US3922485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flying spot scanner with scan detection
Assignee: Xerox Corp
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Filing: 1972-11-27
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Granted: 1975-11-25
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Expires: 1992-11-27
Abstract
Abstract A flying spot scanning system is provided by utilizing reflected light from a multifaceted rotating polygon which is then directed to the scanned medium. A light source illuminates given facets of the polygon to provide the desired function of spot scanning. In each scanning cycle, information is transmitted to the scanned medium by modulating the light from the light source in accordance with a video signal. To assure an effective sequence of spot scans and the resulting scanning cycle, a beam splitter is employed to provide an unmodulated light beam from the original light beam which is directed at the illuminated facets of the polygon at an angle of incidence different from that of the incident modulated beam. An optically sensitive detector is aligned in relation to the scan width of the scanned medium so as to receive only the unmodulated beam during each scan cycle to determine the start/stop of each scan.
Inventors
- 👤 Gary K Starkweather
- 👤 Robert P Kowalski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:27
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1204; G06K15/1219; H; H04; H04N; H04N3/00; H04N3/02; H04N3/08
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
196 words
Apparatus for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of high intensity light, means for modulating the light beam in accordance with the transmission of information represented by an electrical signal, first optical means for expanding said modulated beam, second optical means in convolution with said first optical means for imaging said expanded, modulated beam to a spot in a focal plane coextensive with the surface of a light sensitive medium at a predetermined distance from said second optical means, scanning means positioned between said first and second means for scanning the spot across said medium, said scanning means having a reflective element, a portion of which is illuminated by said modulated beam to direct said spot to said medium, means positioned between said light beam providing means and said modulating means for splitting the unmodulated beam such that an unmodulated beam is directed at the illuminated portion of said scanning means, said scanning means further scanning a spot of unmodulated light throughout a scan width unassociated with said medium, and means for detecting and indicating the start of the scan of said spot of unmodulated light.
Claim 2
Dependent Claim
196 words
Apparatus for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of high intensity light, means for modulating the light beam in accordance with the transmission of information represented by an electrical signal, first optical means for expanding said modulated beam, second optical means in convolution with said first optical means for imaging said expanded, modulated beam to a spot in a focal plane coextensive with the surface of a light sensitive medium at a predetermined distance from said second optical means, scanning means positioned between said first and second means for scanning the spot across said medium, said scanning means having a reflective element, a portion of which is illuminated by said modulated beam to direct said spot to said medium, means positioned between said light beam providing means and said modulating means for splitting the unmodulated beam such that an unmodulated beam is directed at the illuminated portion of said scanning means, said scanning means further scanning a spot of unmodulated light throughout a scan width unassociated with said medium, and means for detecting and indicating the start of the scan of said spot of unmodulated light.
Claim 3
Dependent Claim
36 words
The apparatus as defined in claim 1 wherein said detecting means includes a timing element for timing the duration of the scan in order for said means to mark the end of transmission of the information.
Claim 4
Dependent Claim
28 words
The apparatus as defined in claim 2 wherein the start and end of scan indications synchronize said electrical signal to the movement of said spot across said medium.
Claim 5
Dependent Claim
28 words
The apparatus as defined in claim 3 wherein said detecting means further includes means for providing edge discrimination for indicating the precise instant of the start of scan.
Claim 6
Dependent Claim
47 words
The apparatus as defined in claim 4 wherein said scanning means includes a multifaceted polygon having reflective facets for reflecting said respective light beams incident upon it and means for rotating said polygon such that the respective reflected light beams are scanned through their respective scan paths.
Claim 7
Dependent Claim
25 words
The apparatus as defined in claim 5 wherein said light source is a laser which emits a beam of collimated light of substantially uniform intensity.
Claim 8
Dependent Claim
175 words
A flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of high intensity light, means for modulating the light beam in accordance with the information content of an electrical signal represented by a stream of binary digits, means for focusing said modulatEd beam to a spot upon the surface of a light sensitive medium, scanning means positioned in the optical path of said modulated beam for scanning the spot across said medium, said scanning means having a reflective element, a portion of which is illuminated by said modulated beam to direct said spot to said medium, means positioned between said light beam providing means and said modulating means for splitting the unmodulated beam such that an unmodulated beam is directed at the illuminated portion of said scanning means, said scanning means further scanning a spot of unmodulated light throughout a scan width unassociated with said medium, and means for detecting and indicating the start of the scan of said spot of unmodulated light.
Claim 9
Dependent Claim
175 words
A flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of high intensity light, means for modulating the light beam in accordance with the information content of an electrical signal represented by a stream of binary digits, means for focusing said modulatEd beam to a spot upon the surface of a light sensitive medium, scanning means positioned in the optical path of said modulated beam for scanning the spot across said medium, said scanning means having a reflective element, a portion of which is illuminated by said modulated beam to direct said spot to said medium, means positioned between said light beam providing means and said modulating means for splitting the unmodulated beam such that an unmodulated beam is directed at the illuminated portion of said scanning means, said scanning means further scanning a spot of unmodulated light throughout a scan width unassociated with said medium, and means for detecting and indicating the start of the scan of said spot of unmodulated light.
Claim 10
Dependent Claim
37 words
The system as defined in claim 7 wherein said detecting means includes a timing element for timing the duration of the scan in order for said means to mark the end of the stream of binary digits.
Claim 11
Dependent Claim
30 words
The apparatus as defined in claim 8 wherein the start and end of scan indications, respectively, are indications of the initiation of said stream of binary digits and its termination.
Claim 12
Dependent Claim
24 words
The apparatus as defined in claim 9 wherein said detecting means further includes means for discriminating the precise instant of the start of scan.
Claim 13
Dependent Claim
47 words
The system as defined in claim 10 wherein said scanning means includes a multifaceted polygon having reflective sides for reflecting said respective light beams incident to it and means for rotating said polygon such that the respective reflected light beams are scanned through their respective scan paths.
Claim 14
Dependent Claim
25 words
The system as defined in claim 11 wherein said light source is a laser which emits a beam of collimated light of substantially uniform intensity.
Claim 15
Dependent Claim
168 words
A flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of high intensity light, means for modulating the light beam in accordance with the information content of the electrical signal, means for focusing said modulated beam to a spot upon the surface of a light sensitive medium, scanning means positioned in the optical path of said modulated beam for scanning the spot across said medium, said scanning means having a reflective element, a portion of which is illuminated by said modulated beam to direct said spot to said medium, means positioned between said light beam providing means and said modulating means for splitting said unmodulated beams such that an unmodulated beam is directed at the illuminated portion of said scanning means, said scanning means further scanning a spot of unmodulated light throughout a scan width unassociated with said medium, and means for detecting and indicating the start of the scan of said spot of unmodulated light.
Claim 16
Dependent Claim
168 words
A flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of high intensity light, means for modulating the light beam in accordance with the information content of the electrical signal, means for focusing said modulated beam to a spot upon the surface of a light sensitive medium, scanning means positioned in the optical path of said modulated beam for scanning the spot across said medium, said scanning means having a reflective element, a portion of which is illuminated by said modulated beam to direct said spot to said medium, means positioned between said light beam providing means and said modulating means for splitting said unmodulated beams such that an unmodulated beam is directed at the illuminated portion of said scanning means, said scanning means further scanning a spot of unmodulated light throughout a scan width unassociated with said medium, and means for detecting and indicating the start of the scan of said spot of unmodulated light.
Claim 17
Dependent Claim
34 words
The system as defined in claim 13 wherein said detecting means includes a timing element for timing the duration of the scan in order for said means to indicate the end of the scan.
Claim 18
Dependent Claim
28 words
The system as defined in claim 10 wherein the start and end of scan indications, respectively, are indications of the initiation of said electrical signal and its termination.
Claim 19
Dependent Claim
24 words
The system as defined in claim 15 wherein said detecting means further includes means for discriminating the precise instant of the start of scan.
Claim 20
Dependent Claim
70 words
The system as defined in claim 16 wherein the scanning means includes a multi-faceted polygon having reflective sides for reflecting the light incident to it and means for rotating said polygon such that the modulated light which illuminates certain of said sides is scanned in successive traces across said medium and the unmodulated light which further illuminates said illuminated sides is scanned in successive movements away from said detecting means.
Claim 21
Dependent Claim
25 words
The system as defined in claim 17 wherein said light source is a laser which emits a beam of collimated light of substantially uniforM intensity.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |