US5208701A
Expired / Lapsed
US
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Wobble correction lens with binary diffractive optic surface and refractive cylindrical surface
Assignee: Xerox Corp
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Filing: 1991-12-24
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Granted: 1993-05-04
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Expires: 2011-12-24
Abstract
Abstract A wobble correction lens for a raster output scanner combines a positive cross-scan plano-cylindrical lens, which provides most of the optical power for focusing the light beam to a scan line, with a diffractive surface, which corrects the cross-scan field curvature of the cross-scan plano-cylindrical lens. The diffractive surface will have a multi-level structure (binary diffractive optical surface) which possesses a diffractive phase function that will flatten the cross-scan field curvature of the plano-cylindrical lens.
Inventors
- 👤 Patrick Y. Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:28
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/0025; G02B27/0031
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
93 words
An optical scanning system for correction of wobble and correction of cross-scan field curvature comprising: a rotating polygon mirror with a plurality of facets, means for generating a collimated laser beam directed onto one of said facets, a lens which focuses said beam reflected off said one of said facets to a scan line, said lens comprising a binary diffractive optic lens surface and a refractive cylindrical surface to correct for wobble of said beam at said scan line and to correct the cross-scan field curvature of said beam at said scan line.
Claim 2
Dependent Claim
93 words
An optical scanning system for correction of wobble and correction of cross-scan field curvature comprising: a rotating polygon mirror with a plurality of facets, means for generating a collimated laser beam directed onto one of said facets, a lens which focuses said beam reflected off said one of said facets to a scan line, said lens comprising a binary diffractive optic lens surface and a refractive cylindrical surface to correct for wobble of said beam at said scan line and to correct the cross-scan field curvature of said beam at said scan line.
Claim 3
Dependent Claim
29 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 1 wherein said refractive cylindrical surface is a positive cross-scan refractive cylindrical surface.
Claim 4
Dependent Claim
28 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 1 wherein said binary diffractive optic lens surface is formed by photolithography.
Claim 5
Dependent Claim
28 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 1 wherein said binary diffractive optic lens surface is formed by molding.
Claim 6
Dependent Claim
35 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 1 wherein said binary diffractive optic lens surface and said refractive cylindrical surface are coated with an antireflective coating.
Claim 7
Dependent Claim
50 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 1 wherein the surface profile of said binary diffractive optic lens surface has a diffractive phase function consisting of terms proportional to x 2 and y 2 to correct for said cross-scan field curvature.
Claim 8
Dependent Claim
46 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 6 wherein said diffractive phase function also consists of terms proportional to x 4 , x 2 y 2 , and y 4 to correct for third-order spherical aberration correction.
Claim 9
Dependent Claim
50 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 7 wherein said diffractive phase function also consists of terms proportional to x 6 , x 4 y 2 , x 2 y 4 , and y 6 to correct for fifth-order spherical aberration.
Claim 10
Dependent Claim
116 words
An optical scanning system for correction of wobble and correction of cross-scan field curvature comprising: a rotating polygon mirror with a plurality of facets, means for generating a collimated laser beam directed onto one of said facets, a lens which focuses said beam reflected off said one of said facets to a scan line, said lens comprising a binary diffractive optic-plano lens, a refractive plano-cylindrical lens, and bonding means for securing said plano surface of said binary diffractive optic-plano lens to said plano surface of said refractive plano-cylindrical lens; said lens to correct for wobble of said beam at said scan line and to correct the cross-scan field curvature of said beam at said scan line.
Claim 11
Dependent Claim
116 words
An optical scanning system for correction of wobble and correction of cross-scan field curvature comprising: a rotating polygon mirror with a plurality of facets, means for generating a collimated laser beam directed onto one of said facets, a lens which focuses said beam reflected off said one of said facets to a scan line, said lens comprising a binary diffractive optic-plano lens, a refractive plano-cylindrical lens, and bonding means for securing said plano surface of said binary diffractive optic-plano lens to said plano surface of said refractive plano-cylindrical lens; said lens to correct for wobble of said beam at said scan line and to correct the cross-scan field curvature of said beam at said scan line.
Claim 12
Dependent Claim
29 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein said refractive plano-cylindrical lens is a positive cross-scan refractive plano-cylindrical lens.
Claim 13
Dependent Claim
27 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein said binary diffractive optic-plano lens is formed by photolithography.
Claim 14
Dependent Claim
27 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein said binary diffractive optic-plano lens is formed by molding.
Claim 15
Dependent Claim
45 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein said binary diffractive optic surface of said binary diffractive optic-plano lens and said refractive cylindrical surface of said refractive plano-cylindrical lens are coated with an antireflective coating.
Claim 16
Dependent Claim
50 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein the surface profile of said binary diffractive optic lens surface has a diffractive phase function consisting of terms proportional to x 2 and y 2 to correct for said cross-scan field curvature.
Claim 17
Dependent Claim
46 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 14 wherein said diffractive phase function also consists of terms proportional to x 4 , x 2 y 2 , and y 4 to correct for third-order spherical aberration correction.
Claim 18
Dependent Claim
50 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 15 wherein said diffractive phase function also consists of terms proportional to x 6 , x 4 y 2 , x 2 y 4 , and y 6 to correct for fifth-order spherical aberration.
Claim 19
Dependent Claim
25 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein said bonding means are an epoxy resin.
Claim 20
Dependent Claim
24 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 9 wherein said bonding means are a polyimide.
Claim 21
Dependent Claim
97 words
An optical scanning system for correction of wobble and correction of cross-scan field curvature comprising: a rotating polygon mirror with a plurality of facets, means for generating a collimated laser beam directed onto one of said facets, a lens system which focuses said beam reflected off said one of said facets to a scan line, said lens system comprising a binary diffractive optic-plano lens, and a refractive plano-cylindrical lens; said lens system to correct for wobble of said beam at said scan line and to correct the cross-scan field curvature of said beam at said scan line.
Claim 22
Dependent Claim
97 words
An optical scanning system for correction of wobble and correction of cross-scan field curvature comprising: a rotating polygon mirror with a plurality of facets, means for generating a collimated laser beam directed onto one of said facets, a lens system which focuses said beam reflected off said one of said facets to a scan line, said lens system comprising a binary diffractive optic-plano lens, and a refractive plano-cylindrical lens; said lens system to correct for wobble of said beam at said scan line and to correct the cross-scan field curvature of said beam at said scan line.
Claim 23
Dependent Claim
29 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 19 wherein said refractive plano-cylindrical lens is a positive cross-scan refractive plano-cylindrical lens.
Claim 24
Dependent Claim
27 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 19 wherein said binary diffractive optic-plano lens is formed by photolithography.
Claim 25
Dependent Claim
27 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 19 wherein said binary diffractive optic-plano lens is formed by molding.
Claim 26
Dependent Claim
40 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 19 wherein said surfaces of said binary diffractive optic-plano lens and said surfaces of said refractive plano-cylindrical lens are coated with an antireflective coating.
Claim 27
Dependent Claim
50 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 19 wherein the surface profile of said binary diffractive optic lens surface has a diffractive phase function consisting of terms proportional to x 2 and y 2 to correct for said cross-scan field curvature.
Claim 28
Dependent Claim
46 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 24 wherein said diffractive phase function also consists of terms proportional to x 4 , x 2 y 2 , and y 4 to correct for third-order spherical aberration correction.
Claim 29
Dependent Claim
50 words
The optical scanning system for correction of wobble and correction of cross-scan field curvature of claim 25 wherein said diffractive phase function also consists of terms proportional to x 6 , x 4 y 2 , x 2 y 4 , and y 6 to correct for fifth-order spherical aberration.
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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) | 1996-05-03 | 1996-11-02 | 1997-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-03 | 2000-11-02 | 2001-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-03 | 2004-11-02 | 2005-05-04 | $7700.00 | Window Closed / Lapsed |