摘要:
In an optical disc player or other apparatus in which a light beam is directed through an objective lens to be focused thereby at a record medium surface for optically reading information recorded in a track on such surface; the objective lens has its central axis offset in respect to the longitudinal axis of a cylindrical body forming part of a movable assembly and through which the light beam passes axially, and such cylindrical body is both angularly displaceable about its longitudinal axis and axially displaceable relative to a guide bearing forming part of a fixed assembly to correct for tracking errors and for focusing errors, respectively. The fixed assembly further includes a magnetic circuit generating a magnetic field which intersects coils included in the movable assembly to receive focusing error and tracking error signals, respectively.
摘要:
An optical disc, and a disc recorder and a disc reproducer therefor, wherein in a lead-in region of the disc table of contents data indicating the record position on the disc of main data, e.g. musical numbers or the like, are recorded as subcodes and display data of, e.g. the titles of the musical numbers, the performers, etc., are also recorded as main data and wherein in a data region on the disc are recorded play data for the musical numbers as well as display data of the titles, performers, etc. of the musical numbers.
摘要:
A muting circuit which includes an amplifier having input and output terminals and a bi-directional transistor connectd between the output terminal and a circuit point of low reference potential. The transistor has emitter base and collector regions, the emitter region having a low impurity concentration substantially the same as that of the collector region and a potential barrier being provided opposite to the junction of the emitter and base regions at a distance which is smaller than the diffusion length of minority carriers of the base region. A control signal generating means including time constant means for turning on the bi-directional transistor is provided. The time constant means assures that the bi-directional transistor will be on for only a brief interval of time to bypass the output signal of the amplifier to the low reference potential circuit point and thereby avoid the presence of a pop noise at the speaker.
摘要:
An optical disc includes a disc base plate of a light-transmitting synthetic material having a recess for mounting a magnetic plate, and a holding part, integral with the disc base plate, for loosely holding the magnetic plate mounted in the recess with respect to the disc base plate. It is possible with the present optical disc to prevent distortion of the disc base plate otherwise caused by the difference in thermal expansion coefficients of the two components to inhibit double refraction of the disc base plate otherwise caused by such distortion to maintain good recording/reproducing characteristics.
摘要:
An optical disc recording apparatus in which audio data obtained by digitizing analog audio signals and time base compressing the resulting digital audio signals are read from a buffer memory on the cluster-by-cluster basis so as to be recorded on a recording track of a first optical disc and then a second optical disc. During the time interval when a cluster audio data unit next to the last cluster audio data unit written on the first optical disc by a first optical disc driver 14 is read from a memory 14, a second optical disc driver is captured into synchronization for continuously recording audio signals on the first and the second optical discs under the control of a system controller.
摘要:
The present invention relates to a recording method and a recording apparatus for use with a disc having a data area in which data has been recorded and an area for recording control information (i.e., Table of Contents information) for accessing a head to the data area. The recording apparatus comprises means for inhibiting the fetching of a disc if the control information has not been recorded in a predetermined area of the disc. Further, by providing a memory for storing the control information, the invention permits the accessing of a head to the data area in accordance with the content of the memory. Thus, information recorded on the disc before the control information is recorded onto a predetermined area on the disc can be reproduced.
摘要:
An optical disc player comprises a rotating member for rotating the optical disc, an optical pickup member for reproducing a digital audio signal including an error correcting code such as the Reed-Solomon Code from the disc, an error correcting decoder for decoding the error correcting code so as to produce a corrected or interpolated digital audio signal and condition flag data indicating the correction of the digital audio signal, and a display for indicating the condition flag data as a stain or contamination condition of the disc.
摘要:
An optical disc, and a disc recorder and a disc reproducer therefor, wherein in a lead-in region of the disc table of contents data indicating the record position on the disc of main data, e.g. musical numbers or the like, are recorded as subcodes and display data of, e.g. the titles of the musical numbers, the performers, etc., are also recorded as main data and wherein in a data region on the disc are recorded play data for the musical numbers as well as display data of the titles, performers, etc. of the musical numbers.
摘要:
A disc-shaped recording medium and a recording/reproducing apparatus employing the disc-shaped recording medium as a recording medium, are disclosed. The recording medium has a diameter of not more than 80 mm, and a recording track is formed on the recording medium with a track pitch of approximately 1.6 .mu.m. Information in excess of 130 Mbytes is recorded in a data compressed state on the recording track and the recording medium is rotationally driven at a constant linear velocity for recording and optically reproducing the information. The recording/reproducing apparatus employing the disc-shaped recording medium as a recording medium includes a buffer memory between a data compressing circuit for compressing input digital data and a recording encoding circuit for processing the compressed data by modulation suitable for recording, as long as a recording system of the apparatus is concerned, and a buffer memory between a playback decoding circuit for processing the compressed data by error correction decoding and demodulation complementary to the modulation and a data expansion circuit for expanding the compressed data to the original state. By suitably selecting the capacity of the buffer memories, recording and reproduction may continue satisfactorily even if the scanning position of the recording head and the optical head undergoes track jump during recording or reproduction.
摘要:
In an optical disc player or other apparatus in which a light beam is directed through an objective lens to be focused thereby at a record medium surface for optically reading information recorded in a track on such surface; the objective lens is mounted eccentrically in a circular end wall of a body member having a cylindrical side wall depending from the periphery of the end wall, a bearing sleeve extends axially from the center of the end wall and is slidable on a shaft extending upwardly from a base member so that the body member is both angularly displaceable about the shaft axis and axially displaceable relative to the base member to correct for tracking and focusing errors, respectively, inner and outer yokes extend upwardly from the base member at the inside and outside, respectively, of the cylindrical side wall and have respective radially aligned gaps, a magnet is associated with the yokes for generating magnetic flux through the side wall of the body member between the inner and outer yokes, and tracking and focusing coils are provided on the cylindrical side wall of the body member, with the tracking coils being shaped to have first and second portions extending parallel to the shaft axis and through which current will flow in opposed directions in response to the supplying of a tracking error signal to the tracking coils, with each first tracking coil portion being located between the inner and outer yokes to interact with the magnetic flux and thereby effect angular or rotary displacement of the body member in response to tracking error signals and each second tracking coil portion being located proximate to gaps of said inner and outer yokes so as to be substantially free of the magnetic flux, and with the path of a light beam through the objective lens being arranged to pass through a gap of the inner yoke and between the bearing sleeve and the cylindrical side wall of the body member.