Hitachi, Ltd.

Nippon Hoso' Kyokai

Noboru Kojima

Akira Shibata

Keiichi Komatsu

Kuniaki Miura

Tomomitsu Kuroyanagi

Teizo Tamura

Toshiyuki Sakamoto

Makoto Konosu

Takao Arai

Yoshizumi Watatani

Yuichi Ninomiya

Takashi Hoshino

Shigeru Hirahata

Isao Nakagawa

Yoshito Nejime

Takumi Okamura

Juichi Morikawa

Koichi Hirose

Shinobu Torikoshi

Koichi Yamaguchi

Toshifumi Shibuya

Toshimichi Terada

Toshiro Kamiuchi

Isao Kondo

Toshiro Ohmura

Tetsuo Mitsuhashi

Yasuji Moriyama

A communication device having an automatic answering telephone function which can record a message spoken by a sender in a record/reproduction part when there is an incoming signal in an automatic answering mode and also which can interlacedly reproduce only head parts of messages when the received message is to be reproduced. The communication device, which further has a speech processing part for changing a speech rate while keeping a speech pitch constant, can reproduce a recorded message at a speech rate designated by a user and can transmit a rate-changed speech message.

Communication device

There is disclosed a compatible television receiver capable of receiving and reproducing both the standard system television signal and the high definition television signal and capable of confining the degradation of picture quality of the high definition television signal to the minimum, in which the received standard system television signal and high definition television signal are respectively converted to non-interlace signals, and scanning is selectively performed with either of non-interlace video signals to display images. The television receiver according to the present invention comprises a first conversion circuit for receiving an interlace standard system television signal and converting it into a non-interlace television signal, a second conversion circuit for receiving an interlace high definition television signal and converting it into a non-interlace televison signal, a circuit for discriminating whether the received signal is the standard system television signal or the high definition signal, and a circuit for selecting either of outputs of the first and second conversion circuits on the basis of the result obtained in the discrimination circuit.

Television receiver compatible with both standard system television

A television signal recording/reproducing apparatus of the color-under recording type wherein an input composite video signal is separated into a luminance signal and a color signal. For the separated luminance signal, calculation of the interframe signals is executed so that the color signal component remaining in the separated luminance signal is removed by a frame comb filter. And the input signal and the output signal of the frame comb filter are mixed with each other. For the separated color signal, calculation of the interframe signals is executed so that the luminance signal component remaining in the separated color signal is removed by a frame comb filter. And the input signal and the output signal of the frame comb filter are mixed with each other. Each of the signal mixing ratios is controlled in accordance with the interframe level difference in the luminance signal. And the mixed signals are recorded on a recording medium after predetermined recording processes. Mutual interference between the luminance signal and the color signal is eliminated to consequently prevent deterioration of the signal-to-noise ratio while achieving a high image quality.

Television signal recording/reproducing apparatus of color-under

A helical scan type magnetic recording/reproducing apparatus in which a magnetic tape is guided helically around a rotary magnetic head assembly over an angular range approximating to 360.degree.. Two magnetic heads are disposed relatively closely to each other at an angle smaller than 180.degree.. The rotary magnetic heads assembly performs a single complete rotation for a unit period, for example, one field period. In recording, video signal of the unit period undergoes time axis compression to be compressed to a period corresponding to a scanning period of the heads during which the magnetic heads are in contact with the magnetic tape in each rotation of the head assembly and supplied to alternately the magnetic heads which are so designed that the azimuth angles of the respective gaps differ from each other. Alternatively, the video signal is separated into a luminance signal and a chrominance signal, wherein the former is supplied to one of the magnetic heads while the latter is simultaneously supplied to the other.

Video signal recording/reproducing apparatus

Disclosed is a color video signal recording apparatus wherein the chrominance signal and the luminance signal are separated from the composite color video signal, the luminance signal is transformed into a frequency modulation signal and the chrominance signal is converted to have a lower frequency so that both reformed signals are recorded on a frequency multiplex basis on a recording medium. In processing a TV signal of CCIR system, the chrominance signal is controlled to have a frequency of 3/8 N.multidot.f.sub.H (where N is an odd number) and have its phase shifted by 90.degree. in every horizontal scanning period; in processing a TV signal of NTSC system, the chrominance signal is controlled to have a frequency of 3/8 N.multidot.f.sub.H (where N is an integer) and have its phase shifted by 90.degree. or 180.degree. in every horizontal scanning period, while the control being made such that 1/4 N is an integer in case of 90.degree. phase shift of (3N-2)/4 is an integer in case of 180.degree. phase shift.

Color video signal recording apparatus

A chroma signal recording and reproducing circuit of a magnetic recording and reproducing apparatus having a recording circuit for frequency-modulating a luminance signal of a color video signal, low-frequency converting a chroma signal and frequency-multiplexing those signals for recording and a reproducing circuit for frequency-converting the low-frequency converted chroma signal in a reproduced signal and frequency-demodulating the FM luminance signal to reproduce a color video signal is disclosed. The circuit comprises a chroma signal recording circuit including a first ACC circuit and a first frequency converter connected to the first ACC circuit, and a chroma signal reproducing circuit including a second ACC circuit, a second frequency converter connected to the second ACC circuit, a comb filter connected to the second frequency converter and a deemphasis circuit connected to the output of the comb filter.

Chroma signal recording and reproducing circuit

A picture reproducing apparatus for a helical scanning video tape recorder including an impedance transformer; a video head connected to the input of the impedance transformer; a resonance circuit connected to the output of the impedance transformer; a pre-amplifier connected to the output of the resonance circuit; a feedback resistor connected between the junction of the pre-amplifier and resonance circuit and the output of the pre-amplifier; and an output terminal connected to the output of the pre-amplifier. The impedance transformer has the output impedance four times as high as the input impedance thereof.

Picture reproducing apparatus in a helical scanning video tape recorder

In a magnetic recording and reproducing apparatus of 2-head helical scan type, an overlapping portion is formed at one end of each video track on a magnetic tape, and a PCM audio signal is recorded on this overlapping portion. Video/audio selective switching circuits are disposed on the input or output side of video and audio recording amplifiers, and video/audio selective switching circuits and video/audio playback equalizer circuits are disposed on the output side of video and audio playback amplifiers. Each of the heads acts as both of a video head and an audio head.

Magnetic recording and/or reproducing apparatus

A record/reproduce circuit for VTR comprising two normal reproducing heads with different azimuth angles, a special reproducing head with the same azimuth angle as that of the one normal reproducing head, a rotary transformer through which signals from these heads are supplied to a static circuit section, a change-over means for alternately switching a signal from the special reproducing head and a signal from the other normal reproducing head with a different azimuth angle from that of the special reproducing head, a feedback type preamplifier for amplifying the output of the change-over means, and another feedback-type preamplifier for amplifying a signal from the normal reproducing head with the same azimuth angle as that of the special reproducing head.

Record/reproduce circuit for VTR

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Yokohama, Japan

Noboru Kojima