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 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 mediums is replaced, the recording mediums can smoothly be played back.

Abstract: A laser video disk master is operated at 2.times. speed for duplicating video information to be recorded in VHS format. Two last disk video players are modified to operate in synchronism in order to multiplex from one to the other in duplicating video programs of length equal to the two recorded disks. The 2.times. frequency NTSC format video output signal is then demodulated, drop out detection is performed, and the digitally-encoded stereo audio information is separated, error corrected, and converted by digital to analog (D/A) conversion to left and right channels of stereo analog information. The left and right channels of audio information are presented simultaneously to an FM modulator for presentation to rotating video heads and to a 2.times. Dolby processor for presentation to linear heads. The demodulated 2.times. video information is converted to digital information by an analog to digital (A/D) converter and then time-base corrected and drop out compensated.

Abstract: An apparatus for recording information on a disk-shaped medium with an appropriate amount of information, and allowing immediate verifying of the recorded information. The apparatus includes a unit for recording information of a recording unit on a recording medium, a verifying unit for verifying the recorded information, adapted, after recording the information of the recording unit, to effect a track jump from the last sector of the recording unit to a first sector; and a unit for selecting the number of sectors in the recording unit in such a manner that the position after the track jump from the last second of a recording unit is in front of the first sector by a predetermined number of sectors.

Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a

Abstract: A servo loop controls an actuator and read head, the loop being responsive to training signals to cause the actuator to move the read head. An error signal is produced that indicates a less than optimum positioning action by the actuator. A compensating filter alters the servo loop's response to a training signal to cause the actuator to produce a more optimum positioning action, the filter exhibiting an initial value filter characteristic. A processor is responsive to a first training signal to alter the filter's initial characteristic value in a first direction to cause the filter to act upon the first training signal in accordance with the altered characteristic value, and is further responsive to a second training signal to alter the filter's initial characteristic in a second direction to cause said filter to act upon the second training signal in accordance with the altered characteristic value.

Abstract: An optical disc playback device for playing back video data employs a rotation signal generation circuit for generating a signal at a period of a rotation angle provided by dividing one rotation of a disc motor to detect a record position on a disc of picture data stored in a picture memory. A laser beam spot is caused to jump a predetermined number of tracks each time a position on the disc has a specific relation to the record position in response to a signal generated by the rotation signal generation circuit whereby a still picture playback and a still picture shifting can be made frame by frame.

Abstract: A memory device for recording information on a recording medium includes a recording mechanism for recording information on the recording medium. A control device controls the recording mechanism such that information is recorded in a first predetermined arrangement on a first portion of the recording medium and in a second predetermined arrangement on a second portion of the recording medium.

Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a

Abstract: A disc storage unit includes discs having surfaces with concentric tracks for storing data in sectors. Each sector has identification information including a physical address designating a particular disc surface, sector and track. The physical addresses are contiguous for one surface to another at a first or last sector in a radially outermost or innermost track, respectively. Heads are provided for reading and writing data from and onto the discs. The position of each head within a track is determined using servo information recorded between adjacent sectors. Address converting circuitry converts logical addresses from an external computer into physical addresses on the discs, including physical addresses which span a plurality of tracks located on both surfaces of a disc, when reading or writing data at logical addresses is commanded. Head selecting circuitry responds to the physical addresses by selecting each head corresponding to a surface of the disc on which the physical addresses are located.

Abstract: A fine tracking miniature galvanometer actuator is used as a fine tracking positioner for a read/write head in the optical disk drive of an information storage and/or retrieval system. An efficient magnetic circuit is used in conjunction with a small and lightweight rotor design which offers high performance characteristics in terms of frequency response and sensitivity. No mechanical springs or torsion bars are necessary to maintain the rotor in a neutral or zero position. The present invention is also useful in other systems using electro-optical transducers including reflecting-type galvanometer recording systems used for producing variable-area sound tracks .

Abstract: An electric charge recording/reproducing apparatus for focusing an electromagnetic radiation ray containing a recording object information signal onto a photoconductive layer member (PCL) in an electric charge image recording medium (D) comprising a laminate of at least an electric charge retention layer, member (CHL), photoconductive layer member (PCL) and a first electrode (E) using an objective lens (318) which is driven and displaced in an optical axis direction by an actuator (ACT) of an automatic focusing system; and to integratedly connect and fix a moving electrode (Em) onto the objective lens (318), the moving electrode (Em) being intended to generate an electric field for positioning the electric charge image recording medium (D) in the electric field of a predetermined electric field intensity, towards the electrode in, the electric charge image recording medium (D).

Abstract: A video noise reduction system is incorporated with a video recorder for the elimination of high frequency noise from only the gray level portions of a video signal being retrieved from magnetic tape. The frequency modulated video signal retrieved from the tape is directed through a demodulator into a voltage dependent low pass filter having a cutoff frequency which is normally sufficiently high to pass the unmodulated video signal from the demodulator without attenuation. The frequency modulated video signal is also fed into a band elimination filter having an attenuation band corresponding to the gray level of brightness. The output from the band elimination filter is detected, and a variable voltage is impressed to the low pass filter for lowering its cutoff frequency whenever the frequency modulated video signal has gray frequencies. Alternate embodiments are disclosed in which the cutoff frequency is lowered to different preselected values for different levels of brightness.

Abstract: A MUSE signal recording/reproducing apparatus for converting a MUSE signal into a digital signal and for recording/reproducing the same, including an HDVTR, a signal processing device, and a control device for controlling the HDVTR and the signal processing device. The HDVTR is a device capable of recording/reproducing effective lines and effective picture elements of a high definition television signal. The signal processing device performs A/D conversion and multiplex processing of two synchronizing MUSE signals to convert the same into frequency double that of a MUSE signal, and further performs rate conversion corresponding to recording frequency and phase of the HDVTR. The HDVTR records the rate-converted data.

Abstract: An information recording medium playing apparatus detects a preset memory command of every data unit of a graphics information signal of a subcode of a CD format signal which playing an information recording medium. During play operation, address data corresponding to the respective preset memory commands are constantly stored in a memory. In a search mode, the head of desired graphics information is searched on the basis of the address data stored in the memory.

Abstract: A video recorder for recording composite video signals includes an analog to digital converter for digitizing samples of the composite video signal being recorded. A sync separator separates horizontal synchronizing information from the composite video signal being recorded. Filtering separates the chrominance information portion of the composite video signal being recorded, and a down-converter mixes that separated chrominance information with a nervous carrier signal thereby to generate a color-under signal. A controlled oscillator generates a succession of pixel clock signals at a rate the frequency and phase of which are determined in accordance with an oscillator control signal, the rate being more than twice the frequency of the nervous carrier signal and setting the rate of the sampling by the analog to digital converter. A counter counts the number of pixel clock signals supplied by the controlled oscillator, and a frequency divider divides the count by a prescribed factor.

Abstract: A video tape recorder has a recording current setting unit for setting recording currents to be supplied to a recording head for recording audio and video signals on a magnetic tape. The recording current setting unit controls electronic volume controls to adjust and output audio and video signals to set the recording currents. Level detectors detect reproduced signals, which have been recorded on the magnetic tape by the recording head, and supply the detected signals to the recording current setting unit. The recording current setting unit controls the electronic volume controls to hold the audio signal at a constant level and to simultaneously vary levels of luminance and chrominance signals of the video signal with the levels being kept at a constant ratio, and at the same time controls the recording head to preliminarily magnetically record the audio and video signals on the magnetic tape.

Abstract: A sum signal processing device for use in an optical disk drive for detecting a sum signal which is a groove-crossing signal used to detect a relative position of a beam spot for recording and reproducing information from a medium and the medium and a relative velocity in the radial direction of the medium. The device identifies a recorded portion on the basis of high-frequency components and, in the recorded portion, processes the high-frequency components to generate a groove-crossing signal, thereby detecting an accurate sum signal.

Abstract: In an optical head apparatus for recording or reproducing information onto or from an optical disc, a carriage is movable along a guide shaft extending in a direction parallel with the radial direction of the optical disc, and an armature is mounted on the carriage so that it can rotate about a pivotal axis perpendicular to the surface of the optical disc. An objective lens is fixed to the armature and positioned to traverse the tracks on the optical disc when the armature rotates. Guide yokes extend in parallel with the guide shaft. Tracking and carriage-servo coils are fixed to the armature and have a hollow through which the guide yokes loosely extend. A magnetic field means creates magnetic lines of force perpendicular to the longitudinal direction of the guide yokes and parallel with the surface of the optical disc.

Abstract: A color video signal reproducing apparatus for reproducing a color video signal and a control signal for indicating a color frame of the color video signal from a record medium includes a generator for generating a reference color frame, a generator for generating a signal having a frequency which is a multiple (integer) of the frequency of a reference frame signal, a circuit for separating a reproduced color frame and a reproduced frame signal from the control signal being reproduced, a circuit for generating a phase where intervals of the reproduced frame signal is divided, a circuit for determining a start reference signal phase by using the reproduced color frame and the divided phase, the start reference signal phase causing movement of the record medium to be started, and a controller for controlling the movement of the record medium in accordance with the start reference signal phase and a predetermined acceleration duration of the record medium.

Abstract: A method and apparatus for disabling the effect of copy-protect signals placed in a recording video signals which is based on differences in the characteristics of television and VCR circuitry. Copy-protect signals include pseudo-sync pulses and/or added AGC pulses in the blanking interval of a video signal. The specific method described includes altering the level of the video signal during the vertical blanking interval, e.g., level-shifting, so as to render the copy-protect signals ineffective to prevent unauthorized copying by a VCR. A circuit for achieving the method includes a sync separator for detecting the vertical blanking interval, pulse generating circuits for producing pulses of predetermined widths during this interval, and a summing circuit for summing the predetermined pulses with copy-protect signals thereby to shift their level.