Still image video telephone transmission system
First Claim
1. A still image video telephone transmission system for transmitting and receiving, via telephone lines, a still picture taken by a camera, comprising:
- (a) a transmitting means including means for converting analog signals from a video camera into digital signals, means for modulating phase and amplitude of the digital signals, composing a screen picture frame signal including a plurality of groups of picture blocks made of a plurality of picture element signals, and transmitting the signal, and means for adding a picture correcting signal to each picture element signal or a picture block; and
(b) a receiving means including means for receiving the screen picture frame signal, means for demodulating the picture frame signal, means for subjecting the frame signal to D/A conversion, means for indicating a still picture on a display, means for extracting clocks from the received screen picture frame signal, means for demodulating picture element signals of the screen picture frame signal into picture element data, a picture memory for counting the clocks and storing picture element data by using a counted value as an address, and a correcting means for correcting the picture element data in the picture memory according to a condition of the extracted picture correcting signal.
1 Assignment
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Accused Products
Abstract
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.
18 Citations
11 Claims
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1. A still image video telephone transmission system for transmitting and receiving, via telephone lines, a still picture taken by a camera, comprising:
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(a) a transmitting means including means for converting analog signals from a video camera into digital signals, means for modulating phase and amplitude of the digital signals, composing a screen picture frame signal including a plurality of groups of picture blocks made of a plurality of picture element signals, and transmitting the signal, and means for adding a picture correcting signal to each picture element signal or a picture block; and (b) a receiving means including means for receiving the screen picture frame signal, means for demodulating the picture frame signal, means for subjecting the frame signal to D/A conversion, means for indicating a still picture on a display, means for extracting clocks from the received screen picture frame signal, means for demodulating picture element signals of the screen picture frame signal into picture element data, a picture memory for counting the clocks and storing picture element data by using a counted value as an address, and a correcting means for correcting the picture element data in the picture memory according to a condition of the extracted picture correcting signal. - View Dependent Claims (2, 3, 4, 5)
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6. A still image video telephone transmission system for transmitting and receiving, via telephone lines, a still picture taken by a camera, comprising:
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(a) a transmitting means including means for converting analog signals from a video camera into digital signals, means for modulating phase and amplitude of the digital signals, composing a screen picture frame signal including a plurality of groups of picture blocks made of a plurality of picture element signals, and transmitting the signal, and means for adding a phase inversion detecting signal to each picture element signal or a picture block; and (b) a receiving means including means for receiving the screen picture frame signal, means for demodulating the picture frame signal, means for subjecting the frame signal to D/A conversion, means for indicating a still picture on a display, means for extracting clocks from the received screen picture frame signal, means for demodulating picture element signals of the screen picture frame signal into picture element data, a picture memory for storing picture element data, means for storing picture element data, an inversion information memory for determining presence or absence of phase inversion based on the received phase inversion detecting signal and for storing a picture element number where phase inversion occurs, and a correcting means for correcting the picture element data in the picture memory according to the phase inversion information in the inversion information memory. - View Dependent Claims (7, 8, 9, 10)
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11. A still image video telephone transmission system for transmitting and receiving, via telephone lines, a still picture taken by a camera, comprising:
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(a) a transmitting means including (1) means for converting analog signals output from a video camera into digital signals, (2) means for modulating phase and amplitude of the digital signals and transmitting picture frame signal consisting of one or more picture element signals for one or more lines or files, and (3) means for adding a first settling signal which is same as the picture element signal at a leading edge of a line or file picture block to each line or to immediately before a line file picture block; and (b) a receiving means including (3) means for demodulating the screen picture frame signal, (4) means for subjecting the screen picture frame signal to D/A conversion, (5) means for demodulating the first settling signal and the second settling signal into picture element data according to the received clocks, and (6) a image memory for storing the remaining picture element data.
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Specification