An ultrasonic diagnostic apparatus including a three-dimensional scanner for carrying out a three-dimensional scanning by ultrasonic waves. The apparatus also includes a three-dimensional image data former for forming three-dimensional image data based on scanning data obtained from the three-dimensional scanner. An image data memory is included as part of the apparatus for storing in time series a plurality of pieces of three-dimensional image data formed by the three-dimensional image data former. The apparatus includes a memory controller for controlling write and read of the three-dimensional image data into or from the image data memory. And the apparatus further includes a display image former for forming a display image based on three-dimensional image data read out from the image data memory by the memory controller, and for displaying the formed display image on a display unit.

1. Field of the Invention
The present invention relates to a three-dimensional ultrasonic diagnostic apparatus. More particularly, the present invention relates to an image memory technique for easily achieving many varieties of three-dimensional image analyses under arbitrary display conditions for volume data obtained in the past, by storing an obtained volume data in a loop memory in time series in a real-time three-dimensional ultrasonic diagnostic apparatus for carrying out an acquisition and display of the volume data in real time.
2. Description of the Background Art
A two-dimensional ultrasonic diagnostic apparatus conventionally utilized employs a system for displaying a tomographic image obtained by scanning one tomographic plane by an ultrasonic wave beam. In the mean time, in recent years, there have been carried out various trials of three-dimensional ultrasonic diagnosis for obtaining three-dimensional image data (that is, volume data) by acquiring diagnostic images while moving an ultrasonic probe that is an ultrasonic transceiver in a three-dimensional ultrasonic diagnostic apparatus. Thus, there has been placed a large expectation in a potential of a new diagnosis based on a three-dimensional image in this three-dimensional ultrasonic diagnostic apparatus. More particularly, researches have been progressed which is concerning the use of a manually or mechanically moving a convex probe or a linear-arrayed probe for abdomen or a multi-plane probe through esophagus having a function of rotating an electronic sector probe.
Particularly, there have recently been progressed researches and developments on a real-time three-dimensional ultrasonic diagnostic apparatus for acquiring and displaying three-dimensional information in real time, by electronically carrying out a three-dimensional scanning by ultrasonic waves at high speed. In other words, this real-time three-dimensional ultrasonic diagnostic apparatus is an apparatus for sequentially displaying volume data that is three-dimensional image data acquired.
The above-described three-dimensional ultrasonic diagnostic apparatus, however, has the following problems.
This real-time three-dimensional ultrasonic diagnostic apparatus is still at a research stage, and fundamentals including a detailed method of achieving this apparatus or utilizing the apparatus have not yet been established.
According to the above-described two-dimensional ultrasonic diagnostic apparatus, as tomographic image data acquired by ultrasonic waves is simply displayed as a two-dimensional image, the tomographic image displayed and the acquired data basically correspond to each other at 1 to 1. Therefore, by merely storing the acquired image data itself on the image memory, it is easy to analyze the past data of image displayed in the past, by displaying of this past data again.
In this conventional two-dimensional ultrasonic diagnostic apparatus, the past image is an image data itself acquired in the past. For example, although there has been a technique for separately storing a plurality of kinds of images such as B mode images, Doppler images like CFM, M mode images, etc., these kinds of images are basically two-dimensional image data respectively. Therefore, there has never been a case of displaying images quite different from the images displayed in the past.
As a technique that can be used for storing the above-described past record of image data, there is available a cine-memory replay technique. This cine-memory is a loop-structured memory (loop memory) for storing data arranged in time array by sequentially updating the data at prescribed time intervals. This technique is disclosed in, for example, Japanese Patent Application Laid-open Publication No. Hei 3-210247.
On the other hand, according to the above-described three-dimensional ultrasonic diagnostic apparatus, it is not possible to display all the acquired three-dimensional image data (hereinafter to be referred to as volume data) on an image display unit (a cathode-ray tube, CRT). Therefore, it is necessary to image-process these volume data and display the processed result on a two-dimensional CRT as a three-dimensional display image. In other words, as compared with the two-dimensional ultrasonic diagnostic apparatus, the conventional three-dimensional ultrasonic diagnostic apparatus, particularly the real-time three-dimensional ultrasonic diagnostic apparatus for scanning ultrasonic image information three-dimensionally at high speed as not an acquisition of tomogpraphic images but as one volume data, and displaying the scanned result by sequentially processing the images, has a characteristic that the three-dimensional image data acquired by ultrasonic waves does not correspond to the displayed three-dimensional image data at 1 to 1.
Therefore, the above-described three-dimensional ultrasonic diagnostic apparatus has a problem that it is possible to display only limited three-dimensional data when only the displayed three-dimensional image data is used as the past image. The above-described memory for storing only the displayed image data has not been sufficient for a three-dimensional ultrasonic system.
Further, generally, at the time of carrying out an ultrasonic diagnosis, an image is displayed by always changing display conditions of the image in order to perform an optimum analysis of the image displayed.
Therefore, particularly in the case of observing a moving tissue such as a blood stream of a subject (that is, human body under examination), or in the case of observing a display image by moving it, the conventional three-dimensional ultrasonic diagnostic apparatus has a problem that it requires a frequent complex operation for adjusting display conditions each time an image displayed in the past is replayed, making it difficult to replay the past images.
In other words, a method of displaying a three-dimensional image with respect to three-dimensional image data is theoretically limitless. It has, therefore, been required to obtain a new technique for achieving a function of replaying a past image from the viewpoint of display conditions of identifying an angle and conditions from which an object to be diagnosed is observed as a three-dimensional image.
The present invention has been made to solve the above-described problems of the conventional technique. It is an object of the present invention to provide a three-dimensional ultrasonic diagnostic apparatus capable of displaying past three-dimensional display images retroactively to a prescribed past time, by keeping a record of volume data in a memory system of a loop memory (cine-memory) structure that stores data of time- series array by sequentially updating the data at prescribed time intervals.
Further, it is another object of the present invention to achieve a replay of a past three-dimensional display image can be achieved in an easy operation, by storing in the loop memory display conditions of the three-dimensional display image formed from the stored volume data. It may be so structured that a display condition of the past three-dimensional display image can be arbitrarily selected according to the need of desired analysis, from among a display condition based on the past display and a currently-set display condition.
Therefore, it is possible to carry out in an easy operation various three-dimensional image analyses retroactively to the past images based on the past volume data record. Furthermore, it is possible to carry out a three-dimensional image analysis at high speed and in high precision.
According to one aspect of the present invention, as shown in FIG. 1, there is provided an ultrasonic diagnostic apparatus, comprising:
a three-dimensional scanner (1, 2, 3) for carrying out a three-dimensional scanning by ultrasonic waves; a three-dimensional image data former 4 for forming three-dimensional image data based on scanning data obtained from the three-dimensional scanner; a three-dimensional image data memory 5 for storing in time series a plurality of pieces of three-dimensional image data formed by the three-dimensional image data former; a memory controller 6 for controlling write and read of the three-dimensional image data into or from the three-dimensional image data memory; and a display image former for forming a display image based on three-dimensional image data read out from the three-dimensional image data memory by the memory controller, and for displaying the formed display image on a display unit.
According to another aspect of the present invention, as shown in FIG. 2, there is provided an ultrasonic diagnostic apparatus, comprising:
a three-dimensional scanner (1, 2, 3) for carrying out a three-dimensional scanning by ultrasonic waves; a three-dimensional image data former 4 for forming three-dimensional image data based on scanning data obtained from the three-dimensional scanner; a three-dimensional image data memory 5 for storing in time series a plurality of pieces of three-dimensional image data formed by the three-dimensional image data former; a display condition data memory 10 for storing in time series a plurality of pieces of display condition data for forming the three-dimensional display image, the display condition data being corresponding to each of the tree-dimensional image data; a memory controller 62 for controlling write and read of the three-dimensional image data and the display condition data into or from the three-dimensional image data memory and the display condition data memory; and a display image former 7 for forming a display image based on three-dimensional image data read out from the three-dimensional image data memory and display condition data read out from the display condition data memory by the memory controller, and for displaying the formed display image on a display unit.
The apparatus shown in FIG. 2 may further comprise a display condition selector for selecting either the display condition data used in the past for forming a three-dimensional display image based on the three-dimensional image data or currently-set display condition data, according to a user""s instruction; wherein, the display image former forms a display image based on the read-out three-dimensional image data, based on display condition data selected by the display condition selector.
The display condition information may include at least one of a direction of a probe to a subject, opacity, color information added to a Doppler image, and a threshold value for extracting an area of the subject.
The above-described apparatus may further comprise a display image memory 15 for storing in time series a plurality of the display images, the display image being corresponding to the three-dimensional image data, as shown in FIG. 3.
The above-described apparatus may further comprise, as shown in FIG. 5, a position data generator 31 for generating probe position data according to a position of the three-dimensional scanner; and a position data memory 32 for storing in time series the probe position data obtained from the position data generator with making the probe position data correspond to each of the three-dimensional image data stored in the three-dimensional image data memory.
In this case, the display image former 7 may be structured to form a display image of a wider range than that of each of the three-dimensional image data by connecting a plurality of pieces of three-dimensional image data stored in the three-dimensional image data memory, according to the probe position data.
Alternatively, the display image former 7 may be structured to form a display image with corrected image quality of each three-dimensional image data by combining a plurality of pieces of three-dimensional image data stored in the three-dimensional image data memory, according to the probe position data.
Alternatively, the display image former 7 may also be structured to calculate a relative position for indicating what portion of a subject a display image corresponds to, according to reference position data for indicating a position of the three-dimensional scanner set on the subject and the probe position data, and to display an indicator for indicating the relative position based on the calculated relative position together with the display image.
Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

Three-dimensional ultrasonic diagnostic apparatus


A bearing assembly permits one bearing bushing to be employed in both applications that permit self-aligning pivoting movement of a rotating shaft and applications that rigidly support a rotating shaft, thereby eliminating the need to inventory two different types of bearings for these two different applications.

(1) Field of the Invention
The present invention pertains to a bearing assembly that is equally well-suited for use in self-aligning and rigid shaft supporting applications. More particularly, the bearing assembly of the invention permits one bearing bushing to be employed in both applications that permit self-aligning pivoting movement of the support for a rotating shaft and applications that rigidly support a rotating shaft, thereby eliminating the need to inventory two different types of bearings for these two different applications.
(2) Description of the Related Art
Self-aligning bearing assemblies are often used in environments where the bearing assembly provides support from a structure to a rotating shaft while permitting a limited degree of shaft pivoting movement relative to the supporting structure. A typical application of this type is found on the output shaft of an electric motor, although self-aligning bearing assemblies are employed in various other applications. This illustrative environment of the prior art self-aligning bearing assembly is shown in drawing FIGS. 1-3.
The typical prior art self-aligning bearing assembly is comprised of a bearing seat 10, a bearing bushing 12, a retaining ring 14, and a sealing cap 16.
In the application shown in FIGS. 1-3, the bearing seat 10 is formed as part of an end shield 18 of an electric motor housing. The bearing seat 10 is cast integrally with the housing end shield 18. Aluminum is often employed in casting the bearing seat and the end shield. The bearing seat has a shaft opening 20 through its center. When the end shield 18 is assembled to an electric motor (not shown) the rotor shaft of the motor will pass through the shaft opening 20. A bearing land surface 22 supports the bearing bushing 12 in sliding engagement extends around the shaft opening 20. In some bearing seats the land surface extends as a single continuous surface around the shaft opening, and in other bearing seats the land surface is actually formed as several separate surfaces that are spacially arranged around the shaft opening. In the illustrative prior art shown in FIGS. 1-3, the bearing land surface 22 is shown as three separate surface sections spacially arranged around the shaft opening 20. In cross-section, the land surfaces 22 have a concave configuration. Together the land surfaces 22 define a cup or socket shape with the shaft opening 20 at the bottom, center of the socket shape.
Referring to FIG. 2, the prior art bearing bushing 12 has a semi-spherical forward end 24 and a cylindrical rearward end 26. A shaft bore 28 extends axially through the center of the bushing. The interior diameter of the shaft bore 28 is sized to securely mount the motor shaft for rotation in the bore. The semi-spherical forward end 24 of the bushing is defined by the spherical shape of the bushings bearing surface 30 that mates in sliding engagement with the land surfaces 22 of the bearing seat. The shape of the bearing surface 30 is complimentary to the curvature of the bearing seat land surfaces 22. This enables the bearing bushing 12 to pivot to a limited extent on the bearing land surfaces. The bearing bushing 12 is often constructed of powdered metal iron graphite that is a softer material than the aluminum employed in constructing the bearing seat 10. The powdered metal of the bearing bushing is also porous which enables the bearing surface 30 to retain lubricant which enhances its ability to pivot on the bearing seat land surfaces 22.
The method of assembling the prior art self-aligning bearing assembly is shown in FIG. 1. The motor end shield 18 is shown placed face down with the interior surface 32, or that surface that would face the stator and rotor of the electric motor, facing upwardly. The bearing seat 10 is shown at the center of the end shield 18. The bearing bushing 12 is placed in the bearing seat 10 with the bearing surface 30 of the bushing resting on the land surfaces 22 of the bearing seat. A tooling pilot shaft 34 is inserted through the shaft bore 28 of the bushing. The retaining ring 14 functions somewhat like a Belleville spring and is placed over the shaft and press-fit into a cylindrical collar 38 of the bearing seat that extends upwardly from the land surfaces 22. Projecting tabs 40 of the retainer engage against the interior surface of the cylindrical collar 38 and hold the retaining ring in its position pressed downwardly into the cylindrical collar. A center ring 42 of the retainer passes around the cylindrical rearward end 26 of the bearing bushing and engages against an annular shoulder 44 of the bearing bushing that separates the cylindrical rearward end 26 from the semi-spherical forward end 24. When inserted completely into the cylindrical collar 38, the center ring 42 of the retaining ring 36 exerts a biasing force against the annular shoulder 44 of the bearing bushing that forces the bearing surface 30 of the bushing into engagement with the land surfaces 22 of the bearing seat. This biasing force also produces the correcting or centering force on the bearing bushing 12 that urges the bearing bushing 12 to return to a position where a center axis passing through the bearing bushing shaft bore 28 is aligned coaxially with a center axis passing through the bearing seat shaft opening 20. In completing the construction of the prior art self-aligning bearing assembly, a lubricant may be applied within the cylindrical collar 38 of the bearing seat 10 and then the sealing cap 16 is press-fit into the cylindrical collar 38 to retain the lubricant and complete the assembly of the self-aligning bearing assembly.
A primary benefit provided by the self-aligning bearing assembly is that the motor end shield 18 does not have to be perfectly aligned with the center axis of the electric motor rotor and stator when the end shield is assembled to the motor, i.e., the center axis (not shown) of the end shield bearing seat shaft opening 20 does not have to be perfectly aligned with the center axes of the electric motor rotor and the electric motor stator. If these axes are not perfectly aligned when the end shield 18 is assembled to the electric motor, the bearing bushing 12 will pivot slightly on the bearing seat land surfaces 22 to compensate for the misalignment and thereby support the motor shaft for rotation in the end shield 18 without having the end shield perfectly oriented relative to the shaft.
In the construction of electric motors, there are applications where the motor end shield must be properly positioned relative to the shaft. In these applications, the end shield itself is used to orient the motor shaft relative to the environment in which the motor is used. For example, where the electric motor is used to power a transmission such as a gearing transmission, the motor end shield would typically be connected directly to the supporting structure, i.e., the casing of the gearing transmission. If the motor shaft was improperly oriented relative to the motor end shield, for example if the shaft center axis was not perfectly aligned with the center axis of the end shield shaft opening, then the shaft would not be perfectly aligned with the center axes of the gears employed in the gearing transmission attached to the motor end shield. This would result in gears of the transmission not properly meshing with each other and often produced accelerated and uneven wearing of the gear teeth. Similar problems would also occur in other environments. For example, if the motor were powering a belt and pulley transmission, the center axis of the drive pulley mounted on the motor shaft would not be aligned parallel with the driven pulley of the transmission. This would also result in accelerated wear of the belt connected between the drive and driven pulleys. Also, if the motor were used to power a pump, the misalignment of the motor shaft and the pump shaft could cause pump seals to wear and leak. Therefore, in those applications where it was required that the motor shaft center axis be aligned with the center axis of the end shield shaft opening, a fixed bearing assembly was needed which would hold securely the shaft relative to the motor end shield and not permit any misalignment or pivoting movement of the motor shaft.
The two different environments described above have required two different bearing assemblies, i.e., one bearing assembly that would permit self-aligning movement of the motor shaft relative to the supporting structure or end shield of the bearing seat, and a second bearing assembly that would hold the motor shaft securely relative to the supporting structure or the bearing seat of the motor end shield. This required manufacturers of electric motors to inventory two different types of bearing assemblies for their motors which resulted in incurring additional costs for inventorying these two different types of bearing assemblies.

Self-aligning/rigid spherical bearing assembly


A gel-fiber glass (GFG) is a newly-formed sol-gel glass polymerized from tetramethoxysilane on the surface of activated glass wool fibers or activated fibrous glass. GFG is a support for trapped chemical or biochemical reagents. A thin layer of reagents trapped in gel glass during its preparation is present on the surface of a lattice of glass fibers. Columns for affinity chromatography were prepared from the GFG membranes with entrapped antigens or antibodies and were used to isolate different proteins, including tumor-associated antigens; GFG membrane demonstrated high effectiveness and stability, and can isolate proteins in extremely high amounts. The membranes can be used in diagnostic practice, generation of specific antibodies and therapy.

Hydrophilic polymers play a great role as supports for chromatographic procedures in biotechnology. A variety of methods has been available for the analytical isolations of proteins. Plastic and glass supports are common materials which are widely used for chemical binding of proteins. Sol-gel glass is one of the new supports to direct trapping of different materials (Brinker and Scherer, 1990). This matrix was obtained together with chemical and biochemical reagents using the process of polymerization of the support (Zusman et al., J. Non-Crystal. Solids, 122:107-109, 1990; Materials Letters, 10:1-5, 1990; Analyt. Biochem., 201:103-106, 1992).
The first phase hydrolysis of this process can be described as follows: EQU Si(OR).sub.4 +H.sub.2 O<==>HOSi(OR).sub.3 +ROH
As this process continues Si--OH groups are obtained. The next phase of polymerization is the polycondensation. This latter phase is characterized by elimination of H.sub.2 O molecules and alcohol and by transforming SiOH molecules into latticed fibers of SiO.sub.2.
Obtaining a small volume of polymerized glass from 1 ml of tetramethoxysilane has taken about 14 days. In spite of that, the obtained sol-gel glass is a porous material. Part of chemical and biochemical compounds remains inside of the gel-glass mass inaccessible for any external reagent. This decreases the amount of trapped materials for performing analytical reactions, especially in biochemical and immunochemical studies. To have access to all the reagent molecules, the prepared glass was crushed into a powder.
All these procedures have very serious defects. As is known, SiO.sub.2 is insoluble in the water. Alkaline environment dissolves SiO.sub.2 to form silicates according to the reaction EQU SiO.sub.2 +2NaOH<==>Na.sub.2 SiO.sub.3 +H.sub.2 O
SiO.sub.2 in the powder condition passes this reaction very fast, and this makes those columns unstable under effects of alkaline buffers which are necessary for purification of proteins and performing the diagnostic procedures.
In the present invention described herein, all the advantages of the prior art are maintained and a new approach which avoids the disadvantages of the prior art is provided.

Gel-fiberglass and a method for its preparation


An error correction method and apparatus for correcting multiple errors in received digital data word signals calculates syndromes S.sub.0, S.sub.1, S.sub.2 and S.sub.3 from a block of n received data words and a parity check matrix H. First coefficients .sigma..sub.1 and .sigma..sub.2 are calculated from the derived syndromes and a second coefficient K is calculated from the first coefficients .sigma..sub.1 and .sigma..sub.2. An error location value x.sub.1 is calculated from the second coefficient K, actual error location values X.sub.1 and X.sub.2 are calculated from the value x.sub.1, and error values Y.sub.1 and Y.sub.2 are calculated from the actual error location values X.sub.1 and X.sub.2. The received data words are then corrected by applying the calculated error values Y.sub.1 and Y.sub.2. The error location value x.sub.1 calculator is preferably constituted by logic gates which enable the apparatus to be smaller and faster than those using a conventional ROM table.

Generally, an error correction apparatus is applied to a digital communication system or a digital storage system, and can correct errors generated in the data to be received or to be reproduced.
As an example of the conventional error correction technique, there is a Japanese patent laid-open publication No. sho 57-25047 entitled "Error Correction Method" by SONY Corporation of Japan, published on Feb. 9, 1982. This publication discloses a method which can correct even two-word errors in a block of data having n words, each of which is composed of m bits.
The detailed descriptions are as follows.
The K syndromes S.sub.0 to S.sub.K-1 are obtained from a block of data V.sup.T consisting of n words to be received and a parity check matrix H by the following operation: ##EQU1##
Here, the parity check matrix H has n columns and k rows, and each of the elements in a predetermined row is selected among .alpha..sup.0 (=1) to .alpha..sup.2m-2, where the element .alpha. is a root value satisfying the equation F(X)=0. Thus, two identical values are not found within the predetermined row, and the elements in the other rows are selected by the involution of the corresponding elements of the predetermined row. The parity check matrix H is represented as follows: ##EQU2##
In case of a double word error ei and ej, the equations for the syndromes S.sub.0, S.sub.1, S.sub.2, S.sub.3 are as follows: EQU S.sub.0 =ei+ej EQU S.sub.1 =.alpha..sup.i ei+.alpha..sup.j ej EQU S.sub.2 =.alpha..sup.2i ei+.alpha..sup.2j ej EQU S.sub.3 =.alpha..sup.3i ei+.alpha..sup.3j ej.
The above equations can be modified as follows: EQU (.alpha..sup.i S.sub.0 +S.sub.1)(.alpha..sup.i S.sub.2 +S.sub.3)=(.alpha..sup.i S.sub.1 +S.sub.2).sup.2.
If the equation is again modified, the following error location polynomial is obtained: EQU (S.sub.0 S.sub.2 +S.sub.1.sup.2).alpha..sup.2i +(S.sub.1 S.sub.2 +S.sub.0 S.sub.3).alpha..sup.i +(S.sub.1 S.sub.3 +S.sub.2.sup.2)=0 EQU S.sub.0 S.sub.2 +S.sub.1.sup.2 =A EQU S.sub.1 S.sub.2 +S.sub.0 S.sub.3 =B EQU S.sub.1 S.sub.3 +S.sub.2.sup.2 =C
The error locations for two-word errors can be calculated by using the coefficients A, B, and C of the polynomial equation.
[1] In the case of no errors: EQU A=B=C=0, S.sub.0 =0, S.sub.3 =0.
[2] In the case of a one-word error:
When A=B=C=0, S.sub.0 .noteq.0, and S.sub.3 .noteq.0, a one-word error is determined. An error location i can be easily obtained from the equation .alpha..sup.i =S.sub.1 /S.sub.0, and an error correction can be made using ei=S.sub.0.
[3] In the case of a two-word error:
In the case of an error of two words or more, the relationships of A.noteq.0, B.noteq.0 and C.noteq.0 are satisfied. At this time, the following relationship is satisfied: EQU A.alpha..sup.2i +B.alpha..sup.1 +C=0
in which i ranges from zero to n-1.
If it is assumed that the relationships of B/A=D and C/A=E are satisfied, the following equations are obtained: EQU D=.alpha..sup.i +.alpha..sup.j EQU E=.alpha..sup.i .alpha..sup.j.
Accordingly, the following equation is derived from the above equations: EQU .alpha..sup.2i +D.alpha..sup.i +E=0.
Here, when the difference of two error locations is t, that is, when the relationship of j=i+t is satisfied, the following equations are obtained: EQU D=.alpha..sup.i (1+.alpha..sup.t) EQU E=.alpha..sup.2i+t.
Whereby, the following equation can be further derived: ##EQU3##
The values of .alpha..sup.-t +.alpha..sup.t for t=1 to (n-1) are previously stored in ROM, and t is obtained by detecting an agreement between an output of ROM and a value of D.sup.2 /E calculated from the received word. If there is no agreement, the error is determined to be three words or more.
Thus, the following relationships are assumed: ##EQU4## Through derivation, the following equations are true: ##EQU5##
From the above equations, the error locations i and j are obtained. Then, the error patterns ei and ej are represented as follows: ##EQU6## The error locations and error patterns are obtained through the above-mentioned process, so that the error of the received word at the corresponding error locations can be corrected according to the error patterns.
However, in the method proposed in the Japanese patent laid-open publication No. Sho 57-25047, in order to obtain the error locations, the error locator polynomial .alpha..sup.2i +D .alpha..sup.i +E=0 is solved to obtain two roots .alpha..sup.i, .alpha..sup.j from which the error locations i and j are obtained, making the circuit required for the operations overly complicated, and the operational delay time overly long.

Error correction method and apparatus thereof


A system adapts power for minimizing the total amount of transmitted power in a wireless communications network. A transmit station transmits a communications signal requesting a response from receiving mobile stations. A plurality of the mobile stations receives the communications signal and each evaluates the signal reception, such as the signal-to-noise ratio or transmitted power. Each mobile station responds by transmitting a communications signal back to the transmit station in a specific time slot as a function of the signal reception to allow the transmit station to adapt its power based on the time slot of the communications signals received from respective mobile stations. This minimizes the total amount of power transmitted by the wireless communications network.

Some multi-band or other tactical radios operate in the high frequency (HF), very high frequency (VHF) (for satellite communications), and ultra high frequency (UHF) bands. The range of these multi-band tactical radios can operate over about 2 through about 512 MHz frequency range. Next generation radios will probably cover about 2.0 to about 2,000 MHz (or higher) to accommodate high data rate waveforms and less crowded frequency bands. This high frequency transmit mode is governed by standards such as MIL-STD-188-141B, while data modulation/demodulation is governed by standards such as MIL-STD-188-110B, the disclosures which are incorporated by reference in their entirety.
UHF standards, on the other hand, provide different challenges over the 225 to about 512 MHz frequency range, including short-haul line-of-sight (LOS) communication and satellite communications (SATCOM) and cable. This type of propagation can be obtained through different weather conditions, foliage and other obstacles making UHF SATCOM an indispensable communications medium for many agencies. Different directional antennas can be used to improve antenna gain and improve data rates on the transmit and receive links. This type of communication is typically governed in one example by MIL-STD-188-181B, the disclosure which is incorporated by reference in its entirety. This standard specifies a family of constant and non-constant amplitude waveforms for use over satellite links.
The joint tactical radio system (JTRS) implements some of these standards and has different designs that use oscillators, mixers, switchers, splitters, combiners and power amplifier devices to cover different frequency ranges. The modulation schemes used for these types of systems can occupy a fixed bandwidth channel at a fixed carrier frequency or can be frequency-hopped. These systems usually utilize memoryless modulations, such as a phase shift keying (PSK), amplitude shift keying (ASK), frequency shift keying (FSK), quadrature amplitude modulation (QAM), or modulations with memory such as continuous phase modulation (CPM) and combine them with a convolutional or other type of forward error correction code.
These systems often use a number of base station segments that are operative with HF and VHF communications nets and often ad-hoc communications networks in which a plurality of N mobile radios are located on a terrain, typically each moving with no fixed infrastructure. The ad-hoc networks typically require data communications and mobile voice and video that are cheap and reliable. There are different channel access schemes available, but often, there are problems with hidden terminals and some channel access mechanisms use a request-to-send (RTS) and a clear-to-send (CTS) approach to make communication more efficient. In this type of mechanism the channel access is typically receiver directed and uses complex state machines. It behaves similar to Carrier Sense Multiple Access (CSMA), but does not work for broadcast. Other channel access mechanisms may use a time slot approach. These mechanisms are transmitter directed and have good features of Time Division Multiple Access (TDMA), but often require synchronized clocks and a distributed algorithm. There would usually be some delay versus throughput tradeoff in different routing protocols such as a link state (SPF) or distance vector or on-demand routing protocols, and it can be optimized by caching, pruning or source routing. Sometimes there are hierarchical ad-hoc networks, using some degree of power control, and hierarchical link-state routing, and RTS/CPS wave forms.
Power efficient and covert communications systems typically require minimizing the amount of power transmitted in order to reduce the total power expenditure and minimize the probability that users will be detected. Some prior art techniques of adapting power within infrastructure-less networks, e.g., ad-hoc networks, for example, use periodic beacons to inform other users that power levels would use a request/response technique where all users in the communications network are required to respond to the request. The beacon technique requires the communications network to be continually transmitting information and as a result, either energy is expanded or the transmitter is more readily detected. In a request/response network, the complete communication network is transmitting in response to a request, thus expending unnecessary energy or increasing the probability of detection.

System that adapts power for minimizing the total amount of transmitted power within a wireless communications network and related method


The spare disk unit existing in the port other than the parity group to which a failure disk unit in a disk array belongs is most preferentially selected as an alternative destination and data is reconstructed. When a system is made operative, the spare disk unit is allocated to a different port position every rank and the spare disk unit belonging to the rank of the failure disk unit is most preferentially selected as an alternative destination. Due to this, the selection of the alternative destination by the spare disk unit is optimized and the deterioration of performance in data reconstruction is prevented.

The present invention relates to a disk array for accessing a plurality of disk units in parallel and for reading or writing data and, more particularly, to method and apparatus for taking a countermeasure of a disk array, wherein at the time of a disk failure, a spare disk unit is allocated and alternated.
The disk array accomplishes a high performance or a high reliability by combining in parallel a plurality of disk units each of which has been processed as a single physical device and by simultaneously making those disk units operative.
In order to enable data to be reconstructed at the time of a disk failure by providing a redundancy disk unit, it is important to allocate the spare disk unit on the alternative destination side of the failure disk unit. At the same time, it is required to properly allocate the spare disk unit so as not to deteriorate the performance of the disk array.
FIG. 1 shows a schematic diagram of a conventional disk array. A disk array 28 is connected as an input/output (I/O) subsystem to a host computer 10 under the domination of a controller 12. Physical positions of a plurality of disk units 30-00 to 30-35 provided in the disk array 28 are specified by ports P0 to P5 and ranks RO to R3. The ports P0 to P5 denote the device interfaces to which parallel input and output are executed from/to the controller 12. The ranks R0 to R3 denote the numbers of arrangement stages in the port direction of the plurality of disk units connected to the ports P0 to P5. The plurality of disk units 30-00 to 30-35 provided in the disk array 28 are constructed by: data disk units to store data; disk units to store parity data as redundancy data; and standby disk units as spare disk units. One parity group is constructed by every five disk units 30-00 to 30-04, 30-10 to 30-14, 30-20 to 30-24, and 30-30 to 30-34 of the ranks R0 to R3 provided for the ports P0 to P5, respectively. When considering a parity group 56 of the rank R0 as an example, in the operating format of RAID3, four disk units 30-00 to 30-03 are used for data and the remaining one disk unit 30-04 is used for parity. In the operating format of RAID5, the position of the disk unit for parity changes every sector. For example, the spare disk units 30-05, 30-15, 30-25, and 30-35 are allocated to the respective ranks R0 to R3 in which five data disk units and are parity disk unit are included.

Method and apparatus for taking countermeasure for failure of disk array


In the present invention an electron-emitting material is provided wherein the field emission initiation voltage or work function is smaller than that of conventional materials. That is, the present invention relates to an electron-emitting sheet material which is a material comprising a substrate 102 and a graphite sheet 101 laminated on the top of the substrate 102, wherein (1) the graphite sheet 101 has a layered structure of layers of graphenes consisting of a plurality of carbon hexagonal networks, (2) the graphenes are layered relative to one another so that the c-axial direction of each graphene is substantially perpendicular to the plane of the substrate 102, (3) the graphite sheet 101 is laminated on top of the substrate 102 so that the c-axial direction of each graphene is substantially perpendicular to the plane of the substrate 102, and (4) the graphite sheet 101 comprises an element other than carbon as a second element.

In recent years greater demands have been made of display devices, including thinness, larger area and lower power consumption. In order to meet these demands, research is being done into the use of cold cathode electron sources, which have little heat loss at the electron source.
1991 saw the development of carbon nanotubes, a tubular carbon material with a diameter of tens of nm and a length of several μm. Before this development, many displays had been reported using so-called spint-type cold cathodes formed from metal in circular cone form (for example, Journal of Applied Physics Vol. 39, No. 7, p. 3504 (1968)). However, carbon nanotubes have not only the superior electrical conductivity, thermal conductivity and corrosion resistance of carbon material, but also an extremely small radius of curvature. Consequently, carbon nanotubes hold promise as highly efficient and sturdy emissive elements which are stable even in low vacuum. As a result, the main thrust of research and development has begun to turn towards carbon nanotubes (for example, Applied Physics Letters Vol. 78, No. 4, p. 539 (2001)).
In Japanese Unexamined Patent Publication No. 2000-178016 it is disclosed that an artificial graphite sheet can be obtained by two-stage baking of a polymer sheet. This graphite sheet has the high flexibility in addition to the superior electrical conductivity, thermal conductivity and corrosion resistance of the carbon material. And this graphite sheet is made from a polymer sheet. Accordingly, a sheet with a large area can be formed easily.

Electron-emitting material, manufacturing method therefor and electron-emitting element and image displaying device employing same


A feed vessel for pneumatically conveying solid particles includes a cylindrical portion, a first conical portion and a second conical portion. The first conical portion extends downward from the cylindrical portion and is configured to be in fluid communication with the cylindrical portion. The second conical portion extends downward from the first conical portion and is configured to be in fluid communication with the first conical portion. The second conical portion is configured to form a mass flow of solid particles therein and defines at least one outlet thereon for discharging the solid particles. A method for pneumatically conveying solid particles is also presented.

The disclosure generally relates to pneumatic conveyance technology, and more particularly to feed vessels and systems for pneumatically conveying solid particles.
Feed vessels and systems for pneumatically conveying solid particles indicates devices or systems for transporting the solid particles from one place to another by the aid of gas. The pneumatic conveyance technology has many applications, and is particularly widely used in the coal gasification industry. For a traditional gasification system, one example of the solid particles to be conveyed is coal powder. The gasification feed system generally comprises a feed vessel and an output pipeline connecting the feed vessel with a gasifier. The feed vessel introduces the solid particles and a carrier gas. The carrier gas carries the solid particles to flow through the feed vessel and the output pipeline and finally enter the gasifier for generating syngas by partially oxidizing the solid particles.
One problem faced by current feed vessels or feed systems is that the flow rate of the solid particles (referred to as "solid flow rate") is unstable in the feed vessel and/or the output pipeline. The unstable situation may be worse if the feed vessel is operated under a high pressure. The unstable solid flow rate tends to generate unexpected temperature fluctuation in the gasifier, which shortens the lifetime of gasifier and damages gasification performance.
Currently, there are various attempts at solving this problem. One prior way is adding a gas from the bottom of the feed vessels to fluidize the solid particles. Another way is to add inner construction to regulate the solid particles flow. However, these ways make some improvements to the stability, but have yet to satisfy the practical applications. Therefore, there is a need to provide improved feed vessels or feed systems that satisfy practical applications on the conveyance stability of the solid particles.


An electromagnetic effect suppressing termination part for a fastener formed of a metallic material, the fastener having a head, a shank, and a male threaded portion opposite the head, has a metallic core coated by a layer of dielectric material. An internal bore of the termination part includes an inner wall, a counterbore hole, and a cavity disposed therebetween. An outer surface includes an outer wall, and a frustoconical wall positioned proximally relative to the outer wall, the frustoconical wall extending radially outwardly from the outer wall and having an included angle of less than approximately 90 degrees. A seal is disposed in the counterbore hole, and the frustoconical wall is configured so that a compressive force applied to the frustoconical wall deforms the inner wall to conform to the male threaded portion of the fastener and deforms the seal to fill the cavity.

The use of lightweight composite materials in vehicles, such as aircraft, provide an improved strength-to-weight ratio that translates to fuel savings and lower operational costs. Composite materials, however, do not readily conduct away extreme electrical currents and electromagnetic forces generated by lightning strikes. Furthermore, composite or metallic structures used on vehicles are typically assembled using metallic fastener systems, which are conductive and therefore create electromagnetic effect (EME) design considerations. For example, fastener sparking modes must be designed for lightning conditions that include hot particle ejection and arcing between the fastener and surrounding structures.

Electromagnetic effect protective fastener with swageable termination body


Systems and methods for governing access to or use of assets in an analytics platform. Access to assets is controlled with policies that reference attributes. A context of an access request is defined by collecting attributes associated with an access request. The context is then evaluated in light of attributes referenced by the policy applicable to the asset or with a class of the asset. The access request is granted, denied, or partially granted based on whether the attributes defined by the context of the access request comport with the policy.

Generally, data analytics relates to the process of drawing information or conclusions from data. Data analytics relates, for example, to data mining, model development, predictive data modeling, and the like. An analytics platform provides tools so that users of the platform can analyze the data. Users of an analytics platform can use the tools and the data to perform investigations, develop models, make predictions, support policies, and the like.
There are many uses for data analytics. An entity or user, for example, may use an analytics platform to evaluate business data in order to help the business make better decisions or to model their customers or to predict sales. The analytics platform may be used to assess the likelihood of theories (e.g., what offers customers are likely to respond to).
An analytics platform includes assets that allow users to perform various types of operations. The assets used in the analytics platform may include data sets, data sources, searches, tools, applications, services, programs, and other resources. Because users perform analytics using multiple types of assets, there is a need to govern how the assets are accessed and used. Systems and methods are needed to govern access to and use of the assets of an analytics platform.

Data governance through policies and attributes


Isolated nucleic acids encoding a human serine protease PSP1, protein obtainable from the nucleic acids, recombinant host cells transformed with the nucleic acids, oligonucleotides and primer pairs specific for PSP1 polymorphisms and use of the protein and nucleic acid sequences are disclosed.

Mutations in the presenilins (PS-1 and PS-2) account for .about.95% (75% and 20%, respectively) of all cases of early onset familial Alzheimer's disease (FAD). See R. Sherrington et al., Nature 375, 754-760 (1995); E. I. Rogaev et al., Nature 376, 775-778 (1995); and E. Levy-Lahad et al., Science 269, 973-977 (1995). The presenilins are highly homologous (67% identical), multi-membrane spanning proteins whose function is unknown.
It has been demonstrated that the 46 kDa full-length PS-1 protein is normally processed to 28 kDa and 18 kDa fragments; PS-2 has been reported to be similarly cleaved. See M. Mercken et al., FEBS Letters 389, 297-303 (1996). The predicted cleavage site(s) to account for fragments of this size would be in a region of the protein coded for by exon 8 and exon 9. Exon 8 is a hot spot for mutations leading to FAD. Thus, this region of PS-1, and potentially the cleavage of PS-1 in this region by a presenilinase protease, are important events in the functionality of the protein. A region of PS-1 spanning exons 8-11 has been demonstrated in the present invention to specifically bind a protease, PSP1, whose activity against its endogenous substrates and/or ability to bind to PS-1 are important in the pathology of neurodegeneration associated with AD, frontal lobe dementia, cortical lewy body disease, dementia of parkinson's disease, acute and chronic phases of degeneration following stroke or head injury, neuronal degeneration found in motor neurone disease, AIDS dementia and chronic epileps. Thus, a need exists for provision of the nucleotide and amino acid sequences corresponding to PSP1, for modulators of PSP1 binding to PS-1, and/or modulators of PSP1's proteolytic activity, for methods to identify such modulators and for reagents useful in such methods.


A tubular structural member that provides adjustable directional resistance to a device. When orientated in a certain manner with respect to the direction of use, the tubular structural member will provide a different stiffness to the device it is affixed. The tubular structural member may be integrated with these devices so that these devices can have adjustable resistance and stiffness.

1. Field of the Invention
The present invention relates to devices and methods for constructing tubular structural members that allow for variable resistance and stiffness. When the tubular structural member is added to various devices and structures, the tubular structural member gives those devices and structures the ability to change or modify their stiffness or flexing resistance. The tubular structural member is placed over a part of the device along the longitudinal direction over which the stiffness is desired to be changed. The present invention can be used with sports equipment where the user may find it desirable to adjust or change the stiffness of the device, such as hockey sticks, lacrosse sticks, field hockey sticks, bats (for baseball, softball or cricket), golf clubs, fishing rods, skis, snowboards, pole vaulting poles, polo mallets, footwear, masts, scuba fins, bicycles, weightlifting devices, oars and other devices and structures where it may be desirable to change its stiffness. The invention also relates to methods of manufacturing these devices so that the desired stiffness may be set at the time of manufacture.
2. Description of Related Art
application Ser. No. 10/351,307 related to tubular structural members that were inserted into cavities in devices in order to change the stiffness and flexural resistance of that device.
Adjustable sports equipment is known from U.S. Pat. Nos. 6,113,508 and 6,257,997 B1 U.S. that have a cavity in which a stiffening rod is inserted. The use of a stiffening rod, called a structural member, is taught into these references. The cross-section of the structural member can vary along its length with respect to its cross-sectional moment of inertia or plane of flexural resistance. Stiffness then becomes a function of the desired stiffness characteristic of the material or materials at that location and the arrangement of those materials. The present application incorporates disclosure of U.S. Pat. Nos. 6,113,508 and 6,257,997 B1, by reference.
In recent years, sports equipment manufacturers have increasingly turned to different kinds of materials to enhance their sporting equipment. In so doing, entire lines of sports equipment have been developed whose stiffness or flexibility characteristics are but a shade different from each other. Such a shade of difference, however, may be enough to give the individual equipment user an edge over the competition or enhance sports performance.
The user may choose a particular piece of sports equipment having a desired stiffness or flexibility characteristic and, during play, switch to a different piece of sports equipment that is slightly more flexible or stiffer to suit changing playing conditions or to help compensate for weariness or fatigue. Such switching, of course, is subject to availability of different pieces of sports equipment from which to choose.
That is, subtle changes in the stiffness or flexibility characteristics of sports equipment may not be available between different pieces of sports equipment, because the characteristics have been fixed by the manufacturer from the choice of materials, design, etc. Further, the user must have the different pieces of sports equipment nearby during play or they are essentially unavailable to the user.
Golf club shafts may be formed of graphite, wood, titanium, glass fiber or various types of composites or metal alloys. Each varies to some degree with respect to stiffness and flexibility. However, golfers generally carry onto the golf course only a predetermined number of golf club. Varying the stiffness or flexibility of the golf club shaft is not possible, unless the golfer brings another set of clubs of a different construction. Even in that case, however, the selection is still somewhat limited.
U.S. Pat. No. 6,113,508 reveals the use of a stiffening rod in cavities of a golf club shaft to permit the user to adjust the stiffness of the golf club shaft. U.S. Pat. No. 6,257,997 reveals the use of a rotating flexure resistance spine in cavities of a golf club shaft to permit the user to adjust the stiffness of the golf club shaft.


A motor car structure is built up from flat panels joined together, each panel comprising two mutually parallel spaced apart structural skins braced with respect to each other by a core of expanded material united to both skins. Each joint between two panels comprises a series of integral projections formed on a first panel by cutting the panel to a required shape and recesses in the second panel corresponding to the projections. The projections are inserted and bonded into the recesses by means of an adhesive.

The invention relates to motor car structures.
Racing cars and other high performance light-weight motor cars which may be sports-racing cars or road going sports cars incorporate a basic vehicle structural element or chassis which is normally referred to as a tub. The tub normally incorporates a floor, sides, front and rear bulkheads and possibly extensions of some of these elements to carry engines, suspensions, transmissions or other essential parts of the vehicle. In some cases, the tub may also incorporate a roof in which case the sides have to be relatively low to permit driver access.
One established material for manufacture of a tub is aluminium or other light metal sandwich structure. Sandwich material incorporates two skins united by a core of expanded material. One popular sandwich material is known as honeycomb material and has a core constituted by a hexagonal matrix of a material which may be the same as or different from that of the skins. The established procedure for joining together flat sandwich panels to form a tub is by means of angle section strip material bonded and rivetted to at least one skin of each of the panels being joined.
Joins of this kind add weight to the structure, can result in weak points in the structure, are time consuming to assemble and require accurate positioning of rivet holes in the panels and strips.
A more recent development has been to build tubs with a sandwich structure by laying one skin of fibre-resin composite material on a former, applying a sandwich core to the first skin and subsequently laying a second composite skin over the core. With a suitable former, the floor, sides, bulkheads and other parts of the tub can be formed integrally, thus reducing or even avoiding the requirement for joints between individual panels.
Manufacture of a tub in this way is very labour intensive and the cost can amount to several times that of a corresponding tub manufactured from flat sandwich panels joined together.


An apparatus and method for processing handover in a wireless communication system are provided. The method includes selecting a cell for handover when a HandOver (HO) drop occurs, identifying if information for communicating with a serving BS is stored, transmitting a message ranging request signal to the serving BS, identifying provision or non-provision of a service from the serving BS comprised in a response signal to the message ranging request signal, and transmitting/receiving a signal with the serving BS.

1. Field of the Invention
The present invention relates to an apparatus and method for supporting the mobility of a Mobile Station (MS) in a wireless communication system. More particularly, the present invention relates to a handover apparatus and method for maintaining the maximum Quality of Service (QoS) of an MS in a wireless communication system.
2. Description of the Related Art
Wireless communication systems use a handover technology such that Mobile Stations (MSs) can move between cells while maintaining communication. According to the Institute of Electrical and Electronics Engineers (IEEE) 802.16-2004 COR2_D3 standard, there are three basic modes of handover: 1) hard HandOver (HO), 2) Macro Diversity HandOver (MDHO), and 3) Fast Base Station Switching (FBSS). Wireless communication systems adopt a hard HO mode as an Inter Operability Test (IOT) between an MS and BS manufacturer and a service provider due to the stability of technology application and the ease of technology realization.
A hard HO technology is divided into an MS-initiated HO technology and a BS-initiated HO technology. Comparing the MS-initiated HO technology and the BS-initiated HO technology, an HO process performed between an MS and a serving BS has few differences, and an HO entry process performed between an MS and a target BS is substantially identical.
When performing handover, an MS selects a target BS for handover through an HO process with a serving BS. After that, the MS acquires synchronization with the target BS and performs an HO entry process.
The MS may fail to complete the HO entry with the target BS process because of a channel environment, thus causing the occurrence of an HO drop. A wireless communication system can process the HO drop as described below with reference to FIG. 1.
FIG. 1 illustrates a method of processing an HO drop in a wireless communication system according to the conventional art. The following description is made assuming that the wireless communication system uses an MS-initiated HO technology.
Referring to FIG. 1, an MS 100 receives a service from a serving BS 110. That is, the MS 100 transmits/receives traffic with the serving BS 110 in step 131.
The MS 100 measures signal strength of the serving BS 110 and neighboring BSs, determining whether to perform handover in step 133. If the MS 100 determines to perform handover, the MS 100 transmits an HO request signal (MOB_MSHO-REQ) to the serving BS 110 in step 135. The HO request signal includes information on the neighboring BSs to which the MS 100 can perform handover.
The serving BS 110 identifies the information on the neighboring BSs included in the HO request signal, thus identifying if the neighboring BSs can support handover of the MS 100. Then, the serving BS 110 transmits an HO response signal (MOB_BSHO-RSP) to the MS 100 in step 137. The HO response signal includes information on neighboring BSs constructed such that the neighboring BS that can best support the handover of the MS 100 is listed first.
The MS 100 selects a target BS 120 for handover using the HO response signal that includes information on whether neighboring BSs support the handover of the MS 100. Then, the MS 100 transmits an HO indication signal (MOB_MS-IND) to the serving BS 110 so as to inform of HO initiation in step 139. At this time, the MS 100 drives a resource maintenance timer for releasing information on the serving BS 110. If the resource maintenance timer expires, the MS 100 releases the information on the serving BS 110. The information on the serving BS 110 includes a frequency of the serving BS 110, a preamble index, a serving BS 110 IDentifier (ID) and service related context information.
After transmitting the HO indication signal, the MS 100 acquires downlink synchronization with the target BS 120 in step 141.
If the HO indication signal is received, the serving BS 110 drives a resource maintenance timer for releasing information on the MS 100 in step 143. If the resource maintenance timer expires, the serving BS 110 releases the information on the MS 100.
Then, the MS 100 exchanges a signal for HO entry with the target BS 120 in step 145. If the MS 100 acquires Connection ID (CID) information and authentication information through a ranging response signal (RNG-RSP) received from the target BS 120, the MS 100 completes HO entry with the target BS 120.
However, if an HO ranging attempt is repeatedly made more than a threshold number of times due to channel degradation during the HO entry, the MS 100 recognizes that an HO drop occurs in step 147.
When the HO drop occurs, the MS 100 reselects a BS for handover in step 149. Although not shown, when the reselected BS is not the serving BS 110, the MS 100 performs HO entry to the reselected BS.
When the reselected BS is the serving BS 110, the MS 100 identifies if the resource maintenance timer driven to release the information on the serving BS 110 has expired in step 151.
If the resource maintenance timer has not expired, the MS 100 can be aware of information for communication with the serving BS 110 and thus, transmit an HO indication signal to the serving BS 110 to return to service with the serving BS 110 in step 153. That is, the MS 100 transmits an HO indication signal of a type different from the previous HO indication signal, which has been transmitted to the serving BS 110 in step 139, to the serving BS 110. Then, the MS 100 recognizes that it returns to the serving BS 110, thus operating in a mode for transmitting/receiving traffic with the serving BS 110 in step 157.
However, the serving BS 110 may fail to receive the HO indication signal from the MS 100 that was transmitted in step 153 due to channel degradation between the MS 100 and the serving BS 110 in step 155.
At this time, the serving BS 110 fails to recognize that the MS 100 desires to enter the serving BS 110. Thus, the serving BS 110 identifies if a resource maintenance timer driven to release information on the MS 100 expires in step 159.
If the resource maintenance timer expires, the serving BS 110 releases the information on the MS 100 in step 161. That is, because the serving BS 110 fails to receive the HO indication signal, it erroneously assumes that the MS 100 performs handover to a different BS. However, the MS 100 transmits the HO indication signal, thus erroneously indicating that it performs communication with the serving BS 110. Thus, a problem of inconsistency of communication states of the MS 100 and the serving BS 110 takes place.
As described above, when the communication states of the MS 100 and the serving BS 110 are inconsistent with each other, the MS 100 transmits a signal but the serving BS 110 fails to receive the signal from the MS 100, thus causing a problem of communication interruption.
Also, when the serving BS 110 deletes information on the MS 100, the serving BS 110 can allocate a CID, which had previously been allocated to the MS 100, to a different MS. At this time, the MS 100 can receive a downlink signal including the allocated CID from the serving BS 110 and send a signal to the serving BS 110 in response to the downlink signal. In this case, a problem may occur in that the response signal from the MS 100 interrupts a communication between the different MS, to which the serving BS 110 now allocates the CID, and the serving BS 110.

Apparatus and method for processing handover in a wireless communication system


An Adaptive Computing Ensemble (ACE) includes a plurality of flexible computation units as well as an execution controller to allocate the units to Computing Ensembles (CEs) and to assign threads to the CEs. The units may be any combination of ACE-enabled units, including instruction fetch and decode units, integer execution and pipeline control units, floating-point execution units, segmentation units, special-purpose units, reconfigurable units, and memory units. Some of the units may be replicated, e.g. there may be a plurality of integer execution and pipeline control units. Some of the units may be present in a plurality of implementations, varying by performance, power usage, or both. The execution controller dynamically alters the allocation of units to threads in response to changing performance and power consumption observed behaviors and requirements. The execution controller also dynamically alters performance and power characteristics of the ACE-enabled units, according to the observed behaviors and requirements.

1. Field
Advancements in microprocessor architecture are needed to provide improvements in performance, efficiency, cost, power tradeoffs, and utility of use.
2. Related Art
Unless expressly identified as being publicly or well known, mention herein of techniques and concepts, including for context, definitions, or comparison purposes, should not be construed as an admission that such techniques and concepts are previously publicly known or otherwise part of the prior art. All references cited herein (if any), including patents, patent applications, and publications, are hereby incorporated by reference in their entireties, whether specifically incorporated or not, for all purposes. Nothing herein is to be construed as an admission that any of the references are pertinent prior art, nor does it constitute any admission as to the contents or date of actual publication of these documents.
Semiconductor fabrication technology has undergone continuous improvement for four decades at a rate defined by Moore's Law: The number of transistors integrated in a single circuit has grown by a factor of four every three years. Such continuous improvement has allowed the number of transistors available for a single-chip microprocessor to increase from several thousand transistors for the first microprocessor in 1971 to more than one billion transistors currently.
As technology advanced through the early 1980's, integration levels of about 100,000 transistors per chip made it possible to develop a complete processor partitioned into a handful of components, such as a 32-bit integer pipeline, a 64-bit FP pipeline, a memory-management unit, and cache memory. Around 1990, technology permitted integration of about one million transistors, enabling a complete processor to be fabricated in a single chip. As the technology continued to advance through about 1995, microprocessors began to replicate multiple functional units to execute instructions in parallel, a type of computer architecture called "superscalar" that exploits ILP. Further integration through about 2000 led to microprocessors that executed multiple threads on a common set of functional units, a type of architecture called SMT that exploits TLP. Presently, multiple complete processors are being integrated on a single chip, a type of architecture known as CMP.
As the level of integration reaches one billion transistors and beyond, several limitations of technology and applications have grown increasingly important. One technology limitation is in the amount of power that can be supplied and dissipated economically by a single chip. A related limitation is the amount of energy that can be stored in batteries or other power sources for portable applications. In addition to dynamic power, which is dissipated as devices switch, static power caused by leakage current becomes more important as transistor size is reduced. Another technology limitation is that interconnection characteristics do not scale with transistor size and speed, so interconnection of transistors and logic blocks becomes increasingly important in determining overall chip size, power, and performance. Technology further limits chip yield and reliability as device sizes shrink and more devices are integrated. The characteristics of software applications impose additional limitations in the amount of ILP and TLP that can be exploited by individual processors, as well as further limitations that arise when memory used by an application is partitioned across multiple processors.
A number of techniques have been practiced and proposed to address such limitations. For an individual processor, clocks may be gated off to idle logic, and voltage may be lowered to reduce power consumption. Such voltage-scaling techniques also reduce operating frequency and consequently performance. Similar techniques may be applied to complete processors for CMP applications. For example, complete processors may have clocks gated off or the power supply may be disconnected. In practice, such techniques provide coarse control over the tradeoffs between power and performance.
Contemporary techniques provide additional flexibility with asymmetric processors in CMP or multi-chip configurations. For example, an integrated circuit may integrate one large, high-performance processor and a second smaller, lower-power and lower-performance processor. Either or both complete processors may be active depending on application performance requirements, power limitations, and battery life. The processors may also be implemented in separate voltage domains, so that voltage-scaling techniques may be applied separately to individual processors. In addition, techniques have been proposed to provide asymmetric functional units within a processor. For example, a processor may integrate two integer ALUs with differing power and performance. The processor may be configured to execute instructions using either or both ALUs.
Currently practiced and proposed techniques still suffer a number of disadvantages. For example, when asymmetric processors are employed, the resources of an inactive processor are unavailable and wasted. In addition, the resources of an active processor may be underutilized; for example, the FPU of a high-performance processor is underutilized when the processor is allocated to an application that executes FP instructions infrequently or not at all. When asymmetric functional units are employed, the additional unused resources result in unnecessary interconnection, leading to lower performance and additional power dissipation. When voltage is scaled, the processor needs to remain idle for considerable time until clocks are stable at a new frequency appropriate for the scaled voltage.
Throughout the evolution of microprocessor technology it has also been necessary to make tradeoffs between fixed-function and programmable components. Fixed-function components may be optimized for manufacturing cost and performance, but their market volume is limited by demands of their target application(s). Programmable components may have higher manufacturing cost and lower performance for a specific application, but the programmable capability enables much higher volumes covering a range of applications. In addition, programmable components may be more economical because development costs are spread over a larger manufacturing volume. Similarly, systems developed with programmable components may be brought to market more quickly than those developed with fixed-function components because the time to complete and correct a program is generally less than the time to develop a new fixed-function circuit.
As a consequence of the tradeoffs between fixed-function and programmable elements, applications are commonly transitioned from fixed-function solutions to programmable solutions as circuit costs decrease and performance increases over time. For example, the first microprocessor was introduced in 1971 by Intel as an alternate solution to developing a calculator with fixed-function circuits. Similarly, gate arrays have been applied to customize functions either by programming metal interconnections between logic blocks during the last manufacturing steps or else after the circuit is manufactured by blowing fuse connections. Further advances have enabled functions to be customized by loading the contents of SRAM cells associated with programmable logic gates and interconnection, a technology called Field-Programmable Gate Arrays (FPGAs). FPGAs enable functions to be programmed multiple times after manufacturing, a characteristic often described as reconfigurable.
Microprocessors occupy a unique position on the spectrum of fixed-function and programmable components: microprocessors may be programmed, but they commonly implement a fixed-function, namely executing instructions of a predefined architecture. For example, x86 processors, used extensively in IBM-compatible computer systems, generally execute a fixed set of instructions, but are programmed for a wide variety of applications.
Interest has grown in making microprocessors more configurable; that is, in supplementing a microprocessor that executes a standard instruction set with fixed functions that have been optimized for a specific application. What are needed to address the challenges in microprocessor resource management and reconfiguration are improved microprocessor architectures to provide enhanced and superior power efficiency as well as performance characteristics and tradeoffs thereof.

Adaptive computing ensemble microprocessor architecture


Antenna tuning switch circuitry includes an input port, a shunt switch, control circuitry, and an integrated ground. The shunt switch is coupled between the input port and the integrated ground. The control circuitry includes a control signal input port, a switch driver output port coupled to the shunt switch, and a ground connection port coupled to the integrated ground. The shunt switches, the RF input ports, the control circuitry, and the integrated ground are monolithically integrated on a single semiconductor die. The antenna tuning switch circuitry is adapted to selectively couple the input port to the integrated ground in order to alter one or more operating parameters of an attached antenna. By monolithically integrating the shunt switch together with the control circuitry and the integrated ground, the ON state impedance and the parasitic OFF state impedance of the antenna tuning switch circuitry can be significantly improved.

Modern wireless communications standards require a mobile terminal to be capable of transmitting and receiving wireless signals over a wide range of frequencies. On its own, an antenna can generally only transmit and receive signals efficiently within a relatively narrow frequency band. Accordingly, tuning circuitry must be attached to the antenna in order to widen the frequency band over which an antenna can efficiently transmit and receive signals.
FIG. 1A shows an exemplary tunable patch antenna 10 for use in a mobile terminal. The tunable patch antenna 10 includes a substrate 12, an antenna surface 14, a grounding plane 16, an RF feed 18, and one or more tuning leads 20. The substrate 12 is located between the antenna surface 14 and the grounding plane 16. The RF feed 18 runs through the grounding plane 16 and the substrate 12 to contact the antenna surface 14. Each one of the tuning leads 20 runs between a point of the antenna surface 14 and a fixed impedance, such as the grounding plane 16.
In a transmit mode of operation, an RF signal is delivered to the RF feed 18. The RF signal runs past the grounding plane 16 and the substrate 12 to the antenna surface 14, where it is then radiated into the environment. By selectively placing one or more of the tuning leads 20 between a point of the antenna surface 14 and a fixed impedance, the impedance of the tunable patch antenna 10 can be changed. As the impedance of the tunable patch antenna 10 is changed, the transmission characteristics of the tunable patch antenna 10 similarly change. Accordingly, by selectively placing one or more of the tuning leads 20 in contact with a fixed impedance, a "sweet spot" having a maximum efficiency for transmission of a signal about a given frequency band may be found, thereby enabling the tunable patch antenna 10 to efficiently operate over a wider range of transmission frequencies than would otherwise be possible.
In a receive mode of operation, an RF signal arrives at the antenna surface 14 from the surrounding environment. The RF signal is passed from the antenna surface 14 to the RF feed 18, where it is subsequently delivered to one or more components in the front end circuitry of a mobile terminal (not shown). By selectively placing one or more of the tuning leads 20 between a point of the antenna surface 14 and a fixed impedance, the impedance of the tunable patch antenna 10 can be changed. As the impedance of the tunable patch antenna 10 is changed, the reception characteristics of the tunable patch antenna 10 similarly change. Accordingly, by selectively placing one or more of the tuning leads 20 in contact with a fixed impedance, a "sweet spot" having a maximum efficiency for reception of signals about a given frequency band may be found, thereby enabling the tunable patch antenna 10 to efficiently operate over a wider range of reception frequency than would otherwise be possible.
FIG. 1B shows a three-dimensional representation of the tunable patch antenna 10 shown in FIG. 1A. As shown in FIG. 1B, each one of the tuning leads 20 is spread out over the width of the antenna surface 14, and includes conventional antenna tuning switch circuitry 22 for selectively placing the tuning lead 20 in contact with a fixed impedance such as the grounding plane 16. As discussed above, as each one of the tuning leads 20 are placed in contact with a fixed impedance, the transmission and reception characteristics of the tunable patch antenna 10 are changed, thereby allowing for efficient transmission and reception of RF signals across a wide range of frequencies.
Although effective at altering the transmission and/or reception characteristics of the tunable patch antenna 10, the conventional antenna tuning switch circuitry 22 coupled to each one of the tuning leads 20 may itself degrade the performance of the tunable patch antenna 10. For example, the conventional antenna tuning switch circuitry 22 attached to each one of the tuning leads 20 may introduce insertion loss in the signal path of the antenna in the ON state, may introduce parasitic capacitance and/or inductance in the signal path of the antenna in the OFF state, and may be prone to breaking down, thereby causing one or more of the tuning leads 20 to unintentionally turn ON and change the transmission and/or reception characteristics of the tunable patch antenna 10.
FIG. 2 shows conventional antenna tuning switch circuitry 22 for use in the tunable patch antenna 10 shown in FIGS. 1A and 1B. The conventional antenna tuning switch circuitry 22 includes a semiconductor die 24, a shunt switch SH_SW, an electrostatic discharge (ESD) protection switch ESD_SW, an input port 26, a first ground port 28, a second ground port 30, control circuitry 32, a control port 34, a supply voltage port 36, and an off-die ground 38. The shunt switch SH_SW is coupled between the input port 26 and the first ground port 28. The ESD protection switch ESD_SW is coupled between the first ground port 28 and the second ground port 30. The control circuitry 32 includes a control signal input port 40 coupled to the control port 34, a ground connection port 42 coupled to the second ground port 30, a switch driver output port 44 coupled to the shunt switch SH_SW, and a supply voltage input port 46 coupled to the supply voltage port 36. The shunt switch SH_SW, the ESD protection switch ESD_SW, the input port 26, the first ground port 28, the second ground port 30, the control circuitry 32, and the control port 34 are integrated on the semiconductor die 24. The first ground port 28 is coupled to the off-die ground 38 via a first ground connection 48. The second ground port 30 is coupled to the off-die ground 38 via a second ground connection 50.
In operation, the input port 26 of the conventional antenna tuning switch circuitry 22 is coupled to a point on the antenna surface 14 of the tunable patch antenna 10 through one of the tuning leads 20. In order to alter the transmission and/or reception characteristics of the tunable patch antenna 10 in response to one or more control signals CTL_SIG received at the control port 34, the control circuitry 32 may close the shunt switch SH_SW to couple the input port 26 to a fixed impedance, such as ground. Due to the differences in the parasitic inductance of the first ground connection 48 and the second ground connection 50, a potential voltage difference may exist between the first ground port 28 and the second ground port 30 over a variety of operating conditions. Accordingly, the impedance of the path from the input port 26 through the control circuitry 32 to the second ground port 30 has the potential to be lower than the path from the input port 26 through the shunt switch SH_SW to the first ground port 28. Due to the potential for a low impedance path to be presented through the control circuitry 32, should an ESD event occur, it may pass through the control circuitry 32 to the second ground port 30, thereby damaging or disabling the control circuitry 32. Accordingly, the ESD protection switch ESD_SW is necessarily included in the conventional antenna tuning switch circuitry 22 to couple the first ground port 28 and the second ground port 30 in the event of an ESD event so that the lowest impedance path to ground is provided around, rather than through, the control circuitry 32.
FIG. 3A shows a simplified equivalent circuit for the conventional antenna tuning switch circuitry 22 when the conventional antenna tuning switch circuitry 22 is in an ON state of operation. As shown in FIG. 3A, the ON impedance of the conventional antenna tuning switch circuitry 22 can be represented by the following equation:ZON=ZON_SH+[(ZOFF_ESD+LC2)//LC1]  (1)where ZON_SH is equal to the ON impedance of the shunt switch SH_SW, ZOFF_ESD is equal to the parasitic impedance of the ESD protection switch ESD_SW when the ESD protection switch ESD_SW is in the OFF state, LC2 is equal to the equivalent inductance of the second ground connection 50, and LC1 is equal to the equivalent inductance of the first ground connection 48. As shown by FIG. 3A and equation 1, the ESD protection switch ESD_SW, the first ground connection 48, and the second ground connection 50 may significantly contribute to the ON impedance of the conventional antenna tuning switch circuitry 22. The additional impedance provided by the ESD protection switch ESD_SW, the first ground connection 48, and the second ground connection 50 increases the insertion loss of the RF signal path in the tunable patch antenna 10, thereby degrading the quality of signals transmitted and received by the tunable patch antenna 10.
FIG. 3B shows a simplified equivalent circuit for the conventional antenna tuning switch circuitry 22 when the conventional antenna tuning switch circuitry 22 is in an OFF state of operation. As shown in FIG. 3A, the parasitic OFF state impedance of the conventional antenna tuning switch circuitry 22 can be represented by the following equation:ZOFF=ZOFF_SH+[(ZOFF_ESD+LC2)//LC1]  (2)where ZOFF_SH is equal to the parasitic OFF state impedance of the shunt switch SH_SW, ZOFF_ESD is equal to the parasitic impedance of the ESD protection switch ESD_SW when the ESD protection switch ESD_SW is in the OFF state, LC2 is equal to the equivalent inductance of the second ground connection 50, and LC1 is equal to the equivalent inductance of the first ground connection 48. As shown by FIG. 3B and equation 2, the ESD protection switch ESD_SW, the first ground connection 48, and the second ground connection 50 may significantly contribute to the parasitic OFF state impedance of the conventional antenna tuning switch circuitry 22. The additional impedance provided by the ESD protection switch ESD_SW, the first ground connection 48, and the second ground connection 50 increases the insertion loss of the RF signal path in the tunable patch antenna 10, thereby degrading the quality of signals transmitted and received by the tunable patch antenna 10.
Accordingly, a tuning switch for a tunable patch antenna 10 is required that is capable of providing a low impedance path to a fixed impedance in the ON state, introducing a low parasitic load on the antenna in the OFF state, and handling high amplitude signals.

Dedicated shunt switch with improved ground


The zoom lens substantially consists of a positive first lens group fixed while changing magnification, a negative second lens group which moves from the object side to the image side while changing magnification, a positive third lens group which moves while changing magnification, and a positive fourth lens group which moves from the image side to the object side while changing magnification, and a positive fifth lens group fixed while changing magnification in this order from the object side. A floating system in which the third lens group and the fourth lens group move relative to each other while changing magnification is adopted. The image formation magnification rates of the combined lens group formed by the third lens group and the fourth lens group together and the second lens group simultaneously pass −1× point while changing magnification from the wide angle end to the telephoto end.

1. Technical Field
The present invention relates to a zoom lens and an imaging apparatus, and particularly to a zoom lens having a high magnification ratio suitable for mounting onto TV cameras, video cameras, and the like and an imaging apparatus including this zoom lens.
2. Description of the Related Art
Conventionally, zoom lenses of a three-group configuration in which three groups move while changing magnification to have higher performance are known as the zoom lenses to be mounted onto a TV camera, a video camera, and the like (Patent Documents 1 and 2 (Japanese Unexamined Patent Publication No. 7(1995)-248449 and Japanese Unexamined Patent Publication No. 2009-128491)). Further, zoom lenses of a two-group configuration in which two group move while changing magnification are known as zoom lenses having high magnification of 100× or more (Patent Documents 3 and 4 (Japanese Unexamined Patent Publication No. 2010-091788 and Japanese Unexamined Patent Publication No. 2011-039399)).


A method and apparatus for detecting particles on a surface of an object, such as a virgin or patterned semiconductor wafer, ceramic tile, or the like. In one embodiment, an apparatus is provided in which a scanning beam of laser light is brought to focus as an arcuate scan line on a surface of the object at a grazing angle of incidence using an off-axis hypertelecentric mirror. A pair of light detectors are positioned at a meridional angle of about 30 degrees and at an azimuthal angle of about 4 degrees to measure forward scattered light from the surface. The object is then moved translationally so that the beam can scan another line of the surface. A light trap is provided to trap light that is reflected by the surface, and a series of masks are provided to mask light which is scattered by the hypertelecentric mirror and, in the case of patterned objects, light which is diffracted by the pattern imprinted on the object.

The present invention relates generally to a method and apparatus for detecting the presence of particles on the surface of an object and more particularly to a method and apparatus for detecting and measuring the number and sizes of contaminant particles on the surface of an object, such as a patterned or virgin semiconductor wafer or ceramic tile, using the principle of light scattering.
There are a variety of existing ways for detecting and measuring the number and sizes of particles on the surface of a semiconductor wafer for the purpose of rejecting those wafers which have on their surface one or more particles above certain sizes or an excessive number of particles. One of the more simple methods involves having a human operator inspect the wafer using a light field/dark field microscope. Using the eye, the operator actually counts the number of particles and also identifies the size of the particles, such as those between 1 to 20 microns, and then rejects those wafers which have particles of or above a certain size or which have an excessive number of particles. This method, however, is highly inaccurate and very expensive both in terms of wages for the human operator and in terms of the number of rejects both after the inspection and after production of the chips (when an erroneously passed wafer is found to have an electrical defect, e.g., short circuits, because of the presence of contaminant particles).
In P. Burggraaf, "Auto Wafer Inspection: Tools for Your Process Problems," Semiconductor International, pp. 54-61 (December 1988), there are disclosed several types of automatic-vision wafer inspection systems, i.e., systems which do not require a human inspector. One type of system described is the Surfscan TM 7000 manufactured by Tencor Instruments, Mountain View, Calif. This light scattering system uses a laser beam, focused by a telecentric lens, to scan a patterned semiconductor wafer at a shallow angle of incidence, the patterned semiconductor wafer being aligned so that the pattern streets run parallel to the direction of scanning. Side scattered light from the wafer is then detected by a single photomultiplier tube disposed to the side of the wafer in the plane of the scan line.
In U.S. Pat. No. 4,898,471, issued Feb. 6, 1990, and assigned to Tencor Instruments, a system for detecting particles and other defects on a patterned semiconductor wafer, photomask, or the like is disclosed. The system, which corresponds generally to the above-described Surfscan TM 7000, includes a light source for emitting a beam of light. A polarizing filter is used to polarize the beam of light in a direction substantially parallel to the surface of the patterned semiconductor wafer to be examined. The beam is enlarged in cross-sectional diameter by a beam expander placed along the path of the beam after the polarizing filter. The beam is then caused to scan by a deflection mirror. A telecentric lens brings the scanning beam to focus on the patterned wafer at a shallow angle of incidence, the beam striking the wafer surface substantially parallel to the pattern streets formed on the wafer. A light collection system for detecting side scattered light is positioned in the plane of the scan line. The light collection system, which includes a lens for focusing the side scattered light, a polarizing filter oriented in a direction substantially parallel to the surface of the patterned wafer, and a photomultiplier tube for detecting light incident thereon and transmitting electrical signals in response thereto, receives light scattered in a direction less than 15 degrees above the surface and at angle relative to the beam direction in a range from about 80 degrees to 100 degrees. A processor constructs templates from the electrical signal corresponding to individual patterns and compares the templates to identify particles.
In U.S. Pat. No. 4,772,126 to C. D. Allemand et al., there is disclosed a method and apparatus for detecting the presence of particles on the surface of an object such as the front side of a patterned semiconductor wafer. A vertically expanded, horizontally scanning, beam of light is directed onto an area on the surface of the object at a grazing angle of incidence. A video camera positioned above the surface detects light scattered from any particles which may be present on the surface, but not specularly reflected light. The surface is angularly prepositioned (rotated) relative to the incident light beam so that the diffracted light from the surface and the pattern of lines on the surface is at a minimum. The object is then moved translationally to expose another area to the incident light beam so that the entire surface of the object or selected portions thereof can be examined, one area at a time.
In U.S. Pat. No. 4,377,340 to G. P. Green et al., there is disclosed a method and apparatus for detecting and measuring the number and sizes of impurities on the surface of a material, such as a semiconductor wafer, wherein a beam of high intensity collimated light from a xenon arc lamp is directed onto the surface at normal incidence in the absence of any extraneous light, through a collimating mirror and a pin hole device and whereat the particles will scatter the light, and wherein the surface is viewed by a high light sensitive TV camera which is positioned off-axis to pick up scattered light but not specularly reflected light for display on a viewing screen.
In IBM Technical Disclosure Bulletin, Volume 12, No. 10, pp. 1672-1673, dated March, 1970, there is disclosed a system for detecting repeated geometric defects on a reflecting surface. The system comprises a light source combined with a collimator. A beam splitter splits the incident beam into a first beam, which is directed to the wafer, and a second beam, which is directed to a light absorbing surface. The wafer is mounted on a tilted rotatable support. An aperture plate limits the size of the light beam incident upon the sample and at the same time restricts the amount of light reflected back along the direction of the incident beam to a photomultiplier by the surface defects. The incident beam is split by the wafer, the planar surface of the wafer directing the major portion of the beam back to the back side of the aperture plate whereas the defects on the wafer direct a portion of the beam back through the aperture plate. The portion of the beam transmitted through the aperture plate strikes a beam splitter and is directed through a telescope to a photomultiplier.
In IBM Technical Disclosure Bulletin, Volume 21, No. 6, pp. 2336-2337, dated November, 1978, there is disclosed a system for detecting defects on wafers wherein light from a plurality of ring light sources impinges on the wafer at an oblique angle to the wafer surface and wherein light scattered upward from the surface at right angle thereto is fed by a lens system into a broad band array detector.
In IBM Technical Disclosure Bulletin, Volume 27, No. 12, pp. 6971-6973, dated May, 1985, there is disclosed an inspection system for particulate and defect detection on product wafers wherein light from an illuminator impinges on the substrate at an angle of 0 to 5 degrees. Additionally, the beam is oriented at a preferred angle, e.g., 45 degrees, with respect to the wafer circuit geometry. A photomultiplier tube is arranged above the substrate to monitor light scattered therefrom.
In IBM Technical Disclosure Bulletin, Volume 27, No. 12, pp. 6999-7001, dated May, 1985, there is disclosed an automated, grazing angle, oblique light, inspection system for the detection of particulate contamination and metallization defects on semiconductor product wafers.
In U.S. Pat. No. 2,947,212 to R. C. Woods, there is disclosed a method of detecting surface conditions on a strip of sheet metal having line markings in which light from a light source is directed towards the surface of the sheet metal in a direction generally perpendicular to the line markings. Non-specular reflection in a selected direction which is perpendicular to the lines, and which is preferably between the angle of incidence and the angle of specular reflection, is monitored by a photoelectric cell which is able to detect a surface flaw by variation in the intensity of the reflected light. The light in the incident beam may be polarized and the light in the selected non-specular reflected beam filtered to pass only such polarized light.
In U.S. Pat. No. 4,342,515 to M. Akiba et al., there is disclosed an inspection apparatus for detecting unfavorable foreign matters existent on the surface of an object such as a semiconductor wafer. The apparatus includes a collimated beam generator portion which projects a collimated beam towards the object to be inspected from a side thereof and a mechanism which senses light reflected from the surface of the object, through a polarizer plate. In accordance with the disclosed technique for using the apparatus, the signal-to-noise ratio between a detection signal generated by a pattern of the foreign matter to be detected and a signal generated by a normal pattern of the object surface and sensed as a noise component are said to be enhanced.
In U.S. Pat. No. 3,782,836 to C. F. Fey et al., there is disclosed a surface irregularity analyzing system which includes structure for directing light towards a surface in a direction having a certain angular relationship to the surface. If the light strikes irregularities in the surface it is reflected in a direction having an angular relationship to the surface other than equal and opposite the incident direction. The amount of light reflected from irregularities in the surface is determined, either photographically or photoelectrically using a detector positioned over the surface, to provide an analysis of irregularities in the surface.
In Japanese Patent No. 61-162738 assigned to Hitachi, Ltd., there is disclosed a method for preventing a circuit pattern from being misjudged to a foreign matter, the method employing a flat spot-shaped scan laser beam.