenitrogenation catalysts do not possess a high cracking activity component that is capable of being poisoned. Another difficulty is presented when a hydrocracking process is used to maximize naphtha yields from a feedstock containing light catalytic cycle oil which has a very high aromatics content. The saturation properties of the catalyst must be carefully gauged to saturate only one aromatic ring of a polynuclear aromatic compound such as naphthalene in order to preserve desirable high octane value aromatic-containing hydrocarbons for the naphtha fraction. If the saturation activity is too high, all of the aromatic rings will be saturated and subsequently cracked to lower octane value paraffins.
On the other hand, distillate fuels such as diesel fuel or aviation fuel have specifications that stipulate a low aromatic content. This is due to the undesirable smoke production caused by the combustion of aromatics in diesel engines and jet engines.
Prior art processes designed to convert high nitrogen content feedstocks are usually two stage processes wherein the first stage is designed to convert organic nitrogen compounds to ammonia prior to contracting with a hydrocracking catalyst which contained a high amount of cracking component; i.e., a molecular sieve material.
Accordingly, it is an object of the present invention to provide a process for hydrocracking a hydrocracking feedstock.
More particularly, it is an object of the present invention to provide a process for upgrading crude shale oil to distillate fuels.
Other objects and advantages of the present invention will be apparent to those skilled in the art.


1. Field of the Invention
The present invention relates to an auto focus system having an AF frame auto-tracking function, and more particularly, to an auto focus system having an AF frame auto-tracking function that allows an AF area (AF frame), which is the target range of an object brought into focus by the auto focus (AF), to follow a predetermined object moved on an imaging screen.
2. Description of the Related Art
Broadcasting or commercial television camera systems having an auto focus function for auto focusing on a desired object have been known. This type of camera system generally uses contrast-type AF. In the contrast-type AF, the camera system detects the level of the contrast of the captured image, and controls the focus of an imaging optical system such that the contrast becomes the maximum (the largest).
In general, the target range of an object that is brought into focus by AF is not the entire screen of the captured image, but is limited to a portion of the screen, which is called an AF area. Focus control is performed such that the contrast of the captured image (object image) in the AF area becomes the maximum, thereby focusing on the object in the AF area.
In the specification, a frame indicating the outline of the AF area is referred to as an AF frame.
JP-A-2006-258944 (corresponding to US-A-2006/210260) discloses an auto focus system having an AF frame auto-tracking function that allows the AF frame to automatically follow a desired object moved on the screen of the captured image such that the object is continuously in focus. The auto-tracking of the AF frame is performed by detecting the image of an object to be tracked from the captured image and moving the AF frame to the detected position. As a method of detecting the image of an object to be tracked, JP-A-2006-258944 discloses a method of storing the image of the object to be tracked as a reference pattern and detecting an image matched with the reference pattern from the captured image using a pattern matching process.
In addition, the following method has been proposed: when the object to be tracked is a person's face, a known face detecting process is performed to detect a face image as the image of the object to be tracked.
However, during the tracking of the face image detected by the face detecting process, when the face is turned 30 degrees or more from the front side in the vertical or horizontal direction, the object may not be recognized as the face image, and tracking may be unavailable.
When the pattern matching process is performed to track a predetermined object, it takes a long time to perform the process, and it may be difficult to track an object being moved at a high speed.


This invention relates to a conveyor for automatic processing of workpieces. One specific aspect by way of example and not limitation relates to a conveyor for the automatic heating, in an oven relying mainly on forced convection, of many square thin flat chips of polypropylene to a suitable temperature in connection with which the invention will be described.
An object of this invention is to provide means for conveying flat workpieces on removable trays on an endless type of conveyor through one or more processes.
In summary, the invention embraces a conveyor of the endless type having means for clamping and releasing carrier trays that comprises--a pair of parallel and spaced apart endless conveyors such as belts or chains and preferably (as described e.g. hereafter) chains, a plurality of annular rectangular frames connected to and between said chains at equally spaced-apart distances along each and having substantially flat upwardly facing support surfaces; at least one clamping means mounted on each said frame to clamp and release a carrier tray means thereto, a machine base from which said chains are supported to run longitudinally each in an endless path; and a clamp actuator in the form of a fixed cam mounted on said base at a position to engage each of said clamping means seriatim to cause it to release its tray at one position and to clamp its respective tray at another position, said clamping means and clamp actuators coacting to hold the clamping means in an unclamped position over a certain part of the path of said chains and to cause them to move to a clamped position during the other part of the path. In the preferred embodiment, a plurality of such carrier trays and each said carrier tray is a flat perforated member silicone rubber covered on at least one side.


1. Field of the Invention
The present invention generally relates to optical lenses and projection systems, and more particularly to an achromatic, Fresnel lens which may be used in a low-profile overhead projector.
2. Description of the Prior Art
Transmissive overhead projectors (OHP's) are known in the art, and are generally comprised of a base having a transparent stage area, a light source inside the base, a projection head mounted above the stage, and a condensing lens system located near the stage for collecting and directing the light towards the projector head. The condensing lens system often takes the form of a Fresnel lens or a two-element Fresnel lens combination, as depicted in U.S. Pat. No. 4,436,393.
Several attempts have been made to decrease the base height of OHP's, for portability and reduced obstruction of the projected image during use. To achieve such a low-profile base, some machines collapse during storage or transportation, then expand open for actual use. Machines of this type are described, for example, in U.S. Pat. Nos. 4,969,733 and German Patent Application No. 3,519,506. These collapsible OHP's have several disadvantages, however, such as requiring additional parts which increase the complexity of the machine and add to its cost; the moving parts may also adversely affect alignment of the optical elements over time. Finally, there is no base height advantage of these machines over conventional OHP's when in operation.
Other attempts have been made to construct a low base height OHP without the need to collapse the base and optical elements. For example, U.S. Pat. No. 4,741,613 employs a three-element refracting Fresnel lens system to allow the point light source to be very close to the stage. There are several aspects of this invention, however, which could be improved. First, the requirement of three Fresnel lenses necessarily adds to the cost. Secondly, this system does not adequately compensate for the diminished illumination near the periphery of the stage area. Finally, the dispersion (chromaticity) of a conventional Fresnel lens may lead to coloration of the projected image, particularly around the periphery thereof. Most OHP's locate the light source within the base to minimize this effect, but it is noticeable any time the projection head is moved from its optimum position. For example, if the projection head must be lowered to magnify an image or focus it on the projection screen, less red light at the periphery of the stage is captured by the projection lens, leading to a bluish tint at the border of the projected image. Similarly, moving the projection head up (away from the stage) can cause the border to have a reddish tint. This effect (which is even more pronounced in the three-element system of the '613 patent) can be overcome by repositioning the lamp within the base (referred to as "color tuning"), but this involves further user manipulation of the OHP and still requires a subjective judgment regarding the chromaticity of the projected image. Color tunability also adds to the cost of the OHP since it requires a mechanism for repositioning the lamp.
The OHP's disclosed in U.S. Pat. Nos. 4,118,761 and 4,952,053 use folded optical paths to provide a more compact base. In the '761 patent, the light source is also "off-axis," meaning that the apparent location of the light source does not coincide with the center of the stage, i.e., the apparent location is displaced from the normal to the stage center. That device requires a complex optical system including a parabolic reflector to provide collimated light, two planar grooved reflectors, and the condensing lens assembly; it may exhibit a slightly darkened edge, furthest from the light source. In the '053 patent, the darkened edges are compensated for by providing two light sources. The twisted and curved mirrored, grooved prisms are also more difficult to fabricate than flat condensers. Finally, folded optical paths may create problems with full-size stage formats, such as European (A4) styles, since extremely tight folds such as are necessary to achieve a low-profile may cause the light source itself to interfere with the folded light path.
The OHP of the present invention overcomes several of the above limitations by using a novel catadioptric Fresnel lens. While the use of any catadioptric lens in an OHP is in itself novel, catadioptric lenses are known in other art areas. The term "catadioptric" refers to a lens which uses both reflection and refraction to redirect or bend light waves. See, e.g., U.S. Pat. Nos. 2,003,804, 4,859,043 and 5,097,395. As depicted in those patents, catadioptric lenses are useful in collimating light, similar to Fresnel lenses. In U.S. Pat. No. 5,150,966, a catadioptric lens is used to adjust light intensity distribution by discarding light. See also U.S. Pat. No. 4,755,921, which describes a single element catadioptric lens having increased efficiency at high entrance angles, thereby providing a "fast" lens (low f-number) that is suited for compact optical devices.
Chromatic aberration is also a problem with catadioptric Fresnel lenses. The dispersion is caused by the optical properties of the lens material, i.e., its index of refraction varies with the wavelength of the light passing therethrough. There are several techniques, however, for minimizing this effect. For example, attempts have also been made to minimize chromatic aberration in single element lenses, such as by providing discontinuous axisymmetric surfaces, or by using aspheric surfaces. Diffraction gratings may be placed on the lens, including on a Fresnel lens, as depicted in U.S. Pat. No. 5,161,057. See also U.S. Pat. No. 4,337,759, which describes a curved base, catadioptric Fresnel lens with a controlled amount of chromatic dispersion for use as a solar concentrator. Many of the foregoing techniques minimize dispersion only for selected wavelengths, as opposed to the full (visible) spectrum. Most of the techniques (including the '759 patent) also require materials having specific indices of refraction, to achieve a specific focal length with color correction.
In light of the foregoing, it would be desirable and innovative to design a Fresnel lens which is usable in a low-profile OHP. The lens would advantageously be achromatic and constructed of any number of light-transmissive materials having a large range of refractive indices, and efficiently focus the light to the projection lens of the OHP. The condensing system preferably would avoid the use of micro-precision diffraction gratings, and would generally minimize the number of optical elements (such as grooved mirrors), including the number of elements in the condensing lens, but still be compatible with a folded optical path. Provision of such an achromatic lens would greatly reduce or minimize the need for color tuning.


1. Field of the Invention
The present invention relates to a hoisting apparatus for a load such as luminaires used at high elevations, and particularly a hoisting apparatus with a horizontal stabilizing means for a load holder, to which the load is detachably attached.
2. Disclosure of the Prior Art
In high-ceilinged structures such as concert hall, gymnasium, and convention hall, a hoisting apparatus has been utilized to readily carry out maintenance work of luminaires operated at high elevations. For example, as shown in FIG. 10, European Patent Publication No. 1193442 A2 discloses this kind of hoisting apparatus. That is, this hoisting apparatus 1S is mainly composed of a base 2S secured to a ceiling, a load holder 3S, to which a luminaire is detachably attached, a pair of cables 4S extending between the base and the load holder, a drive unit (not shown) mounted to the base, to which one ends of the cables are connected, so that the drive unit is operative to take in or let out the cables from the base.
From the viewpoint of facilitating the maintenance work of the luminaire under safe working condition, this hoisting apparatus also has a cable-length adjusting means in the load holder 3S, by which the cable length can be readily adjusted such that a descending position of the load holder matches a position adequate for the maintenance work of the luminaire to avoid dangerous operations at high elevations,
As shown in FIGS. 11A to 11C, the cable-length adjusting means comprises a winding shaft 60S of a round-bar shape, which is rotatably supported in a holder case 30S of the load holder 3S. Each of the cables 4S is fixed connected at its one end to a winding drum (not shown) of the drive unit and at the opposite end to the winding shaft 60S. The winding shaft 60S also has an elongate hole 64S, to which a dedicated tool 48S can be inserted through a slit 34S formed in the upper surface of the holder case 30S to inhibit the rotation of the winding shaft. In addition, the winding shaft 60S has engagement grooves 65S at its opposite ends, to which a tip of the dedicated tool 48S can be engaged. The grooves 65S of the winding shaft 60S are exposed to be accessible from outside of the holder case 30S, as shown in FIG. 10.
By use of the cable-length adjusting means described above, the cable length can be adjusted as follows. That is, the tip of the dedicated tool 48S is engaged to one of the grooves 65S of the winding shaft 60S, and then the winding shaft is rotated by the dedicated tool to wind desired amounts of the cables thereon. In this hoisting apparatus, since both of the cables 4S are wound around the winding shaft 60S in the same winding direction, as shown in FIG. 11A, the winding operation of the cables can be achieved by rotating the winding shaft 60S. In addition, since a proper tension is applied to the cables 4S under the suspended condition of the load holder 3S, it is possible to readily wind the cables around the winding shaft 60S without looseness. After the desired amounts of the cables 4S are wound on the winding shaft 60S, the dedicated tool 48S is removed from the groove 65S, and inserted into the elongate hole 64S of the winding shaft through the slit 34S of the holder case 30S, so that the rotation of the winding shaft is inhibited to prevent unwinding of the cables 4S from the winding shaft.
By the way, from another viewpoint of preventing an inclination of the load holder with the luminaire, an improvement of the conventional hoisting apparatus is being awaited. For example, due to variations in cable length, and variations in position of the cable ends respectively connected to the winding shaft and the winding drum of the drive unit, it is difficult to provide the same effective length between the pair of cables. This means that the inclination of the load holder may easily occurs.
According to the hoisting apparatus described above, it is possible to adjust the cable length by rotating the winding shaft to obtain the desired effective length of the cables between the base and the load holder. However, since both of the cables are wound around the winding shaft in the same winding direction, this cable-length adjusting means do not have a function of correcting the inclination of the load holder in a horizontal position. In other words, when one of the cables is wound around the winding shaft by rotating the winding shaft, the other one is also wound around the winding shaft. Therefore, the inclination of the load holder can not be solved by the rotation of the winding shaft.
Thus, from the above viewpoint of stably maintaining the load holder in a horizontal position, there is still room for improvement of the conventional hoisting apparatus.


Haematite, having the chemical formula Fe2O3, is one of the most abundant minerals in nature. It exists as iron ore, in other minerals such as bauxite, and is also a component in clay minerals. It is the major component in laeritic soils (red soils found in the tropics). Similarly, manganese oxide, having a formula Mn2O3 is also a very common component in several laeritic soils and also exists as a mineral of manganese in the tropics.
U.S. Pat. Nos. 5,645,518 and 5,830,815 issued to Wagh et al. on Jul. 8, 1997 and Nov. 3, 1998, respectively, disclose processes for utilizing phosphate ceramics to encapsulate waste. U.S. Pat. No. 5,846,894 issued to Singh et al. on Dec. 8, 1998 discloses a method to produce phosphate bonded structural products from high volume benign wastes. None of these patents provides a method for utilizing the waste materials of iron and manganese.
U.S. Pat. No. 6,153,809 issued to Singh et al. Nov. 28, 2000 and U.S. patent application Ser. No. 09/751,655 filed Dec. 29, 2000, publication no. U.S. 2002/0123422 to Wagh et al. represent additional development of the use of chemically bonded phosphate ceramics to useful materials. Each of the aforementioned patents, that is U.S. Pat. No. 5,645,518 issued to Wagh et al., U.S. Pat. No. 5,846,894 issued to Singh et al., U.S. Pat. No. 5,830,815 issued to Wagh et al., U.S. Pat. No. 6,153,809 issued to Singh et al., U.S. Pat. No., 6,133,498 issued to Singh et al. and the above-identified publication no. US 2002/0123422 (patent application Ser. No. 09/751,655) is incorporated herein in their entireties.
The phosphate ceramics disclosed in the various patents and publication hereinbefore mentioned illustrate a continuing effort to use the chemically bonded phosphate ceramics disclosed therein for a variety of purposes including the encapsulation of hazardous or radioactive waste as seen in the aforementioned publication, as well as the production of low cost structural materials. Accordingly, therefore, a need exists in the art for a low cost structural material which combines with synthetic organic resin based structures, for particular usage in the construction industry. Typically, in warm weather climates, low cost housing may be constructed using styrofoam as a base material onto which is sprayed a concrete-like material as a finish coating to seal the styrofoam base material against the elements and to provide a satisfactory looking structure. Heretofore, the phosphate ceramics disclosed in the above-captioned patents and publication were used as a finish coating in warm temperature climates but have not been satisfactory because the bond between styrofoam and the phosphate ceramics herein above disclosed is physical and peelable such that durable coatings have not been able to be provided with the extant material.


The goal of plant breeding is to combine, in a single variety or hybrid, various desirable traits. For field crops, these traits may include resistance to diseases and insects, resistance to heat and drought, reducing the time to crop maturity, greater yield, and better agronomic quality. With mechanical harvesting of many crops, uniformity of plant characteristics such as germination, stand establishment, growth rate, maturity, plant height and ear height, is important. Traditional plant breeding is an important tool in developing new and improved commercial crops.


Recent development in the image sensing field has resulted in image sensors that feature security and machine vision applications, including gesture sensing, depth analysis, iris detection, eye tracking, night or low light vision, etc. In one aspect, these image sensors use traditional, VIS spectrum image sensing pixels to produce VIS images. In another aspect, these sensors also use additional, IR spectrum pixels to produce IR images. Basically, these sensors serve a dual purpose of producing both VIS and IR images.
Conventionally, such a dual purpose image sensor employs a direct combination design wherein an IR sub-sensor is physically juxtaposed next to a VIS sub-sensor. The VIS sub-sensor only includes VIS imaging pixels, and the IR sub-sensor only includes IR imaging pixels. This design offers simplicity, but the VIS and IR sub-sensors inevitably have different vantage points with regard to an imaging target. As a result, the resulting VIS and IR images not only have different optical spectra (VIS versus IR), but are also not able to be completely superimposed onto each other. This creates difficulties for subsequent image processing.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.


Degradable polyelectrolytes are useful materials in a variety of biological applications ranging from biomedical implant coatings and immunostimulants to vehicles for drug and nucleic acid delivery. A significant fraction of these applications rely on polyelectrolytes that perform a specific function, after which they degrade into non-toxic byproducts, thereby preventing bioaccumulation and toxicity. Many known degradable polyelectrolytes contain hydrolytically unstable functionalities in the polymer backbone, including ester, anhydride, acetal, carbonate, amide, phosphate, and siloxy ether functionalities. While natural polyelectrolytes such as collagen and chitosan have garnered substantial interest in various biological applications, new approaches to degradable synthetic polyelectrolytes will continue to furnish well-defined materials with tunable structures, controlled molecular weights, and variable backbone charge densities and hydrophilicities.
Some of the most widely studied synthetic degradable polyelectrolytes are based on polyphosphazene and poly(β-amino ester) scaffolds. Anionic and cationic derivatives of poly(phosphazene) are promising vaccine adjuvants and nucleic acid delivery agents, respectively; however, complex monomer syntheses and harsh polymerization conditions limit the types of chemical functionality that may be introduced into these materials. Synthesized by the Michael addition polymerization of diamines with diacrylates, poly(beta-amino esters) comprise a modular platform of polycationic materials exhibiting highly variable hydrophilicities and tunable degradabilities depending on the specific monomers used. Various groups have demonstrated the utility of these materials as components in drug delivery vehicles and in erodible polyelectrolyte multilayer films for therapeutic small molecule and nucleic acid delivery. In spite of the demonstrated potential of poly(beta-amino esters), their widespread utility in biomedical applications is curtailed by synthetic difficulties associated with tuning the charge density along the polymer backbone.
What is needed are readily accessible monomer and polymer platforms that provide new materials, particularly for biological applications.


A biomarker is a measurable characteristic that reflects the severity or presence of or is associated with some disease state and that can be used as an indicator of a particular disease state or some other physiological state of an organism. Biomarkers can be specific cells, molecules, genes, gene products, enzymes, receptors, mutated versions of any of these cellular elements or hormones that can be used to identify and/or measure the presence or progress of disease state, such as a particular cancer or tumor. Further, it is well known that tumors and cancers can express a set of tumor biomarkers that can be used to identify the presence of or measure the progress of or the effects of treatment on the tumor or cancer.
Despite the abundant use of biomarkers for diagnosing disease and monitoring progression of the same, there remains a need for developing therapeutic approaches that make use of this information to specifically target biomarkers expressed by the disease that are directly associated with the proliferation or existence of the diseased state and subsequent deterioration of a subject's overall health
Listeria monocytogenes (Lm) is an intracellular pathogen that primarily infects antigen presenting cells and has adapted for life in the cytoplasm of these cells. Listeria monocytogenes and a protein it produces named listeriolysin O (LLO) have strong adjuvant properties that unlike the majority of adjuvants used for cellular based immunotherapies, can be administered after providing an antigen specific treatment or can be used to itself provide antigen-specific treatment when fusing an antigen of interest to an adjuvant protein expressed by the Listeria, such as LLO or an ActA protein.
The present invention addresses this need by providing a combinatorial, multi-target immunotherapeutic approach wherein individual compositions each comprising a recombinant Listeria-strain expressing a different disease-associated antigen than a counterpart Listeria present in a separate composition, are administered separately to a subject having a disease, or the compositions are administered in combination as single bolus administration. The present invention further addresses this need by providing a predetermined number disease-associated antigens or fragments thereof by using a recombinant Listeria expressing at least one fusion protein comprising the antigen fused to an immunogenic Listeria peptide such as an N-terminal LLO, truncated LLO, an ActA protein fragment, or a PEST peptide. Use of such compositions will allow diseases, including tumors, cancers, or others having sub-populations of diseased cells expressing more than one biomarker to be successfully treated.


Surface representations in computer graphics can be orders of magnitude smaller than polygonal or patch based surface representations which may be a desirable feature for memory constrained devices like game consoles. Constructive Solid Geometry (CSG) operations are a powerful method for defining surfaces of high genus (e.g. a sphere with a hole) from surfaces of low genus, such as plain cylinders and spheres. Defining parametric procedural surfaces of genus 0 (e.g., a sphere) and some surfaces of genus 1 (e.g., a torus) is usually straightforward since there are no holes in the surface domain. However, for surfaces of higher genus, it is much more difficult since domains of some parametric surfaces may have holes whose boundaries are, in some sense, only implicitly defined (e.g., as an intersection of surfaces). These boundaries are difficult to program manually.
CSG operations may provide methods for defining surfaces of high genus from surfaces of low genus, such as cylinders and spheres. Virtually any manufactured object may be modeled using CSG operations in combination with surfaces of revolution and generalized extrusions, both of which are easily programmed procedurally. Also, the addition of CSG operations to procedural surfaces dramatically increases the scope of objects that can be modeled procedurally.
Among other things, CSG operations may require computing and representing curves of intersection between the two or more surfaces being operated upon. These curves, in general, are defined only implicitly as the solution to an equation of the form f(x1, . . . , xn)=0. These equations are not easy to evaluate and typically require a sophisticated, slow, and computationally costly global zero finding solver. A more compact, exact and resolution independent representation of such curves on the other hand may be efficiently evaluated at runtime on a graphics processor. Such representation may be a highly desirable feature for memory constrained devices, like game consoles or for bandwidth constrained applications. Also, such representations may make it possible to represent high genus surfaces in an entirely procedural way without significant computational costs.


(1) Field of the Invention
The present invention relates to a television device for providing images with appropriate quality in accordance with a viewing environment.
(2) Description of the Related Art
Various functions of the video display device such as a television device have been proposed for adjusting the video image quality in accordance with the viewing environment such as ambient brightness. For example, Japanese Published Unexamined Patent Application No. 4-342373 discloses the television receiver structured to automatically adjust the image quality to the level adapted to the viewing environment based on the illuminance data of the ambient brightness and the distance data with respect to the viewing distance between the receiver and the viewer. Japanese Published Unexamined Patent Application No. 2000-112021 discloses a display device of projection type structured to allow the light detection unit to detect the light flux from the display area, and automatically adjust the light flux projected to the display area based on the output signal from the light detection unit.


The following publications are believed to represent the current state of the art:
U.S. Pat. Nos. 5,659,771; 5,907,839; 6,424,983; 7,296,019; 5,956,739 and 4,674,065
U.S. Published Patent Application Nos. 2006/0247914 and 2007/0106937;


The invention relates to a tool-driving device that is particularly designed for use in machine tools or in machining units of machining centers, and has at least one machine spindle that is seated to move.
Machine tools are used especially for material-removal processes, such as boring, milling, turning on a lathe, etc.
The tool is inserted into a corresponding tool receptacle that is secured in the work spindle of the relevant machine tool. Various tool receptacles are available.
During the machining process, the work spindles are driven by associated drive apparatuses. Control devices, which can include expanded electronic circuits or execution programs, are provided for controlling the spindle movement, notably its rotation and/or adjustment.
The control device establishes the rpm of the spindle within an rpm range. This range is inherently limited. It may be that, particularly for very small tool diameters or for other reasons, rpms outside of the rpm range of the spindle are required.
It is the object of the invention to provide a tool-driving device that expands the application range of a machine tool or machining unit, preferably with as little intrusion as possible into the existing machine control.
This object is accomplished with a tool-driving device having the features of claim 1.
The tool-driving device of the invention has a spindle insert, which can preferably be clamped, fixed against relative rotation, in a machine spindle and can support a tool for machining workpieces. A coupling device serves to secure the spindle insert in the machine spindle. A drive that is supplied by a drive source located outside of the spindle insert, and can be controlled by a control device, is provided for driving the tool. The drive is effected by way of a coupling element that can be connected to the supply lines of the drive. The drive is controlled as a function of the movement of the machine spindle; the tool-driving device is provided with a detection device for detecting this movement.
From the spindle movement, the detection device obtains a signal that characterizes, for example, the rpm, and is used as an input signal for the control device for controlling the drive, and therefore the movement, of the tool. The detection of the rpm requires no access to the machine control, especially if no control signals originating from the machine control are necessary. The control device is separate from the other machine control, and is therefore independent and self-sufficient.
If desired, the power supply can be effected by the tapping of the machine control or the drive source of the machine tool. A dedicated drive source can, however, also be provided for the power supply.
The tool-driving device permits the increase of the rpm of the machine spindles above and beyond the capabilities of the machine spindle. Unlike in a passive accessory gear, in this instance the additional supply of power in the drive of the tool permits the conversion of an output that exceeds the output of the machine spindle. The maximum torque can be completely retained while the rpm is increased.
The spindle insert has a coupling device, e.g., a 7/24 taper shank, which permits a secure, detachable connectionxe2x80x94fixed against relative rotationxe2x80x94with the machine spindle. It also has an essentially cylindrical, one- or multiple-part housing, inside which the drive is disposed.
If material-removal operations are to be executed with a rotating tool, the drive is embodied as a rotary drive. A motor, e.g., an electric motor, serves to drive the tool. DC motors, synchronous motors or asynchronous motors can be used for a single- or polyphase alternating current. Hydraulic or pneumatic drives, with which rotational or axial movements of the tool can be attained, can also be used. The motors can be connected to the tool directly, or via a gear in a driving arrangement.
In a preferred embodiment of the invention, a receiving apparatus is provided for receiving the tool; the apparatus has a tool spindle, into which the tool is clamped, fixed against relative rotation. The tool spindle preferably has a conical inside shape. The tool spindle is then formed by a rotatably-seated shaft, and projects out of the housing. The shaft is connected to a rotating part of the motor (internal or external rotor) so as to be fixed against relative rotation. The shaft and the tool spindle are preferably embodied to rotate symmetrically relative to an axis of rotation established by the machine spindle. The tool spindle can, however, also support a quick-clamping element, a jaw chuck or the like.
At least one slip ring, which is mounted to the outside of the housing and is electrically insulated from it, and can be brought into engagement with an associated sliding contact of the coupling element, is provided for supplying power to the electric motor. When the machine spindle rotates, the sliding contacts slide along the slip rings, thereby assuring the power supply to the drive. Rollers can also be used instead of sliding contacts. The supply can also be effected contactless, e.g., with transformers.
The slip rings are preferably disposed on a conical part of the housing whose diameter increases starting from the machine spindle. The slip rings therefore have different diameters. The smallest diameter is larger than that of an arbitrary part of the coupling device. Thus, the spindle insert can be inserted into the machine spindle without altering the position of the contact set. The contact set can then be rigidly secured to the machine tool, in which case it is disposed at a slight incline, corresponding to the incline of the conical housing part. The insertion of the spindle insert produces the contact between the slip rings and the sliding contacts. The contact set can also be seated to be adjusted, and/or can be separate.
The safety of the tool-driving device is increased when voltage is only applied to the sliding contacts during the machining process. If the detection device detects rpms that are at least as high as a defined threshold value, preferably 30 rpm, the current supply to the sliding contacts is enabled, for example, by the automatic closure of a switch. The circuit is opened at rpms below the threshold value.
Contactless, magnetic or optical methods are preferred for rpm detection. For example, a metal part connected to rotate with the spindle insert or the machine spindle can serve to induce a short voltage pulse in a stationary coil with each rotation.
In an advantageous embodiment, the detection device has a signal generator, particularly a light source, and a signal receiver, particularly a light sensor. The detection device is preferably adjustably mounted to the machine tool, for example to the spindle head that guides the machine spindle. A marking, such as a narrow metal plate, that reflects the light emitted by the light source is secured to the tool coupling or the machine spindle. A signal that is thereby generated, and characterizes the rpm of the machine spindle, e.g., a pulse signal that is proportional thereto, is then transmitted to the control device.
A circular clamping body having different visual properties from the location where it is to be secured can serve as a marking. The clamping body can have a gap or a recess.
The passage of the gap or recess in front of the sensor generates the signal.
Markings that effect the generation of a plurality of signals with each rotation can also be provided. In the simplest case, the markings can be equidistantly spaced and provided on, for example, an adhesive strip.
The control device utilizes the signals arriving from the detection device to generate a corresponding drive signal for the drive. Hence, the rpm range of the tool can be expanded with the device of the invention. Existing machine tools can therefore be rendered more versatile without its mechanical or electronic components being disturbed.
The control device can be integrated into the spindle insert, or accommodated separately. It can also be controlled by programs running on a computer. A console can be provided for the user.
At least one supply line for a cooling fluid or compressed air is preferably provided in the tool-driving device for cooling the tool, as is an outward-oriented nozzle, which is preferably pivotable and comprises plastic, for example. At the same time, the nozzle can conduct heat out of the tool-driving device.
Further advantageous details about embodiments of the invention ensue from the dependent claims, the drawing and/or the associated description.


(1) Field of the Invention
The present invention relates to a transmission system having a plurality of terminals linked by a working channel line and a protection channel line in a redundant structure wherein a connection is switched from the working channel line to the protection channel line while avoiding instantaneous cutoff when the working channel line has failed.
It is desired to provide reliable data communication in a transmission system having a plurality of terminals linked by a working channel line and a protection channel line in a redundant structure. In order to attain this objective, it is necessary that the transmission system reliably switch a connection from the working channel line to the protection channel line while avoiding instantaneous cutoff when one of the two channel lines has failed.
(2) Description of the Related Art
FIG. 22 shows a conventional transmission system having a plurality of terminals linked by a working channel line and a protection channel line in a redundant structure. In the conventional transmission system, a connection is switched from the working channel line to the protection channel line while avoiding instantaneous cutoff when a switching command to switch one of the channel lines to the other is received.
As shown in FIG. 22, the conventional transmission system includes a transmission terminal 101 (which is called a terminal A), a reception terminal 103 (which is called a terminal B), and a transport terminal 102 (which is called a terminal C). The terminal A and the terminal B are linked by a working channel line, and the terminal A, the terminal C and the terminal B are linked by a protection channel line. In the conventional transmission system of FIG. 22, transmission of a digital signal in the existing synchronous digital hierarchy (SDH) frame format is assumed.
In the transmission terminal 101 (the terminal A), a frame pulse insertion unit (FP INS) 104 and a distribution unit (DIS) 105 are provided. The FP INS 104 inputs the SDH frame and inserts a frame pulse (FP) in the SDH frame at a given location of the SDH frame. The frame pulse (FP) inserted by the FP INS 104 indicates a reference position in the SDH frame on the related channel line. When a switching command is externally supplied to the reception terminal 103, the FP in the SDH frame is used by the reception terminal 103 to synchronize the SDH frame on the working channel line with the SDH frame on the protection channel line.
The DIS 105 supplies the SDH frame (with the FP inserted) from the FP INS 104 to both the terminal B through the working channel line and the terminal C through the protection channel line.
In the transport terminal 102 (the terminal C), a data delay unit 106 is provided. The data delay unit 106 provides a delay for the SDH frame on the protection channel line from the terminal A.
In the reception terminal 103 (the terminal B), a fixed delay unit 107, a frame pulse detection unit (FP DET) 108, and a control unit 109 are provided. The fixed delay unit 107 provides a fixed delay for the SDH frame on the working channel line from the terminal A. The fixed delay is provided by the fixed delay unit 107 such that a total delay for the SDH frame on the working channel line due to the transmission between the terminal A and the terminal B and due to the transmission through the fixed delay unit 107 within the terminal B is always greater than a delay for the SDH frame on the protection channel line due to the transmission between the terminals A, C and B and due to the transmission through the data delay unit 106 within the terminal C.
The frame pulse detection unit (FP DET) 108 detects the frame pulse (FP) in the SDH frame on the working channel line, and separates the frame pulse (FP) from the SDH frame on the working channel line. The FP DET 108 supplies the frame pulse to the control unit 109 and outputs the reconstructed SDH frame (with no frame pulse) which is the same as the SDH frame originally sent on the working channel line from the terminal A.
Further, in the reception terminal 103, a data delay unit 110, a frame pulse detection unit (FP DET) 111, and a selector 112 are provided. The data delay unit 110 provides a variable delay for the SDH frame on the protection channel line from the terminal C. The delay provided for the SDH frame on the protection channel line by the data delay unit 110 is controlled by the control unit 109 such that a position of the FP in the SDH frame on the protection channel line matches with a position of the FP in the SDH frame on the working channel line.
The frame pulse detection unit (FP DET) 111 detects the frame pulse (FP) in the SDH frame on the protection channel line, and separates the frame pulse (FP) from the SDH frame on the protection channel line. The FP DET 111 supplies the frame pulse (FP) to the control unit 109 and outputs the reconstructed SDH frame (with no frame pulse) which is the same as the SDH frame originally sent on the protection channel line from the terminal A.
The control unit 109 receives the frame pulse (FP) from the FP DET 108 and the frame pulse (FP) from the FP DET 111, and controls the variable delay of the data delay unit 110 based on the FP from the FP DET 108 such that a position of the FP in the SDH frame on the protection channel line matches with a position of the FP in the SDH frame on the working channel line. Further, the control unit 109 controls the selector 112 in response to an externally supplied switching command, so that the selector 112 outputs a selected one of the SDH frame on the working channel line from the FP DET 108 and the SDH frame on the protection channel line from the FP DET 111.
The selector 112 outputs the selected one of the SDH frame on the working channel line from the FP DET 108 and the SDH frame on the protection channel line from the FP DET 111, under the control of the control unit 109, as the output data from the terminal B.
FIG. 23 shows an operation of the conventional transmission system of FIG. 22.
In the above-described conventional system, when a digital signal in the SDH frame format is input to the transmission terminal 101, the frame pulse insertion unit 104 inserts a frame pulse (FP) in the SDH frame. The SDH frame with the FP inserted is produced at the output of the FP INS 104.
The distribution unit 105 outputs the SDH frame (with the FP inserted) to both the reception terminal B through the working channel line and the transport terminal C through the protection channel line ("S1" in FIG. 23).
A first delay due to the transmission of the digital signal on the working channel line is provided for the SDH frame having the FP on the working channel line. The delayed SDH frame is input to the fixed delay unit 107 in the terminal B ("S2" in FIG. 23).
A second delay due to the transmission of the digital signal on the protection channel line and through the data delay unit 106 of the terminal C is provided for the SDH frame having the FP on the protection channel line. The delayed SDH frame is input to the data delay unit 110 in the terminal B ("S3" in FIG. 23).
A third delay is further provided for the SDH frame having the FP on the working channel line by the fixed delay unit 107 in the terminal B. The delayed SDH frame is output from the fixed delay unit 107 ("S4" in FIG. 23).
The third delay (or the fixed delay) is provided by the fixed delay unit 107 such that a total delay (the first delay plus the third delay) for the SDH frame on the working channel line input to the FP DET 108 is always greater than the second delay for the SDH frame on the protection channel line input to the FP DET 111.
The control unit 109 controls the variable delay of the data delay unit 110 based on the FP from the FP DET 108 such that a position of the FP in the SDH frame on the protection channel line matches with a position of the FP in the SDH frame on the working channel line. Further, the control unit 109 controls the selector 112 in response to an externally supplied switching command, so that the selector 112 outputs a selected one of the SDH frame on the working channel line from the FP DET 108 and the SDH frame on the protection channel line from the FP DET 111. The selector 112 normally outputs the SDH frame on the working channel line from the FP DET 108. When the switching command to switch the working channel line to the protection channel line is externally supplied to the control unit 109, the selector 112 outputs the SDH frame on the protection channel line from the FP DET 111.
Accordingly, when both the working channel line and the protection channel line normally function and a switching command to switch one of the channel lines to the other is externally supplied, the conventional transmission system of FIG. 22 can switch a connection from the working channel line to the protection channel line without causing instantaneous cutoff in response to the command. However, when the working channel line has failed, the switching command cannot be supplied to the control unit 109 in the reception terminal 103. Therefore, when the working channel line has failed, it is impossible for the conventional transmission system of FIG. 22 to switch a connection from the working channel line to the protection channel line while avoiding instantaneous cutoff. It is difficult for the conventional transmission system of FIG. 22 to provide reliability for data communication if the working channel line has failed.


1. Field of the Invention
The present invention relates to a push button switch for use as a key switch for a data input apparatus for a personal computer, a word processor or the like, and, more particularly, to a push button switch the thickness of which can be easily reduced.
2. Related Art Statement
A conventional push button switch of the type described above will be described with reference to FIG. 13.
Referring to the drawing, reference numeral 1 represents a reinforcing plate made of metal or the like. A membrane switch 2, comprising an upper sheet 2b having a movable contact 2a and a lower sheet 2d having a fixed contact 2c, is placed on the reinforming plate 1. A case 3 is placed on the membrane switch 2, the case 3 having an annular first projecting portion 3a and a second projecting portion 3b. An operation member 4a of a key top 4 is movably positioned along an inner surface 3c of the first projecting portion 3a. The operation member 4a has a fastening claw at the lower end portion thereof so that the fastening claw is fitted within a recessed portion (omitted from illustration) formed in the first projecting portion 3a. As a result, the fastening claw can be moved within the recessed portion and the operation member 4a can be vertically moved along the inner surface 3c. Furthermore, a coil spring 5 is interposed between a flat surface 3d of the case 3 and the lower surface of the key top 4 in such a manner that the coil spring 5 is positioned around the first projecting portion 3a. In addition, another coil spring 6 is positioned in the operation member 4a by press-fitting for the purpose of pressing the movable contact 2a of the membrane switch 2. Although omitted from the illustration in FIG. 13, a recessed portion is formed in the second projecting portion 3b in a direction perpendicular to the direction of the drawing sheet for FIG. 13. As a result, the upward separation of the key top 4 is prevented by fastening the fastening claw provided for the key top 4 to the recessed portion.
Thus, when the key top 4 is depressed against the urging force of the coil spring 6, the outer portion of the operation member 4a is downwards moved along the inner surface 3c. As a result, the lower end portion of the coil spring 5 press-fitted in the operation member 4a presses the upper sheet 2b of the membrane switch 2, causing the movable contact 2a to be brought into contact with the fixed contact 2b. Therefore, the switch is switched on. When the pressure applied to the key top 4 is then released, the original state can be restored by the elastic restoring force of the coil spring 6.
Recently, there has been a desire for a compact keyboard having a reduced thickness, causing a necessity for reducing the thickness of the push button switch to arise.
When a push button switch having a reduced thickness is constituted, the push button switch must have a certain depressing stroke (3 to 4 mm).
It is assumed that the thickness of the key top 4 is b, the distance of the movement of the key top 4 is S, the length of a portion (omitted from illustration) for fastening the case 3 and the key top 4 is a, the thickness of the reinforcing plate 1 and the membrane switch 2 is c and the overall height is expressed by H.
Then, the length a of the fastening portion can be expressed by a=H-(2S+b+c). In this case, the thickness b of the key top 4, the movement distance S of the key top 4 and the thickness c of the membrane switch 2 and the reinforcing plate 1 become substantially constant depending upon the molding condition and the parts composition. Therefore, there has conventionally been a necessity for the length a of the fastening portion to be shortened at the time of realizing the above-described thickness reduction.
However, if the length a of the fastening portion is shortened, the lower end portion of the operation member 4a of the key top 4 is caught by the inner surface of the first projecting wall 3a of the case 1 when the end portion A of the key top 4 is depressed. As a result, the conventional push button switch cannot be depressed smoothly.