Still picture transmission apparatus
First Claim
1. A still picture transmission apparatus for transmitting still pictures over a transmission line comprising:
- means responsive to a plurality of video signals for sequentially selecting one of them;
memory means for compressing the video signals delivered from said selecting means and for storing the compressed video signals at predetermined areas, each of said areas corresponding to one of said plurality of video signals;
means for reading the compressed video signals from said memory means at a speed corresponding to the frequency bandwidth of the transmission line;
means for transmitting the compressed video signals read by said reading means to said transmission line; and
means for advancing the selection operation of said selecting means when a selected video signal delivered from said selecting means does not contain video information.
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Accused Products
Abstract
A still picture transmission apparatus operable in the quad-split mode, includes a switcher device for receiving a plurality of video signals and for transmitting the received video signals one at a time in a sequential manner. The switcher transmitted video signals are compressed and stored at defined locations of a suitable memory for subsequent transmission over a transmission line. To increase efficiency, each sequentially selected video signal is investigated to determine if it contains video information. If it is found that no video information is present, the switcher is directed to immediately select the next video signal and not wait out the time period normally allowed for the compression, storage and transmission of video information. The video signals are investigated by detecting the presence or absence of a television synchronizing signal in each of the video signals.
90 Citations
9 Claims
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1. A still picture transmission apparatus for transmitting still pictures over a transmission line comprising:
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means responsive to a plurality of video signals for sequentially selecting one of them; memory means for compressing the video signals delivered from said selecting means and for storing the compressed video signals at predetermined areas, each of said areas corresponding to one of said plurality of video signals; means for reading the compressed video signals from said memory means at a speed corresponding to the frequency bandwidth of the transmission line; means for transmitting the compressed video signals read by said reading means to said transmission line; and means for advancing the selection operation of said selecting means when a selected video signal delivered from said selecting means does not contain video information. - View Dependent Claims (2, 3, 4, 5)
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6. A still picture transmission apparatus for transmitting still pictures over a transmission line comprising:
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switcher means for sequentially selecting a plurality of video signals, one at a time; signal storage and compression means for compressing and storing each of the video signals selected by the switcher means; means for transmitting the compressed and stored video signals over said transmission line; means for detecting a synchronizing signal in each of said plurality of video signals; signal generating means, responsive to said synchronizing signal detecting means for producing an output signal representing the absence of video information in the then selected video signal when a synchronizing signal is not detected; and means responsive to said output signal for causing said switcher means to switch to thereby select the next video signal and send it to said signal storage and compression means for compression and storage. - View Dependent Claims (7, 8, 9)
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Specification