Disclosed is a communication mechanism among hardware, firmware and system software in order to redirect interrupts or other hardware events to only one thread execution context of an error domain for a multi-threaded processing system. Other embodiments are also described and claimed.

1. Technical Field
The present disclosure relates generally to information processing systems and, more specifically, to error handling in processor systems.
2. Background Art
Error handling in computer systems involve error detection and error recovery. In error recovery, errors should be contained and computer systems should be highly available. Computer systems utilizing error handling that is coordinated among processors, system logic hardware, firmware and operating system can contain errors and reduce the time computer systems are not available. Additionally, the processor(s), system logic hardware, firmware and operating system should have interfaces to one another to allow coordination between them during error handling.
System software is defined herein as any code, including firmware code, that is executed in a privileged mode, such as any code that runs at ring 0 privilege level. This definition of system software is intended to include the firmware and operating system (OS) kernel that is executed by a single CPU in a single processor system, or is executed by a plurality of CPUs in a multi-processor system. Thus, system software may include firmware, such as PAL and SAL code (discussed below), as well as operating system kernel software code.
Firmware as used herein refers to code routines that are stored in non-volatile memory structures such as read only memories (ROMs), flash memories, and the like. These memory structures preserve the code stored in them even when power is shut off. Even though firmware is stored in non-volatile memory, firmware may be copied or shadowed to volatile memory. Typically, this is done for performance reasons.
One of the principal uses of traditional firmware is to provide necessary instructions or routines that control a computer system when it is powered up from a shut down state, before volatile memory structures have been tested and configured. Firmware routines may also be used to reinitialize or reconfigure the computer system following various hardware events and to handle certain platform events like system interrupts.
Another typical use of traditional firmware is to provide complex sequences to be performed in processors that utilize complex instruction sets. A typical instruction in a CISC (complex instruction set computer) computer processor performs a series of operations, with microinstructions that define some of the more complex operations being encoded in a non-volatile storage area in the form of microcode. The microcode defines all or a portion of the executable instruction set for the processor, and may also define internal operations that are not implemented in software-accessible code. The microcode is typically placed in a read-only memory (ROM) within the processor at the time the processor is manufactured.
Operating systems (OS) interact with firmware to provide an environment in which applications can be executed by the CPU. By utilizing firmware, an OS can be designed to run on many different processing systems without re-writing the OS for each variation in platforms. For at least one embodiment, the term operating system, as used herein, is intended to broadly encompass any privileged software layer that performs scheduling, including a scheduling layer that is distributed over a cluster of platforms.

Method and apparatus for redirection of machine check interrupts in multithreaded systems


A dynamic multiple input rail switching unit includes a plurality of DC input voltage rails and a rail switching section coupled to the plurality of DC input voltage rails that is configured to individually connect selected ones of the plurality of DC input voltage rails to a switched rail output. The dynamic multiple input rail switching unit also includes a rail selection section that is coupled to the rail switching section and configured to dynamically choose the selected ones by balancing rail supply currents from the plurality of DC input voltage rails based on rail supply current capacity margins and a switched rail output current. A dynamic multiple input rail switching unit operating method, and a dynamic multiple input rail power converter are also provided.

Input power balancing of applications employing multiple input rails is typically very challenging. This situation is very common in PCIe boards that provide more that 75 watts of power and devices with redundant power supplies, such as servers. Currently, common approaches for load balancing are typically based on linear solutions, intermediate switched mode power supply (SMPS) converters or statically assigned current or power sharing. These solutions either incur power loss or do not allow the load sharing to be changed at run time. Improvements in this area would prove beneficial to the art.

Input rail dynamic power balancing and merging


A sheet handling apparatus comprises: a stacking mechanism to stack sheets of one or more printable media as a sheaf; a sheet conveyance mechanism to transport the sheaf to a respective position; a stapling mechanism to perform a stapling operation with respect to the sheaf; and a plurality of sheet regulating mechanisms disposed at positions spaced from each other along a sheet conveyance path, each sheet regulating mechanism being operable to align ends of the sheets in the sheaf according to a sheet conveyance direction. An image forming apparatus comprises such a sheet handling apparatus and an image forming device to form respective images upon the sheets and to provide the sheets to the sheet handling apparatus.

In recent years, there are various kinds of demands associated with sheet processing of documents output from image forming apparatuses such as a copier, a facsimile, a printer and so forth. Among such demands, in addition to the side stapling, there is a growing demand for saddle stitching in which a plurality of locations of the sheet, generally two locations, are stapled down at a given interval along a centerline dividing the sheet into half. When performing saddle stitching compared with the side stapling, a sheet conveyance distance will vary depending on the size of the sheet, as the sheet is transported to the position at which the saddle stitching is performed.
Related arts associated with the saddle stitching proposed in Japanese Patent Laid-Open Application Publications, No. 2002-128383 and No. 2004-292163, for example, are known. According to Japanese Patent Laid-Open Application Publications, No. 2002-128383 and No. 2004-292163, a rear end portion of a sheaf of paper in a conveyance direction stacked on a stacking mechanism is aligned by a rear-end plate, and subsequently, the rear-end plate retracts from the conveyance path so that the sheaf of paper is transported to a position at which the side stapling or the saddle stitching is performed. When the sheaf of paper reaches the stapling position, the conveyance operation is stopped, and a stapling operation is carried out.
According to the related arts, the end portion of the paper sheaf in the conveyance direction stacked on the stacking mechanism is in contact with the rear-end plate so that the paper sheaf in the sheet conveyance direction is aligned. At this time, the position of the rear-end plate is already fixed. Then, the rear-end plate is moved forward, i.e., away from the fixed position. As may be understood from the related arts, only a single rear-end plate is provided. Consequently, when large size paper such as A3 paper or Double Letter Size (DLT) is stacked on the stacking mechanism, the distance at which the paper sheaf conveyance mechanism carries the sheet so as to perform saddle stitch will be extended. As a result, the center portion of the paper sheaf projects causing the sheet to be misaligned during the transfer of the paper sheaf, or the positioning accuracy of the position of the saddle stitching is deteriorated due to variations in the conveyance amount of the paper sheaf, environment and so forth.

Sheet handling apparatus capable of effectively performing sheet processing, and an image forming apparatus using the same


A motorcycle exhaust system, which can prevent the generation of noise by vibrations and interference of an exhaust pipe heat insulating cover and a muffler heat insulating cover for protecting exhaust pipes and a muffler. Exhaust pipes and a muffler are protected by an exhaust pipe heat insulating cover and a muffler heat insulating cover, and confronting ends of the covers and are joined via an elastic member.

1. Field of the Invention
The present invention relates to a covering unit for a motorcycle exhaust system comprising exhaust pipes connected to an engine mounted on a body frame of a motorcycle and extending rearwardly. A muffler is mounted on the with rear end of the exhaust pipes.
2. Description of Background Art
In a motorcycle including exhaust pipes extending to an exhaust port and mufflers, the exhaust pipes are usually protected by a heat insulating cover in order to provide insulation from hot exhaust gases. See Japanese Utility Model Publications No. Sho. 63-32895 and No. Hei 311371.
In order to promote heat insulation of the foregoing covering unit, it is conceivable to protect the exhaust pipes and the muffler of the motorcycle with separate heat insulating covers. The heat insulating cover for the exhaust pipes and that for the muffler are different in size, shape, etc. It is very difficult to join such insulating covers by welding a tightening band or the like in order to make them integral. Therefore, it is inevitable that confronting ends of the heat insulating covers are not joined and remain free.
Usually, the foregoing heat insulating covers are made of thin heat resisting plates. Therefore, when vibrations caused by the operation of the engine or running of the motorcycle are transmitted to the heat insulating covers, beat noise will be generated at the free ends of the heat insulating covers. Further, the free ends of the heat insulating covers will interfere with each other and generate interference noise. Both the beat noise and interference noise will increase traffic noise. In order to overcome this problem, it is necessary to reinforce the heat insulating covers, which may increase their weight and cost. This is a further problem to be solved.

Covering unit for motorcycle exhaust system


An implement linkage for an excavator, backhoe, or like apparatus is provided wherein the speed and force (speed/force) characteristics of the linkage, and the implement connected thereto, are selectively variable by an end-user depending upon the task to be performed with the implement.

The present invention relates generally to an improved linkage adapted for operatively connecting buckets and other implements to an arm of an excavator or like apparatus. In particular, the present invention relates to an improved implement linkage for an excavator that is adapted for being adjusted to improve digging efficiency by varying the speed and force characteristics of the linkage as desired depending upon the particular task to be performed. For ease of understanding the invention, it will be described with particular reference to excavators and the connection of a bucket implement to the arm of the excavator. Of course, those of ordinary skill in the art will appreciate that the invention has wider application and provides a speed/force adjustable linkage for connecting any implement to the boom or arm of any apparatus such as a backhoe, tractor, or the like.
Excavators are well known and widely used in various industries. Typically, such excavators include a boom extending from a base of the excavator to an outwardly and upwardly extending distal end, at which end an arm (or xe2x80x9cdipper stickxe2x80x9d) is attached. The arm pivots relative to the boom, and the distal end of the arm is adapted for operative securement of an implement thereto such as a shovel or bucket for removing and depositing earth or the like. Other industries, such as the materials handling industry, employ shears, grapples, magnets, and other such devices at the distal end of the arm. Regardless of the type of implement employed at the end of the arm, it will be understood by those skilled in the art that an excavator employs fluid cylinders and the like for raising and lowering the boom, the arm, for moving the implement relative to the arm, and for operating any mechanisms of the implement, itself.
In a most basic arrangement, the implements are manually pinned to the excavator arm and any associated fluid cylinders by way of a linkage assembly. Such operation necessarily requires manual removal and replacement of multiple pins to achieve the desired engagement. The removal and placement of such pins involves manually and hydraulically manipulating the heavy and cumbersome arm, a fluid cylinder, and/or the implement.
More recently, quick couplings have been developed and have enjoyed widespread commercial success. One suitable coupling is commercially available from JRB Company, Inc., Akron, Ohio under the trademark SLIDE-LOC(copyright). Such quick couplings are pinned to the distal end of the arm and, once in place, are adapted for selective connection to any of a wide variety of implements as desired in a convenient and secure manner. More particularly, these prior quick couplings include mechanisms for selectively mating with and retaining the pins of an associated attachment, often without requiring an operator of the excavator to leave the operator""s cab.
In either case, once the implement is connected to the arm of the excavator or other apparatus, the structural relationship between the implement cylinder and the implement (i.e., the implement linkage), itself, is fixed and may not be varied to change the speed and force characteristics of the linkage arrangement. Thus, with conventional implement linkages, exertion of a select force (F) on the implement link member results in a select amount of the force (X*F) being transferred to the implement, wherein the parameter (X) is fixed and cannot be varied. Likewise, movement of the implement cylinder with a select speed (V) results in movement of the implement, itself, at a speed (Y*V), wherein the parameter (Y) is fixed and cannot be varied. Thus, the speed/force characteristics of the linkage are fixed and are often sub-optimal for a particular task.
In practice, when excavating sand or other soft, easily displaced materials, it is desirable to excavate with more speed; however, less force is required. In contrast, if excavating clay, mud, or other packed, dense materials, more force is required, and speed is of less importance. Therefore, an excavator or other machine with a conventional, fixed implement linkage will be used inefficiently and in a manner that increases expenses for labor and equipment, and that also decreases project efficiency overall. Also, improper speed/force characteristics for a particular excavating or other task can unnecessarily strain fluid cylinders and other components.
In light of the foregoing specifically noted deficiencies and others associated with prior fixed implement linkages, a need has been identified for a new and improved implement linkage for an excavator or like apparatus wherein the speed and force characteristics of the linkage are adjustable by and end-user as desired based upon the task to be performed.
In accordance with the present invention, a novel and non-obvious implement linkage for an excavator, backhoe, or like apparatus is provided wherein the speed and force (speed/force) characteristics of the linkage, and the implement connected thereto, are selectively variable by an end-user depending upon the task to be performed with the implement.
One advantage of the present invention resides in the provision of an implement linkage for an excavator or like apparatus wherein the implement linkage is adjustable by an end-user in the field to vary the speed/force characteristics of the linkage and an implement operatively coupled thereto.
Another advantage of the present invention is found in the provision of a speed/force adjustable implement linkage for an excavator or the like that allows for convenient and rapid speed/force adjustments to be made to the linkage, without disconnecting the associated implement from the linkage.
Still another advantage of the present invention is the provision of a speed/force adjustable implement linkage for an excavator or the like that does not add significant weight to the arm or boom of the excavator or other unit to which the associated implement is connected, and that is usable without requiring any modifications to the bucket or other associated implement to be operatively coupled thereto.
Yet another advantage of the present invention resides in the provision of a speed/force adjustable implement linkage for an excavator or other apparatus that allows the excavator or other apparatus to be used with optimum efficiency.
A further advantage of the present invention is found in the provision of a speed/force adjustable implement linkage that minimizes undue strain on the fluid cylinders that operate the linkage and implement and on the linkage assembly, itself.
Still other benefits and advantages of the present invention will become apparent to those of ordinary skill in the art to which the invention pertains upon reading and understanding the following specification.

Speed/force adjustable implement linkage for an excavator


One embodiment described herein relates to a system for removing pollutants from a flue gas. The system includes a selective catalytic reduction (SCR) system having a SCR reactor containing a NOx reducing catalyst and one or more SCR protective devices. At least one of the SCR protective devices is connected to a rapping hammer system that actively remove fly ash collected on the SCR protective devices.

1. Field of the Invention
This invention relates to a device and method of cleaning protective screens used in a Selective Catalytic Reduction (SCR) system.
2. Description of the Related Art
Selective Catalytic Reduction (SCR) systems are increasingly being applied to coal-fired power stations to reduce nitrogen oxide (NOx) emissions. SCR systems commonly include a SCR reactor that contains a NOx reducing catalyst that converts NOx present in flue gases emitted from a combustion source into by-products of nitrogen and water. Many power station installations place the SCR reactor system in a "high dust" location between the combustion source and a particle collection system. Generally, these installations have ductwork that directs or diverts the particle-laden flue gases from the combustion source to the SCR reactor system and then to an air preheater.
The dust loading ability of these SCR systems, located in such "high dust" locations, is an important consideration in their design and use. In particular, the NOx reducing catalyst composition and construction thereof should be designed to withstand erosion and potential chemical degrading effects of the fly ash and other particles in the flue gases. Similarly, the ductwork to and from the SCR reactor system and the associated internal structures within the SCR system should be designed to withstand this erosive environment. For example, certain aspects of the ductwork design parameters, such as the duct's gas velocity, may be closely monitored to insure proper operation. In particular, undesirable operating results such as unwanted fly ash drop out should be prevented or minimized by selection of proper operating design parameters.
The NOx reducing catalyst construction in the SCR reactor also requires proper design considerations. Generally, the NOx reducing catalyst is constructed in a manner that has gas channels whereby the flue gases can pass through such channels to maximize contact with the catalyst surface thereby maximizing the reduction of NOx. The gas channels of the NOx reducing catalyst typically have a diameter in the range of about 5 to 7 mm. However, particles in the flue gas (hereinafter referred to as "fly ash") generally have a wide range of sizes (e.g. from 1-2 microns up to 7 mm and larger).
The larger particles of fly ash, sometimes referred to as "popcorn ash" or large particle ash ("LPA"), may pose problems with the NOx reducing catalyst. For instance, when the gas channel diameter is 5-7 mm and the fly ash particles are larger than 7 mm, the large fly ash particles may lodge within the channels and block the flow of flue gas through the catalyst. Even fly ash particles smaller than 7 mm have been shown to plug the catalyst channels because of the irregular shape of those particles. If just one irregular shaped fly ash particle gets lodged in the catalyst channels, other fly ash particles cannot pass through the channel, thereby blocking the channel.
This blockage decreases the overall NOx reduction capability of the system because once a gas channel is blocked, that reaction channel in the NOx reducing catalyst becomes ineffective. Once many reaction channels become blocked, fly ash accumulation on the NOx reducing catalyst surface increases rapidly. Over time, the surface of the NOx reducing catalyst can eventually become so covered with fly ash that the SCR system cannot meet its NOx reduction target. Also, the resulting increase in catalyst pressure drop will require the system to be cleaned. For SCR units without a gas bypass capability, this build-up may require the combustion source to be shut down as well.
A known practice to mitigate this ash or dust build-up over the NOx reducing catalyst has been to place one or more mesh screens over the NOx reducing catalyst. The openings in the mesh screens are selected to be slightly smaller than the diameters of the channels in the NOx reducing catalyst. Thus, large fly ash particles are stopped from entering the channels in the NOx reducing catalyst. While this method can keep the actual catalyst channels clean, its ability to lengthen the time between outages for cleaning is uncertain. Cleaning is still necessary for this method because the quantity of large fly ash particles entering the SCR reactor remains unchanged and these fly ash particles are now collected on the screens instead of on the catalyst or within its channels. Large fly ash particles may accumulate on the screens, thereby creating blockages which will then start collecting smaller fly ash particles. It is therefore possible to have mounds of fly ash on each screen.
Mounds of fly ash that are collected on the screens can significantly increase the pressure drop across the SCR system and may lead to localized areas of high velocity, which have been known to cause erosion within the catalyst. The accumulation of fly ash on the screens will also affect gas distribution and gas velocity into the NOx reducing catalyst. This in turn will reduce the efficiency of the SCR system.

Device and method for cleaning selective catalytic reduction protective devices


A disc cutting apparatus for cutting opposite surfaces of a disc-shaped workpiece such as a disc rotor for an automobile disc brake includes a rotating mechanism for positioning and rotating the workpiece which is pressed, under uniform pressure, radially inwardly by a plurality of holder mechanisms. While the workpiece is being rotated by the rotating mechanism and pressed by the pressing mechanism, the workpiece is cut by a cutting mechanism. The cutting mechanism includes cutters for cutting opposite surfaces of the workpiece, and the cutters are positionally adjusted with respect to the workpiece based on positional information detected by a detector which has a probe held against the workpiece.

1. Field of the Invention:
The present invention relates to a disc cutting apparatus for cutting at least one surface of a disc-shaped workpiece which is being rotated, while pressing an outer circumferential surface of the workpiece at a plurality of locations thereon with a plurality of holder mechanisms to preventing the workpiece from swinging in the circumferential direction thereof and also from being displaced in the axial direction thereof.
2. Description of Background Art:
Disk-shaped workpieces such as disc rotors for use in automobile disc brakes are required to have parallel and flat surfaces on the both sides. Attempts have been made to hold disc rotors parallel to cutters while cutting the disc rotors, but they have proven unsatisfactory.
Disc rotor cutting apparatus are disclosed in Japanese laid-open patent publications Nos. 62-218042 and 59-37002 and U.S. Pat. No. 4,266,454, for example.
According to Japanese laid-open patent publication No. 62-218042, a sleeve has a cylinder defined therein and a rod with a piston movably disposed in the cylinder, the sleeve and the rod being coaxially placed in a body. Stoppers for controlling the strokes of the sleeve and the rod are attached to an outer end of the body, and tool bits are mounted on the other outer end of the body for simultaneously cutting the opposite surfaces of a disc rotor.
According to Japanese laid-open patent publication No. 62-218042 or U.S. Pat. No. 4,266,454, two cutter bases are fitted over a main spindle and support respective tool bits thereon. The opposite surfaces of a disc rotor are simultaneously cut by the tool bits while the disc rotor is rotating between the tool bits.
In the conventional disc cutting apparatus, the center of the disc rotor is required to be fitted over the main spindle perpendicularly thereto when the disc rotor is rotated and cut by the tool bits. If the disc rotor were slightly tilted with respect to the main spindle, the circumferential edge of the disc rotor would periodically be displaced axially, i.e., rotate in a tortuous path, with resulting chattering of the disc rotor. Therefore, the opposite surfaces of the disc rotor would have a chatter mark and not be machined to a smooth finish.
Removal of such a chatter mark requires the opposite surfaces of the disc rotor to be machined again by the disc cutting apparatus. Therefore, the entire process of cutting the disc rotor is lengthy and complex, and the rate of production of disc rotors is relatively low.


Each of record information blocks in various modes is divided into predetermined information units each having a head indicator indicating a head of respective one of the predetermined information units. An information recording apparatus, to which the record information blocks are inputted in time sequence for each of the modes, is provided with: an emulation device for emulating the predetermined information units one after another; an indicator memory device for temporarily storing the head indicator in a current information unit, which is one of the predetermined information units and is currently emulated by the emulation device, for a time duration while the current information unit is emulated; an update device for updating the head indicator, each time when an emulation for the current information unit is completed by the emulation device; and an error judgment device for judging whether or not an error is generated during the emulation for the current information unit. The emulation device re-emulates the current information unit, which is indicated by the head indicator stored in the indicator memory device, by use of one emulation method, which corresponds to a mode of the record information block including the current information unit and is different from another emulation method which has been used hitherto by the emulation device, when the error is generated according to a judgment by the error judgment device.

1. Field of the Invention
The present invention relates to an information recording apparatus such as a printer apparatus, which receives a plurality of record information blocks in various modes to be emulated by different emulation methods from each other, emulates each of the received record information blocks and outputs the emulated record information blocks.
2. Description of the Related Art
There is an information recording apparatus such as a printer apparatus, which receives the record information outputted from an external processing device such as a computer, applies an appropriate emulation process to the received record information, and records the emulated record information onto a predetermined record sheet.
Incidentally, as a record information block outputted from the external processing device, there are a plurality of record information blocks in various modes, which require emulation processes for recording different from each other. As the modes for the record information blocks, for example, there are the Post Script (which is a registered trade mark owned by Adobe Systems Incorporated USA) mode (hereinbelow, it is referred to as a "PS mode") and the PCL (which is a registered trade mark owned by Hewlett Packard USA) mode and so on, which are known as the emulation process modes for the printers. These emulation process modes are different from each other by their programs etc. executed in the external processing devices. Therefore in the above mentioned information recording apparatus, the emulation process mode of the data is judged for each division of the data, and the emulation process mode is changed in case that the judged emulation process mode of the current division of the data is different from that of the previous division of the data, so as to process and output the data by the new mode, as explained in U.S. Pat. No. 4,968,159, U.S. Pat. No. 5,295,233, U.S. Pat. No. 5,306,102 and U.S. Pat. No. 5,467,432, for example.
Recently, one information recording apparatus is often commonly used for a plurality of external processing devices, or after executing different programs in one external processing device, the processed results of theses programs are often to be collectively recorded by one information recording apparatus. In other words, a plurality of record information blocks in various modes which require different emulation processes are often outputted continuously in time sequence with respect to one information recording apparatus.
However, in the above mentioned information recording apparatus, immediately after the record information block in the PS mode is inputted and the emulation process by the PS mode is executed with respect to this inputted record information block in the PS mode, if the record information block in the PCL mode is successively inputted after this record information block in the PS mode, the record information block in the PCL mode may not be precisely emulated or recorded depending upon the content of the record information block since the emulation process for the PS mode, which has been executed, may be performed with respect to the record information block in the PCL mode, which is a problem.

Information recording apparatus and program storage device readable by the apparatus having emulation processing with error recovery


A focal plane array detector in a sensor for IR imaging. Pixel readout and analog to digital conversion is performed in an integrated circuit which includes the imaging array. The charge of each pixel is accumulated in a capacitor (16) and a digital to analog charge converter cancels this charge. A controller controls this charge converter providing the appropriate amount of charge. An analog to digital converter incorporating a comparator (92) switches the controller on/off. In some embodiment a programmable device external to the sensor participates in the control of the analog to digital converter. In a typical embodiment of the invention a cycle generator controls the charge output of the digital to analog converter. In a preferred embodiment the analog to digital converters are grouped wherein all such converters group operate simultaneously.

Photonic detector devices respond to received photons by creating an electric effect which can be quantified and hence provide information as regards the flux of the received photons. Focal plane arrays (FPAs) of detectors are used to obtain images of objects, whereby each detector provides a pixel in is the image array. In the image, each pixel is provided with a unique address and a numeric value, which can further be used for manipulating the image for extracting information from the image.
Thermal Infra red (IR) FPAs are used for obtaining images in the thermal IR range. The resolution of an imaging array in the IR is limited by two factors, namely noise equivalent temperature (NET) and spatial noise, of the analog chain: the focal plane processor (FPP), the external analog circuitry and the analog to digital conversion. An external interference, such as RF interference or signals induced by the digital system may also degrade the performance. The temporal noise of the FPP can be reduced by careful design to be negligible relative to the signal noise, providing low NET values. Yet, to overcome the spatial noise, an external process of non uniformity correction (NUC) must be carried out. A "two point correction" process is generally used, assuming the analog chain to be linear and having stable offset and gain. The final results depend upon the validity of these assumptions, and the spatial resolution becomes a main restriction, limiting the dynamic range and requiring frequent calibrations. The FPP is kept at a steady temperature, e.g. at about 77° K while the external circuitry is exposed to wide temperature variations, degrading the gain and offset stability. Also, the FPP is relatively shielded against external interference, which is not the case with the external elements. In order to reach such a low temperature and keep it steady, the sensor is disposed within a cooled dewar. The dewar has electric connections installed in the walls, in order to facilitate electrical connection with external circuits.
Heat production is a matter of high importance in the design of FPPs. The efficiency of the cooling system being very low, the amount of power consumed by the circuits of the FPP at any time must also be limited. Sampling rates, sampling resolution, and output rates are factors which affect heat production. The use of components and combinations thereof having a low power consumption is favoured in the design of cooled FPPs. A trade-off between imaging parameters is a compromise often imposed for obtaining desirable image parameters. Accordingly, image frame rate at the expense of image resolution or image size are known in the art. Continuous attempts are made by various system designers to overcome the limitations described, striving to attain a high frame rate and a high resolution, with a reasonable power dissipation.
The value of the electric effect associated with each detector of the FPA is converted into a digital format, before it can be subjected to digital image processing. However, there are a number of critical reasons favouring conversion to digital format at an early stage as possible of the signal corresponding to each pixel. U.S. Pat. No. 5,886,659 discloses an on-focal plane analog to digital conversion application. Benefits of having the analog-to-digital conversion in the focal plane are discussed in that publication, the contents of which are incorporated herewith by reference.
Integrated converters have used several types of conversion schemes. Single-slope analog to digital conversion is a well-established technique. For example, U.S. Pat. No. 5,742,058 discloses an analog to digital conversion in the focal plane utilizing a single slope conversion cycle. The Dual-slope conversion provides better accuracy and stability (R. Van De Plassche, cited below). Yet, both techniques require quite long conversion times, being based on counters: the full-scale time of an n-bit single-slope converter is 2n*Tc, where Tc is the clock cycle time. The dual slope requires up to twice that time. The dual-ramp single-slope method, described by R. Van De Plassche in: INTEGRATED ANALOG TO DIGITAL AND DIGITAL TO ANALOG CONVERTERS, Kluwer Academic Press, pp. 274–289, 1994, the contents of which are incorporated herein by reference, promises both high resolution and reduced conversion time.
It is on the background hitherto described, that the present invention was conceived. The invention described below provides a basis for increasing the rate of sampling digitally at the FPP level, without compromising the resolution of each pixel.

Semi Conductor Devices (SCD) Partnership


An fan motor assembly for driving a fan of a gas boiler. The motor assembly has a core having a hollow portion at a center thereof, a coil assembly for magnetizing the core by applying an electric current to the core, a rotor rotatably disposed in the hollow portion of the core and having a rotating shaft including a first shaft which extends towards a fan so as to be coupled with the fan and a second shaft which extends opposite to the first shaft, a first cover attached to a front surface of the core and having a first bearing therein for rotatably supporting the first shaft of the rotating shaft, and a second cover attached to a rear surface of the core and formed at an inner portion thereof with a first recess for installing a second bearing for rotatably supporting the second shaft of the rotating shaft and a second recess for installing a printed circuit board on which a sensor for detecting revolutions per minute of the rotor is mounted. The motor assembly has a simple construction and can be easily assembled so that not only are the assembling steps and assembling time reduced, but also the manufacturing cost is saved.

1. Field of the Invention
The present invention relates to a gas boiler, and more particularly to a motor assembly for driving a fan of a gas boiler.
2. Description of the Prior Art
Generally, a gas boiler boils a fluid such as a water by burning a fuel such as a gas or an air and circulates the boiled fluid to raise the room temperature or to supply a hot water. The gas boiler system is widely used for the purpose of heating a room or a building. In the gas boiler system, the fluid is supplied from a fluid source into a fluid tank through a fluid inlet. The fluid supplied into the fluid tank circulates through a heating pipe via a fluid outlet and a heat exchanger by means of a circulation pump, thereby raising the temperature of a room in which the heating pipe is installed.
As is well known, in the gas boiler system, a gas is introduced into a combustion chamber through a manifold and a burner and is mixed with an air which is introduced into the combustion chamber from the exterior through an air inlet. The mixed gas and air is burned in the combustion chamber and the combustion gas thereof is exhausted into the exterior through an exhaust hood. In the above gas boiler system, the air is introduced into the combustion chamber by means of a fan rotated by a motor assembly.
FIG. 1 shows a conventional motor assembly 500 for rotating a fan installed in the gas boiler.
As shown in FIG. 1, motor assembly 500 has a hollow core 510 which is coupled to a coil assembly (not shown) and is magnetized when an electric current is applied to the coil assembly. Hollow core 510 has a hollow portion 512 in which a rotor 520 having a rotating shaft 520 is rotatably installed. A first end of rotating shaft 525 is coupled to a fan (not shown) so that the fan can be rotated together with rotor 520.
Rotor 520 rotates by an electromagnetic action created between rotor 520 and the coil assembly when the current is applied to the coil assembly. In order to allow rotor 520 to be easily rotated, rotor 520 does not make contact with an inner wall of hollow portion 512 when it is installed in hollow portion 512.
A first cover 530 having a first bearing 532 for rotatably supporting the first end of rotating shaft 520 is attached to a front surface of hollow core 510. In addition, a second cover 540 having a second bearing 542 for rotatably supporting the second end of rotating shaft 520 is attached to a rear surface of hollow core 510.
In order to fix motor assembly 500 to a fan casing 400, a motor fixing plate 410 is coupled to fan casing 400 by means of a pair of screws 412 and 414. Upper and lower projections 572 and 574 are coupled to upper and lower front portions of motor fixing plate 410 by means of a pair of screws 576 and 578, respectively. Motor assembly 500 is screw-coupled to upper and lower projections 572 and 574 so that motor assembly 500 can be suspended in the gas boiler.
On the other hand, a cap 550 is attached to a rear surface of second cover 540. The second end of rotating shaft 525 around which a magnetic ring 560 is disposed extends to an inside of cap 550 so that the second end of rotating shaft 525 is protected by cap 550. On the inside of cap 550, there is installed an HALL sensor 552 which makes the electromagnetic interaction with magnetic ring 560 in such a way to detect an R.P.M. of rotor 520.
In addition, a first elongated screw 582 is screwed into upper projection 572 passing through upper portions of cap 550, second cover 540, hollow core 510 and first cover 530. A second elongated screw 584 is screwed into lower projection 574 passing through lower portions of cap 550, second cover 540, hollow core 510 and first cover 530, so that the above elements are integrally coupled with each other.
In conventional motor assembly 500 having the above construction, when the electric current is applied to a coil of the coil assembly, core 510 is magnetized so that rotor 520 rotates. As rotor 520 rotates, the fan coupled to the first end of rotating shaft 525 also rotates so that the air flows into a combustion chamber of the gas boiler.
The air flowed into the combustion chamber is mixed with the gas. The mixed gas and air is burned by a burner and the combustion gas thereof is exhausted into the exterior through an exhaust port.
However, conventional motor assembly 500 needs to assemble to cap 550, second cover 540, hollow core 510, and first cover 530 by first and second elongated screws 582 and 584 after installing HALL sensor 552 in cap 550, so that assembling steps and assembling time are increased.
In addition, since conventional motor assembly 500 requires a separate element, such as cap 550 for installing HALL sensor 552 therein, the manufacturing cost of conventional motor assembly 500 is increased.

Motor assembly for driving a fan of a gas boiler


The method determines laser stability of an optical material, which is suitable for making an optical element through which high-energy light passes. The method includes pre-irradiation to produce radiation damage and measurement of the resulting induced non-intrinsic fluorescence. The method is distinguished by excitation of induced fluorescence immediately after pre-irradiation and after at least ten minutes after pre-irradiation with light of a wavelength between 350 and 810 nm, and measurement and quantitative evaluation of fluorescence intensities at wavelengths between 550 nm and 810 nm. Especially laser-stable optical materials, particularly CaF2 crystals, have a normalized difference (Z) of the fluorescence intensities measured at a first time immediately after pre-irradiation and at a second time at least ten minutes after the pre-irradiation, as calculated by the following equation (1):Z=(I2,λ1,λ2−I1,λ1,λ2)I2,λ1,λ2  (1),which is less than 0.3.

1. Field of the Invention
The present invention relates to a method of evaluating suitable optical material for making optical elements for high-energy radiation and to the use of the optical materials obtained by this method.
2. Description of the Related Art
It is known that materials from which optical elements are made absorb more or less of the light or radiation that passes through them, so that the intensity of the light and/or the radiation is generally less after passing through an optical element than before passing through it. It is also known that the extent of the absorption depends on the wavelength of the light. The absorption in optical systems, i.e. optically transparent systems, is kept as small as possible, because these systems should have a high light permeability or transmission, at least at their respective working wavelengths. The absorption is composed of absorption from material-specific components (intrinsic absorption) and those components, which are referred to as the so-called non-intrinsic components, such as inclusions, impurities, and/or crystal defects. While the intrinsic absorption is independent of the respective quality of the material, the additional non-intrinsic components of the absorption lead to a loss of quality of the optical material.
Energy that leads to heating is absorbed by the optical material both by intrinsic and also by non-intrinsic absorption. This sort of heating of the optical material has the disadvantage that the optical properties, such as the index of refraction, change, which leads to a change in the imaging behavior in an optical component used to beam formation, since the index of refraction not only depends on the wavelength of the light but also on the temperature of the optical material. Moreover heating of an optical component leads to a change of the lens geometry. This phenomenon produces a change of the lens focal point or to blurring of the image projected with the heated lens. This leads especially in photolithography, such as is used for making computer chips and electronic circuits, to a quality impairment or to an increase in the number of rejects. That is clearly undesirable.
Furthermore it has been shown that the absorption of the material increases with time with longer irradiation with high-energy light. This effect called radiation damage is composed of a more rapidly occurring reversible component and a slower irreversible component. In the case of the more rapid radiation damage a part of the absorbed radiation is not only converted into heat, but is output again in the form of fluorescence. The formation of fluorescence in an optical material, especially in optical crystals, is also known. For example, the production and measurement of laser-induced fluorescence (LIF) in quartz, especially in OH-rich quartz, is described in W. Triebel, Bark-Zollmann, C. Muehlig, et al, "Evaluation of Fused Silica for DUV Laser Applications by Short Time Diagnostics", Proceedings SPIE Vol. 4103, pp 1-11, 2000. Fluorescence and transmission properties of CaF2 are described in C. Muehlig, W. Triebel, Toepfer, et al, Proceedings SPIE Vol. 4932, pp. 458-466. The formation of optical absorption bands in a calcium fluoride crystal is described by M. Mizuguchi, et al, in J. Vac. Sci. Technol. A., Vol. 16, pp. 2052-3057 (1998). A time-resolved photoluminescence for diagnosis of laser damage in a calcium fluoride crystal is described by M. Mizuguchi, et al, in J. Opt. Soc. Am. B, Vol. 16, pp. 1153-1159, July 1999. The formation of photoluminescence-forming color centers by excitation with an ArF excimer laser at 193 nm is described there. However so that these sorts of measurements were possible, crystals with a relatively high impurity level were used, which are insufficient for the high requirements of photolithography. Furthermore the fluorescence measurement is performed during a time interval of 50 nsec and after the laser pulse has finished passing through the sample. It has now been shown that the fluorescence values so obtained may not be used for quality control or for determination of the extent of impurity formation and thus for formation of color centers in crystals of high quality.
Since manufacture of an entire optical component from an optical blank is very expensive and labor-intensive, there is already a need to establish the extent and nature or the radiation damage that would arise in the optical component during later usage at an earlier time point, i.e. prior to working the blank. Unsuitable material must be discarded. Attempts have already been made to determine the extent and the nature of the radiation damage of this sort by means of laser-induced fluorescence. Thus, for example, WO 2004/027395 describes a process for determination of the non-intrinsic fluorescence in an optical material. In this process the fluorescence in the optical material is directly determined with the same laser, with which the pre radiation is performed, i.e. immediately after a pre-radiation with light at an excitation wavelength of 193 nm or 157 nm.
A method for quantitative determination of the suitability of optical materials is described in DE 103 35 457 A1. In this method the energy-density-dependent transmission is measured at wavelengths in the UV by determining an equilibrium value for the transmission at different fluences, measuring the slope of the curve dT/dH for this sample and comparing with the fluorescence properties.
Laser-stable material can already be evaluated at an earlier time point during production by means of the above-described method. Photolithographic illumination devices at the present stage of development require a material, which is especially laser-stable, in their illumination optics, in the laser used in them, or their laser beam guidance system. This requirement results from the productivity requirements of this sort of apparatus, which may well increase because of increases in laser power and thus inherent increases of the energy density. The sensitivity of the aforementioned short-time measuring method for pre-evaluation of suitable optical raw material is thus no longer sufficient in order to distinguish samples with especially good laser-stability from other laser-stable samples.
Material, which should have very good properties according to its later usage, must thus be constantly tested up to now in a long duration test. When this material withstood this long duration test, it could then be further processed or worked. Typical test conditions for this sort of long duration test are, for example, irradiation with a 193 nm excimer laser with a repetition rate greater than or equal to 1000 Hz at an energy density per pulse of 15 mJ/cm2 and a total number of pulses of about 109 pulses. That means a measurement time of about 11.5 days.

Method of determining laser stabilities of optical materials, crystals selected according to said method, and uses of said selected crystals


A device, system and method for adaptively tracking amplitude boundary values of a real time sensor output signal. In accordance with the method of the present invention, an amplitude boundary value, which may be a peak or min amplitude value, representing the current amplitude boundary of the sensor output signal is stored within a digital counter. A two-tap DAC is utilized to convert the digitally stored amplitude boundary value into a reference signal level corresponding in amplitude to the amplitude boundary value. The DAC also converts the amplitude boundary value into an offset reference signal level corresponding in amplitude to the amplitude boundary value offset by a specified multiple of the DAC resolution. The reference signal level and offset reference signal are compared with the real time sensor signal and the digitally stored amplitude boundary value is adjusted in accordance with which reference signal level exceeds the real time sensor signal.

Magnetic sensing devices have many applications, including navigation, position sensing, current sensing, vehicle detection, and rotational displacement. There are many types of magnetic sensors, but essentially they all provide at least one output signal that represents the magnetic field sensed by the device. The Earth, magnets, and electrical currents can all generate magnetic fields. The sensor may be able to detect the presence, the strength, and/or the direction of the magnetic field.
The strength of the magnetic field may be represented by a magnitude and a polarity (i.e., positive or negative). The direction of the magnetic field may be described by its angular position with respect to the sensor. Magnetic sensors measure magnetic fields to determine position related parameters such as shaft rotation, presence of magnetic ink, vehicle heading, etc. One of the benefits of using magnetic sensors is that the output of the sensor is generated without the use of contacts. This is a benefit because over time contacts can degrade and cause system failures.
One type of magnetic sensor utilized in many conventional sensing applications is a magnetoresistive (MR) sensor. MR sensors are a type of magnetic sensor that uses the magnetoresistive effect to detect a magnetic field. Ferromagnetic metals, such as the nickel-iron alloy commonly known as Permalloy, alter their resistivity in the presence of a magnetic field. When a current is passed through a thin ferromagnetic film in the presence of a magnetic field, the voltage will change. This change in voltage represents the strength or direction of the magnetic field. By designing an MR sensor in a Wheatstone bridge configuration, for example, either the strength or direction of the magnetic field can be measured. The characteristic high-sensitivity and accuracy make MR sensors well suited for precision applications.
Magnetoresistive sensors are utilized in many automotive and aerospace applications. In automotive applications, for example, magnetoresistive sensors are often utilized for sensing cam and crank shaft targets. A magnetoresistive sensor system that may be utilized for sensing shaft rotation or linear displacement is depicted in FIG. 1. Specifically, FIG. 1 illustrates an anisotropic magnetoresistive (AMR) sensor system generally comprising an MR bridge 2, differential signal amplification and adjustment circuit 4 and an output signal detect module 6. MR bridge 2, comprising multiple AMR elements configured in a Wheatstone Bridge arrangement, delivers the differential signal, typically about 30 mV peak to peak, sensed across the bridge to amplification and adjustment circuit 4 where the sensed signal is amplified and centered at a specified reference voltage point using standard operational amplifier techniques.
The resultant signal, Vout, is processed by detector module 6 which employs signal conditioning circuitry to provide an accurate determination of the target position of the linear or rotational position and displacement. The primary function of the signal conditioning circuitry within detector module 6 is to capture the peak and min values of the amplified signal, and use these values to generate a threshold voltage signal that is the mid point of the captured peak/min values.
FIG. 1B is a waveform diagram illustrating exemplary signals employed by detector module 6 for conditioning the sensed output signal, Vout. As shown in FIG. 1B, sensor output signal 22 is a single ended signal and varies between peak and min amplitudes and represents the amplified AMR bridge signal. Detector module 6 translates sensor output signal 22 into a corresponding detected output signal 28 with the use of a threshold signal 25 by outputting a signal high when the value of sensor output 22 is above threshold 25 and outputting a signal low when the value of sensor output 22 is below threshold 25.
Threshold signal 25 is determined by averaging a max or peak signal 24 with a min signal 26. Peak signal 24 is determined in accordance with the sensed peaks and min signal 26 in accordance with the min values of sensor output 22. In this manner, threshold signal 25 is able to follow sensor output 22 which is very important in AMR sensing applications in which the MR sensor output is subject to drift due to operating and environmental factors such as temperature changes. It will be noted that during each cycle the peak signal 24 is "pushed down" and subsequently reacquires at the beginning of the next peak of sensor output 22, and conversely, min signal 26 is "pushed up" and reacquires at the beginning of the next min value of sensor output 22. This periodic re-adjustment is necessary to adaptively track the peaks and minimums of the sensor output.
A device that may be employed by detector module 6 for detecting and adjustably tracking the peak signal 24 is depicted in FIG. 1C. Specifically, FIG. 1C illustrates a signal tracking device generally including a comparator 18 which compares the amplified sensor output, Vout, with the presently stored peak value. A digital storage device in the form of a counter 14 is utilized to store the peak value with the output from comparator 18 used for incrementing the presently stored counter value when the signal from AMR sensor 12 exceeds the value of the presently stored peak value. Counter 14 is periodically updated by the output from comparator 18. The stored reference value is applied in the depicted example as a 9-bit output to a 9-bit digital-to-analog converter (DAC) 16 which converts the digitally stored value to the corresponding output peak boundary value which is applied to the input of comparator 18 for comparison with the real time sensor output on the next counter clock cycle. Although not depicted, it will be readily understood that a min detector can be similarly constructed by the use of a decrementing counter and switching the respective comparator inputs.
The mixed signal peak detector device depicted in FIG. 1C addresses analog leakage problems since the peak reference value is digitally stored in the period between sensor output peaks. However, the design of this peak detector is problematic in terms of its practicable application as a high-resolution, high slew rate tracking and low power device. Since the output from DAC 16 varies discretely in conformance with digital increments, the peak reference signal follows discrete steps determined in accordance with the DAC design. In the depicted example of a 9-bit DAC 16 and assuming a DAC range of 2V, the minimum resolution of the peak signal is 3.9 mV. For a 7-bit DAC having the same range, the resolution is 15.6 mV.
A resolution having fine granularity is generally desired to track the peak with maximum real time accuracy but is limited by the clock speed in terms of its ability to track a high slew signal. For example, if the clock speed is 10 MHz and a 9-bit DAC having 3.9 mV steps is used, the fastest slew rate that can be tracked is 39,000V/second while a 7-bit DAC can track at 156,000V/second. This tracking speed versus resolution tradeoff cannot be addressed by increasing the clock speed since, in practical application, a fast settling DAC requires a lower RC time constant and is incompatible with the low power requirements (typically less that 5 mA) of the application specific integrated circuits on which the detector circuits reside.
From the foregoing, it can be appreciated that a need exists for a low power sensor output amplitude threshold tracking device that provides a high-resolution capability with high slew rate tracking. The present invention addresses such a need.

Adaptive integrated circuit for magnetoresistive sensors


A wireless communication system according to an embodiment comprises a first wireless communication device and a second wireless communication device. The first wireless communication device is configured to transmit a signal related to program. The second wireless communication device is configured to compute an angle of departure from the first wireless communication device based on a radio wave transmitted from the first wireless communication device, and to perform updating of the program when a computed angle of departure is a predetermined angle.

In recent years, electronic devices capable of rewriting firmware within devices by using a wireless communication method referred to as "OTA (Over The Air)" have been widespread. However, when the firmware is updated, there is a risk that unintended firmware is written in the devices by a third party intentionally or by a user himself mistakenly.

Wireless communication system, wireless communication device, and wireless communication method

TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION


The present invention provides a method and system for generating a cover page for a fax job. The method comprises the steps of sending a fax job with cover page information to a DID for fax generation and transmittal. The fax job and cover page are suitably separated into two separate jobs prior to submission to the DID. The fax job is then preferably sent to the raster image processor of the DID before the cover page job so that when the cover page job is generated, the number of generated pages has already been determined. After bitmap images are created of both the fax job and cover page job, the fax job and cover page job are suitably swapped and combined into one job such that the cover page job bitmaps precede the fax job bitmaps. After combining the two jobs, the single fax job is suitably sent to a recipient.

This invention pertains generally to digital imaging devices, and more particularly to a method for generating a cover page for a facsimile transmission.
Digital imaging devices ("DID") are complex machines that often perform a plurality of functions. DIDs suitably include devices such as printers, fax machines, scanners, copiers, multi-functional peripherals ("MFPs"), and other like peripheral devices. In addition, DIDs are suitably connected to a network or directly to computer. When a user at a computer communicates with a DID, either directly or over a network, at DID device driver is accessed which is linked both to the computer operating system ("OS") and the DID. Device drivers are pieces of software that enable computers to communicate with peripheral devices. In doing so, they are responsible for accessing hardware registers of the device. Device drivers often form part of the lowest level of an operating system ("OS") kernel, with which they are linked when the kernel is built. OS also accept loadable device drivers that can be installed after the OS is running.
In the case where the DID performs fax functions, the fax properties of the DID for a fax job are suitably set through a fax driver stored on a computer. These fax properties suitably include whether or not a cover sheet is generated by the fax driver and DID. In addition, if a cover sheet is to be generated, the fax properties suitably include the particular information to be included on the fax cover sheet. The various options for cover sheet information selection can cause the cover sheet for a fax to become two or more sheets, depending on the information on the cover sheet. Consequently, when a document is sent from a computer to a DID processing, the total number of pages of the document and cover sheet combination suitably varies. It would be preferable if the fax driver and DID were capable of determining the total number of pages of the document and cover sheet combination.
Furthermore, when a fax job is generated from a software program (i.e. spreadsheet software, word processing software, text editors, etc.) on a computer ("PC fax) the software program does not necessarily calculate the number of pages to be printed. Consequently, the number of pages to be printed in the fax document may not be determined when a fax driver sends a fax to a DID for processing. Therefore, generating a fax cover sheet that includes a number representing the number of pages in the fax document to which the cover sheet corresponds is problematic. It would be preferable if the fax driver and DID were capable of generating the total number of pages of the fax document regardless of the software program from which the fax job originated.


A method of determining a size of an optical disc inserted into an optical disc drive is disclosed. The method includes driving a turntable motor of the optical disc drive to rotate the optical disc at a predetermined rotation frequency for reading data stored on the optical disc, measuring a rotation frequency of the turntable motor, applying a kick-pulse voltage to the turntable motor of the optical disc drive for a predetermined period of time, measuring a change in the rotation frequency of the turntable motor after applying the kick-pulse voltage, comparing the change in the rotation frequency of the turntable motor to a threshold value, and determining that the optical disc is an 8 cm disc when the change in the rotation frequency of the turntable motor is above the threshold value.

1. Field of the Invention
The invention relates to an optical disc drive, and more particularly, to a method of determining the size of an optical disc inserted into optical disc drive.
2. Description of the Prior Art
In typical optical disc drives, users can insert media having different sizes. The compact disc (CD) standard specifies two sizes: 8 cm and 12 cm in diameter. Apart from being able to report the size of the inserted disc to the user, this information might also be necessary for the Turn-Table-Motor (TTM) controller that drives and controls the speed of the disc. Since the moment of inertia of an 8 cm disc and a 12 cm disc differ greatly, a different TTM controller might be required for rotating each type of disc in order to maintain fast, stable, and robust control over the rotation speed of the disc.
FIG. 1 is a partially cut-off perspective view of an optical disc drive of the prior art. In FIG. 1, an optical disc 1 is placed on a turntable 2 and is rotated by a turntable motor 3. Opposed to the lower face of the optical disc 1 there is provided an optical pickup 4 which is supported by a guide rail 5 and a driving screw 6. The optical pickup 6 moves in the radial direction of the optical disc 1 by rotation of the driving screw with a stepping motor 7.
In a typical optical disc drive, the decision of determining whether an 8 cm disc or a 12 cm disc is present in the drive is made in one of two ways. The size can be determined mechanically using switches in the disc-loader module. This method involves additional switches in the loader system, and therefore increases the bill of materials of the optical disc drive. On the other hand, the size can also be determined at start-up using the so-called kick phase. This method is a software solution for detecting the disc size, and therefore potentially does not affect the bill of materials of the optical disc drive.
For the software method, in the kick phase a constant voltage is applied to the TTM that drives the disc in order to accelerate the disc quickly to the target velocity where the TTM takes over velocity control of the TTM. The duration of this kick phase, i.e. from the start of the applied constant voltage until the TTM controller takes over, is a measure of the mass of inertia of the load driven by the TTM and therefore a measure of the disc size.
The disadvantage of the software method of the prior art is that the disc speed needs to be measured during the complete kick phase, or at least at the very end of the kick phase. Although the speed signal might be available for certain TTM types, e.g. for brushless TTM types where in most cases the motor electronics provides such a signal, this is not the case for brush TTM motor types. Here extra effort, and hence cost, must be made to extract this kind of information. The TTM velocity control after the kick phase on these brush TTM drives is based on the data rate of the information stored on the disc. This data rate speed signal, which in a CD module or a digital versatile disc (DVD) module is usually provided by the data acquisition phase locked loop (PLL), becomes available at a later stage of the start-up phase (after several other control loops have been closed and data can be read) and can therefore not be used to determine the disc speed at the end of the kick phase.
Another disadvantage of deciding between 8 and 12 cm discs during the kick phase is that this only works when the initial disc speed equals zero at the start of the kick phase. This means the disc must be slowed down to a standstill before the kick phase starts. Otherwise the detection might provide incorrect results, such as a 12 cm disc being detected as an 8 cm disc, which might be catastrophic if the TTM controller depends on a correct detection of the disc size.

Method for determining size of optical disc inserted into optical disc drive

Philips & Lite-On Digital Solutions Corporation


The present application relates to a communication method in which a succession of time domain symbols (TDS) are transmitted by a transmitter to one or more receivers. Each time domain symbol has a plurality of signals which are transmitted in parallel by the transmitter. The signals may comprise data signals or pilot signals. At the transmitter, a set of pilot signals assigned to a given time domain symbol is provided with information about a phase vector applied to the time domain symbol. The phase vector is preferably selected with consideration of the reduction in the ratio of peak-to-average-power which can be achieved when the vector is applied to the time domain symbol. Transmitters and receivers for use in the communication method are also provided. The invention is particularly application to OFDM communication systems.

1. Field of the Invention
The present invention relates to multi-carrier communication systems, such as frequency division multiplexing (FDM) systems and orthogonal division multiplexing (OFDM) systems, transmitters, receivers and to methods of transmitting a signal in such systems.
2. Description of the Related Art
In a multi-carrier transmission system, such as FDM or OFDM, a single data stream is modulated onto N parallel sub-carriers, each sub-carrier signal having its own frequency range. This allows the total bandwidth (i.e. the amount of data to be sent in a given time interval) to be divided over a plurality of sub-carriers thereby increasing the duration of each data symbol. Since each sub-carrier has a lower information rate, multi-carrier systems benefit from enhanced immunity to impulse noise and reflections. A disadvantage of FDM systems is that a guard band frequency is required between each modulated sub-carrier to ensure that the spectrum of one sub-carrier does not interfere with the spectrum of another. The necessity for guard bands in an FDM system significantly lowers the spectral efficiency of the system.
Orthogonal frequency division multiplexing (OFDM) is a modulation technique that is based on FDM. An OFDM system uses a plurality of sub-carrier frequencies which are perpendicular in a mathematical sense so that the sub-carriers' spectra may overlap without interference. The orthogonality of OFDM systems removes the need for guard band frequencies and thereby increases the spectral efficiency of the system. OFDM has been proposed and adopted for many wireless systems. It is currently used in Asymmetric Digital Subscriber Line (ADSL) connections and in some wireless LAN applications, including WiMAX and IEEE 802.11 a/g. OFDM is often used in conjunction with channel coding, an error correction technique, to create coded orthogonal FDM or COFDM. COFDM is now widely used in digital telecommunications systems to make it easier to encode and decode such signals. The system has found use in broadcasting as well as certain types of computer networking technology.
FIG. 1 shows an example of a signal transmitted in a multi-carrier system such as OFDM. The signal comprises a sequence of time domain symbols (TDS) or symbol "blocks", each time domain symbol comprising a set of N signals, the signals comprising pilot signals or data signals and being transmitted in parallel (i.e. at the same time) each by a different sub-carrier frequency. A sequence of time domain symbols forms an information unit F of the system. The information unit shown in FIG. 1 comprises 38 time domain symbols of which 32 TDS's are data symbol blocks (DSB) and 6 TDS's are pilot signal blocks (PSB).
In an OFDM system, a block of N modulated data source signals are mapped to N orthogonal sub-carriers by using an Inverse Fourier Transform algorithm (IDFT/IFFT) to form a block of N parallel signals, known as an "OFDM symbol", in the time domain at the transmitter. Thus, an "OFDM symbol" is the composite signal of all N sub-carrier signals. An OFDM symbol can be represented mathematically as:
                                          x                                      (              t              )                                =                                    1                              N                                                                                ∑                                  n                  =                  0                                                  N                  -                  1                                                                                c                  n                                ·                                  ⅇ                                      j2π                                                                                n                                                                                Δ                                                                                ft                                                                                ,                  0          ≤          t          ≤                      T            s                                              (        1        )            where Δf is the sub-carrier separation, Ts=1/Δf is symbol time interval, and cn are the modulated source signals. The sub-carrier vector in (1) onto which each of the source signals is modulated c ∈ Cn, c= (c0, c1. . . cN−1) is a vector of N constellation symbols from a finite constellation. At the receiver, the received time-domain signal is transformed back to frequency domain by applying Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT) algorithm.
As can be seen from equation (1), an OFDM time domain symbol consists of the composite of a number N of independent modulated signals which are transmitted simultaneously, in the time internal Ts, by the transmitter of an OFDM system to one or more receivers. There is therefore the potential for all N signals to be in phase and, consequently, for the peak value of the composite OFDM waveform to be the sum of the peaks values of all sub-carrier signals. When these N signals are added up with the same phase, they produce a maximum peak power that is N times the average power. The peak-to-average-power-ratio (PAPR) is defined as follows:
                    PAPR        =                                            max                              0                ≤                n                <                N                                                                                                                  x                                                        (                    n                    )                                                                              2                                            E                                      [                                                                                      x                                                              (                      n                      )                                                                                        2                            ]                                                          (        2        )            Where E denotes expectation/average value. The theoretical maximum of the PAPR for N number of sub-carriers is 10 log(N) dB.
The high PAPR inherent in OFDM systems causes problems when the signal has to be subject to power amplifiers. Specifically, the high PAPR values can drive the amplifier into a saturation region, where an increase in input drive level does not result in an increase in output level. This non-linearity reduces the efficiency of the amplifier.
A number of approaches have been proposed to reduce the PAPR of multi-carrier multiplexed signals, in particular of OFDM signals, including: amplitude clipping, tone reservations (TR), and interleaving. However, these previously proposed techniques have been found to introduce various other problems which negate the improvement seen in the PAPR such as an increase in the required transmit signal power, a reduction in the data rate of the system and an increase in bit error and complexity of the system. Two other previously considered techniques which have proved to be highly effective at reducing PAPR are selected mapping (SLM) and the use of partial transmit sequences (PTS). Both of these techniques involve adjustment of the phase of the sub-carrier signals comprised in a time domain symbol in order to optimise the composite OFDM waveform that is eventually transmitted. Selected mapping (SLM), is described in detail in R. W. Bauml, R. F. H. Fischer and J. B. Huber, "Reducing the Peak to Average Power Ratio of Multicarrier Modulation by Selected Mapping", Electronics Letters, Vol. 32, No. 22, October 1996. The use of Partial Transmit Sequences in described in S.H.Muller and J.B. Huber, "OFDM with reduced Peak-to-Average Power Ratio by Optimum Combination of Partial Transmit Sequences," Elect. Lett., vol. 33, no.5, February 1997, pp.368-69.
According to the SLM technique, a sequence of data source symbols which will comprise a time domain symbol, Cn {Cn=c0, c1, c2, . . . cn−1} is subjected to U different phase vectors Qu, to create a set of different, but equivalent (in term of data content), signal representations of the time domain symbol. Key parts of a basic SLM transmitter 18 are shown in FIG. 2. Each vector Qu consists of a sequence of N phase elements φ0, φ1, φ2. . . , φN−1, and, according to the SLM procedure, each element is applied to a different sub-carrier of the time domain symbol so that the phase of each signal is adjusted by a single phase element of the vector. The vector Qu, may be represented mathematically by:Qu=[ejφ0u, ejφ1u, . . . ejφN−1u], where u∈{0,1, . . . , U−1},Φnu∈(0,2π) for all U vectors.
A set of U phase vectors is preferably stored in a phase vector storage unit of the SLM block 18, wherein the sequence of phase vector elements comprised in a particular phase vector Qu is preferably be generated randomly. Thus, the SLM technique effectively randomises the phase of each sub-carrier so that when the sub-carriers are added together, the signals are less likely to be in phase with one another and the resultant envelope OFDM is flatter. The transmitter then selects the vector which results in the OFDM symbol having the lowest PAPR for transmission.
According to the SLM technique, the original OFDM data symbol can be recovered from the received signal rn by multiplying the conjugate of applied vector, Qu*, to the received signal. To do this, knowledge of the applied vector sequence is needed at the receiver. The present invention is concerned with this technical problem.
There are two main ways in which the identity of the applied vector may be ascertained by the receiver. The first involves sending information about the applied phase sequences to the receiver as side information, so that the receiver is subsequently able to recover the original data symbol from a calculation of rn Qu*. The side information is commonly in the form of index number which uniquely identifies each of the phase vectors Qu. However, this approach utilises bandwidth and increases signalling overhead. Whilst in practice a large number of U vectors leads to a better PAPR reduction, any improvement in PAPR must be weighed against the logarithmic increase in the signalling overhead that is required as the number of U increases. For example, if U=16, then log2(U)=4= the number of bits required per OFDM time domain symbol as side information. In this case, if an information unit, or frame, of the system consists of 32 OFDM symbols, then 32*4=128 bits are needed to be sent to the receiver in every information unit. FIG. 3 shows the possible PAPR reduction that may be achieved with SLM using 4, 8, 16 and 64 vectors in an OFDM system comprising 512 sub-carriers applied on QPSK modulation without coding.
Another technique has recently been proposed in a paper entitled "A blind SLM receiver for PAR-reduced OFDM", by A.D.S. Jayalath and C Tellambura, Proceedings of IEEE Vehicular Technology Conference, pp 219-222, Vancouver, Canada, 24 to 28 Sep. 2002. The proposed technique employs a decoder in the receiver which performs a set of calculations for each received OFDM data symbol. According to this technique, the value, or index number, representing the optimal phase vector which is applied to the OFDM data symbol is not transmitted to the receiver. Rather, the decoder, which has prior knowledge of all possible vectors Qu, performs a set of trial calculations to find the minimum distance between rn Qu* (where Qu* is the conjugate of one of the phase vector elements) and Ĥncn, where Ĥn is an estimate of the channel impulse response and Cn is one of the constellation points of the used modulation scheme which is known at the receiver. The received signal rn, after the DFT demodulation at the receiver is given by:rn=HnPnejφnu+nn  (3)Assuming a distortion less and noiseless channel, we can assume that the receiver gets a received signal vector r=c⊕Qu. Conceptually, for each received signal rn (n=0, . . ., N−1) the decoder computes the difference between each of a set of "trial" received signal and a representation of the actual received signal. If the trial received signal is correct, the difference will be zero, however in reality, the correct phase vector can be identified as the trial vector which results in the minimum difference. The decoder therefore computes the following decision metric for each time domain symbol received from the transmitter.
                    D        =                              min                          Q              u                                                                    ∑                              n                =                0                                            N                -                1                                                                                min                                                      c                    n                                    ∈                  Mod                                                                                                                                                                r                        n                                                                                ⅇ                                                                              -                            j                                                                                ϕ                            n                            1                                                                                -                                                                                H                          ^                                                n                                                                                c                        n                                                                                                              2                                                                        (        4        )
A block diagram of such a receiver is shown in FIG. 4. The proposed scheme works on the assumption that (1) cn's are restricted to the constellation points of a particular modulation scheme, for example, QPSK; (2) the set of applied vectors is fixed and known at the receiver and (3) c⊕Qu and c⊕Qv are sufficiently different for u≠v. In other words, the set of available phase vectors have large Hamming distances, providing inherent diversity which can be exploited at the receiver.
The proposed blind receiver is advantageous in that the need to send side information is averted. However, the improvements seen in the throughput of the system are countered by a significant increase in receiver complexity. The signal processing required by the receiver is substantial and amounts to U*N*Ndata*M operations per information unit, where M refers to the number of constellation points for a particular modulation scheme, (e.g. QPSK) U is the number of possible vectors, N is the number of sub-carriers and Ndata is the number of OFDM time domain symbols. Another disadvantage of the known blind receiver is that for each OFDM symbol, the same modulation scheme should be used on each sub-carrier so that a mixed modulation scheme employing, for example, QPSK on some sub-carriers and 16QAM on other sub carriers, is not permitted. Furthermore, the receiver requires an accurate estimation of the channel where a high level modulation scheme is employed (16/64 QAM) which may mean that more pilot overhead is required.


Analyzers determine the concentration of a test substance by measuring the change of pH in a sample liquid after reaction of the test substance with a reactant. The analyzers have a tube connected between first and second microcapillary pH electrodes. In a first embodiment, the tube functions as a reaction chamber by having a reactant immobilized on a wall of the tubing or confined within the tubing. In a second embodiment, the reactant and test substance are mixed upstream relative to the first and second microcapillary pH electrodes, with the tubing serving as a delay circuit for a kinetic measurement. Output signals of the microcapillary flow-through electrodes are used to determine a change in pH, the change in pH being indicative of the concentration of the test substance.

Differential pH analyzers (Luzzana M., Perrella M., Rossi-Bernardi L. Anal. Biochem. 1971;43:556-563, U.S. Pat. No. 4,353,867 and EP 52718) have been extensively used to measure the concentration of chemicals in various fluids. Indeed, more than 45 papers describing the apparatus and related methods of analysis have appeared in the international literature in the last twenty years.
The essential features of a differential pH analyzer have been described in detail in the original paper and in the patents cited. The apparatus, using appropriately formulated reagents, has been used to determine a variety of substances (such as glucose, urea, creatinine, ethanol, lactate, acetate, ATP, fructose, magnesium) and the activity of several enzymes (i.e., cholinesterase, glucose-6-phosphate dehydrogenase, pyruvate kinase) in the absence or in the presence of inhibitors.
It should be noted that the key analytical equation used in differential pH measurements to calculate .DELTA.[H.sup.+ ] (i.e., the number of hydrogen ions, in moles per liter, liberated or absorbed in a chemical reaction involving the analyte to be determined) is given, under appropriate experimental conditions, by: EQU .DELTA.[H.sup.+ ]=.beta.(pH.sub.(1) -pH.sub.(0))=.beta..DELTA.pH(1)
where .beta. is the so-called "buffer value", i.e., .DELTA.[B.sup.+ ]/.DELTA.pH of the solution at any given pH and pH.sub.(0), pH.sub.(1) are the pH values of the solution before and after the chemical reaction of interest has occurred. In this context, pH is equal to -log.sub.10[H.sup.+ ].
It has been shown in the cited literature that eq. (1) can be used to determine .DELTA.[H.sup.+ ] from the known values of pH.sub.(1), pH.sub.(0) and .beta.. It should be noted that according to (1), the number of hydrogen ions produced or absorbed in a given reaction, which is directly correlated, through a known chemical reaction, to the amount of analyte present in solution, is proportional to the difference in pH and not to the absolute value of this parameter. In actual practice, the concentration of the substance of interest is obtained by the device described in U.S. Pat. No. 4,353,867 by the slightly more complicated equation: EQU [substance]=FCAL(.DELTA.pH.sub.c -.DELTA.pH.sub.b -.DELTA.pH.sub.a)=FCAL .DELTA.pH (2)
where FCAL represents a calibration factor which is a combination of .beta. and a dilution factor of the sample under analysis, .DELTA.pH.sub.c represents the total change of pH in solution after a reaction has occurred, .DELTA.pH.sub.b is the .DELTA.pH value of the solution after the addition of the reagent(s), but without the sample, and .DELTA.pH.sub.a is the .DELTA.pH value indicative of the level of noise and drift of the machine components during the observation time. Since FCAL, .DELTA.pH.sub.b, .DELTA.pH.sub.a can be determined in separate experiments and by the use of a suitable standard, eq. (2) allows the determination of the concentration of the substance of interest from the calculated value of .DELTA.pH.
It should also be stressed that to avoid in current practice measuring .beta. (the buffer value of the solution after the addition of each sample), such a buffer value has to be much higher (50-100 times higher than that of the sample) so that any change in .beta. is made practically negligible after such an addition. This, in turn, leads to the necessity of measuring the .DELTA.pH occurring in a given chemical reaction with an experimental reproducibility of 0.0001 pH units, at least twenty times greater than in the current practice of measuring pH with the already available instrumentation.
The configuration of the apparatus as described in U.S. Pat. No. 4,353,867, and therein shown in FIGS. 1-5, and particularly the simultaneous measurement of the pH difference between two glass pH electrodes respectively filled with a buffer plus sample and buffer plus sample plus a specific reagent(s) to initiate a chemical reaction (typically a small volume of an enzyme) was specially intended to increase the sensitivity and reproducibility of pH measurements In fact, by use of the previously disclosed apparatus and related methods, it has been possible:
a) to zero any unspecific pH drift which may occur (thereby obscuring the measurement of .DELTA.pH) when a biological sample (whole blood, urine, cell suspension and similar solutions or suspensions) is mixed into a buffer of different pH; PA0 b) to minimize the effect on .DELTA.pH by a change in temperature; PA0 c) to practically zero the difference in junction potential that occurs when a traditionally pH cell made by a glass pH electrode and a reference electrode are immersed respectively into a solution having a standard composition and pH and into a solution having a chemical composition and pH different from the standard. PA0 first means to transfer a suitable buffered solution, PA0 second means to transfer a sample liquid containing a substance to be determined, PA0 third means to deliver a liquid containing a reactant; PA0 a reaction chamber wherein said buffered sample liquid and said liquid containing a reactant come into contact, whereby a reaction mixture is formed, causing a pH change in solution; PA0 a first and a second microcapillary pH electrodes; PA0 means to regulate the temperature of said first and said second pH electrodes; PA0 fourth means to deliver said reaction mixture to said first pH electrode, said means comprising means to bring the temperature of said reaction mixture to the same temperature of said first pH electrode, and being at machine ground potential; PA0 fifth means to deliver said reaction mixture to said second pH electrode; PA0 electronic means for processing pH measurements made by said first and second pH electrodes and producing a visual display of the concentration of said substance to be determined. PA0 a block made of metal or another heat-conducting material in which two micro pH glass electrodes are located, said two electrodes being connected together, in parallel, by a piece of small diameter tubing of various lengths which may contain an immobilized enzyme(s) or another suitable chemical to cause the chemical reaction(s) of interest; PA0 said thermal block and the liquid flowing into the two pH electrodes being connected to a common ground, whereas the two electrode outlets are connected to a differential amplifier circuit associated with a measuring device; PA0 a heat conducting tubing, connected to electrical ground, inserted in the hydraulic circuit, between the sample and first measuring electrode so to heat a sample solution to electrode temperature; PA0 a buffer whose known composition can be varied to ensure the occurrence of a chemical reaction in conjunction with a chemical substance, for example an enzyme immobilized or confined in the tubing connecting the two pH electrodes; PA0 electronic means to convert pH electrode potentials into pH values, to program the functioning of the apparatus and to calculate, print or store, according to a known stoichiometry and related equations, the concentration of the substance(s) of interest; PA0 microperistaltic pump(s) or other suitable device(s) to move, in a series of microbore tubings and through the two measuring pH electrodes, the solution under analysis; PA0 a microdialysis tubing to sample, by diffusion through a dialysis membrane, a definite amount of the substance to be determined contained at a known concentration in an outside liquid or in an unknown concentration in a sample to be analyzed. PA0 mechanical means to change in an oscillatory mode the flow rate of the liquid in the measuring pH capillary electrodes, inside the microdialysis probe and in the tubing connecting the various parts of the apparatus so to renew the stagnant layer of liquid around the inner walls of the circuit. PA0 two microperistaltic pumps, the first pump delivering to a mixing chamber a buffer of known suitable composition, or the same buffer containing a standard concentration of the substance to be determined, or a solution containing an unknown concentration of the substance to be determined and the second pump delivering to a mixing chamber a buffer containing a chemical substance(s) such as an enzyme(s) to start the chemical reaction; PA0 a mixing chamber to effectively mix two fluids, which are continuously delivered to said mixing chamber by the two peristaltic pumps; PA0 mechanical means to oscillate the tubing coming from the mixing chamber in order to minimize the stagnant layer of liquid on the inner wall of the hydraulic circuit and of the two measuring pH electrodes; PA0 a small diameter tubing to deliver the mixed fluid into the two capillary electrodes, arranged in series and connected together through a delay tubing.
The practical use of the previously patented apparatus in a variety of analytical problems, although confirming its wide applicability, accuracy and precision, has made clear some of its limitations: the instrument has a weight of no less than 5 kg, it has to be maintained by a trained operator, it requires up to 2-3 ml of reagents for a single determination, especially to assure the complete removal from the electrodes of contamination from the previous cycle of analysis, and, finally, it requires the manual introduction of a precise volume of sample, an operation which may be critical with certain heterogeneous solutions or suspensions. As such, the analyser cannot be uses for the continuous monitoring of an industrial process or chemical parameters of biological and clinical interest in vivo (e.g., urea, creatinine, bicarbonate concentration in an artificial kidney, the determination of glucose in subcutaneous fluids during insulin or glucose perfusion etc.).

Apparatus and method for the determination of substances in solution suspension or emulsion by differential pH measurement