Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electronics America, Inc.

Gary S Fletcher

Koji Kaneko

Shinya Yokodate

Kazuyuki Saigusa

Tatsuhiko Mizushima

Lawrence D Emmons

Hitoshi Fujimoto

Akira Teshima

Scott A Lewis

Janet Miller

A static video telephone for sending an image captured by an image capture-system and receiving a video signal transmitted over a telephone line. A video signal formed for transmission has a frame format including a phase shift correction data signal in addition to a frame synchronization signal, an amplitude calibration signal, an ID (information data) signal, and image data signal. The video telephone includes a frequency shift correction data generating circuit which is activated when frequency shifts are detected in the received signal and produces frequency-shift correction data. The frequency-shift correction data is then delivered to a subsequent demodulation timing generating circuit which scales phase errors in the received signal to produce phase error correction data. Both frequency-shift correction data and phase error correction data are combined together to produce a demodulation timing signal. With this signal, the received signal is demodulated.

Method and apparatus for static video telephone transmission/receiving

A still picture video telephone transmission system for transmitting and receiving, via a telephone line, a still picture taken by a camera; a picture signal is transmitted and received by a transmitting circuit and a receiving circuit, to which improvements are made so as to display a still picture clearly without distortion. For this purpose, the transmitting circuit sends picture element signals together with image correcting signals such as a picture element displacement detecting signal, a phase inversion detecting signal, and settling data. The receiving circuit detects the image correcting signals in the picture element signal, and makes the necessary corrections so as to enable the still picture to be displayed in good shape.

Still image video telephone transmission system

Growing community of inventors

Willard Rocklin, CA, United States of America

Gary S Fletcher