Victor Company of Japan, Limited

Kenji Shibayama

Masahiko Tsuruta

Koichi Kido

Koji Suzuki

Hiroshi Yamada

Akira Hirota

Hidetoshi Ozaki

Masato Mihara

Kaoru Kobayashi

Osamu Inoue

Yutaka Isobe

A first reproduction signal is reproduced by use of a first pair of magnetic heads having first and second azimuth angles and arranged around a rotary drum at two opposing angular positions 180 degrees away from each other, respectively. A second reproduction signal is reproduced by use of a second pair of magnetic heads having first and second azimuth angles and arranged around the rotary drum at two opposing angular positions 180 degrees away from each other, respectively. A video signal is reproduced based on the first and second reproduction signals. The magnetic tape travel speed is set to a value (2n+1.+-.m/M) times higher than that in recording, where n is an integer of 0 or more; m and M are a natural number, respectively; T.gtoreq.12/(P+Q) (T: an integer) when m/M=2k/T; and P&gt;0, Q&gt;0.

Video signal reproducing method and apparatus

An HD image signal is recorded and reproduced by a tape head system of a conventional home VTR. An HD image signal (bb) which is of a different broadcasting system from a conventional broadcasting system and contains an information whose amount is larger than that contained in a video signal of the conventional broadcasting system is divided by four by first to eighth memories and resultant four signals are recorded on a magnetic tape through a first to fourth recording signal processing circuits and FM modulators, etc. In reproduction, the four signals are reproduced by FM demodulators and a first to fourth reproduced signal processing circuits, etc., and the HD image signal is produced by using the first to eighth memories.

Magnetic recording and playback apparatus capatible with conventional

A clock signal generator circuit includes a synchronous signal separation circuit for separating a synchronous signal from an input video signal; a phase-locked loop (PLL) circuit for generating a clock signal in synchronism with the synchronous signal of the video signal supplied from the separation circuit; a switch provided between the separation circuit and PLL circuit for intercepting a supply of the synchronous signal of the video signal from the separation circuit to the PLL circuit during a predetermined period; and a control circuit for further separating a vertical synchronous signal from the synchronous signal separated by the separation circuit and controlling, in accordance with the vertical synchronous signal, the switch so as to intercept a supply of the synchronous signal from the separation circuit to the PLL circuit during the predetermined period, the predetermined period being a pulse generation period during which there are present at least an equalizing pulse and dubbing preventing signal in the video signal.

Clock signal generator for video signal capable of generating a stable

A horizontal synchronous signal separation circuit is applied to video apparatus such as a video tape recorder, television receiver, and projector. The separation circuit includes a signal separating portion for detecting the trailing edge of a horizontal synchronous signal and obtaining a separation signal whose timing is referenced to the trailing edge, a window pulse generating portion for obtaining a window pulse whose timing is referenced to the leading edge of the synchronous signal, and a gate for subjecting the separation signal generated by the signal separating portion to a masking process by the window pulse. The gate which causes the separation signal to be subjected to a masking process, may directly output the window pulse as the separation signal if the separation signal is not present within the window. The separated synchronous signal finally obtained has a timing reference related to the trailing edge of the original horizontal signal, and the synchronous signal can be separated reliably and the synchronizing system of a video apparatus can be made stable.

Separation circuit for imposing detection timings of a synchronous

An edge enhancement apparatus comprises an edge detection circuit including differentiators responsive to a video signal and a PLL responsive to a H SYNC for producing a clock for displaying the video signal on a display, for example, a LCD. The PLL further includes an adder between a LPF and VCO thereof for adding an output of the differentiator to an output of the LPF to frequency-modulate the clock for edge enhancement such that when the video signal transits from a shadow to highlight levels at an edge of an image, the clock frequency is increased at the shadow level and is decreased at highlight level. In the display supplied with the frequency-modulated clock and the video signal, a distance between a pixel indicating a shadow level and another pixel showing the high-light level at the edge portion is decreased, so that the video signal is edge-enhanced. In the second apparatus, the clock is frequency-modulated at the edge such that the frequency is increased, then decreased, finally increased. Other apparatus further includes a memory for storing a video signal as a buffer storage in response to the clock to produce a edge-enhanced video signal therein in addition to the first or second apparatus.

Edge enhancement apparatus useful with liquid crystal displays

A video signal processor for processing a composite video signal to be fed to color liquid crystal (LC) panels of a color liquid crystal display which are each assigned to a different color. The pedestal level of each color signal included in the video signal and to be fed to particular one of the LC panels is caused into coincidence with the level of an input signal which reduces the transmittance of the LC panel to the lowest transmittance. The pedestal level is caused to agree with the clipping level of either one of a dark and a white clipping circuit, whereby signal components lower than the pedestal level are removed. The processor insures the maximum contrast available with LC panels and eliminates light-and-dark inversion, thereby enhancing the reproduction of high quality pictures.

Video signal processor for a color liquid crystal display

A magnetic recording and/or reproducing apparatus comprises a cassette discriminating circuit for discriminating whether a loaded tape cassette accommodates a standard tape or a high performance tape in a recording mode, a mode discriminating circuit for discriminating from a signal reproduced from the tape in a reproducing mode a mode with which the tape was recorded at the time of the recording, and a switching circuit for automatically switching the operation mode to a predetermined mode responsive to the discrimination made by the cassette discriminating circuit in the recording mode and responsive to the discrimination made by the mode discriminating circuit in the reproducing mode. The high performance tape is playable either in a standard mode or a high quality mode.

Magnetic recording/reproducing apparatus which accomodates different

A magnetic recording apparatus for carrying out a recording by selectively using one of two kinds of recording systems comprises first through fourth rotary magnetic heads, a first circuit for producing an FM luminance signal, second and third circuits for producing first and second frequency division multiplexed signals, and a switching circuit. The first and second heads are mounted on a rotary body at mutually opposing positions, and have the same height position. The third and fourth heads are mounted on the rotary body at mutually opposing positions respectively in vicinities of the first and second heads along a rotating direction of the rotary body, and have the same height position. The switching circuit selectively supplies the output signals of the first and second circuits to the first through fourth heads when a luminance/color separation recording system is selected as the recording system, and selectively supplies the output signal of the third circuit to the first and second heads or to the third and fourth heads when a low band conversion color recording system is selected as the recording system.

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Tokyo, Japan

Kenji Shibayama