US4763173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Imaging system for compensating for image distortion due to wrinkled or curled documents
Assignee: Xerox Corp
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Filing: 1987-09-18
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Granted: 1988-08-09
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Expires: 2007-09-18
Abstract
Abstract A document imaging system is compensated for distortion caused by non-planarity in the documents by providing a positive lens with varying power at a location beneath the document platen. In a preferred embodiment, an aspheric fresnel lens is used as the compensating optical element.
Inventors
- 👤 Michael E. Harrigan
- 👤 James D. Rees
- 👤 Robert P. Rebres
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:35
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/62; G03B27/6207; G03B27/6221; G03B27/625; G03B27/6264
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
66 words
A document imaging system including: a transparent platen located in an object plane; means for positioning an original document on the surface of said platen; means for projecting an image of said document onto a photosensitive surface; and a positive lens element positioned between said platen and said projection lens said lens adapted to compensate for distortion caused by imaging of non-planar portions of said documents.
Claim 2
Dependent Claim
66 words
A document imaging system including: a transparent platen located in an object plane; means for positioning an original document on the surface of said platen; means for projecting an image of said document onto a photosensitive surface; and a positive lens element positioned between said platen and said projection lens said lens adapted to compensate for distortion caused by imaging of non-planar portions of said documents.
Claim 3
Dependent Claim
19 words
The imaging system of claim 1 wherein said positive lens element is an apsheric positive lens with varying power.
Claim 4
Dependent Claim
16 words
The imaging system of claim 1 wherein said positive lens element is an aspheric fresnel lens.
Claim 5
Dependent Claim
28 words
The imaging system of claim 3 wherein the fresnel lens is located beneath the platen with the grooved surface facing upward towards the bottom surface of the platen.
Claim 6
Dependent Claim
28 words
The imaging system of claim 3 wherein the fresnel lens is located above the platen and the grooved surface faces downward towards the top surface of the platen.
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) | 1991-08-09 | 1992-02-08 | 1992-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-09 | 1996-02-08 | 1996-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-09 | 2000-02-08 | 2000-08-09 | $7700.00 | Window Closed / Lapsed |