Abstract: An automatic loading disc player includes a turntable for rotating a disc to be played back, a disc transfer mechanism for carrying and transferring the disc into a predetermined playback position on the turntable or a position in the vicinity thereof, and a positioning mechanism for positioning the disc in a predetermined position on the disc transfer mechanism. The positioning mechanism is engageable with at least three points on an outer peripheral edge of the disc for positioning the disc and drivable in coaction with disc transferring operation of the disc transfer mechanism. The positioning mechanism is releasable from engagement with the disc while the disc is being played back. The positioning mechanism includes three positioning levers angularly movable by an endless chain for engagement with the outer peripheral edge of the disc. With this arrangement, the disc can accurately and reliably be positioned on the disc transfer mechanism regardless of the diameter of the disc.

Abstract: A picture information processing system comprising an input for generating a play control signal in accordance with external operations (2, 3); memory for storing picture information and for producing a picture information signal (5, 9, 10); display for displaying a picture on a screen in accordance with the picture information (5, 8, 1); detector for producing a detection signal when the picture information signal has an instantaneous magnitude equal to a predetermined value (5, 11, 12); and a controller for performing a predetermined result operation, such as modification of the reproduced picture, reproduction of a score on the screen, and production of a sound, in accordance with the play control signal and the detection signal (5, 6); thereby to perform an advanced and complicated operation without increasing the steps of the program governing the system.

Abstract: In a color video information reproduction system such as video disc player and video tape recorder, the color burst signal is inserted into each horizontal period even during the vertical blanking period of a video information signal when the video information signal is recorded in order to obtain correct time axis variation information of a reproduced signal. Upon reproduction of the recorded video information signal, the color burst signal is separated from the reproduced signal and phase difference between the separated color burst signal and a reference signal is detected. The time axis servo system is driven on the basis of the detected phase difference and a stable and improved reproduced picture can be obtained while preventing an adverse influence to the audio information.

Abstract: A cross-talk detecting device to be incorporated in an information-carrying disc player for detecting an error component appearing within a preselected or predetermined constant frequency period at which the modulating signal has a certain constant frequency corresponding to, for example, a gray level in a video signal.

Abstract: A video disc recording and reproducing system in which a program is stored on a video disc to eliminate the need for the user to manually input a control program. A program and control signal is recorded in place of at least a portion of one of two audio tracks on a video disc along with video signals. The video disc player of the system includes modulator circuits which demodulate the video and audio signals from the disc, a central processing unit connected to the output of the demodulator circuit for demodulating the audio signal for detecting the control signal and program recorded on the video disc, and a memory for storing the control signal and program. The central processing unit controls the memory for storing the program and control signal at predetermined locations corresponding to the state of the control signal.

Abstract: A video disc player in which undesirable frequency variations in reproduced video and audio signals due to absence of the color burst signal during the vertical retrace time are eliminated. A first control unit actuates a tangential mirror driver unit in response to a phase difference produced by comparing a horizontal synchronizing signal from the reproduced video signal with a reference color subcarrier signal. The video signal is delayed by an electronically-controlled variable delay line the delay time of which is set on accordance with a phase difference between the color burst signal and a reference horizontal synchronizing signal.

Abstract: A device for eliminating time base variations in a video disc player in which a gate pulse controlled by the latest time base information is generated for preventing faulty operation during the absence of burst signals. The gate pulse is generated after a predetermined time which is proportional to a delay control signal and which starts from a leading edge of each of the horizontal synchronizing signals. A time base information pulse is generated having a width extending from the leading edge of the gate pulse to the leading edge of the specific color burst signal appearing after the leading edge of the gate pulse when color burst signals are present and having the same width as the gate pulse when the color burst signals are absent. The delay control signal and the timing pulse are generated in turn in response to a sampling pulse and the time base information pulse when the color burst signals are present and in response only to the time base information pulse when the color burst signals are absent.

Abstract: An optical scanner A for a video recording disc B includes a photo detector 6 for sensing the light from a laser source 1 reflected back from the disc. The low frequency and d.c. components of the photo detector output are compared with a reference voltage to derive an error signal. The latter, after compensation, amplification, and limiting, is applied to a regulator 23 to control the laser source discharge current, and thereby its intensity.

Abstract: A focus servo apparatus for an optical information reading system is disclosed, which includes an optical system for a light from an information carrying surface of a recording medium composed of a condenser lens, a cylindrical lens and a light receiving element. A subsystem is employed for maintaining light illuminating focussed on the information carrying surface in response to an output of the light receiving element. The distance between the cylindrical lens and the light receiving element is larger than the focus distance of the lenticular lens.

Abstract: A servo unit in an optical information reading device having a lens for focussing an irradiation light beam on the record surface of a disk. A movable mirror positions the focal point of the irradiation light beam formed on the track of the disk. A cylindrical lens is arranged so that the central axis of the cylinder forms a 45.degree. angle with the track direction of the disk to allow a light beam from the record surface to pass through the cylindrical lens. A focussing light receiver having four separate light receiving units is arranged on two orthogonal straight lines. The focussing light receiver receives a focus controlling light beam passed through the cylindrical lens at a distance twice as long as the focal distance of the cylindrical lens.

Abstract: An optical reader for reading information recorded on a disk. The reader includes a mirror and a focussing lens. The mirror surface is alterable by feedback means to shift the point of incidence of a light beam passing through the lens onto the disk. The position of the surface is always selected to allow the light beam to pass through the image side focal point of the lens.

Abstract: An optical scanner A for a video recording disc B includes a photo detector 6 for sensing the light from a laser source 1 reflected back from the disc. The low frequency and d.c. components of the photo detector output are compared with a reference voltage to derive an error signal. The latter, after compensation, amplification, and limiting, is applied to a regulator 23 to control the laser source discharge current, and thereby its intensity.