A furniture glide protective device comprised of a laminated material comprised of an exterior surface made of synthetic fibers, a middle neoprene portion, and an interior surface made of nylon web meshing; wherein said laminated material is tubular-shaped having an opening on one end for insertion on the furniture leg and a surface on the opposite end to protect the floor; and a fastening mechanism for securing and locking said tubular shaped material over the furniture glide on the leg of a chair and/or table; and related method for securing a furniture glide and protecting a floor surface from scratching by furniture.

The general disclosure of various chair devices used to protect a floor surface are known in the prior art. Representative patents are listed below.
U.S. Pat. No. 1,903,609 to Uhl discloses a chair glide in FIGS. 1 and 6 comprising a cup shaped body 1 made of rubber or elastic material having a bottom plate 4 made of steel that is attached to an embedded anchoring disc 5 (see FIG. 5). The glide is manufactured by molding the material of the cup around the glide embedded disc. The neck portion of the glide is elastic and the glide is attached to the furniture by stretching the elastic portion.
U.S. Pat. No. 2,799,287 to Wagner discloses an anti-slipping attachment for the bottom of crutches that is attached to the crutch with a strap 19 that is trained around the upper ends of arms 13, 15 with pegs extending through holes in the strap, with the strap being secured to its buckle. (See FIGS. 1-3 and col. 2, lines 39-44). The strap 19 can be easily opened.
U.S. Pat. No. 2,865,133 to Hoven et al. discloses a plastic or rubber foot 13 for a furniture leg in FIG. 4 with a toroidal cavity 16 with a restricted opening 17 extending from the cavity to the bottom of the furniture leg. The rubber foot 13 is assembled by forcing the furniture leg 14 through restricted opening 17.
U.S. Pat. No. 4,964,430 to Janis discloses an apparatus for attaching to a walking cane to prevent slippage. The device is attached to the bottom of the cane in FIGS. 1 and 2 with an adjustable strap 5 by a conventional nut and bolt assembly or an externally threaded member or matching slots (col. 3 lines 1-14). FIG. 9 is connected with bolts that can be threaded into a nut and threaded orifice.
U.S. Pat. No. 5,377,710 to Laser discloses a temporary crutch tip assembly for preventing lateral slippage of ground. The engaging tip of the crutch comprises a stud plate with a plurality of sharp teeth projecting downwardly perpendicularly to the stud plate, said plate having a diameter corresponding to outside diameter of the crutch tip and surrounding straight wall sections defining a cup shaped receptacle for the crutch tip. The plate is attached to the crutch by two resilient flexible bands securing the plate to the crutch.
U.S. Pat. No. 6,164,306 to Townsend discloses an attachment to crutches, canes and other walking devices for primary use in soft terrain. A pad of several layers of flexible material is adhered together with adhesives. The pad is attached to crutches and canes by an adjustable strap system having side straps stitched to the top of the pad and an adjustable strap attached to the top of the side straps and being attachable to itself and having a grip tab for easy attaching and detaching.
U.S. Pat. No. 6,324,725 to Green discloses a furniture glide 16 comprising an upper portion 18 of a generally tubular shape for fitting over the bottom of a chair leg made of steel and a lower portion 20 attached to the upper portion and having a bottom surface 22 containing a plurality of stipples 24 (hemispherical or cubic or rectilinear shaped protrusions). The patent also discloses in FIG. 3 a replacement chair glide 16 containing a rim 30 that fits over the rim 36 of existing chair glide. This patent also describes the method of repairing an article of furniture having a defective glide comprising (a) forming a cap with a bottom surface and an inner surface opposed to said bottom surface and (b) attaching the cap to the defective glide whereby the inner surface of the cap contacts the bottom surface of the defective glide and the bottom surface of the cap contacts the floor.
U.S. Pat. No. 6,405,982 to Ferencz discloses a self attaching sliding support 10 for elastic engagement with a leg of an article to be supported comprising (a) and elastomeric element 12 having a base portion 16 and a circumferential inwardly extending rim 18 defining a cup-shaped cavity and (b) a second cup shaped, sliding element 14 made of low friction plastic or metal that is joined to the bottom of the elastomeric element 12. According to Col. 2 lines 6-10, the rim 18 of the elastomeric element 12 elastically engages the leg of the chair and is capable of accommodating legs of various sizes and shapes. As described the sliding support is easily removable.
U.S. Pat. No. 6,527,001 to Saldan et al. discloses a stabilizing cane attachment 10 in FIGS. 1, 2 and 3 that comprises a conically shaped support member 11 having a bore 13 extending there through a first stopper comprising a hose clamp with a fastening member 17 mounted above the support member 11 and second stopper member 18 made of rubber adapted to mount over the bottom end of the cane 26 to attach the cane attachment 10 to the bottom end of the cane 26 comprising a bottom 19 with a bore 20 extending through the top of said second stopper and an annular groove 22 containing washer member 21 at the bottom of the bore 20.
U.S. Pat. No. 6,669,221 to Leppke et al. discloses an apparatus attachable to a motorcycle kickstand having a base plate to prevent the kickstand from sinking into the ground. The stand comprises a supporting pad 2 with a diameter preferably 2-3 times the diameter of the base plate preferably made of reinforced rubber with one, preferably two, flexible supporting tabs 3 and 3′ being bendable to about the leg of the kickstand and being fastened to the leg with a tightener band 12. The tightener band comprises any suitable looped device that may be tightened and locked, e.g. a toothed nylon strip and ratchet clasp or a conventional screw actuated metal strip hose clamp as seen in FIG. 6. (Col. 4, lines 1-66).
U.S. Pat. No. 6,754,934 to Shiffler discloses in FIGS. 1-5 a floor engaging, generally circular cap 100 made of injection-molded polypropylene that attaches to a furniture leg that has a generally planar lower surface 110 and upper surface 120 that cooperates with a cylindrical sidewall 130 to form a cup shaped receptacle that is adapted to receive a furniture leg. Lower surface 110 has a plurality evenly spaced outer protrusions 140 with a height H1 and an evenly spaced plurality inner protrusions 150 with a height H2 that is less than the height of H1. In a further preferred embodiment there are eight outer protrusions and four inner protrusions with the inner protrusions being connected to the outer protrusions by a saddle 162 with height H3 that is less than H2. The outer and inner protrusions 140, 150 and saddles 162 define channels to provide paths for dirt and debris to pass through as a chair is moved across the floor. A method of repairing furniture is also described as having a glide for contacting the floor comprising installing the above-defined glide on the leg of the chair.
U.S. Pat. No. 6,802,482 to Harris discloses in FIGS. 1-3 a cuplike overboot 24 for increasing the foot print of the foot portion of a bi-pod firearm support 22. FIGS. 2 and 3 illustrate a cylindrical wall 42 integrally formed with a toroidal base 44 in the shape of a truncated cone having a circular foot portion 46 integrally formed with a cone portion 48 consisting of a plurality of concentric ribs 60 having an outside ring 58 and an annular flange 54 that define the recess 62 and a band 64 that when tightened around the support 22 hold overboot 24 in place. The overboot 24 is made from flexible material such as rubber and are held in place by a band made of pliant material such as rubber that can be tightened and untightened.
U.S. Pat. No. 6,869,052 to Keast et al. discloses in FIGS. 1-4 a replaceable floor protector assembly 10 having a main body portion 11 that is threaded on its outer periphery 21 with a central hole 107 and two spaced holes 103 and 104 that is joined to the chair or table with a nail 12 and two spaced prongs 101 and 102. A floor protector 14 having an upper flange portion 16 and an integral downwardly extending floor protector portion 15 made of soft, rigid material, e.g. felt, is held in place by a circular retainer 17 that is threaded on its upper interior to attach to the main body portion 11 with the floor protector 14 element forming the bottom patent.
U.S. Patent Publication No. 2005/0183234 to Bushey et al. describes a pliable furniture glide 1 in FIG. 3 having a pliable retention boot 1a having an upper cavity 10 for receiving a foot 5 of a furniture leg 4 containing a nut 12 that the user can adjust the vertical spacing between the foot 5 and a bottom surface of the furniture leg. FIG. 2 shows the retention boot 1a has an upper portion 17 that defines the opening 21 of the upper cavity 10 and bottom portion of the cavity includes a thickened bottom portion 23 with the bottom of the thickened portion bonded to the upper surface of a felt disk 2 the bottom of which is bonded to the upper surface 3a of felt disk 3 whose bottom surface is in contact with the floor. This chair glide is installed by pressing over the foot of a chair leg and is removable.
U.S. Patent Publication No. 2006/0053587 to Chase discloses a furniture glide assembly 10 that is adapted to be removably mounted to the free end 16 of the chair leg 14 comprising a substantially spherical body 20 defining a coaxial bore 22 extending partially through the body 21 and an insert 28 that is adapted to contain the free end 16 of the chair leg 14 disposed and retained in said bore 22 through a ring and groove combination (FIGS. 2-4) or groove formed by a post 154 and sidewall combination (FIGS. 5-7) or by an insert 228 defining a post 254 and passageway 242 (FIGS. 8-10). The floor engaging portion has a round ball shape.
In general, known chair glides although used to protect a floor surface are deficient in that some of the devices actually scratch the floors and others are easily removable. It is known that schools have resorted to using tennis balls to keep chair glides from scratching the surface floors. As described in the patents above, felt stick on pads and special nylon caps with felt will only work on some glides and are not permanent. The present invention provides an advantage over known devices in that the specific construction of the invention device will not snap off and is permanent. The device is a laminated material made of an exterior surface of synthetic fibers a middle layer of neoprene rubber and an interior surface of a nylon web meshing. The material is either seamless or with a seam and in a tubular form which is stretched over the glide. The material is held in place with a locking tie making the application permanent.
The invention can be used on a variety of furniture both for the home as well as on outside deck furniture. In schools and institutions a preferred use of the device is on chairs, desks and tables. In homes preferred use of the device is on furniture in kitchens and dining rooms.
Another advantage over the prior art is when sand and grit accumulates under the furniture glide, the invention device will absorb the grit and sand into the synthetic felt and neoprene material and the floor will not be scratched.
Yet a further object of the invention is where the constrictive locking mechanism will not permit and individuals, particularly a student's, removal.
Another object of the invention is the flexibility of the invention glide permitting easy application to furniture legs of a variety of diameter sizes.
Yet another object of the invention is to provide a "one-size" fits all device that stretches over a variety of different size furniture glides.
In another embodiment a circular shaped rubber material with a plurality of arms, preferably four, each arm having a slit which is threaded with a fastening mechanism. This embodiment provides the same advantages over the prior art as discussed above.


A backup management device includes a database and a processor. The database is configured to store configuration information of physical resource including a physical storage device, configuration information of virtual resource including a virtual storage device, and relationship information of the virtual resource and the physical resource. The processor is configured to generate, when the virtual storage device is provided to a user, backup information related to backup control of the physical storage device associated with the virtual storage device based on information stored in the database. The processor is configured to perform backup of the virtual storage device by copying a physical storage device associated with the virtual storage device to another physical storage device based on the generated backup information.

FIG. 15 illustrates a backup system that backs up data of a storage device connected to a server. As illustrated in FIG. 15, a backup system 80 includes four servers 81 represented by servers A to C and a server M, and two storage devices 82 represented by a storage device #1 and a storage device #2. The four servers 81 and the two storage devices 82 are connected by a management network 83. The servers A to C, the storage device #1 and the storage device #2 are connected by a storage area network (SAN) 84. Note that, the servers A to C, the storage device #1, and the storage device #2 may be connected by a network other than the SAN.
The server M is a management server 81 that manages the backup system 80. The servers A to C are backup target servers 81 for which data is backed up. The storage device 82 includes disks 85 represented by disks A to C. The disk A is a business use disk 85 and a backup disk 85 of the server A, the disk B is a business use disk 85 of the server B, and the disk C is a business use disk 85 of the server C. The unshaded disk 85 is the business use disk 85, and the shaded disk 85 is the backup disk 85.
The backup system 80 implements backup by controlling copy of data in the business use disk 85 to the backup disk 85 by using storage backup management software represented by a manager 86 and an agent 87. The manager 86 is installed on the management server 81. The manager 86 is responsible for overall management of configuration management, setting, and control of the servers A to C, the storage device #1, and the storage device #2. The agent 87 for issuing a backup control instruction is installed in each of the backup target servers 81. The agent 87 provides a backup setting and control interface for its own server 81. The storage device 82 executes a function to copy the data held by the storage device 82 to another disk resource according to the instructions of the manager 86 and the agent 87 to implement the backup.
A backup processing sequence of an agent trigger is as follows. The agent 87 receives backup settings and an execution operation and requests the manager 86 for backup (t91). The manager 86 processes the request of the agent 87 (t92) and instructs the storage device 82 to execute backup (t93). Then, the storage device 82 performs backup settings and executes the backup (t94).
FIG. 16 is a diagram illustrating a backup system on a cloud platform. On the cloud platform, physical resources such as a physical server 91 and a physical storage 92 are virtualized into virtual resources such as virtual servers 94 and virtual disks 95 using virtualization software 93, and the virtual resources are aggregated in one pool. The virtual resources aggregated in the pool are managed by a management server 96 and allocated to each user. The backup virtual disks 95 are similarly allocated from the pool, and the virtualization software 93 performs copy processing among the virtual disks 95 in response to a backup request. Note that, since the virtual disks 95 aggregated in the pool are network-coupled, network communication is also performed in the copy processing among the virtual disks 95. Furthermore, the agent 87 illustrated in FIG. 15 needs to be installed in each virtual server 94.
Note that, as an existing technology for backup, there is a file management system that can efficiently perform backup by adopting a form in which a meta database of a virtual file system is used from a backup processing side as well.
Furthermore, as an existing technology for backup, there is a device for backing up an application running over a plurality of virtual machines. The device executes, in response to the need to back up an application, a first set of scripts used to bring the plurality of virtual machines to work together into a ready state prior to the backup. The device then triggers a backup operation of at least one backup agent that manages the plurality of virtual machines in response to full execution of the first set of scripts. The backup operation involves the backup agent locating data associated with the application on each virtual machine. The device then executes a second set of scripts used to restore operation of the plurality of virtual machines in response to completion of the backup operation.
Furthermore, as an existing technology for user authentication, there is a user authentication technology for effectively preventing an unauthorized access by a third party to a system. In this user authentication technology, an information communication terminal assigns a number or the like constituting a token code generated in time synchronization with an authentication system side to each element constituting a password derivation pattern of a user. Furthermore, the information communication terminal displays, on a user interface, a password table to which randomly generated numbers and the like are assigned to other elements. The user refers to the password table, extracts the numbers and the like assigned to each element constituting his/her password derivation pattern and inputs the numbers and the like as a password, and the authentication system performs authentication determination for the input password on the basis of the generated time-synchronized token code.
Furthermore, as an existing technology for user authentication, there is a single sign-on system that enables a terminal user to implement a server that provides various functions and single sign-on by a single login operation to a terminal without separately installing an authentication server. In this single sign-on system, an information processing device receives a login operation for its own device, sends an authentication linkage request to a permitting server, and sends a second authentication request to a service provision server due to a receipt of a first authentication request from the permitting server. Then, the information processing device sends a third authentication request to the service provision server due to a response to the second authentication request by the service provision server, and receives a redirect instruction to the permitting server including an authorization code from the service provision server that has responded to the third authentication request. Then, the information processing device receives a response to the authentication linkage request including an authentication token from the permitting server that has generated the authentication token using the authorization code included in the redirect.
International Publication Pamphlet No. WO 2013/035517, Japanese National Publication of International Patent Application No. 2016-524752, Japanese Laid-open Patent Publication No. 2014-229306, and Japanese Laid-open Patent Publication No. 2016-9299 are disclosed as related art.

Backup management device, backup management method, and information processing system


A pixel sensor comprises a first reset transistor having a drain coupled to a first potential, a gate coupled to a first reset line, and a source. A second reset transistor has a drain coupled to the first reset transistor source, a gate coupled to a second reset line, and a source coupled to a photodiode cathode. A source-follower transistor has a drain coupled to the first reset transistor source, a gate coupled to the photodiode cathode, and a source. A row-select transistor has a drain coupled to the source-follower transistor source, a gate coupled to a row-select signal line, and a source coupled to a column output line. An array of these pixel sensors further comprises timing and readout circuits that control the transistors in the pixel sensor to effect a reset operation that cancels the fixed pattern of threshold variations of the source-follower transistors.

Prior-art CMOS and related image sensors typically have a dominant fixed-pattern noise caused by the random variation of the thresholds of the source-follower readout amplifiers in the pixel sensors, necessitating a dark-pattern subtraction operation to cancel the pattern. The dark-pattern subtraction is typically implemented either as a dark-frame subtraction using a separately-captured full dark frame, or as a dark-row subtraction or correlated double sampling, using a double read of each row into difference circuits. Each of these ways slows down the chip operation, complicates the readout circuits and timing requirements, and potentially adds new sources of mismatch and noise.
What is desired is a pixel sensor circuit and operating method that removes most or all of the fixed-pattern noise due to threshold variations, at the earliest possible stage, preferably in the pixel sensor cell itself, to eliminate the requirement for dark-frame subtraction, or dark-row subtraction, or correlated double sampling, or to at least reduce the noise in images that do not go through a dark-pattern pattern correction operation.

Intra-pixel fixed-pattern-noise cancellation circuit and method


Under one aspect of the present invention, a structure for providing galvanically isolated communication between first and second spacecraft electronic components includes a semi-insulating substrate; an input port disposed on the substrate and configured to receive a signal from the first spacecraft electronic component; a coupling structure disposed on the substrate, coupled to the input port so as to receive the signal, and configured to provide an isolated replica of the received signal as an output; a signal conditioner disposed on the substrate, coupled to the coupling structure so as to receive the isolated replica of the received signal, and configured to condition the isolated replica; and an output port disposed on the substrate, coupled to the signal conditioner so as to receive the conditioned isolated replica, and configured to provide the conditioned isolated replica to the second spacecraft electronic component.

To be suitable for use in harsh environments, such as space or manufacturing, electronics must be particularly robust, reliable, and have a reduced susceptibility to electromagnetic interference, while at the same time providing a satisfactory rate of data throughput for the application. Additionally, it may be desirable to galvanically isolate electronic components from one another in such environments, so as enhance operational stability of the components by reducing the likelihood that operational parameters or malfunction of one component will interfere with the functioning of another. As is known in the art, "galvanic isolation" between electronic components means that although information may pass between the components, charge-carrying particles do not. Galvanic isolation is particularly useful in situations where the electronic components have different ground potentials, because transfer of charge-carrying particles from one component to another may change the ground potential of one or both components, thus disturbing the operation of one or both components.
For example, electronic components on spacecraft, e.g., space vehicles and satellites, may be configured so as to comply with the SpaceWire (ECSS-E-ST-50-12C) and/or SpaceFibre standards. The SpaceWire and SpaceFibre standards are both incorporated by reference in their entireties herein. SpaceWire is a standard developed by the European Space Agency (ESA) intended to ease the interconnection of various electronic components in spacecraft, and provides for data rates between 2 and 200 Mbits/second. SpaceFibre is an extension of SpaceWire that is also being developed by the ESA, and provides for even higher data rates, e.g., of up to 6 Gbits/second or higher. Neither standard requires that electronic components be galvanically isolated from one another, although both standards permit galvanic isolation. Instead, the SpaceWire and SpaceFibre standards define a physical layer in which low voltage differential signaling (LVDS) techniques use copper media to transmit signals from one line replaceable unit (LRU) on the spacecraft to another. Each LRU may implement physical schemes that are configured to provide LVDS signaling interconnectivity with another LRU, and an electronic element such as a field-programmable gate array (FPGA) that is configured to provide one or more functionalities implementing signal conditioning compatible with SpaceWire and/or SpaceFibre signaling standards, as well as other data generating functions supporting an imager or a sensor. The SpaceWire and SpaceFibre standards require the LVDS signaling scheme between the LRUs comply with the ANSI/TIA/EIA-644 standard, the entire contents of which are incorporated by reference. The LVDS signaling protocol implements differential signaling techniques including that the balanced differential lines have tightly coupled equal but polar opposite signals which reduce EMI. Specifically, at some lower data rate implementations, the magnetic fields radiated by each of the lines are drawn toward each other, causing cancellation of much of the magnetic fields. [AN-5017 LVDS Fundamentals, Fairchild Semiconductor, June 2005]. While single ended, galvanically isolated, interconnects are also attractive, many applications choose to use LVDS which require a pair of differential signals, i.e., a positive going signal and a negative going signal which are inverse mirror images, to gain signal integrity.
However, merely coupling the LRUs with metallic cabling or other non-isolating interface conforming to the LVDS signaling protocol may not sufficiently isolate the LRUs from one another. As such, if the LRUs operate at different grounds from one another, charge-carrying particles may move from one LRU to another via the interface, modifying one or both grounds and thus potentially disrupting proper functioning of one or both LRUs. Or, for example, power supply failure of one of the LRUs may propagate to the other LRU via the interface, which may cause over-voltage emission. Or, for example, immersion of the spacecraft within a plasma while in orbit may cause voltage buildup internally and/or externally, which buildup may discharge to an LRU and propagate via the interface to another LRU, disrupting the operation of both LRUs. Or, for example, electrical transients induced by lightning in electrical circuits due to coupling of electrical fields, e.g., for launcher applications, also may propagate from one LRU to another, disrupting the operation of both LRUs. Furthermore, within a given LRU, any non-galvanic coupling between the internal components of that LRU may render each of the components susceptible to similar disruption.
Some methods that have been considered for mitigating the effects of electromagnetic interference (EMI) in spacecraft include providing a controlled grounding scheme throughout the spacecraft, as well as controlling the local ground level in printed circuit boards (PCBs) and in LRUs. Additionally, it has been considered to use power converters with over voltage protection, so that if a power supply of one LRU fails, the failure does not propagate to a connected LRU. Or, for example, the spacecraft itself may be designed as a "Faraday cage," may have surfaces designed to inhibit or control electrical discharge, may have enclosed electronic boxes, and/or may use shielded cables as well as over-shielding on cable bundles. Nonetheless, despite such safeguards, any non-galvanically isolated coupling between electronic components of the spacecraft, e.g., direct coupling between or within LRUs, may allow the transfer of charged particles from one component to another, thus potentially disrupting operation.
Although galvanic isolation interfaces have been known for some time, previously developed galvanic isolation interfaces may have reduced reliability in harsh environments, may have relatively limited data throughput rates, and/or may be incompatible with SpaceWire or SpaceFibre standards. For example, it has been proposed to use transformer-based or capacitance-based galvanic isolators, or opto-couplers, with SpaceWire links. However, the data throughput rate provided by transformer-based galvanic isolation may be insufficient to meet SpaceWire and/or SpaceFibre standards. Capacitance-based galvanic isolators may support sufficient data throughput rates, but may have reduced reliability if exposed to high electromagnetic interference. Opto-couplers may also support sufficiently high data throughput rates, but may degrade over time and may be susceptible to radiation.
U.S. Pat. No. 8,064,872 to Dupuis discloses an integrated circuit having radiofrequency (RF) isolation circuitry located in metal layers on a silicon substrate. The usefulness of such an integrated circuit in a spacecraft may be limited by eddy currents that may develop in the silicon substrate if the circuit is exposed to electromagnetic interference such as may arise in orbit.
U.S. Pat. No. 5,105,171 to Wen et al. discloses a coplanar waveguide directional coupler formed on a surface of a substrate and/or a microwave monolithic integrated circuit (MMIC) chip that is flip-chip mounted on the substrate and coupled thereto by conductive bumps. Wen discloses that the coupler may be used as part of a Doppler radar transceiver. Wen is silent on configuring the coupler so as to make it suitable for use in interconnecting spacecraft electronic components in a galvanically isolated manner.
U.S. Pat. No. 6,895,224 to Munday et al. discloses a low noise amplifier (LNA) that includes a Lange coupler that receives a signal and splits the signal into two symmetric signals that are then fed into a separate amplification section of the LNA. Munday is silent on configuring the LNA so as to make it suitable for use in interconnecting spacecraft electronic components in a galvanically isolated manner.
Accordingly, there is a need to provide a galvanic isolation interface solution suitable for use in providing signals between electronic components on a spacecraft especially for implementing high data rates needed for applications/functionality within LRUs.

Galvanic isolation interface for high-speed data link for spacecraft electronics, and method of using same


A dump apron for a dump truck, the apron pivotally mounted around a lower end of the dump opening at the rear of the dump body, and movable in response to the tilt position of the dump body between a lower flow-channeling position and a raised tailgate-securing position. In the tailgate-securing position the apron serves to seal leaks of the loaded material around the tailgate, and to function as a secondary lock to back up the tailgate's primary latching or locking mechanism. In the preferred form, the apron is held at an acute angle to the closed tailgate in the raised tailgate-securing position, forming a trough for collecting particulate material leaking around the tailgate from the loaded dump bed, and allowing visual inspection of the lower end of the tailgate and the tailgate's primary lock.

1. Field of the Invention
The invention relates to dump aprons for dump trucks.
2. Description of Related Art
End-dumping dump trucks that carry particulate material loads like gravel, sand, and crushed aggregate often "leak" gravel, etc. through spaces between the tailgate and the dump opening, either because the initial tolerances between the gate and the dump body floor and sidewalls are loose, or because initial tight tolerances are worn away over time by the abrasiveness of the material being carried.
Losing hard, abrasive materials like gravel out through the dump opening while traveling at road speeds can result in damage to vehicles traveling behind a loaded dump truck, can make a mess of the road, and can even result in significant material loss from the load being carried.
End-dumping dump trucks that carry particulate or aggregate materials are often provided with a stationary metal "apron" secured to the rear edges of the dump body, surrounding a lower portion of the dump opening. The apron is a generally U-shaped assembly of plate steel that extends rearwardly from the dump opening and tailgate to channel the flow of material away from the rear of the truck and to limit side spill while the material is being dumped, for example while dumping gravel for a roadbed. In addition to material that might leak around the closed tailgate, some materials tend to stick to the apron after the dumping operation is over, and this material can bounce or be blown off the apron while the dump truck is traveling.
A potentially more serious problem in terms of losing material out through the tailgate is failure of the tailgate locking mechanism, due to mechanical failure or driver error.

Tailgate-securing dump apron for dump trucks


A heat emitting beacon having a rotating parabolic mirror to concentrate the heat from a gas heat source, said mirror back being coated with a passive cold emission material comprised of a metalized plastic film creased and crumpled to form a multitude of reflective facets and preventing any reflected light. In a second embodiment, a rotating, single- or double-sided surface is coated with the passive cold emission material. In another embodiment, a signal beacon is comprised of a plurality of detachable strips of the passive cold emission material. In another embodiment, a plurality of surface elements covered with the passive cold emission material is arranged as a louver.

This invention relates to thermal identification, and more particularly, to a thermal image identification marker utilizing infrared (IR) energy from 1000-1400 nanometers.
The inability of reconnaissance to determine friend or foe in low light or total darkness is a major failing in battlefield and law enforcement operations. The worst effect is that fratricide (the inadvertent killing of friendly forces by other friendly forces) occurs, and at best is a waste of time and resources attempting to confirm identification. Accurate intelligence allows deployment effort to be maximized and focused.
Present marking and identification systems are limited to either Near IR range (1010 nano meters or less) beacons for use with night vision glasses or thermal panel identification marking equipment. Present thermal panel identification marking equipment is passive and provides identification by temperature or emissivity differences between adjacent areas and the marking equipment. Passive marking equipment is easily masked by surrounding operations, and is difficult to differentiate from adjacent targets.
There is a requirement for thermal (heat emitting) devices for military and law enforcement purposes to enable specific identification of distant objects, people, vehicles or positions by means of ground or air mounted thermal imaging cameras in spite of ambient thermal noise. Anti-fratricide protection is one very important application for such devices.
The present invention relates to beacons, and more particularly to a beacon for use as a marker and identifier in conjunction with night vision applications and situations.
However, in the areas of law enforcement and military applications there is a need to provide marker and identification beacons which operate in the wavelength band of 1 to 13 microns to clearly identify friend from foe, this being achieved without anything being seen by the naked eye.
Thermal imaging cameras have now reached a high state of development and produce clear images with clear contrast and magnification across a wide thermal gradient range of temperatures between hot and cold surfaces.
There are two approaches to thermal beacons, active and passive. The active approach uses a tripod with a controlling motor and either an electrically driven head or a gas driven head. The electrically powered head would be used in situations where sufficient power is available to drive the active emission part of the beacon, such as a main power feed or a vehicle battery. The gas driven head would be used in stand alone situations where power is not readily available. In either case, the active element can be rotated causing the unit to appear to flash to an observer with a thermal detection device.
The passive approach uses material which is thermally reflective. Passive technology requires a significant size panel when deployed to provide a surface detectable from 3,000 meters. However, the reflecting panel must be compact for transportation and deployment. To meet these conflicting requirements, it is necessary to construct a folding system which allows the reflection panel to be collapsed and has holes, slits or slots to accommodate wind and prop and helo wash.
In prior applications, applicants have described various forms of beacons which produce a flashing heat output. There is a limitation in these beacons in that they need considerable power in order to operate effectively. From an operational point of view, the power requirement can make them undesirable for certain applications.


A hybrid tuning circuit is used consisting of a digital finite state machine and an analog tuning circuit to effectively keep the RC product of the continuous time integrator constant across process, temperature, supply, and sampling rate variations. Since the implementation is continuous, the tracking is more accurate than traditional techniques. Using a carefully chosen clocking scheme, the technique gets rid of inter-symbol interference in the feedback DAC. The technique does not use a reference frequency, thereby eliminating the need for a user to identify a reference frequency.

Sigma-delta analog-to-digital converters (ADCs) provide for a means to achieve high resolution and low distortion at a relatively low cost compared to traditional Nyquist converters. The high resolution is achieved by oversampling the input signal and shaping the quantization noise in the band of interest into higher frequency region. The higher frequency noise can then be digitally filtered out by the subsequent digital filter stages. The resulting data is then down sampled to the desired sample rate at the output of the converter.
Typically, an audio sigma-delta ADC is implemented using discrete-time circuits such as switched capacitors for the following reasons. Switched capacitor circuits, typically used in the implementation of the first integrator, offer low sensitivity to clock jitter and is readily scalable with sampling rate. Moreover, tracking of coefficients is inherently good due to good matching of capacitors. However, due to the discrete-time nature, the converter suffers from harmonic distortion primarily caused by signal-dependent glitches captured by the sampling capacitors of the first integrator. In highly-integrated circuits such as a digital signal processor (DSP) with on-chip converters, it is very difficult to contain these undesirable glitches since the DSP is running at a much higher clock rate than the converter. Furthermore, for high performance converters, over 100 dB of signal-to-noise ratio (SNR), the sampling capacitors have to be large to reduce the thermal noise. When such large capacitors sample the input voltage, they emit current glitches back into the signal source which leads to electromagnetic interference (EMI).
Instead of implementing the first integrator by switched capacitors, the integrator can be implemented using real resistors and capacitors, such as in the implementation of a continuous-time integrator. The U.S. patent to Sooch et al. (U.S. Pat. No. 5,079,550), hereinafter Sooch, provides for such a combination of continuous-time and discrete integrators in a sigma-delta ADC.
FIG. 1 illustrates a block diagram outlining Sooch's setup 100 comprising summer circuit 101, continuous-time integrator 102, discrete-time integrator(s) 104, quantizer 106, and current feedback digital-to-analog converter (DAC) 108. An analog input signal is connected to the positive input of a summing circuit or summer 101, with the output of summer 101 being connected to the input of loop filter 105, which is also the input to the continuous-time integrator 102. The output of the continuous-time integrator 102 is converted to a discrete-time signal. Connected to the other side of continuous-time integrator 102 is a discrete time integrator 104, wherein the output of the discrete time integrator 104 forms the output of the analog loop filter 105 and is connected to the input of quantizer 106, which, in this example, is a one bit analog-to-digital converter. The output of quantizer 106 forms the output and also forms the input to DAC 108, with the output of DAC 108 being connected to the negative input of summer 101.
Due to the nature of the continuous-time setup of the first stage, any glitches happening in the first stage are averaged out over the clock period instead of being sampled. Hence, the negative effect of these glitches on the performance of the converter is greatly reduced. This is a major advantage of continuous-time versus discrete-time implementations. Moreover, since the input impedance is purely resistive (if the feed forward path from the input is eliminated), the circuit does not emit high frequency current glitches back to the external source. The setup of Sooch yields a much lower electromagnetic interference (EMI) compared to a switched capacitor implementation. But, the Sooch setup of FIG. 1 suffers from various pitfalls, some of which are addressed below.
A major drawback associated with the combination of continuous-time and discrete-time implementation described above is that the RC time constant, or integrator gain varies significantly with process, temperature, and power supply variation. Variation in the RC product changes the noise transfer function of the loop and leads to degradation in performance of the converter.
Another disadvantage associated with such an implementation is that the RC time constant also changes with the period of the master clock of the converter which clocks the switched-capacitor network in the second stage. This essentially limits the converter operation to one particular sampling rate.
Yet another disadvantage associated with the continuous-time implementation is that the continuous-time feedback DAC has inter-symbol-interference (ISI) which dominates the harmonic distortion of the overall performance of the ADC.
An attempt to solve this problem was presented in the article by Xia et al. entitled, "An automatic tuning structure for continuous-time sigma-delta ADC and high precision filters". Xia et al. addressed stabilizing the RC product via a discrete tuning approach. FIG. 2 illustrates a simplified diagram of the prior art tuning technique as taught by Xia et al. The setup of FIG. 2 comprises reference current source 202, programmable capacitor bank 204, fixed capacitor 206, comparator 208, and tuning logic circuit 210. By calibrating the voltage at the capacitor output to a fixed voltage, the circuit produces a control code that will control both the programmable capacitor array of the tuning circuit and the programmable capacitor array of the first stage continuous-time integrator. Xia's technique suffers from a disadvantage with respect to the coarse quantization step size of the counter, which is not suitable for high precision sigma-delta ADCs. Furthermore, the use of programmable capacitor array 204 also limits the tuning to a narrow range, hence not suitable for the large variation of sampling rate required in audio ADCs.
FIG. 3 shows a conventional differential implementation of a continuous-time first stage in a sigma-delta ADC. It consists of an amplifier 300, a pair of capacitors 302, 304, a pair of input resistors 306, 308, and a feedback DAC, 310. In normal operation mode, the input voltage is converted to current via the input resistors 306, 308. The feedback DAC 310 is controlled by the digital output of the converter. As mentioned before, the low frequency content of the digital output tracks with the input. Hence, the error current, the difference between the input current and the output of the DAC, is mostly high frequency shaped noise. This noise is integrated by the capacitors 302, 304 and then sampled by the subsequent switched capacitor integrator.
Whatever the precise merits, features, and advantages of the above discussed prior art implementations, none of them achieves or fulfills the purposes of the present invention.

Hybrid tuning circuit for continuous-time sigma-delta analog-to-digital converter


The cell structure producing apparatus including needles, a sticking unit configured to detachably hold an end portion of each of the needles, descend the each of the needles with respect to a cell tray in which cell aggregates are held, stick and penetrate each of the cell aggregates with the tip end, and ascend the needle after sticking, at least one time or more, a base unit, and a control unit configured to move the sticking unit so that for the each of the needles, each of the needles sticking the cell aggregates is positioned at a predetermined position over the base unit, descend each of the needles by a predetermined amount to stick the tip end into the base unit at the predetermined position on the base unit, and control the sticking unit.

Conventionally, as disclosed in Patent Literature 1, there has been known a method for producing a three-dimensional structure by three-dimensionally stacking cell aggregates so that a plurality of cell aggregates are adjacent to one another by using a support formed of a plurality of needle-shaped bodies fixed in advance to extend in a normal direction of a substrate by virtue of the property that cell aggregates contacting one another to be adjacent to one another are fused. In this method, the cell aggregates are taken out, each of the plurality of cell aggregates held by suction or the like is stuck onto each of the plurality of needle-shaped bodies to produce a support in which the cell aggregates are skewered. The method is such that the cell aggregates are cultivated in this state and the cell aggregates are extracted from the needle-shaped bodies after the cell aggregates are fused to one another, whereby the three-dimensional structure of cells is obtained.
In this relation, Patent Literature 2 discloses a method in which one thin needle-shaped body is caused to ascend and descend in the vertical direction to cell aggregates arranged on a cultivation plate not to move, the one needle-shaped body on which the cell aggregates are skewered is produced, and by repeating this, needle-shaped bodies are aligned in an aligning frame to be cultivated.


A stent and a method for fabricating the stent are disclosed. The stent has an originally flat pattern and connection points where the sides of the flat pattern are joined. The method includes the steps of a) cutting a stent pattern into a flat piece of metal thereby to produce a metal pattern, b) deforming the metal pattern so as to cause two opposing sides to meet, and c) joining the two opposing sides at least at one point. Substantially no portion of the stent projects into the lumen of the stent when the stent is expanded against the internal wall of a blood vessel.

Stents are known in the art. They are typically formed of a cylindrical metal mesh which can expand when pressure is internally applied. Alternatively, they can be formed of wire wrapped into a cylindrical shape.
As described in U.S. Pat. No. 4,776,337 to Palmaz, the cylindrical metal mesh shape is produced by laser cutting a thin walled metal tube. The laser cuts away all but the lines and curves of the mesh.
The method of U.S. '337 is applicable for relatively large mesh shapes and for meshes whose lines are relatively wide. However, for more delicate and/or intricate shapes, the spot size of the laser is too large.


Systems, methods, and media for detecting the presence of return-oriented programming (ROP) payloads are provided, comprising: identifying a potential gadget address space; determining if a piece of the data corresponds to an address of the potential gadget address space; and in response to determining that the piece of the data corresponds to an address of the potential gadget address space: determining whether a plurality of operations, each associated one of a plurality instructions beginning at the address, indicates that an ROP payload is present in the data, and indicating that an ROP payload is present in the data in response to making a determination that a plurality of operations indicates that an ROP payload is present in the data a given number of times.

The exploitation of memory corruption vulnerabilities in server and client applications has been one of the prevalent means of system compromise and malware infection. By supplying a malicious input to a target application, an attacker can inject and execute arbitrary code, known as shellcode, in the context of a vulnerable process.
The prevalence of code injection attacks has led to the wide adoption of exploit mitigations based on non-executable memory pages, such as Data Execution Prevention (DEP), in recent versions of popular operating systems.
In turn, attackers are increasingly relying on return-oriented programming (ROP) to bypass these protections. ROP allows the execution of arbitrary code on a victim system without the need to inject any code. ROP relies on the execution of code that already exists in the executable address space of a process, but, instead of executing the code of a whole library function, ROP is based on the execution of a combination of tiny code fragments, dubbed "gadgets," scattered throughout code segments of the process. The execution order of the gadgets is controlled through a sequence of gadget addresses that is part of the attack payload. This means that an attacker can execute arbitrary code on the victim system by injecting only control data.
During an attack, each gadget called by an ROP payload transfers control to the next gadget through an indirect control transfer instruction that reads the sequence of gadget addresses contained in the injected ROP payload.
In order for the ROP payload to be able to control the execution of these gadgets using the gadget addresses stored in the ROP payload, the gadgets selected by the ROP payload are typically stored in non-volatile portion of executable memory space. For example, such a non-volatile portion of executable memory space would typically not be subject to address space layout randomization (ASLR). The executable memory space in which the gadgets are present can be referred to as gadget address space.
An example of an ROP payload and how it controls the execution of gadgets is shown in FIG. 1. As shown, an ROP payload can exist in data memory starting at an address X and each n byte(s) of data can be a new piece of the payload, where n is the address size used in the target system (e.g., such as four bytes). The instruction pointer (EIP) and the stack pointer (ESP) of the target system can be controlled by the ROP payload to cause it to call the desired gadgets.
More particularly, for example, initially, EIP and ESP may be initialized with values of 070072F7 and a memory address of X+n*1 as shown in FIG. 1. Any suitable mechanism can be used to give EIP and ESP these values. For example, a stack pivot instruction sequence can be used to set EIP and ESP.
This will cause the first gadget call (marked "1st" on the right side of FIG. 1) to occur. As shown, during this call, a "pop eax" instruction and a "ret" instruction are executed. The "pop eax" instruction causes the value (0x0010104) at the address (X+n*1) pointed to by the stack pointer (ESP) to be copied to register EAX, and causes ESP to be incremented by one memory address size (e.g., four bytes, assuming an address size of 32 bits). The "ret" (return) instruction causes the value at the address pointed to by the stack pointer (ESP) to be put into the instruction pointer (EIP) and causes ESP to be incremented by one address size. This "ret" command thus sets up the next gadget call (marked "2nd" on the right side of FIG. 1) at address 070015BB by setting the instruction pointer with the value (070015BB) at the address (X+n*2) pointed to by ESP. Other gadget calls (marked "3rd," "4th," and "5th" on the right of FIG. 1) can then be performed in the order specified by the addresses specified in the ROP payload. As can be seen, this allows ESP to be used as an "index" register for transferring control to the desired gadget according to the list of gadget addresses in the ROP payload.
Although gadgets may end with a "ret" instruction as shown in FIG. 1, other indirect control transfer instructions may also be used.
Accordingly, mechanisms for detecting return-oriented programming payloads are desirable.

Detecting return-oriented programming payloads by evaluating data for a gadget address space address and determining whether operations associated with instructions beginning at the address indicate a return-oriented programming payload

The Trustees of Columbia University in the City of New York


A method of transmitting timing critical data via an asynchronous channel without changing any datum to be transmitted. The timing critical data can be an MPEG transport stream. The asynchronous channel can be a computer or telephone network, a digital storage media such as a digital VCR, or a digital interface. The method involves tagging each transmission unit of the data stream, before inputting to the channel, with timing information, and using the timing information at the output end of the channel to recreate the proper data timing, Various schemes are described for packing the timing information tags with each or a plurality of transmission units.

The invention relates to a recording arrangement for recording an information signal in tracks on a record carrier, the recording arrangement comprising                an input terminal for receiving the information signal,        channel encoding means for channel encoding the information signal so as to obtain a channel signal suitable for recording in a track on said record carrier,        writing means for writing the channel signal in the track, the channel signal comprising subsequent or a succession of signal blocks, each signal block comprising a first block section which comprises a synchronization signal and a second block section which comprises a number of channel bytes, to a record carrier obtained with the recording arrangement, and to a reproducing arrangement for reproducing the information signal from the record carrier.
A recording arrangement as given in the opening paragraph is known from-EP-A 492,704, document (1) in the list of references that can be found at the end of this application.
The known arrangement is a recording arrangement of the helical scan type, such as used in a digital VCR (DVCR) and records an information signal comprising a digital audio signal and a digital video signal in audio signal recording sectors and video signal recording sectors respectively in subsequent tracks, where, when recording a track, the video signal recording sector in a track comes first and is followed by the audio signal recording sector. The order in which the sectors occur in a track can however also be in the reverse order. Further, other sectors may be included in a track, such as a clock run-in area located at the beginning of a track, so as to enable a locking-in of the internal system clock on the signals read from the track, and preamble and postamble areas that are located between the various sectors and function as an edit gap. Reference is made in this respect to the earlier filed European patent applications No. 93.202.950, reference (2) in the list of references, and No. 93.201.263, referenced (3) in the list of references.
The prior art reference documents relate to proposals for the realization of a new digital video cassette (DVC) recorder standard, which enables the recording and reproduction of digital video and digital audio on/from a longitudinal magnetic record carrier such as magnetic tape. This new digital video recorder standard will lead to new digital video recorders/reproducers of the so-called DVC type.

Recording and producing an MPEG information signal on/from a record carrier


An austenitic, non-magnetic, stainless steel alloy is disclosed which, in the wrought condition, is essentially ferrite-free and has a relative magnetic permeability of less than about 1.02, a room temperature 0.2% yield strength of at least about 100 ksi, and good resistance to stress corrosion cracking in chloride environments. Broad, intermediate, and preferred ranges are disclosed as follows:. ______________________________________ w/o Broad Intermediate Preferred ______________________________________ C 0.08 max. 0.05 max. 0.035 max. Mn 14-19 15-18 16-18 Si 1.0 max. 1.0 max. 0.75 max. Cr 12-21 14-19.5 16-18 Ni 3.5 2.5 max. 1.5 max. Mo 0.5-4 0.75-2.5 1.0-2.0 Cu 2.0 max. 1.5 max. 1.0 max. N 0.2-0.8 0.3-0.7 0.4-0.6 B 0.06 max. 0.005 max. 0.005 max. ______________________________________. the balance being iron. The alloy is balanced to be essentially ferrite-free and to provide good chloride SCC resistance in accordance with the following relationships: ##EQU1##

This invention relates to an austenitic, non-magnetic, stainless steel alloy and articles made therefrom and, more particularly, to such an alloy which, when significantly warm-worked but not subsequently annealed, has an outstanding combination of non-magnetic behavior, high yield strength, and good corrosion resistance, particularly resistance to chloride stress corrosion cracking.
Chromium-manganese stainless steel alloys are used in the manufacture of oilwell drilling equipment, including certain kinds of drill collars and housings for measurement-while-drilling (MWD) assemblies. More specifically, modern deep-well drilling methods, including directional drilling, require close monitoring of the location of the borehole to minimize deviations from the desired course. This may be accomplished by incorporating electrical measuring equipment in certain drill collar sections. However, since such measurements are disturbed by magnetic behavior, those drill collars containing such equipment must be non-magnetic, meaning here and throughout this application, having a relative magnetic permeability of less than about 1.02. Also, drill collars and other such articles are required to have high strength, particularly, a room temperature 0.2% offset yield strength of at least about 100 ksi. Chromium-manganese stainless steels have been favored in the manufacture of such articles because they satisfy both of these requirements at reasonable cost.
The following are hitherto known chromium-manganese stainless steel alloys, the compositions of which are listed in Table I: UNS S28200; UNS S21300; the experimental alloy described in V. Cihal and P. Pohoril, "Austenitic chromium-Manganese Steels Resistant to SCC in Concentrated Chloride Solutions" in Stress Corrosion Cracking and Hydrogen Embrittlement of Iron Base Alloys, 1170-1182, NACE (1977), identified here as Heat No. 7412; U.S. Pat. No. 3,075,839, issued to E. J. Dulis et al. on Jan. 29, 1963; U.S. Pat. No. 3,112,195, issued to H. Souresny on Nov. 26, 1963; U.S. Pat. No. 3,904,401, issued to D. L. Mertz et al. on Sep. 9, 1975 (UNS S28200 and UNS S21300 are both exemplary alloys of this patent); U.S. Pat. No. 4,514,236, issued to W. T. Cook et al. on Apr. 30, 1985; U.S. Pat. No. 4,523,951, issued to R. J. Andreini et al. on Jun. 18, 1985; Duvall XM-19H; and U.S. Pat. No. 4,481,033, issued to K. Fujiwara et al. on Nov. 6, 1984. The foregoing alloys suffer from one or more deficiencies. For example, UNS S28200 and UNS S21300 (representative of the 3,904,401 patent) have less than desirable stress corrosion cracking (SCC) resistance. The alloy described by Cihal et al. contains excessive amounts of ferrite, causing undesirable magnetic behavior. Further, the balance of elements in these alloys reflects a lack of recognition of the important relationship between the manganese and the nickel plus copper contents of the alloy on the one hand, and the chromium plus molybdenum contents on the other hand, in ensuring good resistance to SCC in chromium-manganese stainless steel alloys.
Recent developments in deep-well drilling methods have placed more stringent demands on parts such as drill collars.
TABLE III __________________________________________________________________________ w/o Ex/Ht Cr + Mo - 14.6 No. C Mn Si Cr Ni Mo Cu N Ni + 2 Cu Cr + Mo 1.5 Fe __________________________________________________________________________ 1* 0.052 17.46 0.45 17.56 0.99 1.06 0.06 0.48 1.11 18.62 2.68 Bal. 2* 0.049 17.38 0.48 17.42 0.99 1.04 0.06 0.50 1.11 18.46 2.57 Bal. 3 0.036 15.13 0.39 14.79 0.23 1.48 0.24 0.31 0.71 16.27 1.11 Bal. 4 0.021 14.89 0.41 15.09 <0.01 0.98 <0.01 0.35 <0.01 16.07 0.98 Bal. 5 0.024 14.93 0.43 13.92 <0.01 1.92 <0.01 0.35 <0.01 15.84 0.83 Bal. 6 0.039 14.74 0.37 14.74 <0.01 1.50 <0.01 0.31 <0.01 16.24 1.09 Bal. 7 0.038 13.18 0.37 14.68 <0.01 1.49 <0.01 0.29 <0.01 16.17 1.05 Bal. 8 0.037 14.79 0.40 14.79 0.50 1.52 0.24 0.32 0.98 16.31 1.14 Bal. A 0.026 15.02 0.39 15.98 0.02 0.98 0.98 0.38 1.98 16.96 1.57 Bal. B 0.026 14.83 0.40 15.87 0.99 1.94 <0.01 0.36 <1.00 17.81 2.14 Bal. C 0.039 15.32 0.39 14.75 0.24 1.52 0.49 0.32 1.22 16.27 1.11 Bal. D 0.042 15.25 0.38 14.87 0.50 1.50 0.50 0.32 1.50 16.37 1.18 Bal. E 0.028 17.92 0.39 15.95 <0.01 1.96 <0.01 0.38 <0.01 17.91 2.21 Bal. F 0.036 14.84 0.53 16.21 1.01 0.94 0.54 0.40 2.09 17.15 1.70 Bal. G 0.034 14.80 0.54 16.20 1.11 0.96 0.57 0.40 2.25 17.16 1.71 Bal. H* 0.031 15.12 0.47 16.34 0.95 0.92 0.56 0.40 2.07 17.26 1.77 Bal. I 0.030 15.32 0.44 15.67 1.02 0.96 0.50 0.37 2.02 16.63 1.35 Bal. J 0.117 17.78 0.46 17.54 0.42 0.95 0.98 0.46 2.38 18.49 2.59 Bal. K 0.108 17.85 0.46 17.85 0.32 0.95 0.97 0.48 2.26 18.80 2.80 Bal. L 0.040 14.83 0.40 17.50 0.38 0.36 0.33 0.44 1.04 17.86 2.17 Bal. M 0.038 17.36 0.38 14.77 <0.01 1.52 <0.01 0.36 <0.01 16.29 1.13 Bal. __________________________________________________________________________ The following quantities of boron were present: Ex. 1, 0.0023 w/o; Ex. 2, 0.0023 w/o; Ex. H, 0.0028 w/o.
For instance, such parts are required to operate in increasingly severe chloride environments, for example, in contact with drilling muds containing high concentrations of chlorides, leading to increased risk of costly premature failure due to chloride stress corrosion cracking. Thus, a significant problem encountered by the oil drilling industry is that drill collars used to house critical measurement-while-drilling equipment, fabricated from known chromium-manganese stainless steel alloys, do not possess the requisite combination of non-magnetic behavior, high yield strength and good resistance to chloride stress corrosion cracking necessary for acceptable performance under more exacting operating conditions.

Austenitic, non-magnetic, stainless steel alloy and articles made therefrom


Apparatuses for inflating inflatable devices and associated methods of leak detection relying on the inclusion of a radioactive isotope leak trace material.

This invention relates generally to pressurized fluid-containing devices and, more particularly, to such a device used in the inflation of an inflatable device such as an inflatable vehicle occupant restraint airbag cushion used in inflatable restraint systems.
It is well known to protect a vehicle occupant using a cushion or bag, e.g., an "airbag cushion," that is inflated/expanded with gas when the vehicle encounters sudden deceleration, such as in a collision. In such systems, the airbag cushion is normally housed in an uninflated and folded condition to minimize space requirements. Upon actuation of the system, the cushion begins to be inflated, in a matter of no more than a few milliseconds, with gas produced or supplied by a device commonly referred to as "an inflator."
Many types of inflator devices have been disclosed in the art for inflating an inflatable restraint system airbag cushion. One category of such inflator devices is often referred to as "compressed gas inflators" and refers to various inflators which contain compressed gas.
In one particular type of compressed gas inflator, commonly referred to as a "stored gas inflator," the inflator simply contains a quantity of a stored compressed gas which is selectively released to inflate an associated airbag cushion. Unfortunately, to properly inflate a typically sized airbag cushion at an appropriate rate, such an inflator commonly requires the storage of a relatively large volume of gas at relatively high pressures. As a result of such high storage pressures, the walls of the gas storage chamber of such an inflator are typically relatively thick for increased strength. The combination large volume and thick walls typically results in a relatively heavy and bulky inflator design. In addition, the operation of such an inflator device requires the design and provision of a technique to initiate the release of the stored gas into the airbag cushion, when desired.
In a second type of compressed gas inflator, commonly referred to as a hybrid inflator, inflation gas results from a combination of stored compressed gas and the combustion of a gas generating material, e.g., a pyrotechnic. Hybrid inflators that have been proposed heretofore have been subject to certain disadvantages. For example, such inflators commonly result in the production of a gas having a relatively high particulate content. The removal of such solid particulate material, such as by the incorporation of various filtering devices within or about the inflator, undesirably increases the complexity of the inflator design and processing and can increase the costs associated therewith.
In view of these and other related or similar problems and shortcomings of prior inflator devices, a new type an inflator, called a "fluid fueled inflator," has been developed. Such inflators are the subject of commonly assigned U.S. Pat. No. 5,470,104, Smith et al., issued Nov. 28, 1995; U.S. Pat. No. 5,494,312, Rink, issued Feb. 27, 1996; and U.S. Pat. No. 5,531,473, Rink et al., issued Jul. 2, 1996, the disclosures of which are fully incorporated herein by reference.
Such an inflator device utilizes a fuel material in the form of a fluid, e.g., in the form of a gas, liquid, finely divided solid, or one or more combinations thereof, in the formation of an inflation gas for an airbag cushion. One form of the fluid fuel inflator utilizes a compressed gas. In such a fluid fueled inflator, the fluid fuel material is burned to produce gas which contacts a quantity of stored pressurized gas to produce inflation gas for use in inflating a respective inflatable device.
While such an inflator can successfully overcome, at least in part, some of the problems associated with the above-identified prior types of inflator devices, there has been a continuing need and demand for further improvements in safety, simplicity, effectiveness, economy and reliability in the apparatus and techniques used for inflating an inflatable device such as an airbag cushion.
To that end, the above-identified pending application, U.S. Ser. No. 08/632,698, filed on Apr. 15, 1996, discloses a new type of inflator wherein a gas source material undergoes decomposition to form decomposition products including at least one gaseous decomposition product used to inflate an inflatable device.
Such an inflator can be helpful in one or more of the following aspects: reduction or minimization of concerns regarding the handling of content materials; production of relatively low temperature, non-harmful inflation gases; reduction or minimization of size and space requirements and avoidance or minimization of the risks or dangers of the gas producing or forming materials undergoing degradation (thermal or otherwise) over time as the inflator awaits activation.
In general, all inflators (including pyrotechnic-based inflators) have specific requirements and thus necessitate the checking of the inflators, or at least particular components thereof, for the presence of undesired leaks.
For example, in pyrotechnic inflators, the gas generating material may often be susceptible to undesirably absorbing water, such as from the ambient environment. Since pyrotechnic inflators are generally not pressurized, there is a potential for atmospheric moisture to diffuse into such an inflator. Thus, assuming the inflator is in a humid surrounding environment and the existence of a leak path into the inflator, moisture could potentially be absorbed into or by the generant. As a result, the inflator may not perform as optimally as desired, particularly if the inflator has been exposed to elevated amounts of moisture. Consequently, pyrotechnic inflators generally contain internal seals to prevent or minimize such entry of water or moisture into the device. During manufacture of the inflator, these internal seals are checked for the presence or occurrence of undesired leak paths.
Compressed gas inflators, such as described above, commonly require the presence of at least certain specified quantities of the compressed material in order for the inflator to perform in the designed for manner. In such inflators, it is generally desired that the amount(s) of stored compressed material(s) be maintained in the inflator within at least a certain tolerance in order to ensure proper operation of the inflator. While proper inflator operation can be variously defined, ultimately, an inflator and the associated airbag need provide adequate vehicle occupant protection over an extended period of time (typically 15 years or more) after original construction of the vehicle. Thus, beyond simple functioning of the inflator and deployment of the associated airbag, the airbag desirably deploys in the desired and proper manner.
There are various methods to determine the leakage rate of a compressed gas inflator. In practice, a typically preferred method involves the use of helium as a tracer gas in a compressed gas mixture. In such a method, a certain fraction of the composition of the stored gas which escapes from the inflator consists of helium. (The exact fraction of helium detected as a result of the leak may be equal, less than, or greater than the corresponding loading conditions of the originally stored compressed gas. The physics associated with these various situations, however, is beyond the scope of the present discussion. In general, however, these different situations are typically dependent on certain, particular factors such as the magnitude of the leak, the total pressure within the storage vessel, as well as the initial gas composition, for example.)
The leak rate of helium from a pressure vessel is normally detected using a mass spectrometer system. For this specific practice, the mass spectrometers are normally designed to detect the presence of helium in the gases constituting the sample. The utilization of helium in leak tracing is advantageous in several respects: a) First, since the presence of helium is rather rare in the atmosphere, background helium (or residual helium in the environment such as that surrounding the detection apparatus) is normally very low. As a result, the possibility of the mass spectrometer being falsely influenced and possibly producing a spurious signal is significantly reduced or minimized. b) Second, the mass spectrometer signals for certain different molecular species can be nearly the same. Consequently, the mass spectrometer signal produced or resulting from the presence or occurrence of one molecular species may interfere or mask the mass spectrometer signal produced or resulting from the presence or occurrence of a different molecular species. For example, the molecular weights of nitrous oxide and carbon dioxide are approximately 44.02 and 44.01, respectively. As a result, it is very difficult to distinguish between these molecular species via mass spectrometry. Helium, however, with a molecular weight of 4, produces a mass spectrometer signal that is relatively easily distinguishable from the signal produced by other potentially present species. c) Third, helium is a relatively small monatomic gas, facilitating the passage thereof through even relatively small or narrow leak paths.
Conventional helium leak detection techniques, however, suffer or potentially suffer from a number of problems or disadvantages. For example, in order to permit leak check to the relatively small range of leakage acceptable in airbag module inflators, it is commonly necessary to include relatively large amounts of helium in the compressed gas mixture. In practice, the amount of helium required will be dependent on factors such as the magnitude and type of leak, the design life of the inflator, and the criteria for adequate performance for the inflator as a function of time. However, the incorporation of even moderate amounts of helium within a compressed gas inflator is or can be disadvantageous as, for a given volume, the storage pressure of the contents is significantly increased. Conversely, at a given pressure, the storage volume needs to be increased in order to accommodate the mass of the added helium.
While the release of such stored helium would also normally contribute to the inflation of the associated airbag, the storage of a compressed gas mixture of two or more molecular species is typically more expensive than the storage of a single compressed gas molecular species. The use of two or more molecular species commonly necessitates the use of additional storage, handling, and mixing equipment.
A significant limitation on such use of helium in such leak detection schemes is that the leak rate from a pressure vessel normally cannot be accurately checked at a date substantially later than the date the inflator is manufactured, unless the helium concentration within the vessel is known. That is, unless the leak is of the type that the compressed gases (e.g., both the primary stored gas and the helium tracer gas) are escaping in equal proportion to that at which they were loaded (as in the original composition), then the leak rate determination will normally be in error. Since knowledge of the type of leak cannot be definitively known a priori, the making of such an assumption can result in significant error. Moreover, if a pressurized vessel is returned at a later date for the leak rate to be reevaluated, a helium leak rate determination may be inaccurate.
An additional possible limitation or drawback to the use of such helium leak detection techniques is that the occurrence or presence of liquid materials within the storage vessel may impede or "mask" the helium. For example, if a liquid with a relatively high surface tension is present in the vessel, such liquid could possibly flow into a hole through which gas would normally leak and may, at least temporarily inhibit the passage of the gaseous material leak passage and out of the inflator. However, with time, the liquid may no longer occupy the leak path and the stoppage of gas leakage therethrough may only be temporary.
In addition, though helium is relatively rare in the general atmosphere, it will be appreciated that relatively high background concentrations of helium can be created in manufacturing environments. This may necessitate that the tested vessel be isolated such as by being placed in a closed chamber in which a vacuum is created in the surrounding environment, with the helium leak rate then being determined. Such special handling can add significant time and expense to the manufacturing process.
Further, the use of helium may undesirably result in the addition of considerable expense to the cost of the inflator, both through the inherent cost of the helium itself, the cost of purchasing and maintaining the mass spectrometers, as well as the costs associated with the equipment required to store, mix, and handle the helium.
Thus, there is a need and a demand for a pressurized fluid-containing inflator design which facilitates leak detection.
Moreover, there remains a continuing need and a demand for an inflator device which satisfies one or more of the following objectives: increased simplicity of design, construction, assembly and manufacture; avoidance or minimization of the risks or problems associated with the storage, handling and dispensing of gas generant materials; permits even further reductions in assembly weight and volume or size; and realizes enhanced assembly and performance reliability.

Pressurized fluid containing airbag inflator


Systems and methods for managing data, such as metadata or non-metadata such as content. In one exemplary method, a composite document is received and it is determined whether the composite document contains at least one subdocument and if it does, the method captures metadata and/or content from the subdocument and stores the captured metadata and/or content for use in future searches (or an immediate search). The metadata and/or content from the composite document is typically combined together with information about the hierarchy of the subdocuments in the document. The type of information in metadata for one type of file differs from the type of information in metadata for another type of file. Other methods are described and data processing systems and machine readable media are also described.

Modern data processing systems, such as general purpose computer systems, allow the users of such systems to create composite data files which include a variety of different types of data formats. The information often has a composite nature, and the modern computer system allows the integration of these components into a composite data file. For example, a typical document contains text, generated from a text editing program or a word processing program such as Microsoft Word, and may also contain images, generated from an image processing program such as Adobe's PhotoShop program. The document can also contain an embedded document, thus creating an arbitrarily deep hierarchy of data storage. Other examples include a drawing or CAD document containing text objects, a video project containing multiple audio and video clips, an audio/video clip containing information about persons such as the copyright holders, an archive document containing multiple documents, which themselves may be composite documents and multiple directories, which contain multiple documents. In addition, there are numerous other types of files and formats that are capable of being created or modified, edited, and otherwise used for a typical data processing system. The arbitrarily deep level of information storage within a document can present a challenge to a typical user who is seeking to find particular information.
Modern data processing systems often include a file management system which allows a user to place files in various directories or subdirectories (e.g. folders) and allows a user to give the file a name. Further, these file management systems often allow a user to find a file by searching for the file's name, or the date of creation, or the date of modification, or the type of file. An example of such a file management system is the Finder program which operates on Macintosh computers from Apple Computer, Inc. of Cupertino, Calif. Another example of a file management system program is the Windows Explorer program which operates on the Windows operating system from Microsoft Corporation of Redmond, Wash. Both the Finder program and the Windows Explorer program include a find command which allows a user to search for files by various criteria including a file name or a date of creation or a date of modification or the type of file, and even the file content. However, this search capability searches through information only at the top level and for a particular type. Thus, for example, the searchable data for a Microsoft Word file is the text contained in the document, or other related data such as the file name, the type of file, the date of creation, the date of last modification, the size of the file and certain other parameters which may be maintained for the file by the file management system. The searchable data do not include information about embedded files such as a drawing or a image file in the Microsoft Word file.
Further, certain presently existing application programs allow a user to maintain data about a particular file. This data about a particular file may be considered metadata because it is data about other data. This metadata for a particular file may include information about the author of a file, a summary of the document, and various other types of information. A program such as Microsoft Word may automatically create some of this data when a user creates a file and the user may add additional data or edit the data by selecting the "property sheet" from a menu selection in Microsoft Word. The property sheets in Microsoft Word allow a user to create metadata for a particular file or document. However, in existing systems, a user is not able to search for information deep within the document using one search request from the user. Furthermore, existing systems can perform one search for data files, but this search does not also include searching through metadata for those files.

Methods and systems for managing composite data files


A work piece transfer system particularly suited for transferring semi-conductor wafers from one environment, through a loadlock, to another environment and back again employs a series of pivotally interconnected levers located within the loadlock when the device is in its central collapsed position. Only a single shaft extends through the loadlock, the main drive shaft for operating the device. The lever arm, which is attached to the input shaft for rotation with it, has a hole through its center for pivotally supporting a composite lever arm half of which is located above the first lever arm, and the other half of which is located below the lever arm, with the two portions connected by a pin passing through a hole in the center of the first lever arm. The work piece is pivotally attached to the opposite end of the first lever arm; and an interconnecting lever arm is pivotally attached between one end of the composite lever arm and an intermediate pivot on the work piece. The composite lever arm also has a primary pivot which is slidably located in a channel or groove aligned with the axis of the input drive shaft; so that as the drive shaft rotates, this pivot slides in the groove to different locations establishing the overall positioning of the work piece support member to one or the other of two sides of the central position located in the loadlock.

Precision material handling devices are required in a number of industries. In particular, the handling of semi-conductor wafers at various stages of processing, and the handling of integrated circuit chips after they have been processed from such wafers, requires sophisticated automated handling equipment.
With respect to the handling of semi-conductor wafers, devices are required for moving a wafer from one location through a loadlock (or air lock) to another location, as part of the processing of such wafers in the manufacture of integrated circuit chips. The placement of the wafers throughout the transfer must be precise because of the processing steps which are carried out in the different environments or chambers on opposite sides of the loadlock. Loadlocks or air locks are used to isolate one environment from the other during the processing of the semiconductor wafers.
Because of the nature of the transfer, it is necessary to precisely extend the wafers alternately on two different sides of the loadlock, beyond the loadlock itself, while fully enclosing the wafers and the transfer mechanism within the loadlock as an intermediate step. The use of loadlocks in the processing of semiconductor wafers differs in many respects from larger loadlocks of the type used in space vehicles, manufacturing clean rooms, and the like. The loadlocks which are employed in the processing of semiconductor wafers are used in conjunction with handling equipment for handling very thin, lightweight circular or disk-shaped work pieces having thicknesses in the range of 0.010 to 0.050 inches and diameters measured in inches. Because the processing of the wafers requires them to be free from contamination, the loadlocks, as well as the apparatus used within them, needs to be as free as possible from contaminants and from components which produce contaminants.
The U.S. Pat. No. 4,483,654 to Koch discloses one type of semi-conductor wafer transfer mechanism for transferring wafers from one environment, through a loadlock, to another environment. The mechanism of this patent includes a three-piece gear-driven mechanism. A central drive gear operates through an intermediary or idler gear to rotate a driven gear for effecting rotational positions of lever arms to transport the wafer from a first position in one environment to a second intermediate position within the loadlock, to a third position in another environment on the opposite side of the loadlock chamber. While the mechanism which is disclosed in this patent is capable of relatively rapidly transferring the wafer from one or the other of the two environments to the loadlock and out again, contamination can take place during the isolation vacuum step of operation when the work piece is in the loadlock. This occurs as a result of the wear of the gears involved in the mechanism. Constant wear takes place on these gears, which subjects the interior of the loadlock chamber to minute particle (dust-like) transfers as a result of the wear. In addition, as the gears wear, undesirable play takes place in the transfer mechanism, which cannot be tolerated in the delivery of the wafer to its final processing position on one side or the other of the loadlock.
Another patent for transferring semi-conductor wafers employing a rotary driving source is the U.S. Pat. No. 5,333,986 to Mizukami. The system disclosed in the Mizukami patent inherently has twice the potential for vacuum leaks over the one disclosed in the Koch patent described above. In the Koch system, only a single shaft passes through the loadlock chamber to operate the mechanism located within the chamber. In Mizukami, two shafts extend through the loadlock or vacuum chamber. One of these is the driven rotating shaft (which must be sealed, and the other is an idler rotating shaft (which also must be sealed). Both of these shafts pass through the base or bottom of the chamber. Whenever a seal in a shaft fails, the entire transfer mechanism is down. In the case of Mizukami, there is twice the opportunity for such a failure.
The Mizukami patent employs a parallelogram positioning device utilizing a pair of stainless steel belts to transfer the rotary motion of the input to the different positions of the wafer holding arms. The belt transmission mechanism has low friction between the pulleys and the belts; and there is no gear wear in the system of this patent, as contrasted with the system disclosed in the Koch patent. Typically, however, stainless steel flat belts often involve a large number of strands of wire in the belt in order to obtain the desired flexibility. Internal friction between the strands generates particulate contaminants much in the same way as the wear of the gears described above in conjunction with the Koch patent. The belts of Mizukami must be sufficiently tight to prevent any undesirable play in the overall system which could affect the placement positioning of the wafers and cause a jerky or choppy motion in the wafer positioning arm. If the belts, however, are too tight, internal wear is increased. This is true, either with a flat belt or with a wire rope. Another disadvantage of the apparatus disclosed in Mizukami is that while the system has a fairly extended reach in one direction, in the opposite direction the reach is considerably less.
Another device for handling work pieces is disclosed in the U.S. Pat. No. 4,801,235 to Rauschdorf. This patent employs a rotary drive to produce a linear movement through an arc of travel. The device disclosed in this patent is not a wafer transfer mechanism; so that it does not have a small loadlock chamber of the type typically used with such mechanisms. There also is no linear tracking; and it appears that there is no intention to stop the system operation at some intermediate or "center" position. Rauschdorf does not appear to be concerned with smoothly moving work pieces, but simply moving work pieces from one position to another. With wear at the various pivot points in the Rauschdorf apparatus, the transition through the center position may not be a smooth transition.
Additional U.S. Pat. No. 4,585,045 to Richards; U.S. Pat. No. 4,955,780 to Shimane; and U.S. Pat. No. 5,151,008 to Ishida disclose the uses of belt drives or gear drives in wafer positioning transport apparatus. In the device of the Richards patent, an inherent problem exists through the use of a spring in one of the arms of the transfer mechanism. As the belt wears or stretches, the spring extends the arm to keep the belt tight. This alters placement of the semiconductor wafer in the chamber. As mentioned previously, wafer positioning devices necessarily must be very accurate in the positioning at all stages of operation of the device. Such a wear, which alters placement, is undesirable.
The patent to Shimane employs multiple belts. This involves the potential for much fretting or wear, producing contaminants. In addition, as the belts wear or stretch, they need to be replaced on a regular basis, both in order to maintain the accuracy of the operation of the device, as well as to keep the number of contaminating particulates down within the apparatus. Replacement of belts produces additional maintenance costs and undesirable down time for the system.
The system disclosed in the Ishida patent involves a number of bearing seals, and includes multiple gears which can wear and fret, as described above, to produce contaminants. Again, as discussed previously, when there are more bearing seals in a system, the potential for failure of a seal, and therefore down time for repair of the apparatus, increases directly with the number of seals involved. Another very complex wafer transport mechanism is disclosed in the U.S. Pat. No. 4,728,252 to Lada. The device of this patent has one shaft sealed within another shaft, which rotates independently of the outer shaft. This complex seal mechanism inherently exposes the device to potential failure and fretting. Also, the device employs belts and requires two motors and two motor control circuits, with the attendant wire harness and the like. The complexity of this device makes it expensive; and the problems associated with belt drives located within a loadlock chamber, as described above, also are present with the device of this patent.
It is desirable to provide an accurate wafer transfer mechanism for transferring a wafer or work piece from one environment, through a loadlock, to another environment, which overcomes the disadvantages of the prior art devices discussed above, and which is simple and accurate in its operation.


A control flow is prepared by connecting blocks in an execution order, each block not including a branch and comprising a series of statement, based on a syntactical analysis of a program. A second control flow is prepared by cutting the first control flow at one portion and combining the cut result with a symbol designating a loop. A third control flow is prepared by expressing a portion of a loop, branch and merge in the second control flow and the second control flow in a hierarchical manner. The third control flow expresses a portion of a sequential execution other than the loop, branch and merge, a portion of the loop, and a portion of a branch and merge in a hierarchical order by using a symbol for a sequential execution. A specification of the program is extracted by using the third control flow.

1. Field of the Invention
The present invention relates to a data processing apparatus, and more particularly to an apparatus for analyzing an execution of a program to extract a specification of the program.
2. Description of the Related Art
For a purpose of aiding maintenance and reconstruction of the program, software tools which extract various computed information based on control flow or a dataflow, namely, a reverse engineering tools or a reengineering tools, have been developed.
However, analysis technology in a conventional reverse engineering tool or reengineering tool remains to such a level where a flowchart or control flow of the programs, or a specific data referred to or defined in the program play main roles. For example, conventional reverse engineering tools cannot obtain information about business-rules out of programs.
Namely, the conventional reverse engineering tool cannot obtain information relating to the value to be finally set for the data or to a condition/constraint for an execution of a specific process on program statement. When business-rules are attempted to be extracted by using the traditional symbolic execution technology, there is a problem that it takes time to extract the information to perform an analysis necessary for respective different data.

Method of performing a reverse analysis of a program and its apparatus


This invention relates generally to portable drawing surfaces and more particularly to a base structure with interchangeable components. The invention permits the manufacture of a base structure that can be combined with an accessory unit and a working surface to create either a lighted drawing surface or a drawing surface with a utensil accessory tray. This results in substantial savings in manufacturing costs as tooling requirements are substantially lowered. The lighted drawing surface includes a working surface, a lighting accessory unit and a base structure to provide a backlit surface for tracing and drawing. The portable drawing surface replaces the lighting accessory unit with a utensil accessory unit and thereby provides a drawing surface with a tray for displaying and organizing utensils.

This invention relates generally to portable drawing surfaces and more particularly to a base structure with interchangeable components. The invention permits the manufacture of a base structure that can be combined with an accessory unit and a working surface to create either a lighted drawing surface or a drawing surface with a utensil accessory tray. Without this invention, it would be necessary to manufacture separate base structures to create drawing surfaces of different characteristics. For example, one manufacturing line would be needed for molding base structures for a drawing surface with a utensil accessory tray. An entirely separate line with another set of manufacturing equipment and operating personnel would be needed to mold base structures for a lighted drawing surface. Thus, a great deal of wasteful duplication in machinery and personnel would be necessary to make two distinct drawing surfaces.
This invention obviates the need for such duplicative efforts. The interchangeable nature of the base structure and other components enables the manufacture of multiple drawing surfaces with distinctive characteristics from the same base parts. This invention greatly reduces molding costs since molds for only one base structure, not two, are needed. This invention results in substantial savings in manufacturing costs as tooling requirements are substantially lowered. Thus, this invention permits the economical manufacture of portable drawing surfaces with either an accessory tray for storing drawing utensils or a backlit working surface.

Portable drawing surface with interchangeable components


A servo controlling apparatus of an optical disk drive and a control method thereof are provided for achieving precise control by automatically controlling the gain of error signals caused by the difference in the amount of light irradiated during recording and reproducing, and then using the automatically gain-controlled signal. In a first control step, a focus error signal and a tracking error signal generated from a photodetecting portion via an operator are multiplied by a predetermined value in different multipliers, and then each obtained value is divided by an RF sum signal to control the value of error to within a predetermined target value. In a second control step, each multiplied focus error signal and tracking error signal are divided by a DC signal corresponding to the average level of the RF sum signal when the error value reaches the target value.

The present invention relates to a servo controlling apparatus of an optical disk drive and a control method thereof, and more particularly, to a servo controlling apparatus of an optical disk drive and a control method thereof for controlling the gain of an error signal caused by a difference in the amount of light irradiated during recording and reproducing and controlling the error signal to within a target value.
Generally, the intensity of light required for recording information on an optical disk is much higher than that for reproducing information from the disk. Thus, an optical disk drive for recording and reproducing includes a light source of which the intensity of light irradiated onto the optical disk can be controlled according to the recording and reproducing modes.
The amount of light reflected from the disk differs according to the difference in the intensity of light irradiated onto the optical disk (hereinafter, referred to as "disk") during recording and reproducing. Thus, a change of the detected error signal due to the difference in the amount of reflected light affects the gain of the whole control system for a servo controlling apparatus of the optical disk drive. Accordingly, there are oscillations in the servo control circuit.

Servo controlling apparatus of optical disk drive and control method thereof