Abstract: A hologram recording and reproducing apparatus includes a movable galvanomirror, a mirror controller and a reproduction unit. The galvanomirror guides a reference beam toward a hologram recording medium and changes the incident angle of the reference beam. The mirror controller causes the galvanomirror to move for adjusting the incident angle to a predetermined angle for hologram recording. In reproducing the recorded information, the mirror controller causes the galvanomirror to move, so that the incident angle continuously changes within a predetermined range including the predetermined angle. The reproduction unit receives a detection signal from an optical detector while the incident angle changes continuously. The detection signal corresponds to the intensity of a reflected beam from the hologram recording medium. The reproduction unit reproduces the recorded information, based on the detection signal, when the intensity of the reflected beam is over a predetermined level or reaches the maximum.

Abstract: A hologram recording and reproducing apparatus minimizes reproduction errors by servo control on the tilting of a reference beam relative to a hologram recording medium. The apparatus includes an optical detector for servo control and an optical sensor for reproduction signal conversion. A pixel pattern generator generates, on a wave surface of the recording beam, a discretely distributed recording pixel pattern corresponding to the information to be recorded, and a specifically shaped and localized servo pixel pattern for the servo control. A beam splitter splits the reflected beam from the hologram recording medium into a reproduction beam directed to the optical detector for reproduction signal conversion and a servo beam directed to the optical detector for servo control. A servo controller controls the tilting of the reference beam relative to the hologram recording medium, based on an output signal from the servo control optical detector.

Abstract: A hologram recording medium includes a hologram recording layer and a transparent substrate layer stacked on the hologram recording layer. The recording layer records an interference pattern of a recording beam and a reference beam. The transparent substrate layer has an inner surface facing the hologram recording layer, and this surface is formed with trace zones for guiding the recording beam and the reference beam in a prescribed guide direction. The trace zones have a higher reflectance than that of the remaining area in the inner surface of the transparent substrate layer.

Abstract: A disk-type hologram recording medium and a hologram recording and reproduction device utilizing such a recording medium are provided. The hologram recording and reproduction device includes a spatial optical modulator provided with a plurality of optical elements arranged in a grid-like form. These optical elements are divided into groups each associated with 1 bit of data for performing required light modulation. Thus, a special pattern exhibiting a greater S/N margin for 1 bit can be recorded in the recoding medium. During data recording or data reproduction, the special pattern is read from the recording medium, and based on the retrieved special pattern, fine adjustment by servo control is conducted for adjustment of tilting or focusing of the recording medium and for adjustment of the wavelength of the light emitted from the light source.

Abstract: The resin composition for a platable substrate of the present invention comprises 100 parts by weight of a resin composition (C) comprising 10 to 60% by weight of a graft copolymer (A) prepared by graft polymerization of a rubbery polymer (A1) and a monomer component (A2) containing an aromatic alkenyl compound monomer unit (a) and a vinyl cyanide compound monomer unit (b) and 40 to 90% by weight of the other polymer (B) (provided that the total amount of the components (A) and (B) is 100% by weight), and 5 to 40 parts by weight of a phosphate ester flame retardant (D) having a molecular weight of more than 326 or 2 to 40 parts by weight of a red phosphorus flame retardant (D′). The resin composition for a platable substrate of the present invention is excellent in production stability such as moldability, dimensional stability, mechanical strength and plating properties, and is also environmentally friendly.

Abstract: The object of the invention is to measure, surely and in a stable condition, the orientation of a pig body in the pipe of a pipeline thereby to correct errors caused by measuring the linear shape of the pipeline by means of a gyroscope sensor. A three-axis gyroscope sensor unit 4 is placed in a pig body 2 such that one of measuring axes of the gyroscope sensor unit 4 is parallel to the center axis of the pig body 2 and is fixed so as to prevent the gyroscope sensor unit 4 from being shifted in position with respect to the pig body 2. Two sets of six distance measuring means 5-10 and 11-16 are arranged on the outer periphery of the pig body 2 at two positions in the back and forth direction (in a direction of travel), respectively, and the six distance measuring means of each set are arranged at equal intervals in the circumferential direction of the pig body 2.

Abstract: First and second electrodes are inserted into molten metal. A first pseudo random signal is transmitted to the first electrode, and at the same time the first pseudo random signal and a second pseudo random signal which has the same pattern as the first pseudo random signal but which is slightly different in frequency from the first pseudo random signal are multiplied by each other in a first multiplier to thereby calculate a first product value. A signal obtained from the second electrode and the second pseudo random signal are multiplied by each other in a second multiplier to thereby obtain a second product value. The displacement of the molten metal is calculated from the time difference between maximum correlation values respectively appearing in time series patterns of the first and second product values.

Abstract: A distance measuring method and an apparatus therefor, in which used are first and second pseudo random signals which are equal to each other in pattern but slight different from each other in frequency. A first time-series pattern obtained by multiplying the first pseudo random signal by the second pseudo random signal is generated, laser light intensity-modulated with the first pseudo random signal is radiated to a target, the light reflected from the target is received, and a intensity change of the received reflected-light is converted into an electric signal. A second time-series pattern is obtained by multiplying the electric signal as a reception signal with the second pseudo random signal. The distance to the target is measured by calculating the time difference between the first and second time-series patterns.

Abstract: Disclosed is a in-furnace slag level measuring method for measuring a slag level in a convertor and an apparatus therefor. A sublance and an antenna of a microwaver radar are arranged exchangeable therebetween so that the sublance and the antenna are alternatively inserted in to the convertor from about the convertor. The antenna is inserted into the convertor in first and middle stage of the refining operation of the converter to thereby measure the slag level, and the sublance is inserted into the convertor to thereby perform various measurement.

Abstract: An in-furnace level meter for measuring a slag level, or the like, in a convertor, and an antenna used therefore. An antenna position is controlled so that the distance between the antenna inserted in the convertor and the slag level can be established to be constant or within a predetermined range. A water-cooled structure antenna is used as the antenna.

Abstract: Disclosed is an in-furnace slag level measuring apparatus having a microwave radar for measuring a slag level in a convertor or the like. The level of a transmission signal or a reception signal is adjusted in accordance with the level of a detection signal so that the signal level in the microwave radar is adjusted to be constant. Further, the level measurement value and the detection signal are inputted and the level measurement values obtained in a predetermined time are subjected to averaging operation. In the averaging operation, when the detection signal is smaller than a set point, the averaging operation is performed while disregarding the level measurement value at that time.