Abstract: A control board connected to a main body of a computer, which has access to an optical recording medium through an optical recording medium read/write device, and for controlling and enabling the optical recording medium read/write device to have access to the optical recording medium in the same manner as an existing magnetic disk device and the like have with respect to a magnetic medium. This control board is composed of a directory development processing station, various types of interface processing stations, a retrieval processing station, a data transfer/receiving processing station, a data input/output processing station and a directory update processing station. It is possible to have access as easily to the optical recording medium as to other existing media by using commands, I/O functions, and so on in the computer body.

Abstract: A magnetic head usable in a reader-writer for reading and writing data which can be magnetically processed. The magnetic head is characterized in that: it comprises a core (1), an exciting coil (2) for exciting the core (1), and a head case (3) for tightly enclosing the core (1) and the exciting coil (2); and a fuse is provided in a part of the exciting coil (2). When the reader-writer in which the magnetic head is incorporated is to be abandoned, the magnetic head can be easily destroyed, thereby enabling the prevention of fraudulent uses, such as the forging, of magnetic cards.

Abstract: The present invention comprises a magnetic card 1 in which punched holes 5 are punched to indicate incidence of use data and a punched hole detection apparatus 4 for detecting the punched holes 5 of the magnetic card 1. The magnetic card 1 has a hole punch section 3 in the shape of a strip. The punched hole section 3 has a plurality of small segments 31 in a row which are arranged parallel to the length of the card, and two kinds of ink having different optical characteristics are applied to the small segments 31 according to prescribed rules.

Abstract: A data reading apparatus for an optical card which reads the optical card having a data area by a reading sensor. The data area on the optical card is formed by aligning a plurality of data tracks, each of which consists of a plurality of data bits, along a reference line extending perpendicular to the data tracks. The data reading apparatus includes a reference line detecting unit for outputting an average position signal on the reference line from a signal obtained by reading the reference line, and a data clock generating unit for generating data clocks which serve as a reference when the data bits are read on the basis of the average position data on the reference line. In consequence, very accurate data clocks can be obtained, and adjustment of an optical system, which would be required in a conventional apparatus, can be eliminated.

Abstract: The present invention relates to system for reading an optical recording medium having a data region formed by arranging, in parallel, a plurality of data tracks each of which is constituted by a plurality of bits along a reference line positioned perpendicular to the data tracks enabling the recording capacity of the optical recording medium to be enlarged. A bit included in the data track and positioned adjacently to the reference line is arranged to be a clock bit.

Abstract: A writing device for an optical memory card is disclosed. In this writing device, tracking correction is performed by moving a mobile objective lens of an optical system in the transverse direction of a track in accordance with a tracking error of the optical system relative to the optical memory card, and the range in which tracking correcting can be performed is enlarged by moving a retaining portion of the objective lens by a moving device when first comparison device has determined that tracking error information was outside a predetermined first standard range. The writing device includes a writing stoppage device for stopping writing data on the optical memory card when a second comparison device has determined that the tracking error information exceeded a second standard range which is wider than the first standard range.

Abstract: A card type optical recording medium according to the present invention relates to a card type optical recording medium arranged in such a manner that a plurality of tracks are formed on a recording region provided on a card type substrate and the tracks are divided into a plurality of blocks so that data is optically recorded to each of the blocks. The card type optical recording medium according to the present invention is characterized in that a portion of the recording region is provided with a defective block information region for determining a good or bad condition of the block to which the data is recorded. As a result, the defective block information can be read prior to the reading of data. Therefore, the necessity of accessing the defective block can be eliminated, causing a good reading efficiency to be realized.

Abstract: An optical recording medium having at least one data track and at least one clock track including clock bits provided in a predetermined optical pattern, in which the clock track comprises regular, periodical clock bits arranged regularly in a line and at least one irregular clock bit disposed in the line, breaking the regularity of the periodical clock bits. When a PLL circuit is reinstated into a locked state after it has been unlocked, a leading word can be identified by the irregular clock bit provided in the clock track. This enables data reading thereafter to be accurate.

Abstract: The invention relates to an optical recording medium having a plurality of guide lines (1) and data regions (5) which are defined between adjacent guide lines and in which data is optically recorded. Each guide line (1) includes a start guide (2) indicating the leading end of the data region, clock guides (3) arranged at a predetermined interval to follow the start guide (2) and enabling synchronization during reading and writing, and sector marks (4) arranged at a predetermined interval so as to divide the data region (5) into a plurality of sectors. The clock guides (3) on adjacent guide lines are arranged in such a staggered manner that the clock guides (3) appear alternatingly in both guide lines. The data region having sector number writing portion (5a) provided in the vicinity of each sector mark (4) for writing a sector identification number to be written therein.

Abstract: An apparatus for detecting a read error of an optical recording medium is provided with a reading device which reads data recorded on a data track of an optical recording medium to thereby store the read data in memory therein. This apparatus includes a PLL circuit responsive to a read clock from the optical recording medium for generating a clock synchronized with the read clock, and address updating circuit for updating a write address of the memory to store the read data therein in synchronization with the output clock from said PLL circuit. Also, included are out-of-locking detection circuit for detecting the out-of-locked state of the PLL circuit in response to the read clock and the output clock from the PLL circuit, and address-updating suppression circuit responsive to a detection signal from the out-of-locking detection circuit for suppressing the address updating of the address updating circuit.

Abstract: An interleaving method and apparatus suitable for burst error correction occurring in data transmission or reading of recording medium. In the interleaving method in which data to be transmitted is once written in a storing means and then read to be output in order different from a writing order, a plurality of counters for dividingly generating addresses of the storing means is used; and an operational relationship between the counters is changed between writing and reading of the storing means. ROMs for address translation can be omitted so that the number of gates is reduced very much. Thus, a reasonable interleaving apparatus suitable for LSI formation can be realized. In addition, since ROMs for address translation interposed between the counter and the storing means in the conventional apparatus are omitted, access time for the storing means can be shortened substantially.

Abstract: A machine translation system for automatically effecting translation from Japanese the source language into another or target language. Conventional translation systems entail problems, e.g., the reduction in processing efficiency owing to the need for an additional step such as pre-editing prior to translation.

Abstract: Tracking device for an optical memory card includes an inclination information sampling unit for calculating changes per unit time of the low-frequency component of a tracking error signal, a detection unit for outputting a detection signal for duration of a deviation occurring during tracking that exceeds a predetermined standard range, a cumulative addition unit for cumulatively adding the output of the inclination information sampling unit of the low-frequency component of the tracking error signal that is generated when the detection signal is generated at each unit time during the generation of the detection signal, and a switch-over unit for outputting as an optical system tracking control signal the tracking error signal during the normal operation and the output of the cumulative addition unit during the outputting of the detection signal.

Abstract: An optical recording device which writes and reads data by radiating laser beams from an optical head onto an optical recording medium. A diffraction grating is provided on the optical head and a plurality of laser beams are generated. Some of the laser beams are positioned on a track guide on the above-mentioned optical recording medium. Some of the other laser beams are positioned on another track guide and a plurality of tracking beams are thus constituted. The optical recording device is also provided with a tracking detection circuit for outputting a tracking error signal indicating the difference between the amounts of reflected light to a photo detector which receives light reflected from the above-mentioned optical recording medium for tracking beams and for switching the above-mentioned tracking beams used for tracking. The plurality of tracking beams enables tracking to be performed even when a track guide has defects by switching tracking beams, thereby improving tracking reliability.

Abstract: An error signal generating circuit which generates an error signal based on a read signal from an optical recording medium, which circuit comprises an error detection means responsive to the read signal to output the error signal; a disorder detection means responsive to the read signal to detect disorder; a signal hold means holding an output from the error detection means just before the disorderly state has occurred, during a period when the output from the disorder detection means represents the disorderly state; and a switching means responsive to the output from the error detection means and the output from the signal hold means to selectively supply the output from the hold means when the output from the disorder detection means represents the disorderly state and selectively supply the output from the error detection means when the output from the disorder detection means does not represent the disorderly state.

Abstract: The present invention provides a defect inspecting apparatus which can easily and accurately carry out the inspection of a defect in a recording medium and which does not require electrical image processing or image processing by means of software in order to eliminate a regular pattern.This defect inspecting apparatus has an optical image forming system, such as a microscope, which enlarges an optical recording area of an optical recording medium having a regular pattern and an image processing part which converts the enlarged image sent from the optical image forming system into an image signal and detects the defect in the optical recording area from the image signal. In addition, a space filter which eliminates the space frequency component of the regular pattern is mounted on the optical image forming system.

Abstract: A reading apparatus for reading an optical recording medium having a clock track, data tracks and a tracking guide line.The apparatus comprises a photodetector which receives light images of the clock track, data tracks and tracking guide line; a clock detecting circuit which is responsive to a signal from the clock track by the photodetector to output a clock signal; data detecting circuit which encodes data read from the data tracks by the photodetector into a binary code in response to the clock signal; a focus error detecting circuit for detecting a focus error and a tracking error circuit for detecting a tracking error in response to a signal from the tracking guide line by the photodetector. The photodetector comprises first to fourth light-sensitive elements which receive a light image of the tracking guide line, a fifth light-sensitive element which receives a light image of the clock track and a sixth light-sensitive element which receives a light image of the data track.

Abstract: A burst error correction apparatus suitable for correcting burst error due to a bit slip in a self-clocking signal containing resync codes at predetermined intervals, e.g., a self-clocking signal read out from a digital recording medium before the signal is demodulated. This apparatus has a shift register for receiving the self-clocking signal in series; a detector for detecting, an inhibited pattern which has not existed in the self-clocking signal in response to parallel outputs from a section in the vicinity of the entrance of the shift register; and a controller for shifting, by respectively controlling clocks applied to the shift register and a rear stage of the same, data appearing from a position in the vicinity of the inhibited code between adjacent resync codes to the subsequent one of these resync codes in accordance with the direction and the number of bits based on a detection signal from the detection means.