Abstract: A magazine-housed disk reproducing apparatus is disclosed which enables the user to easily determine the contents of the various disks contained in the magazine. The names of tunes and the like provided on the various available disks are stored in a memory. An identifying device detects which magazines containing which disks have been loaded. A display device is activated to indicate to the user the desired content information.

Abstract: An apparatus for playing a composite disk containing separate audio-only and video-plus-audio portions, as well as an ordinary compact disk. It is first detected whether the disk being played is a compact disk or a composite disk, and if the disk is a composite disk, whether the portion presently being played is a region containing only audio data or a region containing a frequency modulated video signal recorded in multiplex form with a digital signal. A reference signal for driving a spindle servo circuit is produced as a fixed frequency signal when the disk is a composite disk or the region of a composite disk being played contains only audio data, and as a variable frequency signal of frequency determined in accordance with the frame sync signal contained in the reproduced signal when a region of a composite disk containing a multiplex-type signal is being reproduced.

Abstract: A method and device for playing a composite disk containing separate audio-only and video-plus-audio portions in which the time until the commencement of the playing of the video-plus-audio portion is reduced. When playing of only the video-plus-audio portion is designated, a data detection point of the pickup is immediately moved toward the lead-in area of that portion, whereupon reproduction is started immediately. In another embodiment, index data is directly read from the lead-in area of the video-plus-audio portion without reading similar data for the audio-only portion. When the playing of the video-plus-audio portion is completed, the pickup is stopped at a rest position corresponding to the lead-in area of the second region.

Abstract: A data recording and reproducing device including a recording device which makes a determination of the level of an input signal every predetermined period, converts the input signal, which has been level-controlled according to the result of the determination into a digital signal, and records the digital signal together with the result of the determination on a recording medium; and a reproducing device which reads the digital signal from the recording medium and converts the digital signal thus read into an analog signal, while level-controlling the analog signal according to the result of the determination, and outputting the analog signal thus level-controlled.

Abstract: A focus servo device in which loop gain is reduced in response to detected abnormalities in a recorded disk, in order to prevent interference with a tracking servo device in an optical disk player.

Abstract: A method of generating a servo signal for a servo system of a disc player employing an optical method of data read-out, whereby a pair of sensing signals derived from reflection of a single light beam from the disc, which differ in phase by an amount corresponding to a tracking error, are processed to derive a first difference signal representing the difference between the respective LF components of the sensing signals and a second difference signal representing the difference between the respective HF envelope components of the sensing signals, with the first and second difference signals being mixed in a differential amplifier in a specific ratio to thereby derive servo signal having no DC offset component, and with the relative proportions of these difference signals prior to this mixing being adjusted by amplifying or attenuating one of the signals such as to established a value for the mixing ratio which is optimized with respect to an amount of tilt of the recording disc or an amount of inclination of

Abstract: A tracking servo device for controlling the relative position in the radial direction of a recorded disc between an information reading point of a pick-up and a recorded track having an improved accuracy in performing track-jumping operations. In accordance with the invention, the track jumping operations are performed only in response to a tracking error signal, that is, without the use of a jump drive signal or brake signal, whereby fine control and adjustment of various signals within the circuit are made unnecessary and accurate and quick track jumping operations are ensured. To achieve this, an in-phase and an out-of-phase signal with respect to the tracking error signal are produced and alternately selected through a switch. The levels of the signals applied to the switch may be clamped to prevent them from passing through zero.

Abstract: A method for performing sound field enlargement in a digital audio reproducing apparatus such as a compact disc player. A sum is calculated between each received pair of right-channel and left-channel data read from the disc, and the resulting sum data is stored in a random access memory. After a predetermined delay time, the sum data are read from the memory and multiplexed with the then-incoming right-channel and left-channel data. The resulting data stream is converted to respective right-channel, left-channel, and delayed-sum analog signals, which are then subjected to low-pass filtering. The filtered signals are processed in a conventional manner to yield outputs signals which, when reproduced, produce a perception of an enlarged sound field.

Abstract: A digital audio system constructed to reproduce an audio signal by separating low frequency components of a PAM (Pulse Amplitude Modulation) signal made up of pulses being produced at predetermined time intervals and representing a predetermined audio signal, the digital audio system including a pulse width control means for varying the pulse width of each of the pulses of the PAM signal in accordance with a predetermined command signal, whereby an automatic fade in and fade out operation is performed.

Abstract: A tone arm device for a turntable in which the tone arm is mounted upon an inner movable member rotatably supported on an outer movable member freely rotatable with respect thereto. The rotational position of the inner movable member and hence the tone arm is detected as is the rotational position of the outer movable member. Control means operates in response to the signals representing the rotational positions of the inner and outer movable members to produce a control signal which is used to drive a magnetic actuator which causes the outer movable member to rotate so as to track the rotational position of the inner movable member.

Abstract: In a pickup arm drive device of a record player capable of automatically selecting a desired music on a record disc on which a plurality of pieces of music are recorded, at least two inter-music sensors are arranged near a stylus on the pick-up arm to detect inter-music spaces on the record disc. The outputs of the sensors are subjected to processing and by using the resultant processed outputs, the driving of the pickup arm is switched from "lead-in" or "return" operation to an inter-music position servo operation. Therefore, the stylus of the pickup arm can be lowered exactly onto the inter-music space on the record disc even if the record has an eccentricity or warp.

Abstract: An automatic music selecting device in which a pickup cartridge is accurately lowered onto a disc at an intermediate position between adjacent songs on the disc even if the disc is eccentric. An intersong sensor mounted on the pickup cartridge detects the intersong intervals upon movement of the arm. The arm is stopped at a predetermined interval designated by an externally supplied song number. To do this, the output signal from the intersong sensor is held corresponding to the position just before the arm is stopped. Then, the position of the arm is finely adjusted on the basis of the difference between the level of the output signal thereafter produced by the sensor and the held level.