US3609225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable rate facsimile system
Assignee: Northrop Grumman Guidance and Electronics Co Inc
•
Filing: 1969-10-14
•
Granted: 1971-09-28
•
Expires: 1989-10-14
Abstract
Abstract A variable rate facsimile system characterized by scanning and recording mechanisms which traverse a fixed raster pattern but whose scanning and recording rates vary according to the information content of the graphic material. The data is compressed by a known run length coding technique to effect redundancy reduction. Scanning of the copy to be transmitted and reproduction of the copy at the recorder employ cathode-ray tube flying spot scanners whose spot deflection is controlled by horizontal and vertical digital counters each driving a digital/analog converter.
Inventors
- 👤 Langdon B Stallard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:40
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/17; H04N1/41; H04N1/411; H04N1/413; H04N1/419
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
In a variable rate facsimile communication system having a line-scan mode of scanning a document utilizing digital transmission of intelligence signals and data compression, the improvement comprising: cathode-ray tube flying spot scanning means for line-scanning said document; control means for generating an end of line signal at the end of each line-scan; driving means for advancing the document through the scanning means; encoder means connected to said driving means for generating signals representing the instantaneous position of the document; counting means connected to said encoding means and said control means for generating an output signal dependent on the difference between said end of line signal and said signals representing said document position; means connecting said output signal from said counting means to said driving means and to said cathode-ray tube flying spot scanning means for controlling the driving means and deflecting the cathode-ray tube spot to follow the document as it is fed through the scanning means by said driving means.
Claim 2
Dependent Claim
161 words
In a variable rate facsimile communication system having a line-scan mode of scanning a document utilizing digital transmission of intelligence signals and data compression, the improvement comprising: cathode-ray tube flying spot scanning means for line-scanning said document; control means for generating an end of line signal at the end of each line-scan; driving means for advancing the document through the scanning means; encoder means connected to said driving means for generating signals representing the instantaneous position of the document; counting means connected to said encoding means and said control means for generating an output signal dependent on the difference between said end of line signal and said signals representing said document position; means connecting said output signal from said counting means to said driving means and to said cathode-ray tube flying spot scanning means for controlling the driving means and deflecting the cathode-ray tube spot to follow the document as it is fed through the scanning means by said driving means.
Claim 3
Dependent Claim
100 words
A variable rate facsimile communication system according to claim 1, additionally comprising: said encoder means and said counter means including means for generating digital signals; said counting means including a digital counter for generating a digital output signal; said means connecting said output signal from said counting means to said driving means including a digital to analog converter connected to said counting means; a level detector connected to said digital to analog converter; and said driving means, connected to said level detector, and including a stepping motor and drive roller means driven by said stepping motor for driving said documents.
Claim 4
Dependent Claim
78 words
A variable rate facsimile communication system according to claim 1, in which said encoder means and said control means each generate digital signals, and said counting means includes an up/down counter responsive to said digital signals for advancing said driving means whenever said counted digital signal from said control means is greater than said counted digital signal from said encoder means and for deflecting the cathode ray tube spot in proportion to the difference between said counted signals.
Claim 5
Dependent Claim
56 words
A variable rate facsimile communication system according to claim 3, in which said means connecting said digital output signal from said counting means to said driving means includes a binary operated servo, and said driving means includes motor means driven by said servo and drive roller means driven by said motor means for driving said documents.
Claim 6
Dependent Claim
37 words
A variable rate facsimile communication system according to claim 3, in which said means connecting said digital output signal from said counting means to said cathode-ray tube flying spot scanning means includes a digital to analog converter.
Claim 7
Dependent Claim
165 words
In a variable rate facsimile communication system having a line-scan mode of scanning a copy sheet utilizing transmission of signals with data compression, the improvement comprising: cathode-ray tube flying spot scanning means for line-scanning said copy sheet; control means for generating a digital end of line signal at the end of each line-scan; driving means for intermittently advancing the copy sheet through said scanning means; encoder means connected to said driving means to generate digital signals representing the position of the copy sheet before said cathode-ray tube; a single up/down counter for accumulating said digital end of line signal and said digital encoder signals and for producing a digital output signal representative of the difference therebetween; digital to analog conversion means connecting said counter output signal to said cathode ray tube for deflecting said flying spot to compensate for the advance of the copy; and means connecting said counter output signal to said driving means to synchronize said copy sHeet and said flying spot location.
Claim 8
Dependent Claim
165 words
In a variable rate facsimile communication system having a line-scan mode of scanning a copy sheet utilizing transmission of signals with data compression, the improvement comprising: cathode-ray tube flying spot scanning means for line-scanning said copy sheet; control means for generating a digital end of line signal at the end of each line-scan; driving means for intermittently advancing the copy sheet through said scanning means; encoder means connected to said driving means to generate digital signals representing the position of the copy sheet before said cathode-ray tube; a single up/down counter for accumulating said digital end of line signal and said digital encoder signals and for producing a digital output signal representative of the difference therebetween; digital to analog conversion means connecting said counter output signal to said cathode ray tube for deflecting said flying spot to compensate for the advance of the copy; and means connecting said counter output signal to said driving means to synchronize said copy sHeet and said flying spot location.
References Cited (Backward Citations)
US2922841A
Cited
US3339017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |