US3882270A
Expired / Lapsed
US
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Image transmission system
Assignee: Ricoh Co Ltd
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Filing: 1973-05-31
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Granted: 1975-05-06
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Expires: 1993-05-31
Abstract
Abstract A system for converting optical images into digital image signals characterized by low redundancy and for transmitting said digital signals. An image is scanned at a low sensitivity level for the first scanline, a high sensitivity level for the second scanline, a low sensitivity level for a third scanline, etc., to generate a succession of analog image signals each corresponding to a single scanline. Each of the analog image signals is compared with a threshold level signal which alternates, in square wave fashion, between two different threshold levels many times during a single scanline. the comparison results in a transmission signal which is at 0 when the analog image signal is within a first theshold span, which alternates between 0 and 1 when the analog image signal is within a second threshold interval, and which is at a steady 1 when the analog image signal is within a third threshold interval.
Inventors
- 👤 Mutsuo Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:48
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
125 words
An image transmission system comprising means for scanning an image at a repeating plurality of sensitivity levels to generate a sequence of image signals, each image signal corresponding to a scan at a single one of said sensitivity levels; means for generating a threshold level signal comprising a repeating plurality of threshold levels in timed relationship with each of said image signals; and means for comparing each image signal with said threshold level signal to generate a first transmission signal when the level of the image signal is higher than the time related level of the threshold level signal and for generating a second transmission signal when the level of the image signal is lower than the time related level of the threshold level signal.
Claim 2
Dependent Claim
125 words
An image transmission system comprising means for scanning an image at a repeating plurality of sensitivity levels to generate a sequence of image signals, each image signal corresponding to a scan at a single one of said sensitivity levels; means for generating a threshold level signal comprising a repeating plurality of threshold levels in timed relationship with each of said image signals; and means for comparing each image signal with said threshold level signal to generate a first transmission signal when the level of the image signal is higher than the time related level of the threshold level signal and for generating a second transmission signal when the level of the image signal is lower than the time related level of the threshold level signal.
Claim 3
Dependent Claim
98 words
A system as in claim 1 wherein the means for generating the threshold level signal comprises a timing disc having a plurality of slits, a light source and a plurality of photoelectric transducer elements separated by the timing disc, means for rotating the disc with respect to the light source and the photoelectric transducer element and a threshold level switch receiving the output of at least one of said photoelectric transducer elements and providing an output which is a voltage signal alternating between a repeating plurality of threshold levels in timed relationship with each of said image signals.
Claim 4
Dependent Claim
25 words
A systme as in claim 1 wherein the scanning means scans the image at an alternating plurality of a higher and a lower sensitivity level.
Claim 5
Dependent Claim
20 words
A system as in claim 3 wherein the threshold level signal generating means generates a signal alternating between two levels.
Claim 6
Dependent Claim
97 words
A system as in claim 1 wherein the scanning means comprises a fiber optic bundle having an image entry end and an image exit end shaped in the form of a semicircle having an arc of up to 180*, means for moving the image with respect to the entry end of the fiber optic bundle and for projecting the image onto said entry end, and means for converting the intensity of the image emerging at the exit end of the fiber optic bundle to an electrical signal whose voltage level varies with the intensity of the image.
Claim 7
Dependent Claim
43 words
A system as in claim 5 wherein the converting means comprises a photoelectric transducer element and a second fiber optic bundle having an image entry end rotating over said semicircularly shaped exit end and having an exit end facing said photoelectric transducer element.
Claim 8
Dependent Claim
133 words
An image transmission system comprising: means for scanning an image at a repeating plurality of sensitivity levels, one sensitivity level per scan line, to generate a succession of image signals each corresponding to a scan of one line; means for generating a threshold level signal alternating between a repeating plurality of threshold levels in timed relationship with each of said image signals; threshold circuit means for comparing the instantaneous relative levels of the image signal and of the threshold level signal and for generating a first transmission signal at a first defined relationship between the compared signals and a second transmission signal at a second defined relationship between the compared signals; and a counter receiving the output of the threshold circuit and storing said output as a coded representation of the scanned image.
Claim 9
Dependent Claim
133 words
An image transmission system comprising: means for scanning an image at a repeating plurality of sensitivity levels, one sensitivity level per scan line, to generate a succession of image signals each corresponding to a scan of one line; means for generating a threshold level signal alternating between a repeating plurality of threshold levels in timed relationship with each of said image signals; threshold circuit means for comparing the instantaneous relative levels of the image signal and of the threshold level signal and for generating a first transmission signal at a first defined relationship between the compared signals and a second transmission signal at a second defined relationship between the compared signals; and a counter receiving the output of the threshold circuit and storing said output as a coded representation of the scanned image.
Claim 10
Dependent Claim
112 words
An image transmission System comprising: a. means for scanning an image to generate a succession of image signals each corresponding to a scan of one line of the image; b. means for generating a threshold level signal alternating between a plurality of threshold levels at a frequency substantially greater than that of generating said image signals; and c. means for comparing each image signal with the threshold level signal and for generating a first transmission signal at a first defined relationship between the compared signals, a second transmission signal at a second defined relationship between the compared signals and a third transmission signal at a third defined relationship between the compared signals.
Claim 11
Dependent Claim
112 words
An image transmission System comprising: a. means for scanning an image to generate a succession of image signals each corresponding to a scan of one line of the image; b. means for generating a threshold level signal alternating between a plurality of threshold levels at a frequency substantially greater than that of generating said image signals; and c. means for comparing each image signal with the threshold level signal and for generating a first transmission signal at a first defined relationship between the compared signals, a second transmission signal at a second defined relationship between the compared signals and a third transmission signal at a third defined relationship between the compared signals.
Claim 12
Dependent Claim
27 words
An image transmission system as in claim 8 wherein the scanning means inludes means for scanning selected different lines of the image at selected different sensitivity levels.
Claim 13
Dependent Claim
28 words
an image transmission system as in claim 8 wherein the means for generating a threshold level signal generates selected different threshold level signals for selected different image signals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |