US5055663A
Expired / Lapsed
US
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Optical scanning system and method for adjusting thereof
Assignee: Pentax Corp
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Filing: 1989-06-28
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Granted: 1991-10-08
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Expires: 2009-06-28
Abstract
Abstract An optical scanning system has a deflector for deflecting a beam emitted from a light source portion, a telecentric scanning lens for focusing the deflected beam onto a scanning surface, a beam splitter for splitting a beam reflected by the scanning surface on an optical path between the deflector and the light source portion from an outgoing optical path, and a focus point detector for receiving the beam split by the beam splitter and detecting a focused state of the beam on the scanning surface.
Inventors
- 👤 Akira Morimoto
- 👤 Akira Ohwaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:26
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/0005; G02B13/22
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
114 words
An optical scanning system, comprising: a light source portion for emitting a beam of light; a deflector for deflecting said beam of light emitted from said light source portion; a telecentric scanning lens for focusing said deflected beam of light onto a scanning surface; a beam splitter for splitting a beam of light reflected by said scanning surface, said beam splitter being disposed along an optical path between said deflector and said light source portion; and focus point detecting means for receiving a beam of light reflected by said scanning surface and split by said beam splitter, said detecting means detecting a focusing state of said deflected beam of light on said scanning surface.
Claim 2
Dependent Claim
114 words
An optical scanning system, comprising: a light source portion for emitting a beam of light; a deflector for deflecting said beam of light emitted from said light source portion; a telecentric scanning lens for focusing said deflected beam of light onto a scanning surface; a beam splitter for splitting a beam of light reflected by said scanning surface, said beam splitter being disposed along an optical path between said deflector and said light source portion; and focus point detecting means for receiving a beam of light reflected by said scanning surface and split by said beam splitter, said detecting means detecting a focusing state of said deflected beam of light on said scanning surface.
Claim 3
Dependent Claim
33 words
An optical scanning system according to claim 1, wherein said light source portion comprises a semiconductor laser that generates a divergent laser beam, and a collimator lens for collimating said divergent laser beam.
Claim 4
Dependent Claim
18 words
An optical scanning system according to claim 1, wherein said telecentric scanning lens comprises a telecentric fθ lens.
Claim 5
Dependent Claim
17 words
An optical scanning system according to claim 1, wherein said beam splitter comprises a polarized beam splitter.
Claim 6
Dependent Claim
73 words
An optical scanning system according to claim 1, wherein said focus point detecting means comprises an anamorphotic system for focusing said beam of light split by said beam splitter, such that a vertical power differs from a horizontal power, and a light receiving element that is disposed at a spot position of said focused beam of light and which is adapted to detect a deformation of a configuration of said beam of light.
Claim 7
Dependent Claim
41 words
An optical scanning system according to claim 1, wherein said light source portion comprises a gas laser for generating a parallel laser beam, a modulator for modulating said parallel laser beam, and a beam expander for dilating said parallel laser beam.
Claim 8
Dependent Claim
16 words
An optical scanning system according to claim 6, wherein said gas laser comprises an argon laser.
Claim 9
Dependent Claim
41 words
An optical scanning system according to claim 1, further comprising focus point adjusting means for changing a focused position of said beam of light focused by said scanning lens in accordance with an output power of said focus point detecting means.
Claim 10
Dependent Claim
64 words
An optical scanning system according to claim 8, wherein said light source portion comprises a gas laser for generating a parallel laser beam, a modulator for modulating said parallel laser beam, and a beam expander for dilating said parallel laser beam, said focus point adjusting means causing a part of said beam expander to be moved along an optical axis of said beam expander.
Claim 11
Dependent Claim
53 words
An optical scanning system according to claim 8, wherein said light receiving portion comprises a semiconductor laser for generating a divergent laser beam, and a collimator lens for collimating said divergent laser beam, said focus point adjusting means causing said semiconductor laser to be moved along an optical axis of said semiconductor laser.
Claim 12
Dependent Claim
103 words
An optical scanning system according to claim 1, wherein said telecentric fθ lens comprises, in order from an object field side to an image field, a first lens group having a negative meniscus lens with a concave surface thereof that faces towards an object field; a second lens group having four positive lenses, the positive lens nearest to said object field side being a positive meniscus lens with a concave surface thereof that faces towards said object field side; and, a third lens group having a meniscus lens of a weak power with a concave surface thereof that faces towards said image field.
Claim 13
Dependent Claim
76 words
An optical scanning system according to claim 11, wherein said telecentric fθ lens satisfies the equations: 0.80<|f1|/f2.50, f1<0; 0.50<|f2|/f<1.10; -0.5<f/f3<0.04; 0.25<|r1|/f<0.65, r1<0; and 0.60<rL/f<1.20, wherein f is a focus length of said optical scanning system, f1, f2 and f3 are focus lengths of said first lens group, second lens group and third lens group, respectively, r1 is a radius of curvature of a first plane, and rL is a radius of curvature of a final plane.
Claim 14
Dependent Claim
94 words
A telecentric fθ lens comprising, in order from an object field side to an image field, a first lens group having a negative meniscus lens with a concave surface thereof that faces towards an object field; a second lens group having four positive lenses, the positive lens nearest to said object field side being a positive meniscus lens with a concave surface thereof that faces towards said object field side; and, a third lens group having a meniscus lens of a weak power with a concave surface thereof that faces towards said image field.
Claim 15
Dependent Claim
94 words
A telecentric fθ lens comprising, in order from an object field side to an image field, a first lens group having a negative meniscus lens with a concave surface thereof that faces towards an object field; a second lens group having four positive lenses, the positive lens nearest to said object field side being a positive meniscus lens with a concave surface thereof that faces towards said object field side; and, a third lens group having a meniscus lens of a weak power with a concave surface thereof that faces towards said image field.
Claim 16
Dependent Claim
76 words
The telecentric fθ lens according to claim 13, wherein said telecentric fθ lens satisifies the equations: 0.80<|f1|/f2.50, f1<0; 0.50<|f2|/f<1.10; -0.5<f/f3<0.04; 0.25<|r1|/f<0.65, r1<0; and 0.60<rL/f<1.20, wherein f is a focus length of said optical scanning system, f1, f2 and f3 are focus lengths of said first lens group, second lens group and third lens group, respectively, r1 is a radius of curvature of a first plane, and rL is a radius of curvature of a final plane.
Claim 17
Independent Claim
136 words
A method for adjusting an optical scanning system, comprising the steps of: emitting a beam of light from a light source portion; deflecting the beam of light emitted from said light source portion with a deflector; focusing the deflected beam of light onto a scanning surface with a telecentric scanning lens; splitting a beam of light reflected by the scanning surface and returned to a light source side of the light source portion through the scanning lens and the deflector with a beam splitter; receiving the beam of light split by the beam splitter so as to detect a focused state of the beam of light deflected onto the scanning surface; and adjusting optical elements of the optical scanning system based upon the detected focused state of the beam of light deflected onto the scanning surface.
Claim 18
Independent Claim
136 words
A method for adjusting an optical scanning system, comprising the steps of: emitting a beam of light from a light source portion; deflecting the beam of light emitted from said light source portion with a deflector; focusing the deflected beam of light onto a scanning surface with a telecentric scanning lens; splitting a beam of light reflected by the scanning surface and returned to a light source side of the light source portion through the scanning lens and the deflector with a beam splitter; receiving the beam of light split by the beam splitter so as to detect a focused state of the beam of light deflected onto the scanning surface; and adjusting optical elements of the optical scanning system based upon the detected focused state of the beam of light deflected onto the scanning surface.
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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) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
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