US4906061A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collimated light beam scanning method including curvature of field correction
Assignee: Ricoh Co Ltd
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Filing: 1988-06-24
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Granted: 1990-03-06
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Expires: 2008-06-24
Abstract
Abstract A laser beam from a laser beam source is applied via a collimator lens to a rotating light deflector, deflected by the light deflector, and applied via an fθ lens to a surface to scan the same. The fθ lens comprises a single-element lens with its fθ characteristics well corrected. To correct the curvature of field by the fθ lens, the collimator lens is vibrated in simple harmonic motion along the optical axis thereof, or the laser beam source is vibrated in simple harmonic motion along the optical axis of the collimator lens, in synchronism with the scanning of the surface with the laser beam.
Inventors
- 👤 Katsumi Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:21
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/125; G02B13/00; G02B13/0005
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
140 words
A light scanning method of scanning a surface with a light beam by applying the light beam from a laser beam source through a collimator lens to rotating light deflector means, deflecting the light beam with said light deflector means, and applying the deflected light beam to said surface through an fθ lens, said method comprising: making one of said collimator lens and said laser beam source movable in the directions of the optical axis of the collimator lens, and employing as the fθ lens a single-element lens with fθ characteristics well corrected; and vibrating a movable one of the collimator lens and the laser beam source in simple harmonic motion in said directions of the optical axis in synchronism with the scanning of the surface with the light beam, for correcting the curvature of field of said fθ lens.
Claim 2
Dependent Claim
140 words
A light scanning method of scanning a surface with a light beam by applying the light beam from a laser beam source through a collimator lens to rotating light deflector means, deflecting the light beam with said light deflector means, and applying the deflected light beam to said surface through an fθ lens, said method comprising: making one of said collimator lens and said laser beam source movable in the directions of the optical axis of the collimator lens, and employing as the fθ lens a single-element lens with fθ characteristics well corrected; and vibrating a movable one of the collimator lens and the laser beam source in simple harmonic motion in said directions of the optical axis in synchronism with the scanning of the surface with the light beam, for correcting the curvature of field of said fθ lens.
Claim 3
Dependent Claim
18 words
A light scanning method according to claim 1, wherein the collimator lens is vibrated in simple harmonic motion.
Claim 4
Dependent Claim
19 words
A light scanning method according to claim 1, wherein the laser beam source is vibrated in simple harmonic motion.
Claim 5
Dependent Claim
20 words
A light scanning method according to claim 1, 2, or 3, wherein the laser beam source comprises a laser diode.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |