Abstract: A video signal reproducing device for use with a magnetic tape has at least one rotary magnetic head which reproduces the video signals recorded in slant tracks on the tape and a tape transport mechanism which drives the tape at controllably varied speeds. A first circuit selectively generates tape speed signals indicative of respective speeds of the tape. A second circuit selectively generates duration signals indicative of the time periods during which the tape is driven at the respective speeds. A memory stores the tape speed signals and the duration signals, and a system controller connected to the memory controls the tape transport mechanism to drive the tape at speeds and for durations determined by the tape speed signals and the respective duration signals read from the memory.

Abstract: A reproduced color video signal processing circuit in a rotary recording medium reproducing apparatus reproduces a recorded signal from a rotary recording medium which is recorded with a composite color video signal in which a carrier chrominance signal is frequency-converted into a low frequency band and multiplexed using a common frequency band within a part of a frequency band of a luminance signal, and levels of the carrier chrominance signal and a color burst signal are controlled according to the level of the carrier chrominance signal with respect to the color burst signal.

Abstract: A digital video tape recorder (VTR) for use with an NTSC, PAL or SECAM television signal includes a reference signal generating circuit which generates a reference signal having a frequency of 13.5 MHz; a first frequency dividing circuit (1/45045) for use with an NTSC television signal; a second frequency dividing circuit (1/45000) for use with a PAL or SECAM television signal; and a switch which supplies a first or second frequency control signal to a magnetic recording head for recording a pulse of the control signal at the lower edge of a magnetic tape for each of successive, parallel tracks extending obliquely on the magnetic tape in which a television signal is recorded. A discriminator circuit detects whether the television signal to be recorded is NTSC, PAL or SECAM format and controls the switch to supply the appropriate frequency control signal to the magnetic recording head.

Abstract: A method for recording high frequency signals representing data with simultaneous readout of low frequency information, such as servo information prerecorded on a magnetic disk, comprises the step of modulating with the data a carrier signal having a repetition frequency displaced significantly from the baseband of the data. The nonlinearity of the recording channel converts the modulated signal spectrum into the low frequency baseband so that the data is magnetically recorded while the low frequency prerecorded information is read out.

Abstract: An apparatus reads and/or records information on a disc by means of a light beam, which disc rotates about an axis of rotation, and is driven by a drive spindle which is journalled in a spindle support, an objective 1 being moved along two parallel guides by means of a slide in a radial direction relative to the axis of rotation. All parts of an opto-electronic system for producing the light beam and for effecting a conversion between optical and electrical modulation may be arranged on the slide but may alternatively form part of a stationary opto-electronic system. At least the spindle support or the stationary opto-electronic system is supported by at least one of the guides, for example by means of supports and which are formed with locating stops which cooperate with the guides 9A and 9B.

Abstract: A quaternary saturated digital magnetic recording system for enhancing information entropy provides an effective bit density increase of 100% or more over the MFM code. In the simplest implementation, groups of two input binary bits are mapped into one data cell, preferably into four combinations of long or short breaks and positive or negative polarity, with the break optionally centralized within the data cell for self-clocking. A system for reproducing the recorded information provides a peak detector, responsive to the recorded signal, coupled to pulse polarity and break width detector circuitry, with an internally synchronized clock, for remapping the recorded data into binary format.

Abstract: To insure that a tape which is newly inserted into a reversing-type cassette tape transport mechanism will always operate in a first predetermined or priority direction, a direction priority switch (S3) is coupled to the tape cassette receiver (32, 34) to sense introduction of a tape into the receiver. The priority switch is coupled to a logic network which controls change-over of operation of a tape transport system (20, M) if the tape transport system, upon introduction of a tape, was operating counter the priority direction, but leaving unaffected the operation of the tape transport system if it was already in the priority direction. A suitable logic network comprises an AND-gate with a dynamic input, or one with a static input and a buffer memory which is reset upon termination of tape operation. If the tape is merely moved between a transducing position and a park or pause position, no change in direction of tape transport will result.

Abstract: A tracking information detecting device for recording a video signal together with a pilot signal on one track of a magnetic disc and detecting tracking information at the time of reproduction. In this device, the pilot signal has a predetermined frequency at least ten times that of the horizontal synchronizing signal. The pilot signal is recorded in such a manner that its phase is displaced with respect to the horizontal synchronizing signal at every track. The horizontal synchronizing signal is displaced at every track at the time of reproduction of the recorded video signal, and the phase difference between the horizontal synchronizing signal and the pilot signal is detected as the tracking information.

Abstract: Apparatus for controlling the speed of advancement of a magnetic tape in a video tape recordor (VTR) of the type including a rotary magnetic head assembly for recording and reproducing an information signal with respect to a plurality of record tracks extending obliquely on a magnetic tape, comprises a recording section including a control signal generator which generates a control signal, a pilot signal generator which generates a pilot signal having a predetermined frequency, an AM modulator which amplitude modulates the pilot signal by the control signal to produce a superimposed or amplitude-modulated signal which is recorded in a control track on the magnetic tape by a fixed magnetic head; and a reproducing section including the fixed magnetic head for reproducing the superimposed signal recorded in the control track on the magnetic tape, a limiter circuit for detecting the pilot signal from the reproduced superimposed signal, an FM detector for detecting a frequency fluctuated component of the detected

Abstract: In a light spot control signal generating device, a light spot is irradiated on a recording medium having tracks on which information is recorded. In order to jump the light spot from a track being scanned thereby to an adjacent track, a signal representative of light quantity of reflection or transmission of the light spot and a track error signal are detected. The two signals are used to judge whether the light spot has passed through an edge of the track. The track error signal is also used to detect a signal representative of an instant at which the light spot is present at the middle point between adjacent tracks, and this signal is used as a timing signal for changing the polarity of a control signal applied to a spot light deflector.

Abstract: Apparatus for adjusting the speed of an audio tape capstan to a speed such that an audio tone prerecorded on the tape corresponds to a reference frequency, the apparatus thereafter phase locking the frequency of the audio tone to the reference frequency. The apparatus stores a signal corresponding to the last tape speed utilized even after the tape has stopped, allowing for faster phase lock after the tape has started again. Logic circuitry determines the presence of a valid tape audio tone, and means are included for adjusting the system gain to substantially reduce any wow or flutter which normally would result from damaged or spliced tape. A phase adjust knob is provided to allow for offset of the phase locked condition if necessary. The apparatus includes a pair of frequency-to-voltage converters which provide an essentially ripple-free DC voltage output while permitting a response time of only a few cycles of a relatively low (typically 60 Hertz) input frequency.

Abstract: A focus servo system for an optical video disc player. A pair of signals generated by two pairs of photo-cells are supplied to an adder and a differential amplifier, an output signal of the adder is supplied to a first comparator and an output signal of the differential amplifier is supplied to a second comparator. When an output signal of the adder reaches a reference voltage of the first comparator, a focus servo pull-in range is detected. Thereafter, when an output signal of the differential amplifier reaches a reference voltage of the second comparator, a stable operation condition of the focus servo system is detected and a servo system loop is closed so that a malfunction is prevented.

Abstract: An information reproducing apparatus having a tracking servo control loop for causing an information reading unit including device for detecting a tracking error signal for tracking an information bearing track on a disc, to track the information bearing track in accordance with the tracking error signal so as to reproduce information in accordance with an information signal read by the information reading unit. A circuit for extracting a discrimination signal for discriminating a negative feedback region of the tracking error signal is provided so that a tracking servo control loop is closed in the negative feedback region.

Abstract: A method of recording and reading out a latent image which comprises placing a uniform surface charge on the photoconductive layer of a multilayered detector apparatus, biasing said photoconductive layer with an electric field whose polarity opposes said surface charge, discharging some portion of said surface charge of said photoconductive layer by exposing said detector to a modulated radiation flux capable of generating electron hole pairs in the photoconductor; scanning the surface of said partially discharged photoconductive layer with a small diameter photon beam whereby said surface charge is sequentially further discharged, and measuring the changing electric current of said sequential further discharge as a function of time.

Abstract: Disclosed is a method and system for recording and playing back information utilizing a recording medium having a vertical magnetization film on and from which the information is recorded and read out by an optical means, characterized by changing the direction of the magnetic field applied on the recording medium during the application of a recording light beam so as to maintain the recording track of portions of the recording medium on which the previously recorded information is erased by the application of the recording light beam during editing operations.

Abstract: A tape recorder wherein a control transistor is connected between a power source and a load circuit involving, for example, a motor circuit, mechanism control circuit and amplifier; and automatic shut-off circuit is connected in parallel to the load circuit. The automatic shut-off circuit is arranged to render the control transistor conductive at the time of power supply; and nonconductive when a terminal end of the tape is detected. A single-pole double-throw switch is provided which is only required to have a small current capacity, and has a movable contact connected to a power source, a first stationary contact connected to the voltage-detecting terminal of the automatic shut-off circuit and a second stationary contact connected to the base of the control transistor.

Abstract: A misposition correction system for correcting misposition errors due to spindle runout and other slowly varying errors in a servo positioning system of a magnetic disk storage device. The system includes means for dynamically measuring misposition error with respect to a data track centerline using an anti-aliasing analog filter, means for digitizing the measured analog signal and for removing selected harmonics of the fundamental-frequency of the resulting cyclic error signal, means for transforming the digitized error signal by a matched digital filter whose transfer function contains independently adjustable DC gain, fundamental-frequency gain, and phase lead components thereby to generate a misposition error correction signal that matches the electrical and mechanical response characteristics of the servo system.

Abstract: A mechanism to protect a reel of tape against the risk of inadvertent over-writing or erasure, including an actuator installed in the reel hub and rotatable between two angular positions from the front face of the reel, even when mounted on a tape drive. The axis of rotation of the actuator is offset from that of the reel, and the actuator has a peripheral portion that presents a sloping surface toward the rear of the reel, to engage an axially movable rod disposed along the reel axis. Rotation of the actuator from one angular position to another causes axial movement of the rod, which is conventionally detected and employed to control the write protection status of the tape reel.

Abstract: Method and apparatus for the recording onto a recording medium and playback of digital data, such as digitally encoded audio data, such that the recording medium is playable on either of two different commercial television format video type players. For example, according to the present invention an optical disc having digitally encoded audio data recorded thereon may be playable on either a PAL compatible or an NTSC compatible optical video disc player with minimal modification of the player.

Abstract: In a magnetic recording apparatus for frequency multiplexing and recording a frequency-modulated luminance signal, a chrominance signal, a frequency-modulated audio signal and a pilot signal on a magnetic tape, the signal level of the frequency-modulated luminance signal is adjusted by a first signal level adjuster, and the chrominance signal, the pilot signal and the frequency-modulated audio signal are mixed and then subjected to signal level adjustment by a second signal level adjuster. The signal levels of the four signals can be adjusted by the two level adjusters.