US4776654A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scanning optical system
Assignee: Pentax Corp
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Filing: 1987-04-07
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Granted: 1988-10-11
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Expires: 2007-04-07
Abstract
Abstract A scanning optical device including a rotating polygonal mirror or oscillating mirror. Two acoustooptical devices are disposed along the path between the light source and the mirror and are set for respective time-constant angles of deflection to compensate for tilting of the mirror without introducing an offset.
Inventors
- 👤 Tazuko Ishizuka
- 👤 Akira Morimoto
- 👤 Yuji Matui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:17
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/0025; G02B27/0031; G02F; G02F1/00; G02F1/01; G02F1/11
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
189 words
A scanning optical system, comprising: reflecting means including either a rotating polygonal mirror or an oscillating mirror rotating or oscillating along a first direction; a light source; a first lens system for condensing light issuing from said light source; a first acoustooptical device which is disposed at, or near, the position where light is condensed by said first lens system; a second lens system which condenses the light that has passed through said first acoustooptical device; a second acoustooptical device which is disposed at a position that is spaced by a predetermined distance from the position where light is condensed by said second lens system; and a third lens system which allows the light that has passed through said second acoustooptical device to fall upon a reflecting surface of said reflecting means; wherein non-zero constant angles of deflection in a second direction perpendicular to said first direction achieved by said second and first acoustooptical devices are determined according to an amount of tilting of a face of said reflecting surface of said reflecting means and for an offset in incident position of light falling upon said reflecting surface respectively.
Claim 2
Dependent Claim
189 words
A scanning optical system, comprising: reflecting means including either a rotating polygonal mirror or an oscillating mirror rotating or oscillating along a first direction; a light source; a first lens system for condensing light issuing from said light source; a first acoustooptical device which is disposed at, or near, the position where light is condensed by said first lens system; a second lens system which condenses the light that has passed through said first acoustooptical device; a second acoustooptical device which is disposed at a position that is spaced by a predetermined distance from the position where light is condensed by said second lens system; and a third lens system which allows the light that has passed through said second acoustooptical device to fall upon a reflecting surface of said reflecting means; wherein non-zero constant angles of deflection in a second direction perpendicular to said first direction achieved by said second and first acoustooptical devices are determined according to an amount of tilting of a face of said reflecting surface of said reflecting means and for an offset in incident position of light falling upon said reflecting surface respectively.
Claim 3
Dependent Claim
33 words
A scanning optical system according to claim 1 wherein said constant angle of deflection of said first acoustooptical device is made equal to said constant angle of deflection of said second acoustooptical device.
Claim 4
Dependent Claim
73 words
A scanning optical system as recited in claim 1, wherein said second lens system comprises two lens units having respective focal lengths f 2 and f 3 , said third lens system has a focal length f 4 , said predetermined distance is l and said constant angles of deflection of said first and second acoustooptical device are respectively θ M1 and l M2 and are substantially related as θ.sub.M1 =[f.sub.3 ·(l+f.sub.4)/(f.sub.2 f.sub.4)]·θ.sub.M2.
Claim 5
Dependent Claim
50 words
A scanning optical system as recited in claim 1, wherein a signal having a variable frequency is applied to said first acoustooptical device, said variable frequency being a sum of a constant frequency providing said non-zero constant angle of deflection for said first acoustooptical device, and a binary-valued modulation frequency.
References Cited (Backward Citations)
US4180822A
Cited
EP0007197A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-11 | 1992-04-11 | 1992-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-11 | 1996-04-11 | 1996-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-11 | 2000-04-11 | 2000-10-11 | $7700.00 | Window Closed / Lapsed |