A system for reliable multicast distribution includes a primary content engine and a backup content engine sender. The primary content engine sender sends out a multicast message of content to selected content engine receivers. The sender waits for negative acknowledgments from the selected content engine receivers declaring that content was not received. If a negative acknowledgment is received, the sender resends the multicast message a predetermined number of times. If the content is still not received after the number of multicast passes is exhausted, the sender sends out unicast messages to those receivers still requesting content. If the primary sender does not respond to a negative acknowledgment, the receiver sends a second negative acknowledgment to the backup multicast sender. The backup responds with the data requested in the negative acknowledgment and so is able to begin data distribution at the point where the primary sender left off without maintaining synchronicity with the primary sender.

Computer networks such as the Internet allow computer systems to exchange content (e.g., data or information such as documents, web pages, files, database information, streams of audio and/or video data, or the like) in a variety of ways. For example, computer systems (e.g., client computer systems, server computer systems) exchange content over the computer network by using a suite of protocols collectively referred to as the World. Wide. Web. In a typical operation of the World. Wide. Web, a client computer system, configured with a web browser, requests content served by a web server computer system over the Internet. The web server transmits the requested content over the Internet to the requesting client computer system.
Client computer systems that require the ability to access content using the aforementioned techniques may be connected to a computer network at diverse geographic locations. In such situations, a producer, provider or other originator of the content may use a group of technologies, collectively called a content distribution network (CDN), to disseminate or distribute the content.
A CDN enables web content from an origin server to be distributed to other servers at various locations in the network for storage and access. A CDN typically includes a content distribution manager (CDM) to manage the CDN, at least one content router (e.g., operating as a load balancer) and one or more content engines that operate as servers (e.g., web servers) to serve content requested by content requests sent from client computer systems. The content router receives client requests for content, and using various content routing techniques, decides which content engine is to service those client requests. The content router then redirects the client requests to an appropriate content engine. The content engines are also called content servers, or alternatively, caching servers. A content engine that receives redirected requests from a client computer system typically operates to serve the requested content back to those client computer systems, though the content engine may perform further redirection techniques as well in some instances.
When a user requests a. Web page, for example, that is part of the CDN, the CDN typically redirects the request from the origin server to a content engine that is closest to the user. This redirection may be based on a number of factors such as the geographic proximity of the requesting client to an available content engine containing the requested content, or on the specific content requested, or on load balancing considerations between multiple available content engines. The content engine delivers the cached content to the user. The CDN also communicates with the origin server to deliver any content that has not been previously cached. Thus, the CDN accelerates access to content on behalf of client computer systems.
Various conventional techniques and mechanisms also exist for distributing the content from the origin server to the selection of content engines distributed through the computer network in order to accelerate access to the content by client computer systems. One technique for distributing content is the content channel. A content provider defines one or more "channels" to make content available through the CDN. Each channel contains a set of files that is typically expected to be accessed by the same set of users.
For example, a channel may contain training videos intended to be used by sales people, or advertisements directed at an organization's customers. A subset of the content servers in the CDN is assigned to each channel. The content servers in the assigned subset are typically servers located conveniently with respect to the intended set of users of the channel.
Files in a channel are pre-positioned at the content servers assigned to that channel. Pre-positioning enables greater certainty of availability of the content to accessing users. The content servers assigned to the channel may be behind a slow link relative to the origin server, and the files themselves may be very large. Therefore, moving the content from the origin server to a content engine assigned to the channel can be time-consuming. Pre-positioning the content generally reduces delay when users attempt to access files. Pre-positioning content within content engines is especially important when the content is very large or in situations where there is a low speed connection between the origin server and the content engine that will cache or otherwise store the content for access by requesting client computer systems. By pre-positioning the content, client computer systems encounter minimal delays when requesting the content from the content engines.
Routing within the CDN may be further accelerated by creating an overlay network. An overlay network includes a collection of nodes placed at strategic locations in an existing network fabric, also referred to as a substrate network. The overlay network further includes specified connections between the nodes in the collection of nodes. Together the collection of nodes and the specified connections implement a network abstraction on top of the substrate network. Routing is accelerated by selecting optimal nodes and connections. In a CDN, the overlay network includes the content engines and connections between the content engines. The connections are selected in order to optimize data transfer between the content engines.
In some cases, the overlay network includes multicast connections in which content is delivered from one server in the CDN to many content servers using multicast distribution. In multicast distribution, a single message containing content is transmitted to a select group of receiver content engines. Multicasting accelerates distribution of content in the CDN and accordingly accelerates access to content by clients.

Method and apparatus for reliable multicast distribution


A multiconductor cable is reduced in the possibility of break even for use at a place where the cable undergoes twisting, and a method can produce the multiconductor cable easily at a low cost. The multiconductor cable incorporates a plurality of wires that are arranged in a flat array with a specific pitch at both ends of them, that have an intermediate portion at which they are bundled together; and that have lengths different from one another, the lengths varying successively from the minimum length, Ls, to the maximum length, Lm. The multiconductor cable satisfies the formulae “D/E>⅙,” and “(Lm−Ls)>{(D2+E2)1/2−E},” where D is the width of the cable at both ends, E is the distance between the ends of the cable, Lm is the maximum length, and Ls is the minimum length.

1. Field of the Invention
The present invention relates to a multiconductor cable incorporating a plurality of insulated wires, coaxial conductors, or the like and a method of producing the multiconductor cable, particularly to a multiconductor cable in which a plurality of wires and conductors are tied together in a bundle at the intermediate portion and are arranged in a flat array at both ends, where the cable is provided with connectors or similar components, and a method of producing the multiconductor cable.
2. Description of the Background Art
As information communications devices, such as notebook-size computers, cellular mobile phones, and video cameras, have been widely used in recent years, they are required to reduce their size and weight. Consequently, connection between the main body of a device and a liquid crystal display and wiring in a device are made using extremely fine insulated wires and shielded wires including coaxial conductors. In addition, a multiconductor cable in which the foregoing wires and conductors are bound together is also used because it facilitates the wiring. A multiconductor cable is electrically connected through a connector having the shape of a card-edge connector in which a multitude of contacts are arranged in a row (such a connector is used for the connection of a printed circuit, for example).
FIG. 6A is a plan view of an example of the conventional multiconductor cable, and FIG. 6B is a plan view of another example of the conventional multiconductor cable. In many cases, a multiconductor cable 1a provided with connectors as shown in FIG. 6A is used, in which a plurality of electric wires 2 are arranged in parallel with a constant pitch to form a unified structure as a multiconductor cable. The cable 1a is suitable for the wiring along the inside wall of a device. However, when it is used for the wiring through a hinged portion, such as the connection between the main body and a liquid crystal display of a cellular mobile phone, its twisting property is insufficient at the hinged portion. In particular, when the size of the hinged portion is small, the stress applied to the cable 1a is large and, consequently, the cable tends to suffer a break. Therefore, this type of cable is not suitable for use at a small-hinged portion.
To solve this problem, the wiring through a turning portion, such as a hinged portion for an opening-and-closing operation, is made using a multi-conductor cable 1b provided with connectors as shown in FIG. 6B. In this cable, both ends to which electrical connectors 3 are connected have a structure in which a plurality of wires 2 are arranged in a flat array and the intermediate portion has a structure in which the wires 2 are bundled together. In this case, the cable 1b may be produced such that only both ends have a flat shape and the intermediate portion is formed by bundling the intermediate portions of a plurality of disorganized wires. The cable 1b may also be produced by rolling up the intermediate portion of a plurality of wires that arranged in a flat array throughout the length. A plurality of wires 2 are bundled using a bundling member 4 having the shape of a tape. When the wires 2 are coaxial conductors or shielded wires, an intermediate portion of the multiconductor cable is sometimes provided with a grounding member 5 for connecting that portion to the ground.
In the multiconductor cable 1b composed of a plurality of wires 2 having the same length, wires placed in the middle position of a flat array are slackened and wires placed at the outside positions are pulled. As a result, the wires placed at the outside positions tend to break. To overcome this problem, the published Japanese patent applications Tokukoushou 61-230208 and Tokukai 2000-294045 have disclosed a multiconductor cable having a specific structure (see FIG. 4 of Tokukai 2000-294045). In this structure, a wire placed at an outer position has a length longer than that of a wire placed at an inner position so that the slack and tension can be prevented.
However, no disclosure has been made about the length of a wire placed at an outer position. No clarification is made for the case that undergoes twisting. In practical application, when a multiconductor cable provided with connectors has a length of E and a width of D and the length E is at least six times the width D, it is confirmed that the intermediate portions of the wires constituting the multiconductor cable and having the shape shown in FIG. 6A can be simply bundled to obtain the shape shown in FIG. 6B without any problem in use.
However, if the length E is small to the extent that the ratio E/D is less than six, a problem is caused due to the difference in length between the minimum length of the wire placed at the center of the bundle and the maximum length of the wire placed at the outermost position of the bundle. More specifically, at the time of bundling a plurality of wires arranged in a flat array, even when the length of wires to be placed at the outer side and to undergo tension is simply increased, a wire having an excess length tends to buckle or break. In addition, for the use in a turning portion, if no consideration is given to the twisting, a break of wire cannot be prevented, that is, the problem cannot be totally solved.

Multiconductor cable and method of producing the cable


The disclosure presents a formulation to support simulatable subset (also known as ‘simple-subset’) of a property specification language. This method is applicable for model checking and simulation. In this formulation, the ‘simple-subset’ is transformed to a set of basic formulas. Verification engines are required to support the basic formula only. The basic formula is a form of automata in the property specification language. This is called SERE implication. The efficiency of verification is dependent on size of automata. Miscellaneous opportunistic rules are applied to optimize SERE implication formulas.

Confirming that a circuit design satisfies the specified requirements is the basis of verification processes. One main aspect of the verification process includes specification. Conventional specification practices include creating a natural language description of a circuit's design requirements. However, the natural language description lacks a machine-executable representation, which is usually vague and in many cases unverifiable. In addition, in recent years, the demand for formal specification languages is growing as more and more engines capable of handling formal verification languages become available in verification environments. All the advances require a more sophisticated property specification language.
PSL is an Accellera Standard language for property specification. It is used for specifying hardware design behavior and interface requirements. The PSL specification can be used in simulation, emulation, and model checking (formal) verification engines to check the hardware design.
The language PSL, supports linear temporal logic (LTL) and computational tree logic (CTL) formulas. It has unique regular expression based formula called SERE (Sugar Extended Regular Expressions) implication. The LTL and SERE forms together are called foundation language (FL) formulas. The language defines subset of FL, which can also be verified using simulation. This subset is called 'simple-subset' of PSL. The disclosure presents a novel method to support 'simple-subset' of PSL by simulation and model checking.
Buchi Automata is a well-studied form of automata to represent LTL formulas in LTL model checking. The LTL formulas are converted to Buchi Automata. The standard model checking consists of taking cross product of model (design automaton) and Buchi automation of the complement of LTL formula. The cross product is checked for empty language. The Buchi automata could have O(2n) states in worst-case where n is the size of LTL formula. The size of Buchi automation, and hence the quality of LTL formula transformation, is very important for efficiency of model checking. This process is shown in FIG. 2A and described further below.
Formula in 'simple-subset' of PSL can be transformed to a set of SERE implication formulas with optional 'abort'. This disclosure describes a method to show that SERE implication support is powerful enough to support 'simple-subset' of PSL.
Efficiency of automata construction is addressed by two approaches. Handcrafted parameterized automation modules are constructed for generic SEREs. These are specific to modeling checking and simulation engines. In addition, transformation rules have been developed to optimize SEREs before implementing it with automatons for simulation and model checking.

Transformation of simple subset of PSL into SERE implication formulas for verification with model checking and simulation engines using semantic preserving rewrite rules


A quick-release coupler includes a rod having first and second sections. The first section includes an end for coupling with a pneumatic tool. The second section extends from the other end of the first section. A sleeve is slideably mounted around the rod and includes an end for releasably coupling a bit. The sleeve includes an axial bore having larger and smaller sections. The larger section has polygonal cross sections corresponding to polygonal cross sections of the first section. A radial bore is formed in the sleeve and in communication with the smaller section. A ball is moveably received in the radial bore and moveably received in a recess of the second section of the rod to releasably engage the sleeve with the bit. A spring is mounted in the larger section of the sleeve for biasing the sleeve towards the other end of the rod.

The present invention relates to a quick-release coupler and, more particularly, to a quick-release coupler for securely coupling a bit to a pneumatic tool while allowing easy assembly.
FIG. 1 shows a conventional quick-release coupler 2 and a bit 1 coupled to the quick-release coupler 2. Bit 1 includes a driving end 12 for driving a screw or the like and a socket portion 11 having a coupling hole 111. A recessed portion 112 is formed in each of four side walls defining coupling hole 111. Quick-release coupler 2 includes a first end 21 for coupling with a hand-held tool such as a pneumatic tool (not shown) and a second end 22 having a receptacle 221 in which a spring 23 and a ball 24 are received. Ball 24 is biased by spring 23 such that an outermost portion 241 of ball 24 projects out of receptacle 221 and engages in one of recessed portions 112 of bit 1 when coupling hole 111 of bit 1 is coupled to second end 22 of quick-release coupler 2. Thus, bit 1 is locked on quick-release coupler 2 and can be driven when first end 21 of quick-release coupler 2 secured to the pneumatic tool rotates.
To remove bit 1 from quick-release coupler 2, a user generally grasps bit 1 and a handle of the pneumatic tool to pull them away from each other to make ball 24 retract into receptacle 221 to allow removal of bit 1 from quick-release coupler 2. However, it is sometimes difficult to remove bit 1 from quick-release coupler 2, particularly when ball 24 is jammed or the hands of the user are greasy. Moreover, bit 1 may be disengaged from quick-release coupler 2 during operation of the pneumatic tool when the resilience of spring 23 decreases.
U.S. Pat. No. 6,874,392 discloses a connector for a hand tool including a connector seat coupled to an operation member. The connector seat includes a main body, a movable rod, a positioning ball, and at least one spring. The main body includes a square receiving portion having a positioning hole that partially receives the positioning ball. The main body is movable relative to an operation seat of the operation member to retract the positioning ball into a receiving cavity of the movable rod, so that a socket can be mounted on and detached from the connector easily and conveniently, thereby saving the manual work. However, aligning the receiving cavity of the movable rod with the positioning hole of the square receiving portion of the main body while inserting the movable rod into the main body is not always easy, for the movable rod having circular cross sections may rotate relative to the main body also having circular cross sections.
Thus, a need exists for a quick-release coupler to allow secure attachment and easy removal of a bit to and from a hand-held tool while allowing easy assembly of the quick-release coupler.


A chemiresistor sensor probe for detecting target analytes. The probe includes a body having a first control surface and a second control surface recessed within the first. A sensor film comprises numerous conductive particles disposed upon the second surface. The film swells upon absorbing one or more analytes for which it has an affinity, thus causing the conductive particles to become more dispersed and increasing the resistance between the particles. The thickness of the film is equal to the distance between the first surface and the second surface, thus permitting the thickness to be controlled by varying the distance between the control surfaces. The robustness of the sensor probe is enhanced by placing a porous or mesh electrode along with, or in place of, a chemical binding agent between the film and the terminals. The robustness is also improved by placing a diode in series with the sensor circuit.

Detection of specific target analytes, or chemical compounds, is important for many applications, including for example, detecting whether the concentration of analytes exceeds flammability limits. Target analytes are detected by sensors operating according to different detection mechanisms, known in the art. Most sensors employ a sensing component that is physically modified in the presence of specific analytes present in the environment. Thus, a sensor typically comprises a probe that includes both the sensing component and a probe body housing (including terminals for transmitting an output). The terminals are typically coupled to a processor, also part of the sensor, which analyzes the outputs received from the sensor probe. Such processor is coupled to a user interface, typically containing an indicating device, which signals when concentration of an analyte has exceeded threshold values.
Many sensors employ a sensing component that is a sensor film. Many sensor films swell, increasing in volume, while in the presence of the analytes. Various sensors available in the art utilize the physical changes in the sensor film to determine concentration of analyte present. Such sensors may include optical sensors, such as fiber optic sensors, where a beam of light is projected through an optical fiber at a sensor film cladding, and physical changes (e.g. refractive index or color) in the film are monitored. Such changes in refractive index occur when analytes are absorbed and change the physical properties of the cladding (including volumetric changes). Other sensors include sound acoustic wave sensors (SAWS), which project ultrasonic waves through the sensor film between transducers, and likewise detect any modifications in the properties of the sensor film (primarily the mass), translating those changes to the concentration of analyte present.
Another type of sensor film is a conductiometric sensor, more particularly, a polymer-absorption chemiresistor sensor. A polymer-absorption chemiresistor has a polymer film sensor exposed to a surrounding atmosphere containing target analytes (chemical compounds). An electrical charge is applied across the polymer film. The polymer absorbs target analytes and this results in a volumetric change of the film, and hence the electrical resistance of the film. Further, conductive particles may be distributed throughout the polymer film to enhance the sensitivity to resistance changes in the material when the volume of the polymer changes.
While conventional chemiresistor sensors perform adequately for their intended uses, they are subject to improvement. Specifically, as the volume of the sensor film expands and contracts over time in response to the presence of the target analytes, the mechanical bond between the sensor film and the terminals is weakened, thus causing the film to gradually separate from the terminals. As the film separates from the terminals the electrical bond between the film and the terminals is also weakened. This weakening of the electrical bond between the film and the terminals decreases sensor performance because it diminishes the ability of the processor to analyze changes in the resistance of the film through the terminals. Consequently, there exists a need for an improved chemiresistor that provides an enhanced mechanical and/or chemical bond between the terminals and the sensor film to enhance both the robustness of the sensor and the responsiveness of the sensor to the target analytes.
Conventional chemiresistor sensors are also deficient in that they fail to provide a sensor probe having a sensor film of a controlled thickness. The thickness of the sensor film is relevant to the probe's ability to detect the target analytes. Specifically, the use of a thick sensor film is undesirable because thick films require an extended period of time to absorb the target analyte, thus increasing the time required for the sensor film to swell and produce a change in resistance indicating the presence of the target analyte. However, the use of a sensor film that is overly thin is also not desirable because excessively thin films are not durable, are difficult to manufacture, and are unstable. Thus, there is also a need for a chemiresistor that has a sensor probe with a sensor film of a controlled thickness.
Additionally, a build-up of dirt or surface moisture may contaminate the terminals of conventional sensor probes, causing the sensor to produce inaccurate readings. Specifically, the surface moisture effectively creates a bypass resistor in parallel resistance with the sensor probe. This bypass resistor typically desensitizes the performance of the sensor. In particular, if the bypass resistance becomes small enough, the combined resistance of the bypass resistor in parallel with the sensor probe is influenced more by the bypass resistor, thus a very low level current will run into the sensor probe. Consequently, there is also a need for a chemiresistor sensor having a sensor probe with a circuit that is insensitive to bypass resistance.


Cooperating jaws are pivoted together such that working end portions of the jaw members are movable toward and away from each other. The jaws have butt portions extending opposite the jaw pivot from the working end portions. Such butt portions are, in turn, pivoted to elongated handles for swinging about axes parallel to the axis of the jaw pivot. The handles are channel shaped and define recesses into which the interconnected jaw members can be swung so as to be nested in the handles or, alternatively, into which the interconnected jaw members can be retracted so as to be partially contained within the handles. The handles have forward portions interconnected by a link which, in an open position of the handles, is positioned between the handle pivots and the jaw pivot. For a given angle of swing of the handles, the jaws are moved through a smaller angle, i.e., a substantial mechanical advantage is obtained.

Leatherman U.S. Pat. No. 4,744,272, issued May 17, 1988, discloses a "Foldable Tool" including pliers jaws having respective tangs or butt portions remote from the cooperating work or grasping end portions of the jaws. The butt portions are pivoted to channel-shaped handles. The pivots for the jaws and handles are parallel. The handles are swingable relative to the jaws for compact nesting of the jaws within the handles. Pocket knife implements can be separately pivoted to the channel-shaped handles.
Other types of compound tools having cooperating jaws swingable relative to handles are disclosed in German Patentschrift 30788, published Aug. 14, 1984, and in the following U.S. patents: Meloos, U.S. Pat. No. 649,344, issued May 8, 1900; Di Maio, U.S. Pat. No. 1,524,694, issued Feb. 3, 1925; Leatherman U.S. Pat. No. 4,238,862, issued Dec. 16, 1980; Leatherman U.S. Pat. No. 4,888,869, issued Dec. 26, 1989; and Collins et al., U.S. Pat. No. 5,062,173, issued Nov. 5, 1991.
Yet another compound tool having cooperating pliers jaws swingable relative to handles is disclosed in my U.S. patent application Ser. No. 07/891,990, filed May 27, 1992, and issued on Dec. 7, 1993 as U.S. Pat. No. 5,267,366.
In the tools of the patents and application referred to above, the handles of the tools normally form extensions of the butt portions of the jaws, and the handles usually are longer than the grasping or working end portions of the jaws. In order to achieve a mechanical advantage, the handles must be grasped at their end portions remote from the jaws. Nevertheless, such tools often are formed with handles shorter than the handles of standard tools, for compactness when the jaws are swung or otherwise retracted into the handles. Therefore, the mechanical advantage that can be achieved is limited.

Compound pliers tool with linked handles


A trailer quick disconnect ball mount assembly provides a more secure, less cumbersome, more visible and better-fitting connection between the towing vehicle and trailer. The trailer quick disconnect ball mount assembly features a receiver housing with an angled sidewall that defines a tapered opening for rapid and precise alignment of the ball inside the receiver housing. The receiver housing, angled sidewall and fastening pins only cooperate only when the ball is correctly seated inside the receiver housing and also prevents accumulations of dust and dirt. The need for correctly seating the ball allows the user to instantly determine that the ball is securely connected to the receiver housing. A trailer quick disconnect ball mount system and a method for securely hitching a trailer with a quick disconnect ball mount assembly are also provided.

Trailer hitches have found wide-spread use in all phases of ground transportation and can pull boats, campers, cargo trailers and many other types of loads. There are several types of trailer hitches. Most pickup trucks, sport utility vehicles and commercial trucks have the ball trailer hitch. Other types of trailer hitches are gooseneck trailer hitches and fifth wheel hitches. Ball trailer hitches are more versatile than many other types and can be used to haul small cargo trailers, boats and some campers. It is important to have a strong enough truck to haul the load connected to the trailer hitch so the trailer is usually pulled by a truck with adequate engine strength to build up momentum to pull the trailer.
Trailer hitches provide great versatility for recreational, commercial and military transportation throughout the world. Except for the trailer and cargo, the typical ball trailer hitch system comprises three main assemblies: the trailer ball, ball mount and receiver. The trailer ball is the component that attaches the trailer to the hitch. The ball mount is that part of the trailer hitch that slides into the receiver and fastens onto the trailer ball. The receiver is that part of the trailer hitch that is attached to the frame of the towing vehicle. Notwithstanding the many versatile uses and valuable contributions of trailers to today's transportation systems, many difficulties can arise from a poor connection between the ball mount, ball and receiver such as accidents, lost cargo and property damage. Trailer hitches must be installed correctly to the truck or else the entire hitch rig can come off, leaving the cargo behind and causing many problems and concerns. Additionally, in tactical military operations conducted in Iraq and Afghanistan, a loose trailer connection on a military vehicle may well slow down the military vehicle or convoy and expose the troops to the terrible dangers of roadside explosions.
One disadvantage with current trailer receivers is that they are designed in such a way that they easily collect dust, sand and dirt. For example, trailer hitches used by military vehicles in Southwest Asia are frequently hampered by excessive accumulation of desert sand which is trapped by a lip near the interior bottom of the receiver. The unwanted build-up of sand and dirt in the receiver has been a contributing factor to poor trailer connections. Also, current trailer hitch receivers have a relatively small opening so that making a tight-fitting connection between the ball and receiver can be a time-consuming process that requires a precise alignment of the ball and receiver, which can also create dangerous complications on the road or during a tactical military mission in a hostile environment. Another problem with current trailer hitch systems is that the typical ball receiver usually has a somewhat large tolerance within the receiver which tends to pull the ball into the side of the receiver and causes an uneven placement of the ball within the receiver and can result in poor fit and loosened connections during travel. Another disadvantage with the current trailer hitch systems is that they rely upon a latching mechanism that is located inside the hitch and consequently hidden from view so that the user is unable to quickly determine if the ball is properly connected and secured. The combined impact of the disadvantages of excessive road dust collection, cumbersome alignment procedures, poor fit and lack of visibility in current trailer hitches causes many losses of time, cargo and efficiency.
Thus there has been a long-felt need for more secure trailer hitch connections that do not suffer from the disadvantages, drawbacks and shortcomings of prior art trailer hitches. Up until now, this long-felt need for a new trailer hitch structure for more secure, less cumbersome, more visible and better-fitting connections has not been answered.

The United States of America as represented by the Secretary of the Army


A RAID disk drive controller (FIG. 33) implements disk storage operations, including striping and redundancy operations with multiple disk drives connected via respective SATA ports (520). Configurable data path switch logic (460) provides dynamic configuration of two or more attached drives into one or more arrays. Data transfers are synchronized locally by leveraging the SATA port transport layer FIFO (530). Synchronous transfers allow on-the-fly redundancy (XOR) operations (FIG. 36) for improved performance and reduced hardware complexity. XOR accumulator hardware (FIG. 42-FIG. 43) reduces buffer requirements for multiple DMA channels otherwise required for synchronization, and various narrow and wide striping modes are supported.

The hard disk remains the primary mass storage device for small to mid-sized computers. As an electromechanical device, the hard disk performance is limited by the physical characteristics of the drive consisting primarily of seek times and rotational delays. Once the mechanical portion of a read or write access has been performed, the data transfer rate is limited by characteristics of the media, the head, and the R/W electronics. This data transfer rate is in the range of 50 to 100 MBPS (megabytes per second) for currently available products.
The Disk Array
A system might use multiple disk drives, i.e. an array of drives, if the required capacity, performance or reliability exceeds that available from a single drive. Capacity enhancement is the most common motivation. Two drives of a given size can store twice as much data as either single drive; compare FIG. 1A to FIG. 1B. Reliability enhancement is less obvious. Two drives of given type will have twice the failure rate of a single drive. On the other hand, a system may be arranged so that the second drive always has an exact copy of the data on the first drive. (This is often called "mirroring".) If either drive should fail, the data is not lost as there is still a copy; see FIG. 1C (where data A′ is a copy of data A). If a failed drive is immediately replaced and the copy rebuilt, the probability of data loss drops down to the probability of two drive failures within the time required to replace a failed drive and to rebuild the copy. This is much lower than the probability of any single drive failing.
Performance is the third reason that a system might require the use of a drive array. There are two main cases. First, a high speed streaming application may require a higher sustained bandwidth than a single drive can deliver. A system with N drives can potentially provide N times the sustained bandwidth of a single drive. And second, the access time for a given drive, determined primarily by seek and rotational delays, limits the number of IO operations that can be performed per second ("IOPS"). An N-drive array can potentially support N times the IOPS performance of a single drive, in the best case. An example is illustrated in FIG. 1D.
Data Architectures
The simple addition of a second drive to a system will immediately double the capacity, but there may not be a performance improvement. Should the bulk of the accesses be to one of the drives or the other, the performance will be limited by performance of the more popular drive. Striping is a known technique which distributes data over the available drives so that retrieving the data will require the participation of all of the available drives, thereby allowing the system to attain performance approaching the aggregate performance of the drives.
The smallest addressable unit of storage on a typical disk drive is the sector. A sector of data is typically an exponential multiple of two bytes in length. In this application, a sector size of 512 bytes will be used for purposes of illustration but not limitation. To stripe data, an order or sequence is assigned to the drives and a stripe width is selected. A pair of drives may be identified as 0 and 1. The stripe width might be 4K bytes which is eight sectors of 512 bytes each. With these selections, the first 4K block of user data ("User 0" in the drawing) is stored in the first 4K block of drive 0. The second 4K block of user data ("User 1") is in the first 4K bock of drive 1. The third 4K block of user data is stored in the second 4K block of drive 0 and the third 4K block is stored in the second 4K block of drive 1. This arrangement is illustrated in FIG. 2. This process is repeated, alternating the storage of 4K blocks between the two drives, until the ends of the drives are reached. If the system has a large number of small accesses of one or two sectors, the two drives may be accessed concurrently to attain twice the random access performance of a single drive. If the system is accessing relatively large data blocks, say of 100K, the two drives may once again be operated concurrently to attain nearly twice the sustained performance of a single drive. Consequences of the stripe width selection will be discussed below.
Redundancy
As described above, a drive may be added to keep a continuously updated backup copy of a primary drive. For this simple approach, any disk write operation is simply duplicated on the backup drive. The backup drive is an exact copy of the primary drive. This technique is often known as "mirroring" or RAID1. Data may be read from either drive until one of the drives fails at which point the remaining drive is selected for reads. The increased reliability results in a 100% increase in the cost of storage, i.e. one mirror drive is required for each primary drive.
There are techniques for protecting data with an incremental cost of less than 100%. Consider the two-drive array previously described with the 4K data stripe. An additional drive, the same size as the original two, may be added to the array. This drive is referred to as the "redundant" drive. See FIG. 3. In this arrangement, each 4K block of the redundant drive receives the XOR of the corresponding 4K blocks of the other two drives. For any single drive failure, the contents of any 4K block of the failed drive can be reconstructed by computing the XOR of the corresponding 4K blocks of the remaining data drive and the redundant drive. In general, for an array with data striped across N drives, the XOR of all of the data blocks in the stripe is stored on the redundant drive. Once again, any block in the stripe can be reconstructed by XORing the remaining blocks of the stripe (including the redundant drive block). The added cost of the redundancy is reduced to 1/N where N is the number of data drives. FIG. 4 illustrates an array with three data plus a redundant drive. For each stripe, the redundant drive contains the XOR of the corresponding blocks in the three data drives. In general, there is no physical difference between "data drives" and "redundant drives". We use those labels herein as a convenient reference to a drive's designated function in the stripe. These drive functional assignments are typically rotated between stripes because the parity drive tends to become the bottleneck for applications with a high percentage of writes and this rotation tends to balance the load.
For read accesses, assuming no drive failure, the performance of the redundant array is the same as the striped array performance without redundancy. The reconstruction of a data block of a failed drive, however, requires additional disk activity to access each of the remaining drives in the array and additional processing of the data for the XOR computation. Also, the updating of any block will invalidate the redundant block for that stripe, requiring an update of the redundant block as well.
As noted above, a system with two drives can provide either redundancy by using one drive to mirror the other, or it can double the capacity and provide up to a 2× performance improvement. The issuing of extra disk write commands required to maintain a copy or the extra operations required to distribute or collect data striped between two drives can easily be handled by the driver software using a disk controller that does not provide any specialized array functions. For systems with a redundant array of three or more drives, however, the XOR computations and the additional disk activity can significantly benefit from specialized hardware with or without local intelligence. In today's market, the two-drive arrays typically are handled in software. Larger arrays utilize specialized disk controller hardware which may be located on the motherboard, in a plug-in card, or an external box.
Redundancy Hardware
There are industry standards which describe in detail the mechanical, electrical, and logical interfaces of disk drives. A drive may be attached to a system by providing an interface commonly called a controller or an adapter meeting the requirements of the interface standard. For any system in which performance is an issue, Direct Memory Access or DMA is used by the controller to transfer disk data between the drive and system memory.
As a context for examining acceleration hardware, consider the array consisting of three data drives plus a redundant drive; see FIG. 4. Before a drive has failed, accessing a block of data requires only that the target drive be read and the data transferred by DMA to memory. There is one disk access and 4K bytes of data are transferred into the memory. If this drive should fail, accessing the same data block will require reading the balance of the stripe, i.e. the corresponding blocks of the same stripe from all of the other drives.
Each of the remaining drives is read with the data transferring by DMA to memory. Even though the three drives may have identical average access characteristics, the read operations will actually complete at different times for various reasons, including the fact that the initial states of the head position and rotational position are independent. Referring now to FIG. 35A, it shows this asynchronous data transfer from Data 0, Data 1 and PAR (parity or redundant drive) drives via respective DMA channels to corresponding buffer memory. The Data 2 drive has failed. Once the three blocks are stored in a buffer, the XOR operation can be performed to reconstruct the missing data. Referring now to FIG. 35B, to XOR the three streams, one element is read from each of the streams, the three elements are XORed in logic 620, and the resulting element is stored in a new block of the memory 622. Note that an element may be of any convenient size for the memory and DMA hardware involved. This process required three disk accesses: 12K of data was transferred into the memory from the disks (using 4 k blocks for illustration); 12K of data was read back out of the memory for XOR computation; and 4K bytes of data were written back into the memory 622 for a total of 28K of data transfers into or out of the memory.
From the foregoing example, we observe the following:
1. While the accessing of a 4K data block required only 4K of data transfer, the post-failure access required 28K bytes total of buffer access, a seven-fold increase in system bus and memory bandwidth loading.
2. The XOR computation could not begin until data blocks had been received from all three drives. Thus the entire XOR process adds to the total latency of the read operation, creating an incentive to make the buffer memory and XOR engine as fast as might be practical. Note that while the XOR process might have been started on the first two streams, extra bandwidth would be required to store the intermediate results and to fetch them once again to be XORed with the final data block.
3. The post-failure essentially tripled the overhead for drive management.
Synchronous Redundant Data Transfers
Typically disk drives are internally buffered in order to decouple the data transfer rate of the R/W head from the transfer rate of the drive interface. This internal buffer, and its ability to accommodate various interface speeds, can be exploited to enhance redundancy operations while significantly reducing the hardware requirements. Consider the ATA/ATAPI interface in its original parallel Programmed Input Output or PIO mode of operation. In this mode, a single sixteen-bit word of data was read from or written to the drive's internal buffer using a read or write strobe (DIOR or DIOW) provided by the controller/adapter. In the discussion of redundancy hardware above, recall that reconstructing a block of data that was on a failed drive required reading the remaining three drives, transferring their data into a local buffer, and then reading the three streams from the buffers in order to compute the XOR function. This was because the drives, while all operating concurrently, were not synchronized to each other, so each transferred data at different times. (We use "internal buffer" to refer to a disk drive's internal buffer, as distinguished from buffer memory in a controller, adapter or host.)
An alternative technique is known as Synchronous Redundant Data Transfers or SRDT. With Synchronous Redundant Data transfers:
1. The read commands are issued to all three (or N) drives. Read data is not immediately transferred when less than three (or N) drives have data available in their internal buffers.
2. However, when the read data from all three drives is available in their respective internal buffers, the XOR process can begin. An XOR engine fetches a first element from each drive; computes the XOR of the three elements; and outputs the first element of the result to the buffer within the controller/adapter. This redundancy operation is "on the fly" as it occurs as data is moved from the drive to the buffer, as distinguished from first storing data in the buffer, and then having to read it out to do the redundancy operations as described above.
For the ATA/ATAPI drive in PIO mode, the element size is a single sixteen bit word, the width of the interface. The element fetching is accomplished by asserting the DIOR strobe to the three drives simultaneously. The use of the common DIOR strobe makes the data transfer "synchronous". In the scheme described above under redundancy hardware, the XOR process could not start until the data from the last drive had been transferred to the memory.
In the Synchronous (SRDT) scheme, the process begins as soon as the data from the last drive is available in that drive's internal buffer. Assuming that the read strobes are generated at the maximum rate supported by the drives, the advantages of the Synchronous Data Transfer and the On-The-Fly redundancy computation are as follows:
1. From the time when the last-to-finish drive has the read data ready in its buffer, the XOR is computed and the result is transferred with the same latency as the transferring of data from a single drive prior to the failure. The additional latency of fetching the three blocks from the buffer, computing the XOR, and storing the result to the buffer are all eliminated.
2. The total amount of data transferred to the buffer is the 4K block that was originally transferred. The total buffer bandwidth required in this example is that bandwidth required to support a single drive.
3. The data from the three drives is reduced to a single stream. Only a single DMA context (address and count) is required for the operation rather than one DMA context per drive as was required in the original example. This efficient operation, however, is dependent on using a storage element size equal to the width of the drive interface ("narrow striping"), and it is limited to synchronous transfers invoked by applying a common DIOR strobe to all of the drives in the array.
In view of the above background discussion, several problems remain. With the PATA technology, a controller could synchronously access multiple drives allowing it to perform redundancy computations on-the-fly for improved RAID performance with markedly reduced hardware complexity. The technologies which have evolved, first UDMA and then SATA, are source synchronous which would not allow a controller to synchronously transfer read data.
Second, the prior art used synchronous data transfers with on-the-fly redundancy with stripe widths of a few bytes or words, merging the drive data into a single stream which could be transferred to or from a buffer with a single DMA channel. Techniques are needed to extend the use of synchronous data transfers and on-the-fly redundancy to arrays with stripe widths of a sector or more.
In addition, current non-synchronous techniques for implementing wide striped controllers transfer disk data to memory before any XOR computations can be performed. This is wasteful of buffer bandwidth relative to techniques that might perform redundancy operations without first transferring all of the data to memory and having to read it back again for computations.

Disk controller methods and apparatus with improved striping, redundancy operations and interfaces


Cymbals operation control apparatus, comprising a mechanism including a lever, a hook on the lever, and a handle on the lever to achieve release of the upper disc to drop toward a lower cymbals disc, means including a vertically movable upright rod to support the mechanism, and a releasable device to block pivoting of the lever.

This invention relates generally to construction and operation of cymbals apparatus, and more particularly to cymbals control apparatus.
During playing of cymbals, it is at times desirable to release an upper cymbals disc to fall toward a lower cymbals disc, for playing of the discs positioned in adjacent relation. There is need for improved apparatus to achieve such upper disc release, and also to achieve upper disc retrieval in order to raise it above the lower disc. This is important, as where two cymbals stands are being operated, and/or where rapid release control is desired as during playing.


Replacement of the amorphous peptide domain of a structural biopolymer, such as silk from silkworms or spiders, with a nonpeptide segment while maintaining the β-sheet forming crystalline segments provides synthetic multiblock copolymers having solid-state structures and mechanical properties similar to the naturally occurring structural biopolymer is described herein. Such synthetic multiblock copolymers may be produced as films or fibers.

Nature maintains remarkable control over the nanostructure of structural biopolymers, such as silks, elastic, collagen, keratin, and amelogenin, through the manipulation of primary polypeptide sequences to achieve desired functionality. Not only do such natural biopolymers precisely fit their purpose, but in many cases, these materials have a multitude of attributes, each of which is optimized. For example, spider silk is a water-insoluble fiber with outstanding strength and toughness, properties usually considered to be mutually exclusive, that is spun at close to ambient conditions using water as the solvent. Moreover depending on the composition, this silk can be highly elastic or inelastic. These unique combinations of properties are inherently necessary to protect the web from bombardment with foreign objects and the impact energy generated by insects colliding and becoming ensnared in the web. Silkworm silk also has many of these highly desirable mechanical properties. All of these silks are very durable and resistant to degradation.
Applications for fibers or films having the attributes of structural biopolymers, such as spider or silkworm silk, include uses such as tissue-engineering scaffolds, cell-culture substrates, biocompatible coatings, sutures, membranes, grafts, and drug delivery systems among others. However, it is not cost-effective to attempt to harvest the naturally occurring silks for these purposes.
It is therefore an object of this invention to provide synthetic polymers having properties comparable or superior to naturally occurring structural biopolymers, such as silks.
It is another object of this invention to provide fibers and films having high strength and toughness comparable or superior to naturally occurring structural biopolymers, such as silks, that are capable of large-scale production.

Multiblock copolymers having improved mechanical properties


A portable communication device includes an image sensing portion, a display portion (display panel), a touch panel portion, a storage portion that stores personal information on a user, a wireless communication portion and a processing portion that recognizes an address included in a code display member by shooting the code display member, that makes the wireless communication portion acquire data in the address as data on an application form, that adds the personal information to the data acquired by the wireless communication portion to generate print data on the application form in which an item has been entered and that makes the wireless communication portion transmit the generated print data to an image forming apparatus.

The present disclosure relates to a portable communication device that includes an image sensing portion and a display portion which displays the result of image sensing and that makes an image forming apparatus perform printing. The present disclosure also relates to an image forming system that includes such a portable communication device and an image forming apparatus.
Portable communication devices such as a smart phone and a tablet computer are widely used. Such a portable communication device is used to attempt to make an image forming apparatus such as a multifunctional machine, a copying machine or a printer more user-friendly. The following example of a technology in which a portable communication device and an image forming apparatus are coordinated is known.
An image forming system is known that includes: an image forming apparatus which converts setting information on the execution of a job into image data and which outputs the converted image data; and a portable terminal which can shoot the output image data, which can store the shot image data and which can output (display, print and transmit) the stored image data or the setting information indicated by the image data. In this configuration, the image forming apparatus outputs, as images such as QR codes, a plurality of pieces of setting information (registration programs) stored to deliver the pieces of setting information to the portable terminal.
In places where people gather, such as stores like a business convenience store and a convenience store, commercial facilities, public facilities and event venues, the brochures and advertisements of events and products may be provided. However, in some brochures and advertisements, only the outlines thereof are described without application forms of participation and purchase. In this case, additional bothersome actions are needed such as confirmations through the Internet, the acquisition of the application forms and the transmission of the application forms through facsimile. Hence, disadvantageously, it is impossible to immediately acquire an application form to submit the application form to a staff member in a store or a facility.
On the other hand, in the store or the facility described above, an image forming apparatus such as a copying machine or a multifunctional machine may be provided that can be utilized by paying some money. When an application form can be printed in the image forming apparatus provided, it is convenient for a user, and it is also possible to increase the frequency of utilization of the apparatus for the provider. However, at present, it is impossible to easily print an application form, and thus it is impossible to effectively utilize an image forming apparatus that is provided.
In the known technology described above, programs (data indicating a plurality of types of setting values) stored in the image forming apparatus can be delivered from the image forming apparatus to the portable terminal. However, it is impossible to immediately print the application form that is not present. Hence, it is impossible to solve the problem described above.

Portable communication device, image forming system and method of controlling portable communication device


A scanning head for an optical position-measuring system includes a receiver grating, formed of photosensitive areas, for the scanning of locally intensity-modulated light of differing wavelengths. The receiver grating is formed from a semiconductor layer stack of a doped p-layer, an intrinsic i-layer and a doped n-layer. The individual photosensitive areas have a first doped layer and at least a part of the intrinsic layer in common and are electrically separated from one another by interruptions in the second doped layer.

Position-measuring systems play an ever more important role in this increasingly automated world. They furnish the basis for exact positioning of drive systems in many applications, for example, in the field of machine tools. The optical position-measuring systems described herein are based on scanning a scale that has a measuring standard in the form of a line grating. The scanning head used for this includes a light source from which light falls on the scale grating via a transmitting grating. After the interaction with the transmitting grating and the scale grating, the light has a spatial intensity pattern which is able to be detected in the scanning head using a receiving grating and is able to be used for position determination.
It is conventional to form a photodetector from a plurality of photosensitive areas. These photosensitive areas are arranged in the scanning head such that they are able to record the different phases of the intensity pattern and to supply corresponding electrical output signals. The individual, evenly spaced photosensitive areas form a receiving grating, in this context.
Four signals may be generated that are offset by 90 degrees with respect to each other in each case, from which, in a sequential electronic system, counting signals connected with direction may be derived. In response to the shifting of the scale relative to the scanning head, the individual phase-shifted signals change as a function of position.
Usually, from the four output signals mentioned, first of all two signals shifted by 90 degrees with respect to each other and free from offset errors, amplitude errors and phase errors are synthesized, which are suitable for a finer subdivision and interpolation. The counting signals connected with direction are able to permit therewith a substantially finer position determination than would be possible, for example, by counting the maxima and/or minima of the intensity pattern at the photosensitive areas of the scanning head.
For reasons described further on, it may be provided that the individual photosensitive areas are as near as possible to one another. The use of discrete component parts, such as photodiodes, limits the possible miniaturization of the photodetectors. Therefore, structured photodetectors have been implemented which, using conventional process steps of microelectronics, permit the production of structured, photosensitive areas on one single semiconductor substrate.
Because of the low inclination to cross feed between the individual photosensitive areas, in this context, there is available, above all, the technologically well manageable amorphous silicon (a-Si), whose use for converting light to electric current is conventional, for example, in the solar cell field.
German Published Patent Application No. 101 29 334 describes an optical position-measuring system having a light-receiving device based on the principle described above. The photosensitive areas for scanning of locally intensity-modulated light of different phase positions are constructed as receiving gratings in the form of several semiconductor layer stacks of doped and undoped amorphous silicon. The construction of the structured detectors is very complex, however, so that the method for its production is also costly.

Scanning head for optical position-measuring systems


An inspection stage has the following a chuck top on which an object to be examined is mounted, a Z base for which the chuck top is provided and which is vertically movable, an X stage which supports the Z base to be vertically movable and which is movable in an X direction, and a Y stage which supports the X stage to be movable in the X direction and which is movable in a Y direction. The Z base is held and supported by three Z shaft lift mechanisms and is vertically movable. The inspection stage is applicable to an inspection stage.

The present invention relates to an inspection stage on which an object to be inspected is mounted and an inspection apparatus provided with that inspection stage. More specifically, the present invention relates to an inspection stage that does not slant even when a chuck top on which the object is placed is exerted with an offset load during inspection.
Conventionally, a probe apparatus is employed as an inspection apparatus for inspecting an object such as a semiconductor wafer. The probe apparatus is provided with a loader chamber for conveying a wafer and pre-aligning it, and a prober chamber for receiving the wafer from the loader chamber and inspecting the electrical characteristics of the wafer. Inside the prober chamber, an inspection stage is provided. The inspection stage is adapted to hold a wafer mounted thereon, and is movable in the X, Y and Z directions. A probe card is arranged above the inspection stage. With the inspection stage moved, the object to be inspected is positioned with reference to the probe card. Then, the object and the probe card are electrically connected to each other. The probe card is connected to a measuring apparatus, by which the electric characteristics of the wafer are inspected.
An example of a conventional inspection stage is shown in FIG. 5. As shown in this Figure, the inspection stage comprises a chuck top 1 on which a wafer is mounted, a Z shaft 2 (e.g., a ball screw) extending downward from the center of the rear side of the chuck top 1, a Z shaft guide 3 for guiding the vertical movement of the Z shaft 2, and a vertical driving mechanism 4 for moving the chuck top 1 up or down along the Z shaft guide 3. The inspection stage is movable in the X and Y directions and positions the object with reference to the probe card. After the positioning, the chuck top 1 is moved up in the Z direction, thereby permitting the object W to come into contact with a probe card (not shown in FIG. 5).
In recent years, IC chips are integrated at higher density than before. Hence, an object to be examined has a large number of electrode pads, and these are arranged at very short pitches. The probe card has an increased number of contact terminals, accordingly. In addition, the number of objects that are measured at a time is also large. This being so, the load that the contact terminals apply to both objects and a main chuck when they are brought into contact with each other, has increased to a value which is between dozens of kg and 100 kg. When, as shown in FIG. 5, a peripheral portion of the object is inspected, the load P exerted to that peripheral portion is between dozens of kg and 100 kg, and the Z shaft guide 2 leans to one side, due to the insufficient rigidity of the Z shaft guide. As a result, the chuck top slants, with the Z shaft-driving mechanism 4 as a center of the slanting movement, as indicated by the broken lines in FIG. 5. If this occurs, the object and the probe card are not brought into uniform contact with each other. Since there are some contact terminals that fail to come into contact with the probe card, the reliability of the inspection is degraded.
Due to the above-noted load exerted during inspection, the Z shaft 2 may move through the Z shaft guide 3 in a slanted state. If this happens, the Z shaft guide 3 is damaged.
To prevent the chuck top from slanting, it may be thought to employ a long Z shaft guide 3 or to increase the number of balls. These measures, however, do not solve the problem stemming from the insufficient rigidity of the guide shaft 3.
As shown in FIG. 6, it is possible to employ a Z shaft 2A having a large diameter. As shown in FIG. 7, it is also possible to employ a plurality of Z shafts 2B. The former method is useful in improving the rigidity of the Z axis 2A, and the latter method is useful in reducing to the load applied to one Z shaft. Even if these measures are taken, however, the chuck top 1 is exerted with an offset load whose center lies in the vertical driving mechanism 4. This means that the above measures are insufficient to solve the slanting of the chuck top 1. In addition, the inspection stage and the inspection apparatus are inevitably large in size.
The present invention has been developed in consideration of the above problems.
Accordingly, an object of the present invention is to prevent a chuck top from being slanted even if the number of contact terminals provided for a probe card is large, and the number of objects to be examined at a time is large, accordingly. The present invention is therefore intended to provide an inspection stage and an inspection apparatus that ensures high inspection reliability.
According to one aspect of the present invention, there is provided an inspection stage comprising:
a main chuck on which an object to be examined is mounted;
a support table for supporting the main chuck;
a support table lift mechanism including a plurality of Z shafts for supporting the support table, and a Z shaft vertical drive mechanism for vertically driving the Z shafts;
an X stage on which the support table lift mechanism is mounted and which is movable in an X direction; and
a Y stage which supports the X stage and being movable in a Y direction.
In the inspection stage, it is preferable that the support table lift mechanism include a vertical position control device for controlling vertical positions of the Z shafts individually.
In the inspection stage, it is also preferable that the support table lift mechanism be located on an outer side of the main chuck.
In the inspection stage, it is further preferable that the vertical position control device include a slant detection mechanism 27 for detecting the degree of horizontality of the support table. On the basis of the degree of horizontality of the support table detected by the slant detection means, the vertical position control device controls the vertical positions of the Z shaft so as to keep the degree of horizontality of the support table within a predetermined range.
According to another aspect of the present invention, there is provided an inspection apparatus comprising:
a loader chamber in which a plurality of objects to be examined are received;
a prober chamber for inspecting the objects fed from the loader chamber; and
an inspection stage arranged inside the prober chamber,
the inspecting stage including:
a main chuck on which an object to be examined is mounted;
a support table for supporting the main chuck;
a support table lift mechanism including a plurality of Z shafts for supporting the support table, and a Z shaft vertical drive mechanism for vertically driving the Z shafts;
an X stage on which the support table lift mechanism is mounted and which is movable in an X direction; and
a Y stage which supports the X stage and being movable in a Y direction.
In the inspection stage, it is preferable that the support table lift mechanism include a vertical position control device for controlling vertical positions of the Z shafts individually.
In the inspection stage, it is further preferable that the vertical position control device include a slant detection mechanism 27 for detecting horizontality of the support table. On the basis of the degree of horizontality of the support table detected by the slant detection means, the vertical position control device controls the vertical positions of the Z shaft so as to keep the degree of horizontality of the support table within a predetermined range.
According to the third aspect of the present invention, there is provided an inspection stage comprising:
a main chuck on which an object to be examined is mounted;
a support table for supporting the main chuck;
a support table lift mechanism including three Z shafts for supporting the support table, a Z shaft vertical drive mechanism for vertically driving each of the Z shafts, and a vertical position control device for controlling the vertical position of each Z shaft, the vertical position control device having a linear sensor for detecting a position of the support table, and another linear sensor for detecting the degree of horizontality of the support table;
an X stage on which the support table lift mechanism is mounted and which is movable in an X direction; and
a Y stage which supports the X stage and being movable in a Y direction.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

Inspection stage including a plurality of Z shafts, and inspection apparatus


A system is provided with an ultrasonic flow meter. The ultrasonic flow meter includes a first ultrasonic transducer disposed about a fluid flow path, and a pressure balancing system configured to pressure balance the first ultrasonic transducer relative to a fluid flow along the fluid flow path.

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Wells are often used to access resources below the surface of the earth. For instance, oil, natural gas, and water are often extracted via a well. Some wells are used to inject materials below the surface of the earth, e.g., to sequester carbon dioxide, to store natural gas for later use, or to inject steam or other substances near an oil well to enhance recovery. Due to the value of these subsurface resources, wells are often drilled at great expense, and great care is typically taken to extend their useful life.
Chemical-injection management systems are often used to maintain a well and/or enhance throughput of a well. For example, chemical-injection management systems are used to inject corrosion-inhibiting materials, foam-inhibiting materials, wax-inhibiting materials, and/or antifreeze to extend the life of a well or increase the rate at which resources are extracted from a well. Typically, these materials are injected into the well in a controlled manner over a period of time by the chemical-injection management system using a flow meter. Unfortunately, existing flow meters are unable to provide accurate measurements at high pressures and low flow rates.

Ultrasonic flowmeter having pressure balancing system for high pressure operation


An object information acquisition apparatus comprises an irradiating unit configured to irradiate an object with light; a plurality of detecting units configured to receive an elastic wave generated within the object irradiated with light, and convert the elastic wave to a received signal; a distribution acquiring unit configured to acquire a light intensity distribution within the object irradiated with light; a setting unit configured to select a minimum block unit in which light intensity is greater than or equal to a predetermined threshold value, using the light intensity distribution; and a generating unit configured to generate object information of the minimum block unit selected by the setting unit, using the received signal.

Field of the Invention
The present invention relates to an object information acquisition apparatus.
Description of the Related Art
As one in vivo imaging technique using near-infrared light, there is photoacoustic tomography (PAT). In PAT, an object such as a biological body is irradiated with pulsed light generated from a light source, whereby light propagated and diffused within the object is absorbed by a light absorber to generate an elastic wave. This mechanism of elastic wave generation is called a photoacoustic effect. Since a tumor has a higher light energy absorption rate for near-infrared light than surrounding tissues, the tumor absorbs more light than the surrounding tissues. Thus, the tumor momentarily expands and generates an elastic wave.
In an apparatus described in Japanese Patent Application Laid-open No. 2011-245277, the elastic wave is detected with a detection element and converted to a received signal. Through signal processing (reconstruction) of the received signal, object information such as the space distribution of initial sound pressure of the elastic wave generated upon absorption of light energy within the object can be imaged. Since the space distribution of generated sound pressure relates to the absorption coefficient of light, diagnosis of an object using space distribution relating to the absorption coefficient of light has been studied.

Object information acquisition apparatus


A high density image sensor capable of higher resolution reading is realized by laminating layers on the photodiodes of the image sensor to allow additional capacitors to form therein in a vertically overlapping relation with the photodiodes. Each photodiode is formed on a substrate and includes a lower electrode, a photoelectric conversion layer, and a transparent electrode. The capacitors form where a transparent insulating layer and a transparent conductive layer are sequentially formed on the transparent electrode of the photodiode. The photodiode and the capacitors are electrically connected in parallel. The capacitors, one of which is outside the photodiode, do not enlarge the photodiode or affect the photo-/dark current ratio of the image sensor, thus enhancing the density of the image sensor and its resolution.

A conventional facsimile machines or the like uses an image sensor as an optical reader of original images. The image sensor generally includes a plurality of photodiodes aligned along the width of the original, each of the photodiodes having a semiconductor layer of an amorphous material or the like interposed between a pair of electrodes.
The conventional image sensor is illustrated in FIG. 10 in a cross-sectional view, and has a laminated configuration including an insulating substrate 1 of, for example, glass or ceramics, a lower electrode 2 of chromium (Cr), a semiconductor photoelectric conversion layer 3 of amorphous silicon hydride or the like, and a transparent electrode 4 of indium tin oxide. A light emitting device (not shown) emits light, which is reflected by the original document, etc. (not shown), passes through the rod lens array (not shown) such as SelFoc lens manufactured by Japan Sheet Glass Co. Ltd, and is finally focussed on the photoelectric conversion layer 3 through the transparent electrode 4.
The thus-configured image sensor usually uses as image information the electric charge generated by light incident on the photoelectric conversion layer 3, instead of using the photocurrents resulting from the light, since the light illuminating the photoelectric conversion layer 3 is approximately 100 lux in the usual optical mechanism mentioned above. Light of this intensity generates photocurrents of approximately 1 nA, which are too small to detect. The image sensor therefore is usually operated using a charge-reading method, in which the electric charge generated in the photoelectric conversion layer 3 is stored in a first storage element such as a capacitor. The stored charge is then transferred, using switching elements such as thin-film transistors, to a second storage element, such as a capacitor, then read out as an electric signal.
This charge-reading method will be now described in detail with reference to FIG. 11, which shows an equivalent circuit diagram of a portion of the conventional image sensor corresponding to one picture element. Each photoreceptor element, which corresponds to one picture element, may be regarded as equivalent to a photodiode PD and a series-connected capacitor CPD. In operation, the photodiode PD is first reverse-biased at +5 V, and then illuminated to cause a photocurrent flow in the photoelectric conversion layer, which is stored as an electric charge in the capacitor CPD. In response to the energization of an associated field effect transistor T, the stored charge is transferred to a floating capacitor CL in an associated wiring conductor at the bottom of the figure. An external amplifier l then amplifies the transferred charge and outputs an electric signal. After the electric signal is output, a resetting analog switch S resets the circuit.
The above image sensor suffers from the following problems. The capacitance of capacitor CPD of the image sensor is relatively small and generally insufficient. This limited capacitance deteriorates the linearity of the proportional relationship between the exposure (=illumination intensity.times.time) and the output voltage of the image sensor. Insufficient capacitance coincident with poor photo-/dark current ratio cause poor gradation in the electric signal.
In Japanese Patent Laid Open No. SHO. 61-82570 (1986), an image sensor is disclosed which has the capacitance of its capacitor increased by extending the photoelectric conversion layer in the slow scan direction so as to enlarge the portion of the photoelectric conversion layer interposed between the lower electrode and the upper electrode. The photoreceptive area of the image sensor is limited by shielding.
This image sensor, which is illustrated in FIG. 12 in cross-sectional view and in FIG. 13 in perspective view, includes a plurality of photoreceptor elements aligned on a substrate 1 in the fast scan direction. The respective electrodes 5 of the photoreceptor elements extend in the slow scan direction from the tops of the photoreceptor elements to a shift register to introduce the electric charge generated in the photoreceptor elements to the shift register.
Each of the photoreceptor elements has a laminated configuration, including an insulating substrate 1, a lower electrode 2 as a common electrode and formed of chromium (Cr), a photoelectric conversion layer 3 of amorphous silicon hydride or the like extending in the slow scan direction such that a relatively wide portion of the photoelectric conversion layer 3 overlaps with the lower electrode 2, a transparent electrode 4 of indium tin oxide formed over the photoelectric conversion layer 3, and an extracting electrode 5 of chromium partially covering the transparent electrode 4 so as to define the photoreceptive area.
The above configuration creates two capacitors CPD1 and CPD2. Capacitor CPD1 is formed by the lower electrode 2 and the transparent electrode 4, and CPD2 is formed by the lower electrode 2 and the extracting electrode 5, as shown in FIG. 14 of an equivalent circuit diagram of the photoreceptor element. The photoreceptor element having capacitors with increased capacitance can store more electric charge, improving the linearity of the proportional relationship between the exposure and the output voltage of the image sensor.
However, this conventional image sensor shown in FIGS. 12, 13 and 14 has a relatively poor photo-/dark current ratio. By enlarging the photoelectric conversion layer 3 to increase the capacitance of the capacitors, the dark currents in the photoelectric conversion layer 3 are increased, resulting in a lower photo-/dark current ratio.

Multi-capacitance photodiode image sensor


Generally, the embodiments presented are directed to circuits and methods for triggering an event at a fraction of a clock cycle. A triggering circuit can comprise two or more input circuits that output an event signal. The event signal is received by one of two or more delay circuits that trigger the event signal at a predetermined phase of the clock cycle by moving the event signal from a first clock domain to another clock domain. By triggering the event at a phase division, the triggering circuit outputs signals at a rate faster than the clock cycle.

In many electronic devices, logic functions are often performed by an integrated circuit specially designed and made for the particular device. Generally there are two types of custom integrated circuits, an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA). ASICs provide a generally fast processor with clock speeds that may exceed 1 GHz. Unfortunately, ASICs and the engineering effort required to design and produce the ASIC can be cost prohibitive.
Designers often use FPGAs to reduce the cost of electronic devices. However, FPGAs operate at 500 MHz, which is much slower than ASICs, and do not work well in applications that require the higher clock speeds of ASICs.

Triggering events at fractions of a clock cycle


A push-button switch of simple structure and highly reliable operation capable of safely stopping equipment even when the push button of the push-button switch fails to return to its normal position while the push-button switch for operating equipment is being operated. And a push-button switch device capable of easily judging the presence or not of any failure of the push-button switch for operating the equipment by using that push-button switch. In a pushbutton switch in which the push button is provided, in a way to be available for pressing down in resistance to a spring for returning the push button, on a breaker plate provided with a fixed contact for an operating circuit and a fixed contact for a verification circuit, the push button is composed of push button body and auxiliary push button body slidably disposed against the push button body, the push button body is provided with a mobile contact for the operating circuit and the auxiliary push button body is provided with a mobile contact for the verification circuit respectively, and the push button body is urged in the returning direction with a spring for returning the push button body.

The present invention relates to a push-button switch of simple structure and highly reliable operation and a push-button switch device using such a push-button switch.
Conventionally, in a push-button switch device such as a pendant push-button switch device, used for a hoist crane, for example, a push-button switch is provided, in addition to a contact for an operating circuit for operating equipment (Contact A), with a contact for a verification circuit for verifying the state of return of the push-button switch, for example, the open state of the contact for the operating circuit at the time of closing of power, (Contact B). Note, for example, Japanese Utility Model Publication No. 52-53374.
This push-button switch is constructed in such a way that, by being incorporated in a push-button switch device provided with a sequence circuit consisting of operating circuit 7 and verification circuit 8, as shown in FIG. 12, for example, the main electromagnetic contactor MCO is not turned ON even if the power closing switch PB1 is operated in the state where the push button of the push-button switch does not release for reasons of failure of the push-button switch. It is believed that most incidents due to biting of dust (hereinafter referred to simply as "failure of the push-button switch" in the state where at least one of the contacts for the operating circuit is closed. In this case, the contact for the verification circuit corresponding to the closed contact for the operating contact is in the open state.
It is believed that most incidents of the push button of a push-button switch not releasing is believed to be produced more often because of a breaking of the spring for returning of the push button, or locking of the push button as a result of biting of dust in the sliding part of the push button, when the push button of a push-button switch for operating equipment is released from the pressed state, rather than when the push-button switch is out of operation.
However, in the case of a push-button switch device incorporating the conventional push-button switch, because the contact for the operating circuit remains closed when the pressed push button of a push-button switch cannot return when the push-button switch is being operated for operating equipment, (in other words, in the state where the main electromagnetic contactor MCO is turned ON), it is necessary for the operator to operate the switch PB2 for shutting off the power source to stop the equipment. However, in a pendant push-button switch device used for a hoist crane, for example, the operator cannot fully follow the movement of the pendant push-button switch device because the pendant push-button switch device moves together with the hoist crane and therefore cannot manage to operate the switch PB2 for shutting off the power source, thus presenting a risk of reckless use of the hoist crane without any means for preventing such eventuality. For that reason, a push-button switch device incorporating conventional push-button switches could not always fully achieve the purposes of raising the reliability of push-button switch operation and improving the safety of operation of the equipment as originally intended to.
Moreover, in the case of a push-button switch device provided with a conventional sequence circuit consisting of an operating circuit 7 and verification circuit 8, as shown in FIG. 12, there was a problem that the presence or not of any failure of the push-button switch for operating the equipment cannot be judged unless either the main electromagnetic contactor MCO is not turned ON even if the switch PBI for closing power is operated or the equipment does not stop even when the push button of the push-button switch for operating the equipment is released from the pressed state.

Push button switch assembly with interlocking element


The invention is a liquid toner developer for a laser printer. There is an open bath of liquid toner about 50 microns below a moving outer bottom photoconductor surface energized by actinic light. Immediately downstream of the liquid bath and adjacent to it is a charged, reverse direction developer roller, also about 50 microns below the photoconductor surface. Downstream of the developer roller, and in relatively close spaced-apart relationship from it, is a same direction rigidizing/squeegee roller charged about the same as the developer roller. A blade lies close to or in contact with the rigidizing/squeegee roller slightly upstream of its nip point to provide a drain path along the length of the roller to aid excess toner removal from the roller. A common wiping means cleans both the developer and the rigidizing/squeegee rollers, and directs excess toner into a recycle system to save toner supply and replenish the bath of liquid toner. The image on the photoconductor surface leaving the developer system is very dry, and suitable for direct transfer to a sheet of paper. In a preferred embodiment, a series of the developer systems with different color toners are employed to create a multi-color image on the paper.

1. Technical Field
This invention relates generally to image transfer technology, and more specifically to electrophotography. I have invented a laser printer developer which may be used to produce multi-color images with liquid toners.
2. Background Art
In electrophotography, a latent image is created on the surface of an insulating, photo-conducting material by selectively exposing areas of the surface to light. A difference in electrostatic charge density is created between the areas on the surface exposed and unexposed to light. The visible image is developed by electrostatic toners containing pigment components dispersed in an insulating carrier liquid. The toners are selectively attracted to the photoconductor surface either exposed or unexposed to light, depending on the relative electrostatic charges of the photoconductor surface, development electrode and the toner. The photoconductor may be either positively or negatively charged, and the toner system similarly may contain negatively or positively charged particles. For laser printers, the preferred embodiment is that the photoconductor and toner have the same polarity.
A sheet of paper or intermediate transfer medium is given an electrostatic charge opposite that of the toner and passed closed to the photoconductor surface, pulling the toner from the photoconductor surface onto the paper or intermediate medium still in the pattern of the image developed from the photoconductor surface. Thermal energy may also be used to assist transfer of the image to paper or intermediate transfer medium. A set of fuser rollers melts and fixes the toner in the paper, for the case where no thermal transfer is used, subsequent to direct transfer or indirect transfer when using an intermediate transfer medium, producing the printed image.
There is a demand in the laser printer industry for multi-colored images. Responding to this demand, designers have turned to liquid toners, with pigment components and thermoplastic components dispersed in a liquid carrier medium, usually aliphatic hydrocarbon liquids. With liquid toners, it has been discovered, the basic printing colors--yellow, magenta, cyan and black, may be applied sequentially to a photoconductor surface, and from there to a sheet of paper or intermediate medium to produce a multi-colored image.
With liquid toners, however, there is a need to remove the liquid carrier medium from the photoconductor surface after the toner has been applied to it. This way, the photoconductor surface will not transfer the liquid carrier to the paper or to the intermediate medium in the image transfer step(s). Also, this way the liquid carrier may be recovered for recycle and reuse in the developer system, providing economy in terms of printing supplies, and eliminating environmental and health concerns from disposal of excess liquid carrier medium.
It is known from U.S. Pat. No. 3,955,533 to employ a reverse direction roller spaced about 50 microns (about 0.002 inches) from the photoconductor surface to shear off the carrier liquid and excess pigmented solids in the region beyond the outer edge of the image to leave relatively clean background areas on the photoconductor surface.
Also, from U.S. Pat. No. 3,957,016, it is known in a negative toner system to use a positive biased reverse roller maintained at a voltage intermediate the image and background voltages to help clean the background and compact the image on the photoconductor surface.
Also, from U.S. Pat. No. 4,286,039, it is known in a positive toner system to use a reverse roller followed by a negatively biased squeegee roller. The squeegee roller both compacts the latent image and removes excess carrier liquid.
U.S. Pat. Nos. 4,974,027 and 4,999,677 disclose a positively biased reverse roller followed by a negatively biased rigidizing roller followed by a squeegee roller, separate from the rigidizing roller, for removing excess carrier liquid from the image after rigidization. The charge on these rollers may be reversed if the charge on the toner is reversed. In these two patents, an intermediate transfer drum is downstream of the rigidizing roller for receiving the toner image from the photoconductor surface and transferring the image to a sheet of paper.
There is a need in the electrophotography industry then, for a liquid toner developer which provides a rigid latent image leaving the developer unit which is very dry and suitable for direct contact with the paper or intermediate transfer medium onto which the image will be transferred. Also, there is a need for a developer in which the developer roller and rigidizing or squeegee roller are in close proximity to provide a compact developer unit and to minimize any effect of electrostatic charge loss of the toner on the photoconductive surface between the two rollers. Also, there is a need to provide a liquid toner drain path along the length of the rigidizing/squeegee roller to aid excess toner removal from the roller. Also, there is a need for a developer in which the developer roller and rigidizing or squeegee roller are cleaned continuously of residual toner by a common cleaning means which is in contact with both the developer roller and the rigidizing or squeegee roller. Also, there is a need, if the common cleaning means above is a foam roller, for a squeeze rod/roller in contact with the foam roller for removal of toner and carrier liquid from it.

Liquid electrophotographic printer developer


A manufacturing process including a quality control procedure for verifying the completion of forming processes, heat treating and chemically treating parts. Sheet formed blanks, tubular blanks, extrusions and casting are traced through a manufacturing process from the time the parts are received. Metallurgical data relating to parts as received is recorded and marked on the parts. Forming data, heat treating data and chemical treating data may also be recorded by scanning and marking parts throughout the manufacturing process.

There is substantial interest in reducing the weight of parts used to manufacture vehicles such as automobiles, trucks, airplanes and boats for the purpose of improving fuel economy. One approach to reducing the weight of parts is to use light weight/high strength aluminum alloys to manufacture parts. The yield strength of parts made of some aluminum alloys may be increased by aging the parts over a substantial period of time. Waiting for natural aging to occur is generally not economical feasible in manufacturing processes due to the long period of time required to strengthen the parts.
Aging may be accelerated by heating the parts in a process referred to as "artificial aging." For example, parts made of AA6xxx series aluminum may be artificially aged by heating the parts, for example to 225° C. for a period of 30 minutes to double the yield strength of the parts. After heating, the parts are cooled and may be chemically treated by applying a conversion coating and/or removal of oxidation from the surface of the parts in preparation for painting.
Parts made of aluminum alloys may be pre-formed in bending operations and hydro-forming operations. After forming, the parts may be trimmed, punched and de-burred before artificial aging to increase the yield strength. The parts are more malleable before artificial aging and easier to bend, hydro-form, cut and trim.
One problem with artificial aging is that it is impossible to determine by visual inspection whether the parts were subjected to the artificial aging process. A second problem is that raw material may have an age limit after which it cannot be reliably processed into a quality part. A tensile test may be used to verify the yield stress of a part but a tensile test is destructive to the part. While a hardness test could be used to test for artificial aging, hardness test results may not be an accurate predictor of yield stress, is time consuming, and adds expense to the manufacturing process.
Structural beams, such as pillars, roof rails, frame parts, and the like once assembled to a vehicle may be located in inaccessible areas that cannot be readily checked for yield strength. These types of structural parts may be in areas of the vehicle that are tested for crashworthiness such as bumper structures, passenger compartment beams and pillars, roof supports and the like. The yield strength of such parts may be critical to vehicle durability and/or vehicle quality. If it is determined that such structural parts lack the specified strength characteristics after the fact, replacing the parts is not easily accomplished and may result in scrapping the entire vehicle.
This disclosure is directed to solving the above problems and other problems as summarized below.

Process control for post-form heat treating parts for an assembly operation