US4362382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precession scanning system
Assignee: Xerox Corp
•
Filing: 1981-02-23
•
Granted: 1982-12-07
•
Expires: 2001-02-23
Abstract
Abstract The present invention is directed to an object scanning system wherein a dual-rate mirror assembly scans a document on a platen and the scanned image is projected onto a photoreceptor via a corner mirror assembly. The corner mirror assembly is linearly translated during a scan cycle so as to cause the image to be projected onto the photoreceptor in a direction opposite to the photoreceptor movement. The precession rate can be set relative to scanning flyback time so as to reduce or eliminate the interdocument gap on the photoreceptor and to relax rescan time requirements.
Inventors
- 👤 George R. Simpson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:55
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/041; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/522; G03B27/525; G03B27/526
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
153 words
An optical system for a copying device wherein a stationary document lying on an object plane is imaged onto a flat photoreceptor, said system comprising: an illumination scanning means for scanning said document at a scanning speed V A , projection means positioned between said scanning means and said photoreceptor moving at a velocity V P , said projecting means adapted to project reflected images of the document along an optical path towards said photoreceptor, and a corner mirror assembly positioned along the optical path between said projecting means and said photoreceptor, said assembly adapted to move along a linear path during said scanning operation so as to reflect said projected images, in substantially perpendicular orientation, onto said photoreceptor, said linear movement causing said reflected images to precess along the surface of the photoreceptor at a speed V M equal to V A -V P and along a precession distance D P .
Claim 2
Dependent Claim
153 words
An optical system for a copying device wherein a stationary document lying on an object plane is imaged onto a flat photoreceptor, said system comprising: an illumination scanning means for scanning said document at a scanning speed V A , projection means positioned between said scanning means and said photoreceptor moving at a velocity V P , said projecting means adapted to project reflected images of the document along an optical path towards said photoreceptor, and a corner mirror assembly positioned along the optical path between said projecting means and said photoreceptor, said assembly adapted to move along a linear path during said scanning operation so as to reflect said projected images, in substantially perpendicular orientation, onto said photoreceptor, said linear movement causing said reflected images to precess along the surface of the photoreceptor at a speed V M equal to V A -V P and along a precession distance D P .
Claim 3
Dependent Claim
45 words
The optical system of claim 1 wherein said mirror assembly comprises a pair of mirrors having an included angle θ=45° and wherein said linear path is in a direction normal to the bisector of the 45° included angle and along a distance d=D P /√2.
Claim 4
Dependent Claim
37 words
The optical system of claim 1 wherein said scanning means includes a full-rate/half-rate mirror assembly, said system further including a second corner mirror assembly positioned along the optical path between said scanning means and said projection means.
Claim 5
Dependent Claim
22 words
The optical system of claim 3 wherein both corner mirror assemblies are movable along their respective bisectors to accommodate changes in magnification.
Claim 6
Dependent Claim
25 words
The optical system of claim 1 wherein said projection means and said mirror assembly are movable along said optical axis to accommodate changes in magnification.
Claim 7
Dependent Claim
27 words
The optical system of claim 1 further including an exposure slit adjacent said photoreceptor, said slit adapted to move with said projected image and exclude extraneous light.
References Cited (Backward Citations)
US3454335A
Cited
US3650621A
Cited
US3754822A
Cited
US3947188A
Cited
US4212532A
Cited
US4232960A
Cited
US4285590A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-06 | 1986-06-07 | 1986-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-06 | 1990-06-07 | 1990-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-06 | 1994-06-07 | 1994-12-07 | $7700.00 | Window Closed / Lapsed |