An A/D conversion circuit includes a reference signal generation unit, a comparison unit, a delay circuit, a latch unit, an arithmetic circuit, a lower counter, and an upper counter including a second binary counter performing counting using the count clock based on one of the output signals constituting the first lower phase signal, performs counting to acquire a first upper count value, inverts values of respective bits constituting the first upper count value, performs counting using the count clock based on of the output signals constituting the second lower phase signal, and performs counting based on the second upper count clock to acquire a second upper count value, and having a data protection function for protecting an upper count value held by the second binary counter at a time of count clock switching, wherein digital data corresponding to a difference between the first and second analog signals is acquired.

1. Field of the Invention
The present invention relates to an A/D conversion circuit and an image pick-up device provided with the A/D conversion circuit.
Priority is claimed on Japanese Patent Application No. 2011-050812, filed Mar. 8, 2011, the content of which is incorporated herein by reference.
2. Description of the Related Art
All patents, patent applications, patent publications, scientific articles, and the like, which will hereinafter be cited or identified in the present application, will hereby be incorporated by reference in their entirety in order to describe more fully the state of the art to which the present invention pertains.
FIG. 21 is a block diagram illustrating a partial configuration of a conventional A/D conversion circuit. FIG. 21 illustrates a unit of a conventional A/D conversion circuit for measuring a time, which is called a time to digital converter (TDC)-type A/D conversion circuit. The circuit illustrated in FIG. 21 includes a ring-like delay circuit 201 in which a plurality of delay elements NAND0 and INV1 to INV8 are connected to one another in a ring shape, a latch circuit 202 for holding the output of the ring-like delay circuit 201, a binarizing circuit (a full-encoder circuit) 203 for binarizing values held by the latch circuit 202, a counter circuit 204 for performing counting using one of the outputs of the ring-like delay circuit 201 as a count clock, and a memory circuit 205 for holding the output of the binarizing circuit 203 and the counter circuit 204.
Next, an A/D conversion operation will be described. FIG. 22 is a timing chart illustrating a conventional operation. FIG. 22 illustrates the operation timing of the circuit illustrated in FIG. 21. A logic state of a starting pulse StartP changes from an L state to an H state, so that the logic states of the delay elements constituting the ring-like delay circuit 201 sequentially change. Accordingly, a pulse circulates in the ring-like delay circuit 201. After a predetermined time has lapsed, the latch circuit 202 holds (latches) the output of the ring-like delay circuit 201. As illustrated in FIG. 22, the output of the ring-like delay circuit 201 corresponds to any one of nine states (state 0 to state 8). The output of the ring-like delay circuit 201 held (latched) by the latch circuit 202 is fully encoded (simultaneously encoded) by the binarizing circuit 203 to generate binarized data (a lower count value). The counter circuit 204 performs counting using the output of the delay element INV8 as a count clock to generate a count value (an upper count value). The lower count value and the upper count value are held in the memory circuit 205 to be output to the subsequent circuit as digital data.
The above-mentioned A/D conversion circuit is applied to, for example, an image pick-up device. Japanese Unexamined Patent Application, First Publication No. 2011-23887 discloses an example in which an A/D conversion circuit is arranged in a column unit provided to correspond to each of pixel columns to perform A/D conversion with respect to signals output from pixels.
FIG. 23 is a block diagram illustrating the configuration of a conventional image pick-up device. FIG. 23 illustrates a schematic configuration of a (C)MOS image pick-up device in accordance with a conventional example disclosed in Japanese Unexamined Patent Application, First Publication No. 2011-23887. An image pick-up device 1001 includes an image capturing unit 1002, a vertical selection unit 1012, a read current source unit 1005, an analog unit 1006, a clock generation unit 1018, a ramp unit 1019, a column processing unit 1015, a horizontal selection unit 1014, an output unit 1017, and a control unit 1020. The image pick-up device 1001 is provided in column A/D conversion sections 1016 of the column processing unit 1015 thereof with a unit of the circuit illustrated in FIG. 21, and performs A/D conversion using the column A/D conversion sections 1016.
The control unit 1020 controls the vertical selection unit 1012, the read current source unit 1005, the analog unit 1006, the clock generation unit 1018, the ramp unit 1019, the column processing unit 1015, the horizontal selection unit 1014, the output unit 1017, and the like. The image capturing unit 1002 has a configuration in which unit pixels 1003 having photoelectric conversion elements are arranged in a matrix form, generates pixel signals corresponding to the amounts of incident electromagnetic waves, and outputs the pixel signals to vertical signal lines 1013 provided to columns.
The vertical selection unit 1012 controls row addresses or row scanning of the image capturing unit 1002 through row control lines 1011 when the unit pixels 1003 of the image capturing unit 1002 are driven. The horizontal selection unit 1014 controls column addresses or column scanning of the column A/D conversion sections 1016 of the column processing unit 1015. The read current source unit 1005 is a current source for reading the pixel signals from the image capturing unit 1002 as voltage signals. The analog unit 1006 performs amplification and the like according to necessity.
The column processing unit 1015 includes the column A/D conversion sections 1016 provided to the columns of the image capturing unit 1002. The column A/D conversion section 1016 converts an analog signal, which is the pixel signal output for each column from each unit pixel 1003 of the image capturing unit 1002, into digital data, and outputs the digital data. The clock generation unit 1018, for example, includes a ring-like delay circuit (corresponding to the ring-like delay circuit 201 of FIG. 21), and outputs a counter clock. The ramp unit 1019, for example, includes an integration circuit or a DAC circuit, and generates a reference signal which changes in an inclined manner through time.
The horizontal selection unit 1014 includes a shift register, a decoder and the like, and controls the column address or column scanning of each column A/D conversion sections 1016 in the column processing unit 1015. Accordingly, the A/D converted digital data is sequentially output to the output unit 1017 through horizontal signal lines.
Next, the configuration of the column A/D conversion section 1016 will be described. Each of the column A/D conversion sections 1016 has the same configuration, and includes a comparison unit 1110 and a counter 1101 (corresponding to the counter circuit 204 of FIG. 21).
The comparison unit 1110 includes a comparator circuit, and compares the pixel signal output from the unit pixel 1003 of the image capturing unit 1002 with the reference signal. For example, the comparison unit 1110 outputs a High level when the reference signal is larger than the pixel signal, and outputs a Low level when the reference signal is smaller than the pixel signal. The counter 1101 includes a binary counter circuit, and measures a comparison time until the comparison unit 1110 completes the comparison. Accordingly, a measurement value of the comparison time corresponding to the amplitude of the pixel signal is obtained as a count value of the counter 1101.
Next, the A/D conversion operation will be described. The detailed operation of the unit pixel 1003 will be omitted. However, a reset level and a signal level are output from the unit pixel 1003 as the pixel signal.
First, after the reset level is stably read from the unit pixel 1003, the comparison unit 1110 compares the reference signal with the pixel signal. The counter 1101 performs counting in an up-count mode, and a count value at the time of completion of the comparison is digital data of the reset level. Then, the count value of the counter 1101 is inverted.
Next, after the signal level is stably read from the unit pixel 1003, the comparison unit 1110 compares the reference signal with the pixel signal. The counter 1101 performs the counting in the up-count mode, and a count value of the counter 1101 at the time of completion of the comparison is digital data of a signal component (a signal obtained by subtracting the reset level from the signal level).
In the image pick-up device illustrated in FIG. 23, the counter 1101 corresponding to the counter circuit 204 illustrated in FIG. 21 performs the counting, so that an upper count value constituting an upper bit of digital data is obtained. However, since the image pick-up device has no configuration corresponding to the latch circuit 202 and the binarizing circuit 203 illustrated in FIG. 21, it is not possible to obtain a lower count value constituting a lower bit of digital data. Therefore, in the image pick-up device illustrated in FIG. 23, it is not possible to obtain digital data with high accuracy.
Circuits for obtaining an upper count value and a lower count value are arranged at units corresponding to the column A/D conversion sections 1016 of FIG. 23, so that it is possible to obtain digital data with high accuracy. As an example of such a circuit arrangement, an upper counter for obtaining the upper count value and a lower counter for obtaining the lower count value are considered to be arranged at the units corresponding to the column A/D conversion sections 1016.
In this case, the upper counter performs counting using one of output signals of a plurality of delay elements as a count clock, and the lower counter performs counting using a signal corresponding to the states of output signals of a plurality of delay elements as a count clock. When carry digit or shift-down digit has occurred in the most significant bit (MSB) of the lower count value counted by the lower counter, the upper counter performs counting using the MSB output signal of the lower counter as a count clock in order to adjust the upper counter value by the carry digit or shift-down digit.
Therefore, it is necessary to switch the counter clock input to the upper counter between one output signal of the plurality of delay elements and the MSB output signal of the lower counter. Hereinafter, the case in which the upper counter performs counting at the falling of the count clock (the upper counter performs counting when the count clock has changed from a High state (hereinafter referred to as an H state) to a Low state (hereinafter referred to as an L state)) will be described as an example.
The A/D conversion operation is an asynchronous operation, and a logic state of the count clock (one output signal of the plurality of delay elements) at a time point (a comparison completion time point) at which the comparison between the reference signal and the pixel signal has been completed is the H state or the L state. For example, when the logic state of the count clock at the comparison completion time point is the H state and a count clock in the L state is input from the lower counter to the upper counter through count clock switching, the logic state of the count clock changes from the H state to the L state before and after the switching, resulting in the occurrence of a phenomenon (erroneous count) in which the upper counter unnecessarily performs counting by one count. In other words, the erroneous count occurs due to the count clock switching input to the upper counter.

A/D conversion circuit and image pick-up device


Multimedia data objects in memory need not be processed serially from beginning to end but may instead be defined as algorithmically generated data streams. This functionality is provided through an architected application programming interface with a mechanism for defining a method of composing a complex object from smaller objects, for defining a behavior for the complex object, and for allowing that behavior to be varied based on external events.

1. Field of the Invention
This invention relates to multimedia data processing computer systems, and more particularly to a mechanism for specifying audio and video data objects to be asynchronously processed.
2. Description of the Related Art
Multimedia computer systems often deal with digital audio or video data objects that are contained in files, each of which is a named set of records stored and processed as a unit, and which files are recorded or played under control of application software. Application programs may also define these objects in memory, for example, by synthesizing an audio waveform with an algorithm. Once defined in memory, a data object may be played by the multimedia computer under application program control in much the same manner as if it were contained in a file.
The common approach for playing data objects from memory generally involves the application program passing a pointer to the data object to be played. In cases where objects are to be played repeatedly, or are to be played in combination, the application must continuously pass pointers to data buffers through a programming interface. An example is an application program that produces a visual animation of a horse walking, accompanied by a digital audio data stream of the sound of the horse's footsteps. The following code fragment illustrates what is required for the application program to play the representative sounds of the horse's footsteps with two digital audio waveforms of "clip" and "clop" sounds:
While (horse is walking)
send buffer for "clip" sound PA1 send buffer for "clop" sound PA1 send begin loop indicator with repeat count PA1 send buffer for "clip" sound PA1 send buffer for "clop" sound PA1 send end loop indicator
endwhile Note that for the above to be accomplished, the application must call the programming interface continuously, passing pointers to the data buffers.
Some existing programming interface designs provide simple looping constructs whereby data buffers may be played repeatedly. The following code fragment illustrates passing of data buffers to a programming interface that supports looping constructs, to accomplish the previously mentioned audio playback:
This approach, however, limits the application program's control over the data stream that is being produced and offers little, if any, interactive operation by the operator. In the case of the application producing the sound of the horse's footsteps, user interaction or some other stimulus may require that the sound be altered at some point after it is initiated, i.e., at run-time. For example, the surface upon which the horse is walking may be varied, changing the sound of the footsteps. Application programs cannot readily specify different buffers to be used once the initial loop of buffers is started using this approach.
One such example of this practice is for graphics display lists, whereby an application program defines a set of graphics drawing instructions to be executed by an asynchronous graphics display list processor. However, these relate to drawing instructions and not to the processing of multimedia data.

Playlist mechanism for specification of complex memory objects

International Business Machines Corporation


According to the present invention, there are provided a silicon wafer, wherein an epi-layer is not formed on a surface, and number of LSTDs having a size of 50 nm or more existing in a surface layer portion is 0.24 number/cm2 or less; a method for determining production conditions of a silicon single crystal, which comprises pulling nitrogen-doped silicon single crystals by the CZ method while varying V/G and/or PT, producing silicon wafers from the silicon single crystals, subjecting the silicon wafers to a heat treatment, determining acceptability of the wafers based on a predetermined characteristic value, obtaining correlation between the acceptability and V/G and PT, and determining production conditions based on the correlation; and a method for producing a silicon wafer comprising pulling a silicon single crystal so that V/G and PT should be lower than V/G and shorter than PT that are uniquely defined by predetermined nitrogen concentration and oxygen concentration in the silicon single crystal, conditions of heat treatment to which the silicon wafer is subjected, and grown-in defect density of the silicon wafer. According to the present invention, a nitrogen-doped annealed wafer showing a low defect density even under severe examination conditions and little fluctuation thereof depending on the production condition is produced.

The present invention relates to a silicon wafer having a grown-in defect density lower than that of conventional epitaxial wafers, annealed wafers and wafers having an N-region for entire plane, a method for determining production conditions of the same and a method for producing the same. The present invention further relates to a method for determining production conditions of a silicon single crystal that is for stable production of silicon wafers of low grown-in defect density, which-wafers are produced by subjecting silicon wafers produced from a nitrogen-doped silicon single crystal to heat treatment, and a method for producing the same.
In recent years, in connection with use of finer circuit elements accompanying the use of higher integration degree of semiconductor circuits, the demand for quality of silicon single crystals produced by the CZ method, from which substrates of the circuit are produced, has become higher. In particular, there are defects generated during the crystal growth, which are called grown-in defects including FPD (Flow Pattern Defect), LSTD (Laser Scattering Tomography Defect), COP (Crystal Originated Particle) and so forth, and degrade oxide dielectric breakdown voltage characteristics, device characteristics and so forth, and reduction of them has been considered important.
Therefore, there have been developed several kinds of wafers produced form of crystals having few grown-in -defects, including epitaxial wafer consisting a usual silicon wafer on which a silicon layer is newly provided by epitaxial growth, annealed wafers which is produced by subjecting wafers to heat treatments at a high temperature in hydrogen or argon atmospheres, wafers having an N-region (a region free from dislocation clusters existing outside the QSF ring) for entire plane which are produced by improving the growth conditions of CZxe2x80x94Si single crystals and so forth.
In addition, it is required to impart gettering ability to such wafers in order to eliminate contamination by impurities introduced during the device production process. To answer to this requirement, there have been also developed wafers imparted with the IG (Intrinsic Gettering) effect by using additional heat treatment, or doping impurities such as nitrogen or carbon to accelerate oxygen precipitation in bulk portions.
Among these, the wafers obtained by annealing nitrogen-doped wafers (referred to as xe2x80x9cnitrogen-doped annealed wafersxe2x80x9d hereinafter) are extremely useful as wafers showing reduced grown-in defects in wafer surface layer portions and high density of BMD (Bulk Micro Defect) in bulk portions. These are wafers developed by utilizing the defect agglomeration inhibition effect and the oxygen precipitation promotion effect of nitrogen doping, and since they have a smaller defect size compared with usual crystals, they show good efficiency for eliminating the defects in surface layers by annealing and they are wafers of effective gettering ability also showing a high BMD density in bulk portions.
However, if a highly precise defect evaluation apparatus such as MO-601 (produced by Mitsui Mining and Smelting Co., Ltd.) is used, it can be seen that these silicon wafers referred to with the term low defect also have defects, although their density is low. The apparatus MO-601 is a highly precise defect evaluation apparatus, which can measure even extremely fine defects having a size of about 50 nm, and also has a function enabling evaluation of defects along the depth direction for a depth of 5 xcexcm.
According to evaluation of defects having a size 50 nm or more (LSTD) for a depth of, for example, 5 xcexcm by using such a defect evaluation apparatus, it can be seen that there are defects in a density of about 40 number/6xe2x80x3 wafer (0.23 number/cm2) in usual epitaxial wafers and nitrogen-doped wafers undergone epitaxial growth, about 3000 number/6xe2x80x3 wafer (17 number/cm2) in annealed wafers, and about 70/6xe2x80x3 wafer (0.40 number/cm2) in wafers having an N-region for entire plane and nitrogen-doped wafers having an N-region for entire plane. Since these defects have an extremely small size, they do not cause any problem in many cases in the present device production process of the usual level. However, they are considered to inevitably cause a problem for the currently latest devices or devices expected to be produced in future.
Among these low defect wafers, the nitrogen-doped annealed wafers have the aforementioned useful effects, i.e., the grown-in defect agglomeration inhibition effect and the oxygen precipitation promotion effect, and in addition, they undergo the annealing process that eliminates defects, which is not used for epi-wafers or improved CZ wafers. Therefore, they are considered to have high potential as for reduction of grown-in defects in a considerable degree. However, the current nitrogen-doped annealed wafers shows significant fluctuation in the defect density for every production lot, and it was found that they contained defects at a level of at least about 140 number/6xe2x80x3 wafer (0.79 number/cm2) according to a measurement using the aforementioned MO-601. In order to further reduce these defects to stably produce wafers of low defect density, it is necessary to develop crystal growth conditions and annealing conditions in good balance.
Meanwhile, the nitrogen-doped CZ crystals, which are used as the raw material of nitrogen-doped annealed wafers, recently come to be actively studied, and researches about the grown-in defect agglomeration inhibition effect and the oxygen precipitation promotion effect have progressed. However, data have been scarcely obtained concerning if thermal history during the pulling of crystals affects on the formation of grown-in defects in nitrogen-doped crystals in a manner similar to that of non-nitrogen-doped crystals, or if it affects in a manner different much or less. Therefore, it is expected that, even though the annealing conditions are fixed, significant fluctuation of the detect elimination effect after the annealing would be observed, if the pulling conditions of nitrogen-doped crystals such as the thermal history during pulling of the crystals are changed.
In order to ameliorate such fluctuation, it is expected to employ an approach of eliminating more defects by annealing to obtain an extremely low defect density. However, it is not desirable to adopt such an approach because it requires costly annealing (annealing at high temperature for long time). Therefore, the defects should be controlled by the crystal pulling conditions. However, the crystal growth conditions have not been fully studied as described above, and claptrap development has been conducted so far, in which, for example, a crystal was pulled with some growth conditions, wafers are produced and annealed, and then it was confirmed if a necessary grown-in defect (mainly void defect) free region could be secured in the wafers. Thus, development cost might become high, and quality was not stabilized.
Further, since the thermal history also varies depending on the diameter of crystal, the annealing conditions may also be changed depending on it, and the crystal must be optimized for each annealing condition. However, sufficient researches have not been conducted also in this respect.
Therefore, the present invention was accomplished in view of the aforementioned problems, and its object is to produce a nitrogen-doped annealed wafer showing a low defect density and little fluctuation depending on production conditions by controlling grown-in defects in a nitrogen-doped crystal, which serves as a raw material of the nitrogen-doped annealed wafer.
Another object of the present invention is to provide a silicon wafer having extremely few surface defects in spite of not forming an epitaxial layer that invites increase of cost.
The present invention for achieving the aforementioned objects provides a silicon wafer, wherein an epitaxial layer is not formed on a surface, and LSTDs having a size of 50 nm or more existing in a surface layer portion are fewer than those existing in a surface layer portion of an epitaxial layer of a silicon epitaxial wafer.
The silicon wafer of the present invention can be a silicon wafer in which LSTDs existing in a surface layer portion are fewer than those existing in a surface layer portion of an epitaxial layer of an epitaxial wafer in spite of not forming an epitaxial layer on the surface, and it provides an advantage that it does not require any heat treatment for epitaxial growth that takes a long period of time.
In this case, the aforementioned surface layer portion may be a region having a depth of at least 5 xcexcm from the wafer surface.
Such a depth is defined because, if the surface layer portion containing extremely few defects consists of a region having a depth of at least 5 xcexcm from the wafer surface, it would be sufficient for producing, devices on the wafer surface.
The present invention also provides a silicon wafer, wherein an epitaxial layer is not formed on a surface, and number of LSTDs having a size of 50 nm or more existing in a surface layer portion is 0.23 number/cm2 or less.
The silicon wafer of the present invention can also be a silicon wafer containing few defects comparable to those of an epitaxial wafer or fewer defects than those of an epitaxial wafer in spite of not forming an epitaxial layer on the surface. Therefore, it does not require the epitaxial growth process, and thus productivity and cost of highly integrated devices are improved.
In this case, the aforementioned surface layer portion may be region having a depth of at least 5 xcexcm from the wafer surface, and the number of LSTDs having a size of 50 nm or more may be 0.06 number/cm2 or less.
Thus, the silicon wafer of the present invention can be a silicon wafer containing extremely fewer defects compared with even an epitaxial wafer, which has conventionally been considered a silicon wafer containing fewest defects, in spite of not forming an epitaxial layer. Therefore, it can be a wafer that is sufficiently adoptable for the latest extremely highly integrated devices or those expected to be produced in future.
In this case, 1.0xc3x97108 number/cm3 or more of BMDs may exist in a bulk portion of the aforementioned silicon wafer.
If such a sufficient amount of BMDs exist in the bulk portion of the silicon wafer as described above, the wafer can be a wafer having sufficient gettering effect in addition to the surface layer portion containing few defects.
Alternatively, the bulk portion of the aforementioned silicon wafer can be made to have 1.0xc3x97108 number/cm3 or more of BMDs by a heat treatment.
If such a sufficient amount of BMDs are precipitated in the bulk portion of the silicon wafer by a heat treatment as described above, impurities such as heavy metals in the wafer surface layer portion can be removed by a heat treatment. However, if the amount of BMD is too large, strength of the wafer may be degraded, and therefore the number is preferably 1xc3x971012 number/cm3 or less.
In this ease, the aforementioned heat treatment can be a heat treatment in the device production step.
If a device production heat treatment is also used as a gettering heat treatment without separately performing a gettering heat treatment as described above, the operation can be simplified and the gettering effect can be more easily obtained.
The present invention also provides a method for determining production conditions of a silicon single crystal, which comprises pulling one or more nitrogen-doped silicon single crystals by the Czochralski method while varying a ratio V/G of pulling rate V and temperature gradient G at a solid-liquid interfaces and/or a passage time PT for a temperature zone where grown-in defects agglomerate, producing silicon wafers from the silicon single crystal or crystals, subjecting the silicon wafers to a predetermined heat treatment, measuring a characteristic value of the silicon wafers to determine acceptability of the wafers based on a predetermined characteristic value, obtaining correlation between the acceptability and V/G and PT, and determining production conditions based on the correlation.
If the production conditions of single crystals are determined by pulling one or more nitrogen-doped silicon single crystals by the Czochralski method while varying V/G and/or PT, producing silicon wafers, and determining the production conditions according to the correlation between the acceptability based on the characteristic value of the silicon wafers after the heat treatment and V/G and PT as described above, there can be surely produced silicon single crystals that provide nitrogen-doped annealed wafers showing a low defect density even under severe examination conditions and little fluctuation thereof depending on the production condition.
Furthermore, if samples are obtained with various V/G and PT by using a suitable HZ (hot zone: internal structure of furnace in a CZ pulling apparatus) in the manner described above, it becomes sufficient to subsequently produce HZ only once, and single crystals containing extremely few grown-in defects can be surely obtained without producing HZ many times as the conventional practice. Thus, there is also obtained an advantage of reduced development cost.
In this case, the characteristic value of silicon wafers may be a grown-in defect density or electrical characteristic of the silicon wafer surface.
If the grown-in defect density or electrical characteristic of the silicon wafer surface is measured as the characteristic value of the silicon wafer and used as the standard for judgment of acceptability, silicon single crystals having a desired grown-in defect density or electrical characteristic can be stably produced by producing silicon single crystals with the production conditions determined based on the standard.
In this case, the measurement of the characteristic value of the silicon wafer can be performed after the silicon wafer surface undergone the aforementioned heat treatment is polished for a predetermined amount.
If the measurement of the characteristic value of the silicon water is performed after the silicon wafer surface undergone the heat treatment is polished for a predetermined amount as described above, a characteristic value at a position of a predetermined depth from the wafer surface can be easily evaluated, even when, for example, the measurement of the characteristic value is performed by using an apparatus that can measure grown-in defects only for the wafer surface.
In this case, when a nitrogen-doped silicon single crystal is pulled by the Czochralski method, nitrogen concentration and oxygen concentration in the silicon single crystal are preferably determined beforehand.
This is because the nitrogen concentration and oxygen concentration are parameters that closely relate to the BMD density, generation amount of Nxe2x80x94O donors etc., and hence in order to obtain desired values thereof, it is preferable to determine the nitrogen concentration and oxygen-concentration beforehand.
In this case, the nitrogen concentration and oxygen concentration can be determined based on the desired BMD density.
This is because the nitrogen-concentration and oxygen concentration are parameters that directly relate to the BMD density, and they are preferably adjusted to suitable levels, since unduly high oxygen concentration may cause problems such as large size of grown-in defects, while a higher oxygen concentration provides higher BMD density.
In this case, the aforementioned nitrogen concentration can be determined based on the desired generation amount of the Nxe2x80x94O donors.
This is because the nitrogen concentration is a value closely relating to the generation amount of the Nxe2x80x94O donors, and if too many Nxe2x80x94O donors are generated, a silicon single crystal of a desired resistivity may not be obtained.
In this case, when a silicon single crystal doped with nitrogen is pulled by the Czochralski method, it is preferably pulled under such conditions that at least the center of the crystal should become a V-rich region.
This is because, if an I-rich region and a V-rich region are intermingled in a plane of the wafer produced from the pulled crystal, it becomes difficult to eliminate the defects existing in the I-rich region such as the dislocation clusters by a heat treatment.
In this case, when a silicon single crystal doped with nitrogen is pulled by the Czochralski method, it is preferably pulled under such conditions that dislocation clusters are not generated over the entire plane for the radius direction of the pulled crystal.
This is because, in order to eliminate the defects that are difficult to be eliminated by a heat treatment such as dislocation clusters, which exist in the I-rich region, it is preferred that the crystal should be pulled under such conditions that dislocation clusters are not generated over the entire plane for the radius direction of the pulled crystal by controlling the pulling conditions such as V/G.
Furthermore, in the method for determining pulling conditions according to the present invention, the aforementioned change of PT can be attained by changing the pulling rate V during the pulling of silicon single crystal.
By using such a method, portions produced with various values of PT can be obtained in one silicon single crystal, and at least one type of HZ to be used is sufficient. Therefore, it is not required to design and produce various kinds of HZ for the confirmation.
In this case, it is preferable to perform a heat treatment at a temperature of 1150xc2x0 C. or higher for 1 hour or more as the aforementioned predetermined heat treatment.
This is because, if the silicon single crystal produced with the production conditions according to the present invention is subjected to a heat treatment at a temperature of at least 1150xc2x0 C. for 1 hour or more, a silicon wafer containing extremely few defects at a level that has never existed so far can be obtained.
The present invention also provides a method for producing a silicon wafer, which comprises producing a silicon single crystal using production conditions determined by the aforementioned method for determining production conditions of a silicon single crystal according to the present invention, and producing a silicon wafer from the silicon single crystal.
If a silicon wafer is produced by using a silicon single crystal that has been produced under conditions determined according to the present invention as described above, a silicon wafer containing extremely few defects at a level that has never been obtained so far can be stably obtained without fluctuation of their quality.
In this case, the produced silicon water is preferably subjected to a heat treatment, and it is more preferable to perform a heat treatment at a temperature of 1150xc2x0 C. or higher for 1 hour or more as the aforementioned heat treatment.
If the silicon wafer produced from a silicon single crystal that has been produced under conditions determined according to the present invention is subjected to a heat treatment, particularly preferably at a temperature of 1150xc2x0 C. or higher for 1 hour or more as described above, the silicon water can be surely made into a silicon wafer having the predetermined characteristic value.
As for the conditions for the heat treatment, it is preferably performed at a temperature of 1300xc2x0 C. or lower for 10 hours or less, if durability of heat treatment furnace, influence on wafer quality and cost are taken into consideration.
The present invention further provides a method for producing a silicon wafer comprising producing a silicon wafer from a silicon single crystal pulled by the Czochralski method with nitrogen doping and subjecting the silicon wafer to a heat treatment, wherein the silicon single crystal is pulled so that a ratio V/G of a pulling rate V of the single crystal and a temperature gradient G at solid-liquid interface, and a passage time PT for a temperature zone where grown-in defects agglomerate should be lower than a predetermined value of V/G and shorter than a predetermined time of PT, respectively, that are uniquely defined by predetermined nitrogen concentration and oxygen concentration in the silicon single crystal, conditions of heat treatment to which the silicon wafer is subjected, and grown-in defect density of the silicon wafer obtained after the heat treatment.
If the nitrogen concentration and oxygen concentration in the silicon single crystal, conditions of heat treatment to which the silicon wafer is subjected, and grown-in defect density of the silicon wafer obtained after the heat treatment are predetermined, and a silicon single crystal is pulled with V/G and PT respectively lower, and shorter than the values thereof uniquely defined by the above predetermined conditions as described above, a silicon wafer can be obtained with defects fewer than any conventional low defect wafers depending on its production conditions, and the silicon wafer show little quality fluctuation.
In this case, the aforementioned nitrogen concentration and oxygen concentration are preferably defined to be 1xc3x971013 to 2xc3x971014 number/cm3 and 12-18 ppma (JEIDA: Japan Electronic Industry Development Association standard), respectively, and the aforementioned heat treatment conditions are preferably represented as a heat treatment at 1200xc2x0 C. for 1 hour or more, or at 1150xc2x0 C. for 2 hours or more.
If the nitrogen concentration and the oxygen concentration of the silicon single crystal are selected to be within the aforementioned ranges, the problems caused by increase of grown-in defect size, generation of Nxe2x80x94O donors and so forth can be prevented, and if a silicon wafer produced in such a manner is subjected to a heat treatment at 1200xc2x0 C. for 1 hour or more, or at 1150xc2x0 C. for 2 hours or more, there can be produced a silicon wafer containing extremely few defects at a level never existed so far.
Since the wafer of the present invention contains extremely few defects, it can be used for the latest devices or devices to be produced in future, which are severely restricted as for defects, without causing degradation of device characteristics and yield reduction. Further, since the heat treatment conditions for reducing defects are similar to or less severe than those for the conventional annealed wafers, any costly process, such as argon annealing+ oxidation treatment, is not required. Further, by producing an SOI wafer utilizing the surface layer-portion of the wafer of the present invention, which contains extremely few defects, as an SOI (Silicon On Insulator) layer, it also becomes possible to produce devices of higher performance and function. Furthermore, according to the method of the present invention, various samples of V/G and passage time are obtained in a suitable HZ, and thus it is sufficient to subsequently produce HZ only once, In addition, single crystals and silicon wafers containing extremely few grown-in defects can be surely obtained.

Silicon wafer, method for determining production conditions of silicon single crystal and method for producing silicon wafer


A combined ultrasonic and eddy-current method and apparatus for non-destructively determining the liner thickness of a zirconium liner provided at the inner surface of a zirconium alloy nuclear fuel rod tube utilizes dimensional data acquired via conventional ultrasonic measurement techniques and impedance data acquired through electromagnetic techniques to calculate liner thickness in accordance with a specific formula. The apparatus utilizes a computer or programmable arithmetic unit with associated memory and I/O devices connected to electromagnetic and ultrasonic measurement subsystems. A particular eddy-current probe arrangement consisting of a differential coil pair is employed to obtain impedance measurements from the outside of the cladding tube. Calibrated reference impedance values for various different inner and outer tube diameters having a constant liner thickness are measured and retained in a memory. Calibrated reference impedance values for tubes of various liner thicknesses with the same inside and outside diameter dimensions are also measured and stored. A specimen cladding tube is tested and an inside diameter is computed using conventional electromagnetic techniques. The specimen tube inside diameter is also measured ultrasonically and a specific calculation of liner thickness is performed based on the difference between the inside diameter as determined by ultrasonic technique and the inside diameter as measured by eddy-current technique. The specific method of calculation utilized corrects for the erroneous effect that variations in cladding tube liner thickness can have on dimensions computed via conventional electromagnetic eddy-current techniques alone.

In various environments, the dimensional and structural integrity of certain critical components of a particular system or apparatus is of the utmost importance in assuring against future failures. One example of such a critical component is the "cladding" tube of a nuclear fuel rod. Conventionally, a column of nuclear fuel pellets are sealed into a metal cladding tube, which is assembled along with other fuel containing cladding tubes in a lattice structure constituting the fuel rod assembly of a nuclear reactor. The purpose of "cladding" the nuclear fuel is to prevent chemical reactions between the nuclear fuel and the coolant or moderator, and also to prevent partially gaseous radioactive fission products from leaking into the coolant or moderator from the fuel. Moreover, in order to withstand various structural stresses experienced during their service life as nuclear fuel rods, cladding tubes must be manufactured to exacting standards of dimensional and structural integrity. Accordingly, cladding tube wall thickness is an important dimensional criteria since a thin wall section, which is less than a minimum tolerance dimension, may seriously jeopardize the ability of the fuel rod to withstand stresses imposed by differences in thermal expansion between the cladding and the contained fuel pellets. Likewise, inner and outer tube diameters must be precisely controlled such that fuel pellets can be properly loaded within the tube and so that the tubes can be properly assembled into fuel rod bundles.
The structural and compositional integrity of cladding tubes is also very important. Conventionally, a zirconium alloy (e.g., Zircaloy-2 or -4) is used as a preferred material in the construction of cladding tubes as it is well known for its neutron absorption characteristics, corrosion resistance, and chemical stability at elevated steady state temperatures. Moreover, in order to further reduce the possibility of incurring internal tube wall stress corrosion and/or cracking due to localized thermal expansion differences between the nuclear fuel and the cladding tube, a liner of substantially pure zirconium is conventionally bonded to the inner surface of a cladding tube. A pure zirconium liner is utilized because of its superior ability to moderate localized stress/strains occurring along the inner surface of a cladding tube during abrupt temperature changes. It is critically important that the zirconium liner be of a uniform predetermined thickness (typically on the order of 80-100 microns in thickness) to be effective.
Concerning the critical nature of nuclear fuel rod cladding tubes, it is essential to carefully and accurately inspect each cladding tube over its entire length for both dimensional and structural integrity before it can be utilized as a nuclear fuel rod. Prior to the present invention, the thickness of a cladding tube inner lining (also called a "barrier" layer) was determined by destructive metallography of representative samples. However, for obvious practical and economic reasons, it is highly desirable to ascertain compliance of the liner thickness with design specifications using non-destructive testing methods.
As can be appreciated by those skilled in the art, ultrasonic inspection methods utilizing a transducer in a pulse-echo mode are commonly known to provide non-destructive dimensional measurements of critical components for quality assurance. A transducer is scanned over the component, either by motion of the transducer and/or the component while the transducer is periodically electrically excited to admit a probing ultrasonic energy pulse. In the intervals between pulses, the transducer receives echoes which may be analyzed for dimensional information. Unfortunately, when used to inspect cladding tube structure, ultrasonic wave analysis cannot accurately distinguish liner or barrier layer boundary echoes from cladding tube inner surface echoes (presumably due to the similarity of the materials involved and the extreme thinness of the lining).
Non-destructive electromagnetic profilometry techniques are also well known in the art. Some exemplary eddy-current impedance measurement systems of the type are discussed in U.S. Pat. No. 4,741,878, U.S. Pat. No. 4,673,877 and U.S. Pat. No. 3,967,382. However, conventional electromagnetic testing systems that are used to detect various defects and changes in tube wall thickness are known to employ electro-mechanical probes that are inserted into the cladding tubes and generate eddy-currents. These conventional eddy-current probe systems utilize scanning arrangements that require maintaining the probe element in constant sliding contact with the inner surface of the tube throughout the duration of the test. Such an arrangement inevitably increases the chances of scratching or marring the cladding liner during the testing procedure and, thus, damaging the tube in the process. Moreover, eddy-current probe arrangements of this type are typically mechanically complex, costly to manufacture, difficult to use, and susceptible to inherent inaccuracies caused by "lift-off" variations (i.e., varying gaps or distances between the surface of the eddy-current probe measuring coils and the inner surface of the tube).
In accordance with an exemplary embodiment of the present invention, an improved method and apparatus is provided for determining the average circumferential thickness of a zirconium liner or "barrier" layer provided on the inside surface of a nuclear fuel rod cladding tube. In particular, the present invention utilizes conventional ultrasonic measurement techniques and conventional electromagnetic eddy-current analysis techniques in a combined system arrangement that involves a specific method for computing liner thickness which overcomes the aforementioned problems associated with prior art approaches. Briefly, a particular eddy-current probe arrangement consisting of a differential coil pair is employed to obtain impedance measurements from the outside of the cladding tube. Calibrated reference impedance values for different inner and outer cladding tube diameters with the same liner thickness are measured from a calibration standard and retained in a memory. Calibrated reference impedance values for various liner thicknesses with the same inside and outside diameter are also measured and stored. A specimen cladding tube is then tested and an inside diameter is computed using conventional electromagnetic techniques. The specimen tube inside diameter is then measured ultrasonically and a specific calculation of liner thickness is performed based on the difference between the inside diameter as determined by the ultrasonic technique and the inside diameter as measured by the eddy-current technique. A specific computation is then performed which corrects for the erroneous effect that variations in cladding tube liner thickness can have on dimensions computed via conventional electromagnetic eddy-current techniques alone.
Eddy-current impedance measurements of a fuel rod cladding tube, however, are greatly effected by the respective compositions of the cladding tube and liner (e.g., the overall conductance of an induced eddy-current is dependent on the relative proportions of Zircaloy-2 and zirconium in the cladding). Consequently, the tube under test must necessarily have the same liner thickness (or relative proportions of respective metals) as whatever standard is used to initially calibrate the eddy-current measurement apparatus otherwise the measured conductances will not accurately reflect actual inner and outer diameter dimensions. Since this is obviously not feasible, inside diameter measurements as determined by eddy-current electromagnetic techniques may not correspond exactly to the actual inside diameter. Consequently, in accordance with a preferred embodiment of the present invention, cladding tube inside diameter is determined by conventional ultrasonic techniques as well as electromagnetic techniques. The difference between the "actual" inside diameter as determined by ultrasonic techniques and the inside diameter as measured by the above eddy-current technique is then used to accurately calculate the actual thickness of a cladding tube liner by a computational method discussed herein in greater detail below.
Although the present invention was developed as a result of a need for improved techniques to accurately measure the interior liner thickness of nuclear fuel rod cladding tubes, it would be appreciated by those skilled in the art that the invention has other uses, such as, for example, determining the thickness of metallic linings or coatings on other tubular members or other types of conduits.

Combined ultrasonic and eddy-current method and apparatus for non-destructive testing of tubular objects to determine thickness of metallic linings or coatings


A method for treating a surface of a first metallic component with an arrangement that includes (i) a receptacle, (ii) a polishing media located within the receptacle, and (iii) a mixing device operative to cause relative movement between the polishing media and the first metallic component is disclosed. The method includes the following steps (i) positioning the first metallic component within the receptacle so that the surface of the first metallic component is in contact with the polishing media, (ii) actuating the mixing device such that the mixing device causes relative movement between the polishing media and the surface of the first metallic component so that the polishing media polishes the surface of the first metallic component, and (iii) placing a chemical agent within the receptacle so that the chemical agent is in contact with the surface of the first metallic component at the same time the surface of the first metallic component is in contact with the polishing media such that the chemical agent causes an adherent chemical layer to be disposed on the surface of the first metallic component, wherein the adherent chemical layer reduces friction between the surface of the first metallic component and a surface of a second metallic component when the surfaces are in contact with each other. An associated arrangement is also disclosed.

During use, work machine components, such as gears of a crawler tractor, typically fail and must be replaced or reconditioned after a certain period of time. The replacement or reconditioning of these components increases the maintenance cost of the work machine.
The failure of the aforementioned components is usually due to the scuffing, wear, or pitting of a surface thereof, e.g. the surface of a gear tooth. Often more than one of these three failure modes (i.e. scuffing, wear, or pitting) occur concurrently to significantly decrease the "life" of the work machine component. The rate at which scuffing, wear, or pitting occurs on the surface of the work machine component is dependent on the amount of friction between the surface of the work machine component and a contacting surface of another work machine component. For example, the rate at which meshingly engaged gear teeth scuff, wear, or pit is dependent on the amount of friction between the contact surfaces of the gear teeth. Therefore, it is desirable to decrease the friction between the contacting surfaces of work machine components so as to decrease the rate at which they scuff, wear, or pit.
Heretofore, mechanical polishing has been utilized to decrease friction between the contacting surfaces of work machine components. In particular, the contacting surfaces are polished so as to remove surface irregularities thereby making the surfaces extremely smooth. Making oil lubricated contacting surfaces smooth reduces the friction therebetween. However, even after extensive mechanical polishing, microscopic surface irregularities (i.e. asperities) will still be present on the contacting surfaces of the work machine components. Therefore, even after mechanical polishing, there is a significant amount of friction between the contacting surfaces of work machine components due to the aforementioned microscopic surface irregularities. The local friction caused by these microscopic surface irregularities can cause the premature failure of the work machine components.
To address the above described drawback of mechanical polishing, various chemical additives have been added to lubricating oils so as to form a surface chemical film on the contacting surfaces of the work machine components. These surface chemical films allow "boundary lubrication" to occur between the contacting surfaces of work machine components. The occurrence of boundary lubrication further reduces the friction between contacting surfaces and increase the durability of work machine components as compared to the friction reduction obtained with mechanical polishing alone.
However, a drawback to using these chemical additives in a lubricating oil is the lack of control of the boundary lubrication on the surface of the work machine component. Another drawback to using these chemical additives in a lubricating oil is the that the lubricating oil must be in contact with the work machine component for a significant period of time before a surface chemical film can be disposed on the contacting surfaces. During the time it takes for the surface chemical film to be disposed on the contacting surfaces of the work machine components the work machine should not be utilized to its full capacity. In other words, during this "break in period" (i.e. the period of time it takes for the surface chemical film to be disposed on the contacting surfaces of the work machine components), the work machine should only be operated in a somewhat gingerly manner. For example, during the break in period the engine of the work machine should only be operated under a predetermined RPM (revolutions per minute) limit. While this break in period allows the surface chemical film to be formed on the contacting surfaces of the work machine components, it is inconvenient for the operator of the work machine. In addition, not adhering to the various constraints of the break in period can lead to the premature failure of work machine components.
What is needed therefore is a method and arrangement for reducing friction between metallic components which overcomes one or more of the above-mentioned drawbacks.

Method and arrangement for reducing friction between metallic components


In accordance with the present invention, a pyrometer adapter is disclosed for providing the optical head of a pyrometer access to a target area in a gas turbine engine, where the pyrometer adapter is subjected to relative motion between a first mounting surface and a second mounting surface, the pyrometer adapter including an outer tube having a first end mounted to the first mounting surface of the gas turbine engine and a second end terminating in a flange, and a second tube positioned radially inward of and in concentric arrangement with the outer tube, wherein the second tube extends through an opening in the first mounting surface so that the second tube is mounted at its first end to the gas turbine engine at the second mounting surface adjacent the target area and the pyrometer optical head is attached to a second end of the second tube, where the second tube also includes a flange extending from a middle portion thereof which is attached to the flange of the outer tube to form a flexible diaphragm which accommodates the relative motion between the first and second mounting surfaces.

1. Field of the Invention
The present invention relates to a pyrometer adapter for mounting a pyrometer in a gas turbine engine, and, more specifically, to a pyrometer adapter which accommodates relative motion between two mounting surfaces in the gas turbine engine.
2. Description of Related Art
Pyrometers are well-known for the measurement of temperature at certain hot areas in a gas turbine engine, such as turbine blades. Generally, such measurement is performed by exposing the pyrometer to infrared light in the targeted area, from which the temperature is determined by the bandwidth thereof. Typical of such pyrometers is that shown in U.S. Pat. No. 4,687,344 to Lillquist.
Because the pyrometer must be able to sense the light representing the thermal energy at the targeted area, an adapter is provided to penetrate applicable casings, liners, or the like. For example, in order to determine the temperature of a turbine blade, the pyrometer must be able to penetrate the turbine casing and the outer band of the turbine nozzle. This has been done in the past by means of a pyrometer adapter which includes a sight tube retained within a socket on the nozzle outer band (such as on a boss thereof). The prior art pyrometer adapter further includes a second tube concentric with and radially outside the sight tube, with a flanged end adapted for mounting to the turbine casing.
It is well-known that the nozzle outer band and the turbine casing are made of materials having different coefficients of expansion and are physically located in different proximity with respect to the thermal energy in the turbine. Accordingly, the nozzle outer band and the turbine casing thermally grow at differing rates, which causes relative motion between the outer tube and the sight tube of the pyrometer adapter. In order to sustain or accommodate this relative motion, a spherical bearing has been utilized at the junction of the sight tube and the outer tube, which allows the sight tube and outer tube to pivot. However, as the ambient temperature of gas turbine engines has increased (approximately 1200.degree. F.), it has been found that such a spherical bearing seizes and therefore does not reliably accommodate the relative motion. Moreover, the spherical bearing is not able to readily adjust to relative motion in three planes.


A robot-supported grinding method is described. In accordance with one example of the invention, the grinding method includes contacting a surface of a workpiece with a rotating grinding tool, whereby either the grinding tool or the workpiece is mechanically coupled to the tool center point (TCP) of a manipulator. The method further includes controlling an actuator that influences the grinding tool or the workpiece to produce a grinding force between the grinding tool and the workpiece, as well as measuring an actual deflection of the actuator. The rotational velocity of the grinding tool is adjusted depending on the measured actual deflection of the actuator and a reference deflection of the actuator.

The robot-supported apparatuses for abrasive machining, particularly grinding and sanding apparatuses that are presently on the market can only satisfy the demands for high quality surface finishing with great amounts of additional (manual) labor. In the following, the term grinding is used as collective term for grinding and similar abrasive processes (like sanding and polishing), in which material is abraded from a workpiece surface by a rotating tool. The grinding results depend greatly on the degree of contact pressure that the grinding tool (wheel or disk) places on the workpiece, as well as on the circumferential velocity of the grinding tool. A grinding process is not a static process and the parameters influencing it change constantly. When grinding manually, these changes can be recognized by an experienced craftsman and necessary measures can be taken. He/She can also visually monitor the grinding results and manually adapt the grinding process accordingly. This possibility is not readily available in the case of a robot-supported grinding process.
It is therefore an object of the present invention to provide a robot-supported apparatus for abrasive machining that is constructed to satisfy the high precision demands placed on a modem abrasive process such as grinding and that can compensate dynamic changes throughout the duration of the process. A further object is to reduce the deployment of personnel for adjusting and monitoring tasks to a minimum.

Apparatus for robot-supported abrasive machining

FerRobotics Compliant Robot Technology GmbH


An information distribution device includes: an action information collection unit that collects action information from an action information transmission device; a rules construction unit that, on the basis of a plurality of related pieces of action information constructs personalization rules including a selection condition and selection information; a rules transmission unit that transmits the personalization rules to an information reception device; and a distribution information transmission unit that transmits distribution information stored in a distribution information storage unit to the information reception device. The information reception device includes a filtering unit, which extracts, from the personalized rules received by a rules reception unit, personalization rules including a selection condition that matches the action information acquired by an action information unit, and which selects, from the distribution information received by a distribution information reception unit, the distribution information indicated by the selection information in the extracted personalized rules.

Information distribution systems that select distribution information on the basis of action information representing an action of a user and transmit the selected distribution information to a terminal of the user are known (see PTL 1, for example).
In the information distribution system described in PTL 1, information representing the position of a user terminal and information representing merchandise purchased by the user are used as action information. In the related technique, a server device has a registered user file, a purchase history file, a mobility pattern file, and an advertisement request file which contains distribution information representing advertisements. The registered user file is a file in which users who own user terminals are registered, and a purchase history file is a file in which purchase histories of the users are recorded. The mobility pattern file is a file in which users' mobility patterns based on histories of positional information of the user terminals are recorded. The server device extracts users to whom distribution information is to be transmitted on the basis of the purchase history file, the mobility pattern file and the advertisement request file. With this, the information distribution system can transmit distribution information selected on the basis of the purchase history and mobility pattern of a user to the user terminals. Distribution information selected on the basis of user's action information in this way will be hereinafter also referred to as personalized distribution information. A service that transmits personalized distribution information to user terminals will be also referred to as a personalized service.
In the personalized service described above, user's action information is privacy information for the user who provides the information. Accordingly, users may feel a strong reluctance to provide their action information to the information distribution system. However, in the information distribution system described in PTL 1, users who do not provide action information cannot receive personalized distribution information.
An information distribution system that addresses the problem is described in PTL 2. In the information distribution system, a user terminal holds distribution information and a selection logic. The selection logic is a logic for selecting distribution information on the basis of user's action information. The distribution information and the selection logic are distributed from a server beforehand. Such selection logics are generated beforehand by an analysis server which analyses action information acquired from a terminal of a subject. A user terminal collects action information of the user of the own device and applies the selection logic to the collected action information to select and output distribution information. This allows the user to acquire distribution information corresponding to the action information without providing the action information to the server.

Information distribution device information reception device, information distribution method, and recording medium


Described herein are compounds that are inhibitors of autotaxin. Also described are pharmaceutical compositions and medicaments that include the compounds described herein, as well as methods of using such inhibitors, alone and in combination with other compounds, for treating autotaxin-dependent or autotaxin-mediated conditions or diseases.

Autotaxin (ATX) is a secreted enzyme that is important for generating the lipid signaling molecule lysophosphatidic acid (LPA). Autotaxin has lysophospholipase D activity that converts lysophosphatidylcholine to LPA. LPA is a lipid mediator that functions, for example, as a mitogen, chemoattractant, and survival factor for many cell types. The ATX-LPA signaling axis is implicated in, for example, angiogenesis, chronic inflammation, autoimmune diseases, fibrotic diseases, neurodegenerative diseases, reperfusion injury post stroke or myocardial ischemia, reproduction and tumor progression.


An image-forming material includes a perimidine-based squarylium dye represented by the following Formula (I):

1. Technical Field
The present invention relates to an image-forming material.
2. Related Art
In recent years, a technology has attracted attention in which invisible information, which is not visible under normal visual conditions, is recorded on a document. The technology is useful in the security management and in embedding of Internet information or voice, and is able to enhance the added value of the document.
The invisible information may be recorded by a method in which an image-forming material having absorption in a near-infrared region of from 750 nm to 1000 nm—a wavelength region able to be detected by, for example, a silicon light-receiving device (such as CCD) but unable to be detected by human eyes—is used.

Abstract: wherein, in Formula (I), R represents a hydrogen atom or a methyl group.


A multi-diaphragm planar magnetic electro-acoustic transducer is provided, having a plurality of diaphragms arranged in one or more diaphragm modules. Each diaphragm comprises a substrate and at least one electrically conductive circuit on at least one surface of the substrate. Each diaphragm module comprises at least one diaphragm, each held taut by a frame. Each diaphragm module is disposed to one side or the other of at least one planar magnetic array, the diaphragm module being parallel to and aligned with the planar magnetic array to form the multi-diaphragm planar magnetic transducer. The planar magnets many have a vertical arrangement, a sideways arrangement, a staggered arrangement, and may comprise stators and/or a low reluctance backing plate or channel piece. The planar magnet arrays can be linear or circular.

Field
The disclosure relates to devices, methods, and systems relating generally to planar magnetic transducers and more specifically to a planar magnetic transducer having a plurality of diaphragms.
Description of the Related Art
In some approaches, planar magnetic acoustic transducers use a flat, lightweight diaphragm suspended in a magnetic field, rather than a cone attached to a voice coil. The diaphragm in a planar magnetic transducer has a conductive circuit pattern that, when energized with an electric current, reacts with the magnetic field to create forces that move the diaphragm to produce sound. In some approaches, planar magnetic acoustic transducers use a flat, lightweight diaphragm suspended in a magnetic field, rather than a cone attached to a voice coil. The diaphragm in a planar magnetic transducer has a conductive circuit pattern that, when energized with an electric current, reacts with the magnetic field to create forces that move the diaphragm to produce sound.
Diaphragm material consists of a very thin, flexible, and durable substrate. One example material suitable for this purpose is Kapton® polyimide film, as manufactured and marketed by DuPont™ of Research Triangle Park, N.C. The substrate is provided with a thin layer of electrically conductive material that is either laminated to or deposited on one or both faces of the substrate. Thus, diaphragms most commonly comprise either two layers: the conductive, often metal, layer and the substrate; or three layers: the conductive layer, an adhesive layer, and the substrate layer. If both sides of the substrate are to have a conductive layer, this represents an additional layer, or two layers if there is an adhesive layer between the substrate layer and the conductive layer. The conductive layer (or layers) is etched or otherwise cut to produce the conductive circuit pattern, either before or after being attached to the substrate.
The magnetic field is typically produced by a planar array of bar magnets, the bar magnets spaced apart regularly, but aligned parallel to each other, the poles of the bar magnets oriented to be perpendicular to the layer the magnets form. The diaphragm is suspended above the magnets, and substantial portions of the electrically conductive circuit pattern run parallel to individual bar magnets, as when current passes through these portions of the circuit, an induced magnetic field will react with the field produced by the magnets, causing the conductor, and the attached diaphragm, to be drawn to or away from the magnets.
However, there are drawbacks to this classic planar magnetic acoustic transducer design. The electrically conductive pattern can only handle so much power without having to increase the amount of conductive material, which alters the frequency response of the diaphragm due to increased mass and stiffness of the conductive material. This places a limit on the amount of acoustic power that can be developed by a diaphragm. Additional limitations of this design include non-linearity caused by variations in magnetic flux density between individual magnets, and variations with distance from the magnets. Another limitation is that combinations of audio signals from different sources must be electrically mixed before being used to drive the single diaphragm through a single electrically conductive circuit pattern, or if multiple patterns are used, then current capacity of one has been sacrificed for the other. Still another limitation is that when such signals are mixed and provided to a common transducer (the diaphragm), they are both subject to that transducer's resonances and other responses, which may not be optimal for one signal or the other, requiring additional power and equalization to obtain a desired result.
Another drawback of the classic design is when used in noise cancellation systems, where a separate microphone, near the edge of a planar magnetic transducer, is used to detect noise, which is then to be cancelled for a listener by a conjugate signal being fed to the transducer. In such an embodiment, the position of the microphone is not well matched to the natural resonances and other tunings of the transducer, nor are the axes of the microphone and transducer well aligned, for the purpose of addressing noise coming from different directions equally well. If the diaphragm is used as both a microphonic detector (the input transducer) and as a speaker (the output transducer), whether through separate electrically conductive circuits or a common one, there are significant limitations in differentiating what portion of the input signal is the result of noise that should be cancelled, and what portion is induced by the output signal and non-linearity of the diaphragm and magnetic fields.

Planar magnetic electro-acoustic transducer having multiple diaphragms


The present invention develops a new type of SPM, a scanning tunneling charge transfer microscope (STCTM). The STCTM is capable of first, detecting the transfer of an ultrasmall amount of charge (single electrons) or current (attoampere) into or out from a surface with atomic resolution and second, simultaneously measuring the electronic response of that surface to the transferred charge. This dual capability can be achieved by appropriately combining the virtues of the STM and a modified EFM. The STM provides the atomic resolution for the charge transfer, while the modified EFM provides the sub-electronic charge sensitivity for the current and charge detection. The STCTM, with sensitivity many orders of magnitude better than with SPM technology currently available, can be used to characterize the properties of molecules, ultrathin oxides, insulator surfaces, and clusters on insulators with atomic resolution.

The present invention relates to scanning probe microscopes and methods for using the same. In particular, the present invention relates to scanning probe microscopes and methods for using the same to detect the transfer of ultrasmall amounts of charge or current to or from a conducting surface under analysis and additionally measuring the electronic response of that surface to the transferred charge.
Scanning probe microscopes (SPMs) include several related technologies for imaging and measuring surfaces on a fine scale, down to the level of molecules and even single atoms. SPM techniques have the ability to operate on a scale from many microns down to sub-nanometers and can image individual atoms and molecules.
SPM technologies share the concept of scanning an extremely sharp tip (up to 50 nm radius of curvature) across the object surface. The tip is often mounted on a flexible cantilever, allowing the tip to move and follow the surface profile. When the tip moves in proximity to the investigated object, various forces of interaction between the tip and the surface influence the movement of the cantilever and are detected by selective sensors. Various other interactions can be measured and studied depending on the type of SPM used.
There are numerous types of SPM technologies, including atomic force microscope (AFM), scanning tunneling microscope (STM), lateral force microscope (LFM), magnetic force microscope (MFM), electrostatic force microscope (EFM), and scanning thermal microscope (SThM). STMs measure a weak electrical current flowing between the tip and the sample. STMs rely on the electrical conductivity of the sample, so features on the sample surface must be electrically conductive to some degree. STM systems measure the quantum tunneling current between a wire or metal-coated silicon tip and the object surface. An electronic feedback system maintains a constant current by positioning the tip at a substantially constant height above the surface.
The intense interest in understanding and utilizing the properties of atomic scale structure has motivated a significant effort to develop instrumentation for the ultrasmall domain. STMs, in particular, have been developed to provide characterization, manipulation and modification in this domain. The unprecedented atomic resolution achieved by STM has provided a direct method for visualizing and manipulating atoms and atomic scale structures. Additionally, the STM has been used to characterize the electronic properties of atomic scale surface structure of the sample being analyzed via stanning tunneling spectroscopy (STS). These abilities make it extremely useful tool for exploring the xe2x80x9cnanoworld.xe2x80x9d
The capabilities of the STM, however, are not limitless. In particular, the STM is limited to imaging structures having sufficient conductivity to provide a measurable current in a reasonable measurement time. Most STM measurements are performed with currents greater than a picoampere (10xe2x88x9212 ampere). Serious efforts to optimize current detection techniques have pushed the STM current detection limits into the 0.1 picoampere (10xe2x88x9213 ampere) range, and even lower currents can be measured (10xe2x88x9214 ampere range) if integration times are increased. However, imaging rapidly becomes very tedious under such conditions.
If the current detection sensitivity of the STM could be improved from the 100 femtoampere range (10xe2x88x9213 ampere≈106 electrons/sec) to the attoampere range (10xe2x88x9218 ampere≈10 electrons/sec) previously inaccessible surfaces and applications for the STM would emerge. For example, imaging many biomolecules by STM has been significantly limited by the poor conductivity of these molecules. Imaging these molecules at currents of about 103 to about 106 times smaller would provide several benefits, namely allowing imaging at larger tip/sample separations (larger tunneling gaps) that would reduce the tip-molecule interaction forces which have plagued much of the STM work on weakly adsorbed molecules. As well, molecules that appear as xe2x80x9cinsulatingxe2x80x9d at currents in the 10xe2x88x9213 ampere range may appear as xe2x80x9cconductingxe2x80x9d for currents in the 10xe2x88x9218 ampere range.
Due to the limitations of STM, many have turned to AFM to image insulating structures and molecules. While the AFM overcomes the need for electrical conductivity, true atomic spatial resolution by AFM is especially difficult on soft surfaces. As well, AFM devices have not been used to measure the tunneling of electron charges to or from a surface. The AFM also lacks the ability to directly measure the electronic properties of a surface.
If the current detection sensitivity of the STM could be improved to allow detecton of single electrons, then tunneling to or from insulating or localized surface states would be possible. Such sensitivity would also open up a new class of insulating materials that could be studied on the atomic scale. STMs with ultrahigh current sensitivity (i.e., attoamperes) might measure the charge transfer through thin oxides on semiconductors, between quantum dots and clusters, or to single electron devices. Many of these opportunities, as well as others, could be usefully explored by STMs at these ultrasmall currents.
The present invention develops a new type of SPM, a scanning tunneling charge transfer microscope (STCTM). The STCTM is capable of first, detecting the transfer of an ultrasmall amount of charge (single electrons) or ultrasmall current (attoampere) into or out from a surface with atomic resolution, second, detecting the energy at which the charge is transferred, and third, measuring the electronic response of that surface to the transferred charge. These capabilities can be achieved by appropriately combining the virtues of the STM and a modified EFM. The STM capability provides the atomic resolution for the charge transfer via tunneling, while the modified EFM capability provides the sub-electronic charge sensitivity for the current and charge transfer detection. The STCTM, with sensitivity many orders of magnitude better than with SPM technology currently available, can be used to characterize the properties of molecules, ultrathin oxides, insulator surfaces, and clusters on insulators, among others, with atomic spatial resolution.

Scanning tunneling charge transfer microscope


In a real time image recognition circuit, an image signal amplifier recognizes mouth or eye movement by which different functions within an automobile, including operation of a radio, air conditioner, cruise control, door locks, sun roof, windows, wipers, lighter, headlights, and defroster may be controlled. Improved focusing on pertinent portions of a human head, such as eyes and mouth, lessens the need to compensate for contrast in ambient light conditions, and thus enhances recognizability.

The present invention relates to an image signal amplifier, especially used for pre-processing of an image signal in a real time image recognition circuit.
For example by taking a picture of someone's face by television camera and processing the image signal to recognize movement of the mouth or eyes, power on/off or power up/down of a certain electric device can be controlled by optically recognizing such movement. Japanese Patent Application No. 60(1985)-272793 shows an example of this kind of device.
In this kind of optical control device, however, a device may not obtain image information necessary to recognize such movement when differences in image density are not sufficient. When a taken picture image is too dark or light, an automatic gain control (AGC) circuit is used to adjust an amplitude of the image signal to an appropriate density in order to recognize an image. Although a whole picture image may be light enough, a sampling area may be too dark or light. For example, in a bright background when people put on a hat and it makes a shadow on the eyes as shown in FIG. 6a, the eye part has less contrast than the contrast of a whole picture. When a light is applied to a subject from the side or at a slant, a part of the subject, for example hair, may make a shadow so that a contrast within the sampling area is lessened. In these situations, the AGC circuit may not adjust a signal level sufficiently to permit recognition.
When a microprocessor is used as an adjusting circuit, contrast can be adjusted by emphasizing a density of an image signal which is converted into a digital signal by the microprocessor. However, even digital processing has some problems, as mentioned below, when it is used for a real time image recognition circuit.
a) It is less effective if the differences in the density of the sampling area are not sufficiently bigger than an error of the quantization digital quantities.
b) It requires a high speed A/D converter with multi-bit operation and a large frame memory to minimize an error of the quantization digital quantities.
c) It takes a long time to process a recognizing operation of a microprocessor when there are many bits of image information.
When an amplitude of an image signal is adjusted as a full scale to the brightest part of an image signal, if a level of the brightest part is 100, an average density of a sampling area is 5, and the difference in density is 1, an error of the quantization of digital quantities has to be less than 1% in order to sample a preferred area. In this example, a preferred sample area has a 20% contrast; however, the difference in density is 1% of the full scale. Therefore, recognition is difficult.
When there is a wide dynamic range of image density, digital quantities have to be quantized by a large number of bits even if an image contains sufficient contrast This causes the above mentioned problems b) and c). Furthermore, when a part of an image information is emphasized by digital processing, data is required to show how much emphasis has to be done, so that this cannot be used for an automatic image recognition process.


An inflatable implant has a flexible shell that forms an internal lumen. It has a base portion and an envelope portion, with an aperture through the base. A tubing storage shell is in the lumen and attached to the base, forming a peripheral seal with the base around the aperture in the base. A flexible fill tubing is structurally permanently attached to the tubing storage shell, sealed with the aperture in the tubing storage shell and passing freely through the aperture in the base. A substantial length of the fill tubing is stored in the storage shell which can be drawn toward an incision in the skin of the patient so the volume of the implant can be adjusted without directly accessing the shell.

Fluid filled prostheses are widely used to replace excised tissue, for example after a radical mastectomy, or to augment it to improve surface configurations. Examples of both of these are regularly encountered in the field of cosmetic and reconstructive surgery. Although there are many applications where these are used, the most common is the mammary prosthesis, used to change the size or shape of the female breast. These are relatively long-lived applications, and are conventionally referred to as "prostheses".
There is yet another type of inflatable implant, which is typified in Radovan U.S. Pat. No. 4,217,889. The objective of this type of implant is to expand the skin by enlarging an implant underneath it. Then when the implant is removed, a longer surface length of skin remains, which can be used as a flap next to a burn site, for example. Other uses include advancing the hairline of a bald person. These implants are not properly called prostheses due to the short term of their usage, but they both can advangtageously use this invention. They will both be referred to herein as "inplants".
Many or even most implants are manufactured to a given size and shape, and are implanted without means or expectation of changing their size after implantation. However, in many situations it is desirable to be able to adjust the size over a substantial period of time. If the volume can later be adjusted, an implant of lesser initial volume can be implanted, and as the post-surgical swelling goes down, the implant used as a prosthesis can be enlarged. Also, because often the procedure is for cosmetic purposes, it is useful to be able to make a later adjustment of size without having to replace the prosthesis with one of a different size, which would require a subsequent surgical procedure. A useful example of an adjustable prosthesis is shown in Becker U.S. Pat. No. 4,643,733, issued Feb. 17, 1987.
A problem with the adjustable implants known to the instant inventor is that they require a normally-closed valve to be part of the implant itself to retain fluid in the implant once it is filled and to hold it so long as the implant is in place.
While implants of this type are quite durable and are not usually subjected to hard forces, still especially prosthetic implants are left in place for many years, and must also stand up to occasional rough usage. Furthermore the available materials of construction are limited because they are implanted, and some of these materials do permit long-term leaking out of fluids. As a consequence, gradual leakage over a period of time, or even relatively abrupt loss of fluid sometimes occurs, and this requires surgical techniques to replace the fluid or to replace the prosthesis.
The principal problem is in the fill valve itselt, which sometimes leaks. It is an object of this invention to provide an adjustable volume implant which does not require a fill valve at all, and in which, if for some reason more or less fluid is needed in the implant, the adjustment can be accomplished through a minor local surgical incision through the skin, without requiring direct access to the body of the inplant itself. Truly invasive surgery is not needed.


Dye-donor element for thermal dye recording comprising a dye layer comprising a dye and leuco-indoaniline dye as a light-stabilizer. The leuco-indoaniline dye is preferably a compound according to the formula: ##STR1## wherein R.sup.1 is H or any substituent, n is 0-4 each of R.sup.2 and R.sup.3 (same or different) is H or acyl, X is 0 or represents atoms completing a ring (system), each of R.sup.4, R.sup.5, R.sup.6, and R.sup.7 (same or different) is H, (cyclo)alkyl, aryl, alkyloxy, aryloxy, carbamoyl, sulphamoyl, --OH, halogen, --NH--SO.sub.2 R.sup.12, --NH--COR.sup.12, --O--SO.sub.2 R.sup.12, or --O--COR.sup.12, or R.sup.4 and R.sup.7 together and R.sup.5 and R.sup.6 together represent the atoms completing a ring (system), or R.sup.4 and R.sup.8 and/or R.sup.5 and R.sup.9 together and R.sup.5 and R.sup.6 together represent the atoms completing a heterocyclic nucleus, each of R.sup.8 and R.sup.9 (same or different) is H, (cyclo)alkyl, aryl, a heterocyclic nucleus, or R.sup.8 and R.sup.9 together represent the atoms completing a heterocyclic nucleus, each of R.sup.10, R.sup.11, and R.sup.12 (same or different) represents (cyclo)alkyl group, alkenyl, aryl, alkyloxy, aryloxy, alkylthio, arylthio, amino, or a heterocyclic nucleus.

Thermal dye transfer methods include thermal dye sublimation transfer also called thermal dye diffusion transfer. This is a recording method in which a dye-donor element provided with a dye layer containing sublimating dyes having heat transferability is brought into contact with a receiver sheet and selectively, in accordance with a pattern information signal, heated with a thermal printing head provided with a plurality of juxtaposed heat-generating resistors, whereby dye is transferred from the selectively heated regions of the dye-donor element to the receiver sheet and forms a pattern thereon, the shape and density of which are in accordance with the pattern and intensity of heat applied to the dye-donor element.
A dye-donor element for use according to thermal dye sublimation transfer usually comprises a very thin support e.g. a polyester support, one side of which is covered with a dye layer comprising the printing dyes. Usually, an adhesive or subbing layer is provided between the support and the dye layer. Normally, the opposite side of the support is covered with a slipping layer that provides a lubricated surface against which the thermal printing head can pass without suffering abrasion. An adhesive layer may be provided between the support and the slipping layer.
The dye layer can be a monochromic dye layer or it may comprise sequential repeating areas of differently coloured dyes e.g. dyes having a cyan, magenta, yellow, and optionally black hue. When a dye-donor element containing three or more primary colour dyes is used, a multicolour image can be obtained by sequentially performing the dye transfer process steps for each colour.
A primary coloured dye layer e.g. a magenta or cyan or yellow dye layer may comprise only one primary coloured dye (a magenta, cyan, or yellow dye respectively) or may comprise a mixture of two or more primary coloured dyes of the same hue (two magenta, two cyan, or two yellow dyes respectively).
All imaging dyes are unstable to light to some extent. Dyes are indeed known to degrade through a number of pathways, which often involve dye triplet states, radicals and/or singlet oxygen. Any improvement in the light stability of dyes is highly desirable therefore.
In photographic silver halide systems various light-stabilizers for dyes are known. For instance UV-absorbers are used frequently in a top layer to shield dyes from the harmful influence of ultraviolet radiation.
Unfortunately, such technique cannot be used in thermal transfer systems, because the dyes, after having been thermally transferred to a receiver sheet, are located in the very top layer of said receiver sheet. If in that case UV-absorbers would be present as well in said top layer, they would intimately mix with the transferred dyes and thus give rise to a so-called catalytic fading effect, which would degrade the dyes even faster.
For use in thermal transfer other types of light-stabilizers such as singlet oxygen quenchers and metal chelates have been described e.g. in EP 312,812. Although these compounds are known to constitute a class of effective stabilizers to light, their performance is not equally adequate for all types of dyes. But above all, the use of such light-stabilizers is undesirable because most of them comprise heavy metal ions, which nowadays raises increasing resistance for ecological reasons.
Furthermore, certain known light-stabilizers cause an undesirable stain in the receiver sheet.

Light-stabilizers for dyes for thermal dye transfer recording


A dishwasher is disclosed that includes a tub, an upper rack and a lower rack arranged in the tub and configured to receive objects a lower arm, a water supply pump configured to supply water to the lower arm chamber, a tower nozzle included in the lower rack and configured to inject water to the upper rack, a tower connection part detachable from the detachable pipe chamber and configured to connect and supply water to the tower nozzle based on being detached from the detachable pipe chamber, and a channel change unit provided in the lower arm chamber configured to alternately open (i) the chamber communication hole and (ii) an arm channel communication hole based on water pressure inside the lower arm chamber.

Generally, a dishwasher is an electric appliance configured to wash or dry objects, namely, dishes held in a washing room by using washing water.
FIG. 1 is a diagram of a conventional dishwasher. Such a conventional dishwasher includes a cabinet 200 in which a tub 210 for providing a washing room is arranged, upper and lower racks 220 and 230 provided in the tub to place washing objects thereon, a sump 240 arranged under the tub 210 to store the washing water therein, a lower arm 260 for injecting the washing water toward the lower rack, an upper arm 250 for injecting the washing water to the upper rack, a pump (P) for supplying the washing water stored in the sump 240 to the lower arm 260 via a first passage (P1), and a second passage (P2) branched from the first passage through a valve (V) to supply the washing water to the upper arm 250.
The sump 240 is supplied with the washing water via a water supply passage 241 and it has the washing water held therein drained via a drainage passage 243. The second passage (P2) is supplied the washing water drawn via the first passage (P1) to supply the washing water to the upper arm 250.
The upper arm 250 provided in the conventional dishwasher may be arranged between the upper rack 220 and the lower rack 230, to wash the washing objects held on the upper rack. Accordingly, a predetermined space is provided between the upper rack 220 and the lower rack 230 to arrange the upper arm 250 therein.
The size of an object that can be placed in the racks 220 or 230 may be limited by the placement of the upper arm 250. Furthermore, the size of the racks may be limited by the presence of the upper arm 250.
Moreover, the second passage (P2) may limit the size and position of the racks 220 and 230.