Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Hitachi Video Engineering, Incorporated

Hitachi Video and Information Systems, Inc.

Hitachi Ltd., Hitachi Video Engineering, Inc.

Nobutaka Hotta

Keiro Shinkawa

Kazuhiro Ooyagi

Tsutomu Noda

Toshinori Murata

Takatoshi Shirosugi

Akihide Okuda

A sync signal generator of a television receiver for use in a vehicle has a phase reset detector for gradually absorbing a phase fluctuation of an input sync signal which occurs due to a ghost phenomenon or a fading phenomenon and reducing a phase fluctuation. The sync signal generator provides a sync signal synchronized with an output signal of the phase reset signal detector. Thus, a stable sync signal without a sudden change in phase can be obtained although it is synchronized with the input sync signal.

Sync signal generator for generating a second sync signal synchronized

A diversity reception apparatus which has a plurality of antennas and in which one of the antennas having the best receiving condition is automatically selected and connected to a broadcasting signal receiver. The diversity reception apparatus has a feature in that after demodulated signals, obtained by the receiver respectively corresponding to the plurality of antennas, are converted into digital signals by an A/D converter, the best demodulated signal and the antenna corresponding thereto are selected by comparing the digital signals with each other, and that the width of a switch driving pulse from a switch driving pulse generator is made not more than 3 .mu.s.

Diversity reception having a plurality of antennas for use with moving

A sync generator which generates a reference horizontal synchronizing signal, a time difference detector which detects the time difference between the reference horizontal synchronizing signal and a horizontal synchronizing signal within a received television signal, and a variable delay circuit which responds to an output signal of the time difference detector to control the delay time and delay the received television signal are installed in a television receiver. When a plurality of horizontal synchronizing signals exist in one horizontal scanning period of the received television signal, the time difference between the horizontal synchronizing signal with the maximum amplitude and the reference horizontal synchronizing signal is detected, and the delay time of the received television signal is controlled in the variable delay circuit according to this time difference. As a result, the phase of the horizontal synchronizing signal with the maximum amplitude matches the phase of the reference horizontal synchronizing signal. Therefore, when changes in the receiving environment cause the signal strength of ghosts to become greater than that of an original signal and it becomes desirable to receive the ghost as a main signal in place of the original signal, it is possible to switch from reception of the original signal to reception of the ghost signal without resulting in distortion of synchronization.

Television receiver

A multiplex transmission method using especially a vestigial-sideband amplitude-modulated carrier modulated by a video signal. The method includes modulating a carrier having a quadrature phase with respect to an amplitude-modulated carrier by a multiplex-transmitted signal such as a digital-coded signal with a lower level as compared with the amplitude-modulated carrier, suppressing signal components of a signal obtained by modulating the carrier by a multiplex-transmitted signal, which is located near the carrier frequency, combining the result with the amplitude-modulated carrier, and thereafter transmitting the combined signal.

Multiplex transmission method and apparatus

Growing community of inventors

Fujisawa, Japan

Nobutaka Hotta