US3830964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for transmitting a bandwidth compressed digital signal representation of a visible image
Assignee: Revvity Inc
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Filing: 1973-01-03
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Granted: 1974-08-20
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Expires: 1993-01-03
Abstract
Abstract A method and system for producing and transmitting to a remote location a compressed digital signal representation of an image, and receiving at a remote location and expanding that representation to construct a facsimile image. The image to be transmitted is scanned in accordance with a pattern of uniformly spaced lines of scan to produce a digital signal representative of the optical density along the lines of scan. A full scan line signal is encoded in a predetermined pattern in a preselected one of two modes. In the first mode, each scan line signal is represented by a sequence of binary number pairs, each pair corresponding to a contiguous portion of that scan line signal, while in the second encoding mode, corresponding portions of successive scan line signals are compared and a digital signal produced to represent the difference between the successive scan line signals. Reference marker signals are also encoded with the scan line signals to limit error propagation. The encoded scan line signals are further encoded for transmission in a variable length code word format. The encoded scan signals are transmitted to a remote receiver where those signals are decoded and used to generate a facsimile at the remote location.
Inventors
- 👤 D Spencer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:03
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/41; H04N1/411; H04N1/413; H04N1/417
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
355 words
Apparatus for producing a digital signal representation of an image having areas of two discrete optical densities, comprising: means for scanning successively said image in accordance with a pattern of uniformly spaced lines of scan, means for sampling and detecting the optical density of contiguous spatial increments of said image along each of said lines of scan, means for generating two multiple bit binary half-cell signals for each of said lines of scan, the bits of the first of said half-cell signals being directly related to alternate ones of said spatial increments including the first of said increments in each of said lines of scan, and the bits of the second of said half-cell signals being directly related to alternate ones of said spatial increments including the second of said increments in each of said lines of scan, and each bit of said half-cell signals having a one of two amplitude levels, corresponding to the detected optical density of said related spatial increment, said first amplitude level corresponding to the first of said discrete optical densities and said second level corresponding to the second of said optical densities, storing successively for each of said lines of scan said two multiple bit binary half-cell signals, producing successively for each of said lines of scan, a multiple bit full cell line signal, storing successively at least two of said multiple bit full cell scan line signals corresponding to two adjacent lines of scan, wherein said full cell line signal is produced for each of said lines of scan with each bit of said full cell scan line signal related to the bits in said correspondingly positioned two binary half-cell signals, such that the bits of said full cell scan line signal has the same amplitude level as said corresponding bits in said half-cell signals when said corresponding bits have identical levels, and each bit of said full cell scan line signal has the same level as the corresponding bit in said previously stored full cell scan line signal from the preceding adjacent line of scan when the level of said corresponding bits in said half-cell signals differ.
Claim 2
Dependent Claim
355 words
Apparatus for producing a digital signal representation of an image having areas of two discrete optical densities, comprising: means for scanning successively said image in accordance with a pattern of uniformly spaced lines of scan, means for sampling and detecting the optical density of contiguous spatial increments of said image along each of said lines of scan, means for generating two multiple bit binary half-cell signals for each of said lines of scan, the bits of the first of said half-cell signals being directly related to alternate ones of said spatial increments including the first of said increments in each of said lines of scan, and the bits of the second of said half-cell signals being directly related to alternate ones of said spatial increments including the second of said increments in each of said lines of scan, and each bit of said half-cell signals having a one of two amplitude levels, corresponding to the detected optical density of said related spatial increment, said first amplitude level corresponding to the first of said discrete optical densities and said second level corresponding to the second of said optical densities, storing successively for each of said lines of scan said two multiple bit binary half-cell signals, producing successively for each of said lines of scan, a multiple bit full cell line signal, storing successively at least two of said multiple bit full cell scan line signals corresponding to two adjacent lines of scan, wherein said full cell line signal is produced for each of said lines of scan with each bit of said full cell scan line signal related to the bits in said correspondingly positioned two binary half-cell signals, such that the bits of said full cell scan line signal has the same amplitude level as said corresponding bits in said half-cell signals when said corresponding bits have identical levels, and each bit of said full cell scan line signal has the same level as the corresponding bit in said previously stored full cell scan line signal from the preceding adjacent line of scan when the level of said corresponding bits in said half-cell signals differ.
Claim 3
Dependent Claim
92 words
An apparatus in accordance with claim 1, wherein said means for storing said half-cell signals includes: a first storage means being operable in a one of two modes, a first mode for storing a plurality of said bits of said half-cell signals as generated at a first time rate, and a second mode for recirculating said stored bits in said first storage means at a second time rate substantially higher than said first rate. a control means for selecting the one of said two modes of operation for said first storage means.
Claim 4
Dependent Claim
66 words
An apparatus in accordance with claim 2; wherein said means for producing said scan line signal further includes: a second storage means for storing a complete multiple bit full cell binary scan line signal, said second storage means operable to recirculate said storage signal at said second rate, a control means for transferring said stored bits in said first storage means to said second storage means.
Claim 5
Dependent Claim
349 words
Method of producing a digital signal representation of an image having areas of two discrete optical densities, including the steps of: scanning successively said image in accordance with a pattern of uniform spaced lines of scan, sampling and detecting the optical density of contiguous spatial increments of said image along each of said lines of scan, generating two multiple bit binary half-cell signals for each of said lines of scan, the bits of the first of said half-cell signals being directly related to alternate ones of said spatial increments including the first of said increments in each of said lines of scan, and the bits of the second of said half-cell signals being directly related to alternate ones of said spatial increments including the second of said increments in each of said lineS of scan, and each bit of said half-cell signals having a one of two amplitude levels, corresponding to the detected optical density of said related spatial increment, said first amplitude level corresponding to the first of said discrete optical densities and said second level corresponding to the second of said densities, means for storing successively for each of said lines of scan said two multiple bit binary half-cell signals, means for producing successively for each of said lines of scan a multiple bit full cell scan line signal, means for storing successively at least two of said multiple bit full cell scan line signals corresponding to two successive lines of scan, wherein said means for producing said full cell scan line signal includes a means for relating the bits of said full cell scan line signal to the correspondingly positioned bits in said binary half-cell signals, wherein each bit of said full cell scan line signal has the same amplitude as said corresponding bits in said half-cell signals when said corresponding bits have identical levels, and wherein each bit of said full cell scan line signal has the same level as the corresponding bit in said stored next previous full cell scan line signal, when the level of said corresponding bits in said half-cell signals differ.
Claim 6
Dependent Claim
349 words
Method of producing a digital signal representation of an image having areas of two discrete optical densities, including the steps of: scanning successively said image in accordance with a pattern of uniform spaced lines of scan, sampling and detecting the optical density of contiguous spatial increments of said image along each of said lines of scan, generating two multiple bit binary half-cell signals for each of said lines of scan, the bits of the first of said half-cell signals being directly related to alternate ones of said spatial increments including the first of said increments in each of said lines of scan, and the bits of the second of said half-cell signals being directly related to alternate ones of said spatial increments including the second of said increments in each of said lineS of scan, and each bit of said half-cell signals having a one of two amplitude levels, corresponding to the detected optical density of said related spatial increment, said first amplitude level corresponding to the first of said discrete optical densities and said second level corresponding to the second of said densities, means for storing successively for each of said lines of scan said two multiple bit binary half-cell signals, means for producing successively for each of said lines of scan a multiple bit full cell scan line signal, means for storing successively at least two of said multiple bit full cell scan line signals corresponding to two successive lines of scan, wherein said means for producing said full cell scan line signal includes a means for relating the bits of said full cell scan line signal to the correspondingly positioned bits in said binary half-cell signals, wherein each bit of said full cell scan line signal has the same amplitude as said corresponding bits in said half-cell signals when said corresponding bits have identical levels, and wherein each bit of said full cell scan line signal has the same level as the corresponding bit in said stored next previous full cell scan line signal, when the level of said corresponding bits in said half-cell signals differ.
References Cited (Backward Citations)
US2909601A
Cited
US3215773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |