Abstract: The present invention provides a light emitting/receiving composite unit (1) for emitting and receiving lights, which includes a light source (3), an optical splitting unit (4) for splitting returning lights to the composite unit (1) into a plurality of lights, a polarizing unit (5) for increasing and decreasing quantity of lights transmitted therefrom corresponding to polarization state of the returning lights, and an optical receiving unit (6) which has a plurality of photo-detecting elements (6—1 to 6—4) for detecting the lights transmitted through the polarizing unit (5), which are unitedly integrated into one unit.

Abstract: The present invention provides a light emitting/receiving composite unit (1) for emitting and receiving lights, which includes a light source (3), an optical splitting unit (4) for splitting returning lights to the composite unit (1) into a plurality of lights, a polarizing unit (5) for increasing and decreasing quantity of lights transmitted therefrom corresponding to polarization state of the returning lights, and an optical receiving unit (6) which has a plurality of photo-detecting elements (6—1 to 6—4) for detecting the lights transmitted through the polarizing unit (5), which are unitedly integrated into one unit.

Abstract: A magnetic disc apparatus comprises a magnetic disc and a magnetic head for recording and/or playing back an information signal on the magnetic disc. A control signal is generated on the basis of a servo signal recorded on the magnetic disc. The position of the support arm is detected by a hologram grating provided on the support arm and by a hologram sensor unit mounted on a base, whereby a position signal is generated. The control signal is corrected on the basis of the position signal. The actuation of the support arm is controlled based on the corrected control signal, such that the magnetic head can be positioned with respect to the magnetic disc with high accuracy.

Abstract: The characteristic test device 1 supplies the output from the photo detector of the optical pickup 2, as signals A to F, directly to the sample hold circuits 8a-8f. The sample hold circuits 8a-8f, the multiplexer 9, and the second analog/digital converting circuit 10 convert the signals A to F into digital data with the sampling frequency of 50 KHz or more. In the computer 12, the processing division 12d reads out the indicated program from the data storage division 12b, where the program P for measuring the level of RF signal, is stored. The processing division 12d performs the operation of the indicated measurement items, based on the digital data stored in the second memory 11, then measures the characteristic of the optical pickup 2.

Abstract: A jitter measurement device for reproducing a signal from an optical disc, which has simple circuit configuration and can effectively measure the jitter component. A matrix circuit 4 supplies the RF signals to the analog/digital converting circuit 6. Second, the computer 8 computes the slice level from the digitized data of the RF signals. Computer 8 computes the time point at which the RF signals become the indicated slice level, by interpolating, based on the digital data at the sampling point in the neighborhood of the said slice level, and the sampling frequency of the analog/digital converting circuit 6. A computer 8 computes each time breadth between the time points at which the RF signals become the slice level, then computes the jitter component of the reproduced signal, based on the each time breadth.

Abstract: A device for measuring focusing characteristics of an optical pickup and/or an optical disc capable of measuring characteristics of focusing states with high accuracy by a simplified circuit. An arithmetic-logic unit 12d controls an offset supplying circuit 23 for applying an offset voltage to a focusing servo control signal. This arithmetic-logic unit 12d detects an error rate of the playback data in such a state in which the focusing position of the laser light is deviated by a pre-set offset amount. The arithmetic-logic unit 12d sequentially varies the offset voltage to repeat the above processing for detecting the error rate. The arithmetic-logic unit 12d approximates the relationship of the error rate to the offset amount by a quadratic curve based on detected data. The offset amount which minimizes the error rate is found from this equation of approximation.

Abstract: A device for measuring characteristics of an optical pickup and/or an optical disc by which characteristics of tracking signals can be measured accurately in a noise-free manner. The measurement device 1 has a sample-and-hold circuit 8 and an analog-to-digital converter 10 for directly sampling an output of an optical pickup 2 as signals A to F in order to store the resulting digital data in a second memory 11. An arithmetic-logic unit 12d measures tracking error signals based on the digital data stored in the second memory 11. The arithmetic-logic unit 12d eliminates unstable portions of the tracking signals generated responsive to rotational eccentricity of the optical disc to find data.

Abstract: The present invention provides an image collation device having a simple whole structure which is applied, for example, as a fingerprint collation device. Linear images cut from the one image is stored in a memory means, and the other image is collated with the stored liner images. Thereby the image data of the linear images can be recorded in a memory means having a small capacity.

Abstract: An image collation device such as a fingerprint collation device for specifying a plurality of frames for an inspection object, cutting a plurality of linear images from each frame, determining whether images coincide with each other in each frame with reference to a plurality of cut linear images, determining the determination results on a overall basis, and finally determining the coincidence, enabling consistent collation results with a simple structure.

Abstract: An image collation device such as a fingerprint collation device for specifying a plurality of frames for an inspection object, cutting a plurality of linear images from each frame, determining whether images coincide with each other in each frame with reference to a plurality of cut linear images, determining the determination results on a overall basis, and finally determining the coincidence, enabling consistent collation results with a simple structure.

Abstract: The present invention provides a method of collating images and an apparatus for collating images capable of collating an image for collation taken in as digital data with an image for reference stored as digital data comparatively simply and surely.

Abstract: A method for detecting the point of origin of a position sensor such as an optical linear scale by first displacing an object member whose position is to be determined until it butts against a mechanical stopper, then determining the position of the object member at the mechanical stopper and using that position as a reference position for the point of origin, and thereafter detecting the position of the object member by means of the position sensor, thereby detecting the position of the object member relative to the point of origin. In another embodiment, a first point of origin signal is obtained from an optical linear scale used as a position sensor and stored in response to latching signal generated at an end point of travel of the object member. Subsequently, when a second point of origin signal from the optical linear scale is compared with the first point of origin signal, any deviation from the first point of origin signal may be corrected based on the result of the comparison.

Abstract: A method for detecting the point of origin of a position sensor such as an optical linear scale by first displacing an object member whose position is to be determined until it butts against a mechanical stopper, then determining the position of the object member at the mechanical stopper and using that position as a reference position for the point of origin, and thereafter detecting the position of the object member by means of the position sensor, thereby detecting the position of the object member relative to the point of origin. In another embodiment, a first point of origin signal is obtained from an optical linear scale used as a position sensor and stored in response to latching signal generated at an end point of travel of the object member. Subsequently, when a second point of origin signal from the optical linear scale is compared with the first point of origin signal, any deviation from the first point of origin signal may be corrected based on the result of the comparison.

Abstract: A plurality of linear images are cut, the cut linear images are scanned successively on other images to detect positions where the degree of similarity is high, and these detected coordinate values are partially combined, and when the image is collated, combinations which does not satisfy the relative positional relation corresponding to these linear images are excluded from the processing target with reference to the relation between coordinate values of the detected positions. The image collation device thus enables a fingerprint collation device to obtain collation result consistently within a short time.

Abstract: A device for measuring characteristic values of an optical pickup and/or an optical disc capable of detecting tracking signals for measuring characteristic values even if optical disc rotation is not subjected to eccentricity. The device for measuring characteristic values of an optical pickup and/or an optical disc 1 samples outputs of photodetectors of an optical pickup 2 as signals A to F directly by a sample-and-hold circuit 8 and an analog-to-digital converter 10 to store the resulting digital data in a second memory 11. An arithmetic-logic unit 12d measures tracking error signals based on the digital data stored in the second memory 11. A signal generating circuit 25 then sends a sine wave signal to a tracking coil 2b for moving the laser light illuminated on the optical disc along the radius of the disc.

Abstract: A method for detecting the point of origin of a position sensor such as an optical linear scale by first displacing an object member whose position is to be determined until it butts against a mechanical stopper, then determining the position of the object member at the mechanical stopper and using that position as a reference position for the point of origin, and thereafter detecting the position of the object member by means of the position sensor, thereby detecting the position of the object member relative to the point of origin. In another embodiment, a first point of origin signal is obtained from an optical linear scale used as a position sensor and stored in response to latching signal generated at an end point of travel of the object member. Subsequently, when a second point of origin signal from the optical linear scale is compared with the first point of origin signal, any deviation from the first point of origin signal may be corrected based on the result of the comparison.

Abstract: A magnetic reluctance sensor can obtain a stable output without causing a curve around the center of an output waveform of an MR output even if the gap between an MR element and an MR magnet is narrowed. A stable output is obtained without causing a curve in an output waveform even if the facing interval "g" between magnet means 2 and a magnetism-sensitive element 3 is decreased, by setting a magnetism-sensitive pattern width "d" of the magnetism-sensitive element 3 to a value 0.3 to 1.0 times larger than a magnetic pole width .lambda. of the magnet means 2.

Abstract: A linear feeding system comprises a DC motor with brush, a lead screw integrally arranged as the rotational shaft of the DC motor, and a nut member screwed on the lead screw. This linear feeding system further comprises a magnet installed on the rotational shaft of the DC motor, which is provided with a plurality of N-pole and S-pole magnets being magnetized alternately in the circumferential direction, and a magnetoresistive effect sensor fixedly arranged to face this magnet. With this structure, it is possible to provide a simply structured, small linear feeding system capable of performing a high precision high-speed feeding operation at low costs.

Abstract: A method for detecting the point of origin of a position sensor such as an optical linear scale by first displacing an object member whose position is to be determined until it butts against a mechanical stopper, then determining the position of the object member at the mechanical stopper and using that position as a reference position for the point of origin, and thereafter detecting the position of the object member by means of the position sensor, thereby detecting the position of the object member relative to the point of origin. In another embodiment, a first point of origin signal is obtained from an optical linear scale used as a position sensor and stored in response to latching signal generated at an end point of travel of the object member. Subsequently, when a second point of origin signal from the optical linear scale is compared with the first point of origin signal, any deviation from the first point of origin signal may be corrected based on the result of the comparison.