Hitachi, Ltd.

Hitachi Video Engineering, Incorporated

Nobuo Azuma

Takashi Furuhata

Yoshizumi Watatani

Katsuo Mohri

Hiroaki Takahashi

Kenji Satoh

Atsushi Yoshioka

Katsumi Takeda

Yuhiko Yabe

Yuuhei Abe

Tadasu Otsubo

Shuichi Matsuo

Takashi Sasaki

Akira Shibata

Hiroki Mizosoe

Yuji Sano

Masaru Takahashi

Masaji Ishigaki

Yuichiro Kimura

Manabu Katsuki

Hikaru Masui

Katsumi Mikamo

Yoshinori Masuda

Yasunori Tominaga

Kazuyoski Kuwahara

Tadayoshi Oikawa

A plasma display device is capable of controlling the brightness of the entire image on a screen over a wide range without impairing a predetermined number of display gradations determined by the dynamic range of an A/D converter, an analogue input circuit and the like. For this purpose, the plasma display device is provided with means for changing the discharge condition (number of discharge pulses, discharge voltage, discharge voltage waveform and the like) during priming discharging, which is effected for initialization, in accordance with the brightness control to control the brightness of light emission during image display.

Plasma display device and driving method

A magnetic recording apparatus of the rotary head helical scan type which can selectively record input information signals of a plurality of signal formats includes an input signal kind discriminating circuit, a controller for generating control output signals to set each section of the magnetic recording apparatus into a predetermined mode on the basis of a recording mode command, a recording signal processing circuit which is respectively switched to a predetermined mode in accordance with an output signal of the controller, and a servo control circuit, wherein there is an effect such that one magnetic recording apparatus can automatically record the input signals of a plurality of formats such as an NTSC signal, an HD signal, and the like in the optimum mode by a simple and easy to use method.

Magnetic recording apparatus with capability of recording signals of a

An audio signal recording and/or reproducing apparatus of a magnetic recording/reproducing apparatus for recording and reproducing audio signals and a video signal. An audio control signal converting circuit is responsive to a command for selecting an arbitrary one of audio signal modes of the 3-1 system, the 2-2 system and so on to convert an input audio control signal corresponding to the input audio signal mode into a recording audio control signal corresponding to the selected audio signal mode. An audio signal processing circuit converts the input audio signals into audio signals of the selected audio signal mode in accordance with the recording audio control signal. An identification signal generating circuit generates an identification signal including the recording audio control signal. The identification signal and the converted audio signals are recorded on the magnetic tape. Upon reproduction, the audio signals and the recording audio control signal indicating the mode of the audio signals are reproduced from the magnetic tape.

Audio signal recording/reproducing apparatus for recording and

Solid-state imaging elements each having a smaller number of pixels are employed to realize an imaging device for taking a high-definition picture which is four or more times larger in the number of pixels than each of the solid-state imaging elements, and also an apparatus for recording/playing back (or transmitting) the high-definition picture. A two-dimensional space which includes, at least, nH spatial sampling points in a horizontal direction and nV spatial sampling points (nV lines) in a vertical direction, totaling (nH.times.nV) spatial sampling points, is imaged under the condition that light is sensed at, at most, 1/2 of the sampling points of the two-dimensional space. Thus, the imaging device delivers as its output a video signal containing effective pixel information items which correspond to the light-sensed sampling points and which are, at most, (nH.times.nV)/2 in terms of the number of pixels.

High-definition imaging device, and apparatuses for recording and

An audio signal recording and playback apparatus of a magnetic recording and playback apparatus operates to record and play back multiple audio signals together with a video signal in first and second recording areas formed in correspondence to audio signals of first and second sets each consisting of two channels. Among input stereo audio signals in four channels at most, two-channel signals corresponding to left and right side information are recorded as main audio signals in the first recording area and remaining two-channel signals are recorded selectively as ancillary audio signals in the second record area.

Audio signal recording and playback apparatus of magnetic recording and

A video tape recorder/player capable of selectively recording a wide-band video signal including information for forming a picture of an aspect ratio a.sub.1, and a normal video signal for forming a picture of an aspect ratio a.sub.2. The video tape recorder/player comprises video signal discriminating means for discriminating between the reproduced wide video signal and the reproduced normal video signal reproduced from a magnetic recording medium, and time expansion means for expanding the time base of the reproduced video signal by a factor approximately equal to the ratio a.sub.1 /a.sub.2. Either the reproduced video signal or the output signal of the time expansion means obtained by expanding the time base of the reproduced signal by the time expansion means can be selected as an output signal when the video signal discriminating means detects the wide video signal.

Video tape recorder/player

In a magnetic video recording/reproducing apparatus having a recording circuit for recording two kinds of video signals for different aspect ratios a.sub.1 and a.sub.2, where a.sub.1 &gt;a.sub.2, a reproduced signal for aspect ratio a.sub.1 is subjected to a time-axis processing and then delivered to a monitor television having the aspect ratio a.sub.2 in order to avoid a picture on the monitor television from being so distorted as to be elongated vertically. During the time-axis processing, a Y/C interleave set-up processing and a time-axis variation correcting processing are also carried out as necessary. A reproduced signal for aspect ratio a.sub.2 is subjected to a time-axis processing and then delivered to a monitor television having the aspect ratio a.sub.1 in order to avoid a picture on the monitor television from being so distorted as to be elongated horizontally.

Magnetic video recording/reproducing apparatus for video signals of

An audio signal recording/reproducing system is used in a time-lapse video tape recording device for time-lapse recording a video signal on a magnetic tape at predetermined time intervals. The audio signal recording/reproducing system comprises a memory which stores an audio signal and time-compresses the stored audio signal to output it as the time-compressed audio signal at one field period, and a magnetic head for recording the one-field period audio signal on the magnetic tape. Each of the audio signal recording tracks recorded on the magnetic tape is arranged between two adjacent video signal recording tracks. The audio signal recorded on the magnetic tape is read out by the magnetic head and stored in the memory again. The audio signal stored in the memory is expanded in its time-base to be reproduced as continuous sound.

Audio signal recording/reproducing system for use in time-lapse video

A tracking controlling device is provided which is suitable for a rotating head helical scanning-type magnetic video signal recording and reproducing apparatus in which pilot signals of a plurality of frequencies are recorded in advance on tracks on a magnetic tape such as to be superimposed on video signals, and the pilot signals are reproduced during reproduction so as to effect tracking control. This tracking controlling device comprises means for separating and detecting two reproducing pilot signals from both tracks adjacent to the track being scanned by the rotating head, a comparator for comparing the magnitude of the reproducing pilot signals from the adjacent tracks and for generating a binary PWM signal in accordance with the magnitude, and controlling means for controlling the rotation of a capstan motor for driving the magnetic tape using the tracking error signal converted into the form of the PWM signal obtained by the output of the comparator. The tracking error signal converted to the PWM signal is capable of directly switching over and controlling the driving circuit for the capstan motor.

Tracking controlling device using multiple pilot signals in magnetic

During still reproduction, slow-motion reproduction and the like reproduction mode in a magnetic reproducing apparatus, a magnetic tape is travelled intermittently at a standard travel speed, i.e., at the same tape speed as that for recording, and a video signal reproduced over a period during which the magnetic tape runs at the standard travel speed is written into an image memory. During the standard travel speed period of the magnetic tape, a magnetic head correctly traces recording tracks on the magnetic tape and so the video signal of less noise is stored in the image memory. The video signal stored in the image memory is read out to provide for reproduced still and slow-motion output signal.

Magnetic reproducing apparatus

A method and apparatus for reproducing information at variable speeds from a magnetic tape by correcting a deviation between at least one video track of the magnetic tape and a rotating head during a tape stop state of an intermittent drive for a noiseless slow-still picture in a video tape recorder using pilot signals. A series of pulses produced by a frequency generator of a capstan for feeding the tape is counted during the tape feeding state of an intermittent drive in order to detect a timing of the stopping of the tape feeding. As the count number equals a set value corresponding to a regular amount of feeding of the tape during the intermittent drive, the tape feeding is controlled to stop. A tracking error signal is produced from the pilot signals reproduced from the tape by the rotating head within the tape stop state of the intermittent drive and the set value for the next tape feeding of the intermittent drive is adjusted in response to the tracking error signal.

Method and apparatus for reproducing information at variable speeds from

A variable-speed picture reproducing apparatus for obtaining noise-free slow-motion reproduction pictures suitable for use in a helical-scanning magnetic picture recording/reproducing system in which the tracking pilot signal is recorded along with the video signal on the video track. The apparatus include a drive for transporting the tape intermittently, a detecting arrangement for detecting that the tracking error signal derived from the pilot signal picked up during the intermittent tape transportation rises or falls across a predetermined level, and a control arrangement for performing tape stop control including a reversal braking for a capstan motor of the drive upon expiration of a delay time determined by a predetermined computation following the time point of the detection of the signal level.

Variable speed picture reproducing apparatus for video tape recorder

A device for controlling consecutive recording of video information containing signals, on a magnetic recording medium in a magnetic recording and reproducing apparatus, fed from a video camera with variable time spacing. The device comprises a control switch rendered non-conductive or conductive when a pause switch in the magnetic recording and reproducing apparatus is actuated or released, and a member for initializing a sync signal generator in the video camera with a signal produced in synchronism with the rotation of a head carrying disc driving motor of the magnetic recording and reproducing apparatus, whereby energy consumption is lowered and synchronization between successive video information signals is attained rapidly during the consecutive recording of video information signals from the video camera.

Device for controlling consecutive recording of video information

A relay control circuit is disclosed in which a timer circuit is actuated by a reference clock pulse in synchronism with an AC voltage supplied by a commercial power supply. An output signal of the timer circuit causes current to flow in the coil of the relay thereby to close the contact of a relay. The invention further comprises a polarity-reversing device for reversing the polarity in accordance with the variations in the output signal of the timer circuit. The reference clock pulse is applied to the timer circuit through the polarity-reversing device.

Relay control circuit

An automatic control apparatus for protecting the compressor motor used with the refrigeration system of an air conditioning unit. The control apparatus has a timer for prohibiting the restart of the compressor motor until the lapse of a predetermined time after temporary stoppage of the compressor motor, and a holding circuit for holding a power source voltage for a predetermined period of time while the operation of the air conditioning unit is stopped. Even if the power supply is turned off, therefore, the source voltage supplied by the holding circuit enables the timer circuit to continue its operation for a predetermined length of time.

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Yokohama, Japan

Nobuo Azuma