Abstract: A photomagnetic composite head comprising a magnetic head and an optical head that are integrated into one unit, an optical waveguide path of the optical head being located in the surface of the magnetic head that faces a recording medium, and a laser beam that passes through the optical waveguide path being irradiated on a point on the recording medium where a magnetic field is impressed from the magnetic head, whereby recording can be performed under a condition in which the coercivity of the recording medium has been lowered by the laser beam, thus making it possible to achieve high density recording by using a recording medium with a high coercivity.

Abstract: A velocity detection method and an apparatus therefor, in which the relative velocity between a light beam and tracks is detected on the basis of a period for which the light beam crosses the tracks, and under the condition that the light beam has passed by a predetermined position on the way to the target track, the detected relative velocity is compared with a predetermined velocity value so that when the detected relative velocity is larger than the predetermined velocity value the detected relative velocity is invalidated on the assumption that erroneous detection is generated by noise.

Abstract: A color video signal recording and reproducing method for recording and reproducing a color line sequential TCI signal which prevents, upon different speed reproduction, a possible displacement in hue of a reproduction color video signal. First and second time base compressed chroma signals for one horizontal period are combined with a time base elongated brightness signal for one horizontal period, and type code signals representative of types of the chroma components are added to form encoded color video signals for two tracks. The encoded color video signals are shuffled and recorded simultaneously onto a magnetic tape by two heads.

Abstract: In a recording apparatus for a mirror mother tape to be used in a contact-type magnetic printing process, a chrominance signal of an incoming color video signal is converted into a down converted chrominance signal having a reduced frequency fC, a beat cancelling signal having a frequency 2fC is generated from the down converted chrominance signal, the beat cancelling signal is added to a luminance signal of the incoming color video signal thereby generating an added signal, and the down converted chrominance signal is combined with the added signal to provide a composite signal which is recorded on a mirror mother tape.

Abstract: A deceleration control system is applied to an optical disk unit which includes an optical head for recording information on and/or reproducing information from tracks of an optical disk which rotates at a constant velocity by use of a light beam emitted from the optical head, a track actuator for moving the light beam in a direction traversing the tracks of the optical disk, and a tracking error signal generation circuit for deriving a tracking error signal TES from a signal which is output from the optical head and is dependent on a light beam received from the optical disk. The deceleration control system includes a velocity control part and a deceleration part. The velocity control part includes a first circuit for generating a target velocity V.sub.t, a second circuit for detecting a beam moving velocity V based on the tracking error signal TES derived by the tracking error signal generation circuit, and a third circuit for detecting a velocity error V.sub.

Abstract: A superimposing circuit for a video apparatus comprises a first switch circuit for selecting an input video signal in response to a selected record or a playback mode, a second switch circuit for synthesizing a video signal and character information during the record mode, a third switch circuit for synthesizing the video signal and the character information during the playback mode, a switch device, a comparator for receiving the output of the switch device as a reference level, a character generating circuit, and a controller for controlling the switching of the second switch circuit and the third switching circuit in accordance with the selected one of the record mode and the playback mode.

Abstract: A recording and playback system for code recording of VCR which comprises a synchronous separator, an 1/2 frequency demultiplier, a microcomputer, a comparator, a control pulse amplifier, a key matrix, a control circuit, a control head, a pulse generating head, and particularly at least demultiplier, transistor, switch, and resistor, whereby it is made to record a code in initial stage of recording, whereby it can be reproduced only when decoding the code in the initial stage of reproducing, while in a state of not selecting a code mode, it operates as similar as the conventional VCR, and even if one knows the code, the code cannot be decoded in other VCR having not the decoding function whereby it cannot be reproduced normally, whereby complete secret preservation can be kept, while in the normal mode being of not code mode, it operates similarly as the conventional system so that it can be easily applied to conventional system.

Abstract: A track seeking control apparatus includes an optical head for generating a signal comprising a train of track cross pulses when it crosses tracks on a recording medium. A first counter counts the train of track cross pulses generated by the optical head, and produces a signal representative of a count value of the first counter. A signal generator generates a signal of a frequency varying proportional to a frequeny of the track cross pulse signal. A second counter counts the train of track cross pulses generated by the optical head, based on the output signal of the signal generator, and produces an output signal when a count by the second counter reaches a desired value. A second pulse generator outputs to the first counter a correcting pulse for correcting the count value of the first counter, in response to the output signal produced by the second counter.

Abstract: A loudness control circuit for an audio device used in a reproduction circuit for reproducing a music signal recorded on a recording medium comprises one or plural level detection circuits for detecting levels of signal components of low and high frequency regions of a reproduced signal and control circuits for controlling the levels of the signal components of low and high frequency regions of the reproduced signal in response to outputs of the level detection circuits. The level control is made in accordance with a sound-pressure level for each frequency region of a reproduced signal so that an optimum compensation of the level in response to the sound-pressure level becomes possible.

Abstract: In an optical disk apparatus for recording and reproducing data using light beams, the light reflected from a record mark area provided on an optical disk is detected and the amplitude of the signal corresponding to the light is held; the record mark is composed of long pits and long unrecorded areas. This amplitude is compared with that of the signal relative to the light from a data recording area of the optical disk. If the comparison result has a predetermined relation between both signals, an output signal with a prescribed level is produced. This output signal is used to assure the quality of the recorded data.

Abstract: An arrangement for track skipping in a track control circuit with an optical scanner, in which two light beams reflected from an information medium, strike each onto a separate photodetector. The two outputs of the photodetectors are subtracted to generate a sine-shaped track error signal representing a difference between a track being scanned and a desired track to be scanned. The track control circuit is supplied at the beginning of track skipping with an offset quantity for skipping across a number of tracks. This offset quantity is dimensioned so that a light beam incident on the information medium for tracking data thereon, becomes displaced by a predetermined amount of track center and thereby radiates partially on the track being scanned and partially on the space between the track being scanned and an adjacent track. The track error signal becomes inverted by an amount equal to twice the number of tracks skipped.

Abstract: An information reproducing system plays back a group of recording mediums each having recording information to be reproduced and TOC information with respect to the recorded information, so that the recorded information of the recording mediums can be reproduced according to the TOC information. The TOC information of the recording mediums are read before the recording mediums are played back, playback operation of the recording mediums is controlled based on the read TOC information. Since it is not necessary to read TOC information each time a recording medium is replaced or a group of recording medium is replaced, the recording mediums can be smoothly played back.

Abstract: A servo control circuit for an image rotator used in an optical tape recording apparatus that employs a rotary tape drum. Pairs of pulse generators and frequency generators are provided on the image rotator and on the tape drum, respectively. Initially, the pulse generators are used for servo control and, upon detecting a phase lock, servo control is subsequently switched over to be controlled by the frequency generators.

Abstract: A detrack detecting system for detecting deviation of the beam spot from the track in an optical recording/reproducing apparatus in which recording and reproducing of data are performed by irradiating optical beams onto an optical disc. Three beam spots are irradiated at positions on the optical disc which are away from each other by a predetermined distance. The reflected lights are respectively detected by three photodetectors whose photo sensitive surfaces are divided and tracking error signals are detected by a push-pull system. A tracking error signal obtained from the center beam spot of the three beam spots and tracking error signals obtained from other two beam spots are respectively added to obtain the first and second composite tracking error signals. Detracking state is detected based on the polarities of the first and second composite tracking error signals.

Abstract: An optical information reading apparatus comprises an optical integration circuit type pickup in which an optical waveguide for guiding light and a condensing coupler for condensing the guided light propagating within the optical waveguide are formed on an optical integration circuit substrate, sub-couplers for radiating a part of the injected light upon the information recording surface in the vicinity of a light spot formed by the optical pickup and subsidiary light detection elements for receiving reflection light of the light radiated from the sub-couplers reflected from the information recording surface. The sub-couplers and the subsidiary light detection elements are formed integrally with the optical pickup on the optical integration circuit substrate. Thereby the detection error can be reduced, it is not necessary to use attachment parts and therefore the apparatus can be integrated to thereby make it possible to minimize the size.

Abstract: An optical disc playback device capable of detecting a state of a disc which is not set in a normal position on a turntable includes a system control circuit for clamping an optical disc set on a turntable and rotating the optical disc with an optical head being at a standstill in radial direction of the optical disc in a focus-on state, a track crossing detection circuit for detecting a track crossing state of a laser beam spot from a detection signal of the optical head, a track crossing occurrence frequency detection circuit for detecting frequency of occurrence of track crossing detected by the track crossing detection circuit, an abnormal-state-of-mounting judging circuit for judging existence of an abnormal state of mounting of the disc on the turntable if the frequency of occurrence of track crossing is higher than a value set as indicating the abnormal state of mounting, and an abnormal-state-of-mounting elimination control circuit for performing, when the abnormal state of mounting has been detected,

Abstract: An optical information recording and/or reproducing apparatus includes an optical head for recording and/or reproducing information by applying a light beam to an optical recording medium having a plurality of tracks, an actuator for relatively moving the light beam in a direction which intersects the tracks, an optical detector for detecting, by intersecting the tracks, a reflected or transmitted light of the light beam, which has been modulated, a peak holding circuit for holding a peak value of a signal detected by the optical detector, a bottom holding circuit for holding a bottom value of the detected signal, a circuit for obtaining an intermediate value of the held peak value and bottom value, and a comparison circuit for transmitting an on-track/off-track signal by making a comparison between the intermediate value and the detected signal.

Abstract: A program recording system for VCR utilizing telephone ringing sound can be programmed by selecting specific channel in response to the ringing of a telephone when calling from another calling station. The recording system uses a microphone, an amplifying circuit, a tuning amplifier, a clamp, a switch, a data generator, a microcomputer, and a controller. The program recording function can be carried out by calling from another calling station at any time when it is required.

Abstract: A yoke constituting a magnetic actuator for driving an objective lens has a plurality of arms arranged in a plane intersecting the optical axis of the lens perpendicular thereto. An optical system including the objective lens is disposed at one side of the yoke and has the outer peripheral portion of the lens positioned partly in the space between adjacent two arms. The lateral width of the device is decreased by an amount corresponding to the lap of the lens over the yoke. A cover plate is secured to the upper surface of the magnetic actuator in intimate contact with the upper end faces of the yoke arms to give enhanced rigidity to the device.

Abstract: A method for selecting made by one key in the camera recorder is disclosed. The mode selecting method comprises a first step for changing the present mode into the temporary stop mode, the stop mode or the reproduce mode after reading the present mode when one key is pressed one time, a second step for changing the present mode into the fast forward mode or the forward picture search mode after reading the present mode when one key is pressed two times, a third step for changing the present mode into the rewind mode or reverse picture search mode after reading the present mode when one key is pressed three times, and a fourth step for changing the present mode into the standstill picture mode or the record check mode after reading whether one key is pressed the predetermined time or over.