US3840698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video signal transmission system
Assignee: Fujitsu Ltd
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Filing: 1973-07-17
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Granted: 1974-10-08
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Expires: 1993-07-17
Abstract
Abstract A picture transmission system for transmitting a video signal of compressed bandwidth, in which the transmitting station is provided with: means for dividing a picture to be transmitted into a plurality of blocks and regularly scanning and extracting video signals at corresponding sampling points in the respective blocks in a predetermined order; a frame memory for storing video signals of one frame; means for comparing picture elements of the video signals from the scanning and extracting means with those at the corresponding sampling points of the video signal obtained by a preceding scanning and stored in the frame memory and for selecting the block of the video signal of the largest level difference; and means supplied with the output from the selecting means to add the picture element of video signal of the corresponding block with a signal indicating the block and transmitting such signals over a transmission line or medium; and in which the receiving station is provided with a frame memory for storing video signals of one frame; and detecting means for detecting the block indicating signal added to the picture element of video signal transmitted and converting a picture element of video signal in the block of a picture in the frame memory corresponding to the block indicating signal into the picture element of video signal transmitted.
Inventors
- 👤 S Hinoshita
- 👤 Y Minejima
- 👤 T Moriya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:09
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/66; H04N; H04N7/00; H04N7/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
248 words
A picture transmission system for transmitting a video signal of compressed bandwidth over a transmission medium and for receiving and processing the transmitted video signal, said picture transmission system comprising: A. a transmitting station including: a. means for dividing a picture into a plurality of blocks and for regularly scanning and extracting video signals at corresponding sampling points in the respective blocks in a predetermined order, b. a first frame memory for storing video signals of one frame, c. means for comparing picture elements of the video signals from said scanning and extracting means with those at the corresponding sampling points of the video signals obtained by a preceding scanning and stored in said first frame memory and for selecting the block of the picture element of the video signal of the largest level difference, and d. means responsive to the output of said selecting means for adding the picture element of the video signal of the corresponding block with a signal indicating the block and for transmitting them to a transmission line, and B. a receiving station including: a. a second frame memory for storing transmitted video signals of one frame, and b. detecting means for detecting the block indicating signal added to the picture element of the video signal transmitted and for converting a picture element of the video signal in the block of a picture in said second frame memory corresponding to the block indicating signal into the picture element of the transmitted video signal.
Claim 2
Dependent Claim
248 words
A picture transmission system for transmitting a video signal of compressed bandwidth over a transmission medium and for receiving and processing the transmitted video signal, said picture transmission system comprising: A. a transmitting station including: a. means for dividing a picture into a plurality of blocks and for regularly scanning and extracting video signals at corresponding sampling points in the respective blocks in a predetermined order, b. a first frame memory for storing video signals of one frame, c. means for comparing picture elements of the video signals from said scanning and extracting means with those at the corresponding sampling points of the video signals obtained by a preceding scanning and stored in said first frame memory and for selecting the block of the picture element of the video signal of the largest level difference, and d. means responsive to the output of said selecting means for adding the picture element of the video signal of the corresponding block with a signal indicating the block and for transmitting them to a transmission line, and B. a receiving station including: a. a second frame memory for storing transmitted video signals of one frame, and b. detecting means for detecting the block indicating signal added to the picture element of the video signal transmitted and for converting a picture element of the video signal in the block of a picture in said second frame memory corresponding to the block indicating signal into the picture element of the transmitted video signal.
Claim 3
Dependent Claim
25 words
A picture transmission system according to claim 1, wherein said scanning and extracting means divides the picture to be trans mitted into two bilateral blocks.
Claim 4
Dependent Claim
231 words
A picture transmission system according to claim 2, wherein in said transmitting station, said scanning and extracting means includes a first delay circuit having a delay time corresponding to one-half of one horizontal scanning period, and transmission selecting means responsive to video signals appearing at input and outPut ends of said first delay circuit for switching them with a comparison signal and for sending out either one of them together with a discriminating signal; said first frame memory having a second delay circuit of a delay time corresponding to one-half of the horizontal scanning period, connected between its output and input sides with the video signals appearing at the input end of said first delay circuit and a second gate circuit supplied with the video signal appearing at the output end of said first delay circuit; a first comparator circuit for comparing the video signal level at the input end of said first delay circuit with that at the input end of said first gate circuit to provide a difference signal therebetween; a second comparator circuit for comparing the video signal level at the output end of said first delay circuit with that at the input end of said second gate circuit to provide a difference signal therebetween; and a third comparator circuit for comparing the difference signals derived from said first and second comparator circuits to provide a compared output.
Claim 5
Dependent Claim
74 words
A picture transmission system according to claim 1, wherein in said transmitting station, said scanning and extracting means includes a first delay circuit imparting a delay corresponding to one-half of one horizontal scanning period, and transmission selecting means responsive to video signals appearing at the input and output of said first delay circuit for switching them with a comparison signal and for sending at least one of these signals together with a discriminating signal.
Claim 6
Dependent Claim
91 words
A picture transmission system according to claim 4, wherein in said transmitting station, said first frame memory comprises a second delay circuit imparting a delay time corresponding to one-half of the horizontal scanning period and having connected between its input and output terminals a first gate circuit, said first gate circuit supplied at its output and input sides with video signals appearing at the input end of said first delay circuit, and a second gate circuit supplied with the video signal appearing at the output end of said first delay circuit.
Claim 7
Dependent Claim
111 words
A picture transmission system according to claim 5, wherein in said transmitting station, there is further included a first comparator circuit for comparing the video signal level at the input end of said first delay circuit with that appearing at the input end of said first gate circuit to provide a first difference signal; a second comparator circuit for comparing the video signal level appearing at the output end of said first delay circuit with that signal appearing at the input end of said second gate circuit to provide a second difference signal; and a third comparator circuit for comparing the first and second difference signals to provide a compared output.
Claim 8
Dependent Claim
62 words
A picture transmission system according to claim 1, wherein in said receiving station, said detecting means includes an address detector for detecting the transmitted block indicating signal added to the picture element of the video signal, first and second selecting circuits, each responsive to the output of said address detector, and a delay circuit interconnected between said first and second selecting circuits.
Claim 9
Dependent Claim
36 words
A picture transmission system according to claim 7, wherein in said receiving station, said frame memory is responsive to the output appearing at said second selecting circuit for providing an input to said first selecting circuit.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |