US4281889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light beam scanning system
Assignee: Fujifilm Holdings Corp
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Filing: 1979-10-12
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Granted: 1981-08-04
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Expires: 1999-10-12
Abstract
Abstract A light beam scanning system in which deviations perpendicular to the scanning direction of the scan line due to parallelism deviations of a rotary multi-surfaced mirror are eliminated. A first linear image pattern is formed on the reflecting surface of the mirror parallel to the scanning direction by a connex cylindrical lens. The image is reflected to a first convergent lens which forms a second linear image perpendicular to the scanning direction then passes through a concave cylindrical lens which diverges the light in a direction perpendicular to the scanning direction. A second convergent lens converges the beam to form a point image on the scanned surface.
Inventors
- 👤 Masaru Noguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:56
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
196 words
A light beam scanning system having a rotary multi-surfaced mirror comprising in order relative to a light source: (a) a uni-directional convergent optical element for converging an incident light beam to form on a reflection surface of said rotary multi-surfaced mirror a first linear image parallel to its scanning direction; (b) first convergent optical means for converging the light beam reflected by said multi-surfaced mirror to form a second linear image perpendicular to the scanning direction; (c) a uni-directional divergent optical element disposed at a position opposite to said first convergent optical means with respect to the second linear image, said divergent optical element being adapted to diverge the light beam in a direction perpendicular to the scanning direction; and (d) second convergent optical means for converging the light beam to form a point image on a scanning surface; whereby said second linear image and said point image are positioned at conjugate planes having a first object and image relationship in the direction parallel to the scanning direction while said first linear image and said point image are positioned at conjugate planes having a second object and image relationship in direction perpendicular to the scanning direction.
Claim 2
Dependent Claim
196 words
A light beam scanning system having a rotary multi-surfaced mirror comprising in order relative to a light source: (a) a uni-directional convergent optical element for converging an incident light beam to form on a reflection surface of said rotary multi-surfaced mirror a first linear image parallel to its scanning direction; (b) first convergent optical means for converging the light beam reflected by said multi-surfaced mirror to form a second linear image perpendicular to the scanning direction; (c) a uni-directional divergent optical element disposed at a position opposite to said first convergent optical means with respect to the second linear image, said divergent optical element being adapted to diverge the light beam in a direction perpendicular to the scanning direction; and (d) second convergent optical means for converging the light beam to form a point image on a scanning surface; whereby said second linear image and said point image are positioned at conjugate planes having a first object and image relationship in the direction parallel to the scanning direction while said first linear image and said point image are positioned at conjugate planes having a second object and image relationship in direction perpendicular to the scanning direction.
Claim 3
Dependent Claim
30 words
The light beam scanning system of claim 1 wherein said uni-directional convergent optical element comprises a convex cylindrical lens and said uni-directional divergent optical element comprises a concave cylindrical lens.
Claim 4
Dependent Claim
68 words
The light beam scanning system of either of claims 1 or 2 wherein the focal distances of said uni-directional divergent optical element is less than twice that of said second convergent optical means and the product of the focal distances of said uni-directional convergent optical element and said uni-directional divergent optical element are substantially equal to the square of the focal distance of said first convergent optical means.
References Cited (Backward Citations)
US3623789A
Cited
US3865465A
Cited
US3972582A
Cited
US4121883A
Cited
US4073566A
Cited
US4054361A
Cited
US4123135A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |