Victor Company of Japan, Limited

Isami Kaneda

Yasushi Sano

Hiroyuki Sugiyama

Susumu Sakakibara

Ryozo Abe

Yasuo Itoh

Takashi Saito

Osamu Tajima

Atsumi Hirata

Masafumi Mochizuki

A picture switching apparatus for executing a fade-out/fade-in processing between adjacent video recording files includes a multiplier for multiplying a decoded video data with a multiplication coefficient (1-km), a multiplier for multiplying an output data of a data output circuit with a multiplication coefficient km and a data synthesizer for summing results of multiplication from the respective multipliers. The picture switching apparatus thus constructed performs the fade-out/fade-in processing without modification of the original video data for fading processing, by controlling km at the junction between the files such that the mining ratio of the color data for fading to a decoded color data is gradually increased/decreased.

Picture switching apparatus for executing a fade-out/fade-in processing

A method of color data mapping in color video signal recording to a video disc. A predetermined different number of color data are mapped onto first and second color maps respectively. Each data is expressed by color gradation in different format between the maps. The format of the gradation in the first map is converted into the format of the gradation in the second map. A difference is taken between the gradation of the colors in the same format between the maps. The difference is then compared with a reference quantity. The color in the first map is judged as to whether it is the same as or close to the color in the second map in color solid if the difference is smaller than the reference quantity. The color data are then mapped onto a third color map onto which no color data is mapped, if the judgment is made.

Method of color data mapping in color video signal recording to video

A tracking servo circuit corrects for closed loop gain variations due to wear of the disc, the width of the electrode of the reproducing stylus, etc. The disc contains an information track bounded by servo tracks used to derive a tracking error signal. This tracking error signal is supplied to an AGC circuit after being filtered and detected. The gain of the AGC circuit decreases as the voltage level of the tracking error signal increases. The tracking error is also supplied to an electric-mechanical conversion system after an oscillatory signal of constant frequency and amplitude is added to it. The oscillator signal is used to stabilize the gain of the servo loop. The electric-mechanical conversion system corrects the position of the stylus in response to these signals.

Tracking servo with closed loop gain correction

A reference signal detection circuit in a rotary recording medium reproducing apparatus has a reproducing transducer for reproducing an information signal recorded in a rotary recording medium and reference signals for tracking servo recorded for every predetermined period, from the rotary recording medium rotating at a predetermined rotational speed, and a tracking servo circuit for obtaining a tracking servo signal from the reference signals and performing a tracking servo operation according to the tracking servo signal thus obtained. The detection circuit further comprises a single rectifying and smoothing circuit for rectifying and smoothing the reproduced reference signals obtained for every predetermined period. The detection circuit has a lowpass filter characteristic wherein the cutoff frequency is within a frequency range between one third and twice the gain crossover frequency of the tracking servo loop.

Reference signal detection circuit in a rotary recording medium

A rotary recording medium reproducing apparatus reproduces a rotary recording medium in which one and the other of first and second reference signals are alternately recorded every track turn between each track turn of a main information signal track. The reproducing apparatus comprises a reproducing transducer having a reproducing element for reproducing the main information signal and the first and second reference signals at both sides of the main information signal track from said rotary recording medium, where the reproducing transducer has a tracking control mechanism for controlling tracking of the reproducing element, a separation circuit for respectively separating the first and second reference signals from a signal reproduced by the reproducing transducer, a wave detection circuit for respectively wave-detecting the separated reference signals, a time constant circuit for eliminating an unwanted component of an output signal of the wave detection circuit and holding a required signal, a tracking control signal applying circuit for obtaining a tracking control signal from an output signal of the time constant circuit and applying the tracking control signal to the tracking control mechanism of the reproducing transducer, and an interrupting circuit provided at a stage before the time constant circuit, for interrupting transmission of the reproduced reference signals during a mode in which a tracking control operation is not performed.

Rotary recording medium reproducing apparatus with a tracking control

A transfer control device for a reproducing transducer in a rotary recording medium reproducing apparatus having a reproducing transducer for reproducing recorded signals from a rotary recording medium and a driving motor for transferring said reproducing transducer on said rotary recording medium comprises a micro-computer having first and second output ports, where the first output port produces a signal of a pulse form which repeats high-level and low-level periods during a normal-speed transferring mode, and the second output port produces a continuous high-level or low-level signal according to the transferring mode so that a combination of a predetermined level is obtained between the output signal from the first output port, a square wave signal generating circuit applied with the output signal from the first output port of the micro-computer, where the square wave signal generating circuit is triggered to produce a predetermined square wave signal when applied with the signal of a pulse form and not triggered when applied with other signals of constant level, and a switching circuit applied with the output signal from the first and second output ports of the micro-computer, to switch over a plurality of input terminals according to the levels of the applied signals and pass the input terminal voltage through to an output side as an output voltage. The switching circuit supplies the output voltage thus obtained to the driving motor.

Transfer control device for a reproducing transducer in a rotary

A reproducing apparatus reproduces a loaded disc-shaped recording medium derived from a case. The case comprises a jacket which has a space for accomodating the disc-shaped recording medium and an opening for allowing the disc-shaped recording medium to go in and out of the jacket, and a lid member inserted through the opening of the jacket for closing the opening of the jacket. The reproducing apparatus comprises an inserting opening through which the case is inserted, a turntable for rotating the disc-shaped recording medium, a clamping mechanism for clamping at least one of the disc-shaped recording medium or the lid member provided at the innermost part on the opposite side from the inserting opening with respect to the turntable, a detecting mechanism for detecting whether the disc-shaped recording medium is loaded within the reproducing apparatus, and an arresting mechanism provided at the vicinity of the inserting opening, for arresting the insertion of a jacket having the lid member into the reproducing apparatus and allowing the insertion of a jacket not having the lid member into the reproducing apparatus, by displacing according to the detecting operation of the above detecting mechanism. The arresting mechanism allows the insertion of the jacket having or not having the lid member into the reproducing apparatus in a state where the detecting mechanism is not performing a detecting operation.

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Yokohama, Japan

Isami Kaneda