Olympus Optical Company, Ltd.

Mitsuo Oshiba

Naoaki Tani

Takao Rokutan

Takumi Sugaya

Takefumi Sakurada

Akira Shirai

Toshio Horiguchi

Kazutake Sugawara

In an optical card recording/reproducing apparatus having a multi-track read type optical head in which a reproducing light beam is radiated on a plurality of tracks on an optical card having a large number of tracks parallel to each other so as to cause a plurality of reproducing light-receiving elements to simultaneously reproduce data of the plurality of tracks on which the reproducing light beam is radiated, the light beam is moved such that the maximum or minimum address of addresses of the tracks irradiated by the light beam is located at the target track. After one multi-track reproduction is performed, the light beam is moved by the distance corresponding to the number of multi-tracks.

Optical recording/reproducing apparatus capable of multi-track access

An optical information recording and reproducing apparatus comprising a first and a second laser diodes for generating recording light and reproducing light, respectively. A light emission condition of the second laser diode is always controlled to the constant or predetermined light intensity which is adequate for reproduction, by an APC circuit. The first laser diode is controlled by a light-intensity control circuit so as to be brought to the intensity of light emission lower than a level which forms a pit on an optical card, in a reproducing mode other than a period of time of a recording mode. Under a focus and tracking control due to the reproducing light, a value of a focus error and a value of a tracking error due to the recording light at a low level are detected and sampled/held as a focus offset and a tracking offset. During a period of time of the recoding mode, focus control and tracking control due to the reproducing light are performed so that these offsets are brought to zero.

Optical information recording and reproducing apparatus in which

In an optical card recording/reproducing apparatus having a multi-track read type optical head in which a reproducing light beam is radiated on a plurality of tracks on an optical card having a large number of tracks parallel to each other so as to cause a plurality of reproducing light-receiving elements to simultaneously reproduce data of the plurality of tracks on which the reproducing light beam is radiated, when the light beam is to be moved to a target track to be reproduced, the maximum value of an error to be caused during moving the optical head is subtracted from a difference between a current track and the target track so as to determine a moving amount, or when an error generated during the movement of the optical head is represented by .+-.G, and the number of light-receiving elements is set to be 2G+1 or more, any one of the light-receiving elements can be located on the target track by moving the optical head once.

An apparatus for writing and reading information on and from an optical card by projecting a writing light beam and at least two reading light beams onto the optical card includes a first semiconductor laser for emitting a writing laser beam, a second semiconductor laser for emitting a reading laser beam, a diffraction grating for diffracting the reading laser beam into multiple reading laser beams, and an objective lens for projecting the writing laser beam and the reading laser beams onto the optical card. A reading laser beam spot is formed on the optical card at a middle point between two reading laser beam spots. Images of the reading laser beam spots are received by first and second light receiving elements, respectively. By processing output signals from the first and second light receiving elements, it is possible to verify the recorded condition of pits immediately after recording in regardless of a direction in which the optical card is moved. It is also possible to check the condition of the information track immediately before the writing. In this manner, the writing operation can be performed at a high speed in a suitable and reliable manner.

Optical information writing and reading apparatus having two light

An optical card recording/reproducing apparatus scans a track of an optical card which includes a data portion at a center and ID portions at both ends. Each of the ID portions includes first and second address areas (identical address), a first sync area preceding the first address area, a second sync area between the first and second address areas, a third sync area succeeding the second address, a preamble preceding the first sync area, and a postamble (the preamble and the postamble are identical signals) succeeding the third sync signal. This apparatus comprises a RAM for storing data indicating the start and end points of each ID portion and of each sector with reference to a predetermined position of a track (e.g., the left end of the left ID portion), a counter for counting the relative moving distance of the optical card, and detection circuit for detecting the position of a sector by comparing the output from the counter with the data of the RAM. If a sync area is detected after detection of the preamble, the first address is demodulated. If a sync signal is detected after the demodulated address is error-corrected, data corresponding to the position of the boundary between the third sync signal and the postamble is preset to the counter.

Optical card recording/reproducing apparatus with presetting of card

An optical information recording/reproducing device is constituted of a focus control circuit connected to a controller, a tracking control circuit, a data processing circuit, and a card feed control circuit. The data processing circuit includes a plurality of I/V converters for converting signals received by a plurality of signal reproducing light receiving elements arranged to an optical detector into current/voltage, and a plurality of binary circuits each for converting the output from the I/V converters into a binary signal in a reference level. The data processing circuit includes a selector for selecting at least two outputs of a plurality of binary circuits. The data processing circuit includes a plurality of bit-clock producing circuits and a plurality of demodulation circuits. The bit-clock producing circuits produce bit clocks based on binary signals originated from selectors and a plurality of binary circuits which are not connected to the selectors. The demodulation circuits executes sampling the two binary signals in accordance with bit clocks and executes data demodulation using the sampled results. The data processing circuit includes a plurality of memories storing demodulated results from the plurality of demodulation circuits.

Optical information recording/reproducing device which simultaneously

In compliance with a variation in the speed of relative movement between a reciprocating optical recording medium and an optical head, an information regenerating apparatus produces a bit clock precisely and regenerate information correctly. To achieve this purpose, in this apparatus, information regenerating light receiving elements produce preceding and succeeding signals with a time difference between them. Based on a preceding one of the signals, a pulse spacing sampling circuit, a pulse multiple detecting circuit, a memory circuit, and a reference period calculating circuit produce a reference period. Based on a succeeding signal, a circuit for generating a signal to be demodulated produces a demodulated signal. Based on the reference period and a synchronizing signal, a demodulating circuit uses the bit clock generated by the clock generating circuit to demodulate the data carried on the signal to be demodulated.

Information regenerating apparatus for an optical recording medium

In an optical card reproducing apparatus, the data of a front ID portion is read, and whether a track address can be identified is determined. If the track address cannot be identified, a flag is reset, and the data of a data portion is read. If the track address can be identified, whether the identified track address coincides with a target track address is determined. If they do not coincide, the operation is ended. If they coincide, the flag is set, and the data of the data portion is read. After the data read from the data portion is stored in a buffer memory, whether the flag is set is determined. If the flag is set, data in the buffer memory is output as the data of the target track. If the flag is reset, the data of a rear ID portion is read, and whether the track address is identified is determined. If the track address cannot be identified, the buffer memory is cleared, and the operation is ended. If the track address can be identified, whether the identified track address coincides with the target track address is determined. If they do not coincide, the buffer memory is cleared, and the operation is ended. If they coincide, data in the buffer memory is output as the data of the target track.

Apparatus and method for reproducing information data from optical cards

According to the optical information recording/reproducing device of the present invention, upon recording of information, when a pit image on an optical detector which is formed by a recording optical beam spot at an information recording time arrives at a position of a O-order diffraction light spot image, while an optical card is moving in the forward direction, a light receiving element for signal reproducing senses a change in light amount. A verify signal is obtained immediately after recording based on the light amount change to perform a verify operation. Further, when a pit image on the optical detector formed by the recording optical spot arrives at a position of the image of the primary diffraction optical spot while a moving direction of the optical card is reversed and the optical card moves in the reverse direction to perform recording, a signal reproducing light receiving element senses a change in light amount. A verify signal is obtained immediately after recording based on the light amount change to perform a verify operation. Since irradiation is made in which the space between the recording optical spot and the O-order diffraction light spot is made equal to the space between the recording optical spot and the primary diffraction light spot b, an optical detector can receive the verify signal at the same timing even if the optical card moves in the forward or reverse direction.

Optical information recording/reproducing device capable of recording

An optical information recording/regenerating apparatus includes an optical head for irradiating a regeneration light spot to a plurality of tracks on an optical recording medium simultaneously via an objective optical system. A regenerating arrangement is provided for simultaneously scanning the plurality of tracks to which the optical head has irradiated the regeneration light spot, and then reading recorded information from the plurality of tracks. An error-correcting arrangement is provided which receives the recorded information read by the regenerating arrangement for performing error correction using the error-correcting codes for the plurality of tracks. An error-correction result memory arrangement is provided for storing results that indicate whether or not the error-correcting arrangement succeeded in error correction. A control arrangement is responsive to results stored in the error-correction result memory which indicate that error correction has not succeeded for the information regenerated from at least one track among the information regenerated from the plurality of simultaneously-scanned tracks. A driving device drives the regeneration light spot and the optical recording medium relatively to each other. The control arrangement controls the drive device so that the track for which the error correction has not succeeded will be included in a scanning range.

Optical information recording/regenerating apparatus and track scanning

A bit clock regenerating circuit comprising an edge detector made up of two flip-flops for detecting edges of a binary signal and a gating circuit, a counter receiving an edge detected pulse from the edge detector as a load signal for setting an initial value, counting clock pulses with a given frequency, and generating a bit clock according to the result of the counting, and a ROM in which multiple conversion tables are formed to supply an initial value for the counter according to an output value of the counter, and a conversion table for determining regeneration conditions is selected according to a switching signal.

Bit clock regenerating circuit and data regenerating method

A beam-spot control unit is arranged such that a light beam is irradiated onto an optical recording medium having a plurality of tracks, through an objective lens, to detect reflecting light of beam spots formed on the tracks by three or more photo detecting elements which are arranged in a direction corresponding to a track transverse direction. From a tracking error signal which is generated by a difference signal of pairs of photo detecting elements which are selected by a selecting switch from these photo detecting elements, a control signal is generated which positions the beam spots to a plurality of recording lines within a single track. A tracking control mechanism is utilized to enable positioning of the beam spots to a plurality of recording lines within the single track to be performed.

Optical information recording/reproducing apparatus for performing

The present invention reads out track addresses written onto ID sections of a recording medium, for example, from five, tracks of the plurality of tracks read out simultaneously, to execute demodulation and error correction. In case where the addresses are multiple-written onto the ID sections, the optical spot judges the track address of the desired track on the basis of the plurality of read-out track addresses until the optical spot passes through the remaining track address. Further, in case where there is only a single one of the track addresses written on said ID sections, the track addresses are read out one by one, are demodulated and are error-corrected. The track address of the desired track is judged on the basis of the plurality of read-out track addresses, prior to the fact that the optical spot enters an information recording area.

Track-address judging method

In an apparatus for recording and/or reproducing data on and/or from an optical card having a plurality of tracks, each of which includes a data portion and ID portions provided at both ends of the data portion, in said data portion the data is recorded in a plurality of sectors in a reciprocal manner by projecting from an optical head a recording or reproducing light beam onto the optical card, while the optical card is moved with respect to the light beam, a relative position of the optical card with respect to the optical head is detected to derive a sector position signal. A start point of a sector for which the data will be recorded or reproduced is determined by counting the sector position signal. The sector position signal is derived by counting pulses generated by a rotary encoder coupled with the motor for moving the optical card to derive a count value and a comparator for comparing the count value with a reference value which is generated in accordance with a predetermined track format. The sector position signal may be also derived by counting PLL clock pulses which are generated on the basis of a signal obtained by reading PLL synchronizing regions in the ID portion.

Apparatus with position detecting means for recording and/or reproducing

A data recording/reproducing apparatus for recording/reproducing data by use of a recording medium comprises a detector for receiving light beams from a predetermined portion of the recording medium and outputting a corresponding reproduction signal. A first measuring unit measures a time period during which an average level of the reproduction signal output from the detector exceeds a reference value, and outputs a first measurement signal. A second measuring unit measures the number of times, at which an interval of pits recorded on the recording medium meets a predetermined modulation rule, by use of the reproduction signal, and outputs a second measurement signal. A discriminating unit discriminates the recording state of the predetermined portion of the recording medium, on the basis of the first and second measurement signals.

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Hachioji, Japan

Mitsuo Oshiba