Abstract: The invention provides a recording and/or reproduction apparatus and a recording and/or reproduction method by which information can be recorded or reproduced accurately onto or from any of a plurality of record layers of an optical disk. In the recording and/or reproduction method, after an optical disk is started, an optimum focus offset position for a predetermined record layer of the optical disk is searched for. This searching is performed by varying an offset value stepwise and searching for an offset value with which the amplitude of a tracking error signal exhibits a maximum value. After an optimum focus offset position is searched out, the value of it is stored. Similar processing is performed also for any other record layer. When an instruction to reproduce a predetermined record layer is developed in step, focus jumping to the record layer is performed. Then, an optimum focus offset value searched out and stored in advance is read out and added to a focus error signal.

Abstract: A disk driving device for use in recording and/or reproducing data on an optical recording medium having a plurality of recording layers. When a focus jump operation is executed between the recording layers, an actuator displaces an objective lens in response to a selectively generated acceleration or deceleration pulse and a focus error signal. Instability of the focus jump operation derived from noise superimposed on the focus error signal or from sensitivity variations in the actuator is eliminated.

Abstract: A method and apparatus for optically reading out pre-recorded signals on an optical disc by way of data reproduction. If the quantity of playback data read out from an optical disc 1 and stored in a memory 8 during data reproduction is found to be in excess of a quantity for one rotation of the optical disc, data writing in the memory 6 is discontinued and an optical pickup 3 is caused to make track jump to a reproduced track under control by a controller 7. A servo gain control signal or a servo offset control signal is sent to a servo circuit 8 which then performs focusing servo control or tracking servo control of the optical pickup 3. The writing stop position on the optical disc 1 is then detected and data playback is re-initiated. Stabilized data playback is enabled even if servo error signals are fluctuated within the optical disc or the servo error signals are changed due to temperature changes in the optical pickup or in the error signal detecting amplifier.

Abstract: Disclosed is an optical recording and reproducing apparatus capable of recording in a position which is properly synchronous with the position of the last pit in a sector on which a recording was made, the first pit in a sector on which a recording is to be subsequently made. This apparatus is characterized by a recording circuit having a data demodulating circuit which includes a synchronizing signal separating circuit. The synchronizing signal separating circuit outputs a synchronizing signal on the basis of a pit detection signal generated in response to the detection of pits formed on a track of a recording medium and representing data to be recorded.

Abstract: A dual light source optical recording and playback system which comprises a first light source which is a semiconductor laser for irradiating tracks of a recording medium with recording spot light to record pits as information units, a second light source for irradiating the tracts with playback spot light, detection means for detecting the output of the semiconductor laser which changes in response to return light available as the recording spot light is reflected on the track of the recording medium and returned to the semiconductor laser, and a timing signal generator for generating a timing signal for the recording of the next pit on the track in response to a detection output from the detection means which corresponds to the return light due to reflection by the recorded pit.

Abstract: An optical card processing apparatus is disclosed in which an optical head producing an irradiating light beam is forcibly moved in a direction orthogonal to a direction of tracks of an optical card set in the apparatus. A tracking error signal as the moving light beam irradiates the card is analyzed to determine if the optical card is properly set in the apparatus.

Abstract: The present invention relates to an optical card reader that detects any relative inclination of the card by measuring the relative motion of the optical tracks themselves. The optical card reader comprises a card holding portion, an optical head having the ability follow data tracks on the optical card, and a detector that measures the angle of inclination of the optical card from a tracking signal generated from a one-dimensional relative movement of the card holder and the optical card.

Abstract: A card accessing apparatus is provided which includes a stage unit for supporting a data storage card with a data storage area of the card facing downwardly, a housing including a bottom plate, for housing the stage unit, and a stage feeding unit supported on the bottom plate for reciprocating the stage unit. A read/write head is disposed under the stage unit, to read and write data on the data storage area of the card. A head feeding unit is supported on the bottom plate to drive the head unit to a position under the stage unit to access the data storage area of the card.