Patent US5557446A successfully refreshed from Google Patents.
US5557446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical scanning apparatus having tilted scanning lens system
Assignee: Canon Inc
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Filing: 1993-04-08
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Granted: 1996-09-17
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Expires: 2013-04-08
Abstract
Abstract In an optical scanning apparatus, there are arranged a light source, a first optical system for converting a light beam emitted from the light source to a convergent light beam, a deflector for deflecting the convergent light beam from the first optical system, and a second optical system for image-forming the convergent light beam deflected by the deflector as a spot on a surface to be scanned. The symmetrical axis of the second optical system with respect to a main-scanning direction is disposed so as to have an inclination relative to a normal to the scanned surface in a main-scan cross section. As a result, aberrations of the optical scanning apparatus, especially degradation of fθ characteristics due to backward and forward movement of a mirror surface caused by the rotation of the polygon mirror, which occur in an optical scanning system wherein a convergent, light beam is caused to enter the polygon mirror, are reduced.
Inventors
- 👤 Manabu Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:28
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/124
Claims Analysis
Total Claims: 72
Claim 1
Independent Claim
94 words
An optical scanning apparatus comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a deflector for deflecting the convergent light beam from said first optical system; and a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface as a spot, a symmetrical axis of said second optical system with respect to a main-scanning direction being inclined relative,to a normal to the scanned surface in a main-scan cross section.
Claim 2
Dependent Claim
94 words
An optical scanning apparatus comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a deflector for deflecting the convergent light beam from said first optical system; and a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface as a spot, a symmetrical axis of said second optical system with respect to a main-scanning direction being inclined relative,to a normal to the scanned surface in a main-scan cross section.
Claim 3
Dependent Claim
22 words
An optical scanning apparatus according to claim 1, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 4
Dependent Claim
17 words
An optical scanning apparatus according to claim 1, wherein said second optical system comprises a single lens.
Claim 5
Dependent Claim
25 words
An optical scanning apparatus according to claim 1, wherein said deflector is a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 6
Dependent Claim
110 words
An optical scanning apparatus comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface as a spot; and mounting portions for mounting said second optical system, said mounting portions being respectively disposed on either side of an optical axis of said second optical system, a line connecting between said mounting portions being inclined relative to a direction parallel with a main-scanning direction.
Claim 7
Dependent Claim
110 words
An optical scanning apparatus comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface as a spot; and mounting portions for mounting said second optical system, said mounting portions being respectively disposed on either side of an optical axis of said second optical system, a line connecting between said mounting portions being inclined relative to a direction parallel with a main-scanning direction.
Claim 8
Dependent Claim
17 words
An optical scanning apparatus according to claim 4, wherein said second optical system comprises a single lens.
Claim 9
Dependent Claim
25 words
An optical scanning apparatus according to claim 5, wherein said deflector is a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 10
Dependent Claim
117 words
An optical scanning apparatus comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface as a spot; and a reflector mirror interposed between said second optical system and the scanned surface, an angle formed between a symmetrical axis of said second optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section having a value other than 90 degrees.
Claim 11
Dependent Claim
117 words
An optical scanning apparatus comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface as a spot; and a reflector mirror interposed between said second optical system and the scanned surface, an angle formed between a symmetrical axis of said second optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section having a value other than 90 degrees.
Claim 12
Dependent Claim
22 words
An optical scanning apparatus according to claim 8, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 13
Dependent Claim
17 words
An optical scanning apparatus according to claim 8, wherein said second optical system comprises a single lens.
Claim 14
Dependent Claim
25 words
An optical scanning apparatus according to claim 8, wherein said deflector is a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 15
Dependent Claim
22 words
An optical scanning apparatus according to any one of claims 3, 6 or 10, wherein said single lens is a resin lens.
Claim 16
Dependent Claim
29 words
An optical scanning apparatus according to any one of claims 3, 6 or 10, wherein said single lens is designed to be symmetrical with respect to the optical axis.
Claim 17
Dependent Claim
28 words
An optical scanning apparatus according to any one of claims 3, 6 or 10, wherein a lens surface of said single lens is shaped into an aspherical surface.
Claim 18
Dependent Claim
37 words
An optical scanning apparatus according to any one of claims 1, 5 or 8, wherein said first optical system converts the light beam from said light source to a light beam convergent in the main-scan cross section.
Claim 19
Dependent Claim
101 words
A recording apparatus, comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a recording medium; a deflector for deflecting the convergent light beam from said first optical system; and a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface of the recording medium as a spot, a symmetrical axis of said second optical system with respect to a main-scanning direction being inclined relative to a normal to the scanned surface in a main-scan cross section.
Claim 20
Dependent Claim
101 words
A recording apparatus, comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a recording medium; a deflector for deflecting the convergent light beam from said first optical system; and a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface of the recording medium as a spot, a symmetrical axis of said second optical system with respect to a main-scanning direction being inclined relative to a normal to the scanned surface in a main-scan cross section.
Claim 21
Dependent Claim
21 words
A recording apparatus according to claim 16, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 22
Dependent Claim
16 words
A recording apparatus according to claim 16, wherein said second optical system comprises a single lens.
Claim 23
Dependent Claim
24 words
A recording apparatus according to claim 16, wherein said deflector is a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 24
Dependent Claim
116 words
A recording apparatus, comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a recording medium; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface of the recording medium as a spot; and mounting portions for mounting said second optical system, said mounting portions being respectively disposed on either side of an optical axis of said second optical system, a line connecting between said mounting portions being inclined relative to a direction parallel with a main-scanning direction.
Claim 25
Dependent Claim
116 words
A recording apparatus, comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a recording medium; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface of the recording medium as a spot; and mounting portions for mounting said second optical system, said mounting portions being respectively disposed on either side of an optical axis of said second optical system, a line connecting between said mounting portions being inclined relative to a direction parallel with a main-scanning direction.
Claim 26
Dependent Claim
16 words
A recording apparatus according to claim 20, wherein said second optical system comprises a single lens.
Claim 27
Dependent Claim
24 words
A recording apparatus according to claim 20, wherein said deflector is a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 28
Dependent Claim
123 words
A recording apparatus, comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a recording medium; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface of the recording medium as a spot; and a reflector mirror interposed between said second optical system and the scanned surface, an angle formed between a symmetrical axis of said second optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section having a value other than 90 degrees.
Claim 29
Dependent Claim
123 words
A recording apparatus, comprising: a light source for emitting a light beam; a first optical system for converting the light beam from said light source to a convergent light beam; a recording medium; a deflector for deflecting the convergent light beam from said first optical system; a second optical system for imaging the convergent light beam deflected by said deflector on a scanned surface of the recording medium as a spot; and a reflector mirror interposed between said second optical system and the scanned surface, an angle formed between a symmetrical axis of said second optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section having a value other than 90 degrees.
Claim 30
Dependent Claim
21 words
A recording apparatus according to claim 23, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 31
Dependent Claim
16 words
A recording apparatus according to claim 23, wherein said second optical system comprises a single lens.
Claim 32
Dependent Claim
24 words
A recording apparatus according to claim 23, wherein said deflector is a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 33
Dependent Claim
21 words
A recording apparatus according to any one of claims 18, 21 or 25, wherein said single lens is a resin lens.
Claim 34
Dependent Claim
28 words
A recording apparatus according to any one of claims 18, 21 or 25, wherein said single lens is designed to be symmetrical with respect to the optical axis.
Claim 35
Dependent Claim
27 words
A recording apparatus according to any one of claims 18, 21 or 25, wherein a lens surface of said single lens is shaped into an aspherical surface.
Claim 36
Dependent Claim
36 words
A recording apparatus according to any one of claims 16, 20 or 23, wherein said first optical system converts the light beam from said light source to a light beam convergent in the main-scan cross section.
Claim 37
Independent Claim
62 words
A method for scanning using an optical scanning apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; and inclining a symmetrical axis of said optical system with respect to a main-scanning direction relative to a normal to the scanned surface in a main-scan cross section.
Claim 38
Independent Claim
62 words
A method for scanning using an optical scanning apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; and inclining a symmetrical axis of said optical system with respect to a main-scanning direction relative to a normal to the scanned surface in a main-scan cross section.
Claim 39
Dependent Claim
19 words
The method of claim 31, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 40
Dependent Claim
13 words
The method of claim 31, wherein said optical system comprises a single lens.
Claim 41
Dependent Claim
29 words
A method according to claim 31, wherein said deflecting step deflects the convergent light beam with a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 42
Independent Claim
72 words
A method for scanning using an optical scanning apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; disposing mounting portions for mounting said optical system respectively on either side of an optical axis of said optical system; and inclining a line connecting between said mounting portions relative to a direction parallel with a main-scanning direction.
Claim 43
Independent Claim
72 words
A method for scanning using an optical scanning apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; disposing mounting portions for mounting said optical system respectively on either side of an optical axis of said optical system; and inclining a line connecting between said mounting portions relative to a direction parallel with a main-scanning direction.
Claim 44
Dependent Claim
13 words
The method of claim 35, wherein said optical system comprises a single lens.
Claim 45
Dependent Claim
29 words
A method according to claim 35, wherein said deflecting step deflects the convergent light beam with a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 46
Independent Claim
90 words
A method for scanning using an optical scanning apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; interposing a reflector mirror between said optical system and the scanned surface; and disposing said optical system so that an angle formed between a symmetrical axis of said optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section has a value other than 90 degrees.
Claim 47
Independent Claim
90 words
A method for scanning using an optical scanning apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; interposing a reflector mirror between said optical system and the scanned surface; and disposing said optical system so that an angle formed between a symmetrical axis of said optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section has a value other than 90 degrees.
Claim 48
Dependent Claim
19 words
The method of claim 38, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 49
Dependent Claim
13 words
The method of claim 38, wherein said optical system comprises a single lens.
Claim 50
Dependent Claim
29 words
A method according to claim 38, wherein said deflecting step deflects the convergent light beam with a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 51
Independent Claim
19 words
The method of any one of claims 33, 36 or 40, wherein said single lens is a resin lens.
Claim 52
Independent Claim
26 words
The method of any one of claims 33, 36 or 40, wherein said single lens is designed to be symmetrical with respect to the optical axis.
Claim 53
Independent Claim
25 words
The method of any one of claims 33, 36 or 40, wherein a lens surface of said single lens is shaped into an aspherical surface.
Claim 54
Independent Claim
26 words
The method of any one of claims 31, 35 or 38, wherein said deflecting step comprises deflecting the convergent light beam in the main-scan cross section.
Claim 55
Independent Claim
61 words
A method for recording using a recording apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; and inclining a symmetrical axis of said optical system with respect to a main-scanning direction relative to a normal to the scanned surface in a main-scan cross section.
Claim 56
Independent Claim
61 words
A method for recording using a recording apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; and inclining a symmetrical axis of said optical system with respect to a main-scanning direction relative to a normal to the scanned surface in a main-scan cross section.
Claim 57
Dependent Claim
19 words
The method of claim 46, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 58
Dependent Claim
13 words
The method of claim 46, wherein said optical system comprises a single lens.
Claim 59
Dependent Claim
29 words
A method according to claim 46, wherein said deflecting step deflects the convergent light beam with a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 60
Independent Claim
71 words
A method for recording using a recording apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; disposing mounting portions for mounting said optical system respectively on either side of an optical axis of said optical system; and inclining a line connection between said mounting portions relative to a direction parallel with a main-scanning direction.
Claim 61
Independent Claim
71 words
A method for recording using a recording apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; disposing mounting portions for mounting said optical system respectively on either side of an optical axis of said optical system; and inclining a line connection between said mounting portions relative to a direction parallel with a main-scanning direction.
Claim 62
Dependent Claim
13 words
The method of claim 50, wherein said optical system comprises a single lens.
Claim 63
Dependent Claim
29 words
A method according to claim 50, wherein said deflecting step deflects the convergent light beam with a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 64
Independent Claim
89 words
A method for recording using a recording apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; interposing a reflector mirror between said optical system and the scanned surface; and disposing said optical system so that an angle formed between a symmetrical axis of said optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section has a value other than 90 degrees.
Claim 65
Independent Claim
89 words
A method for recording using a recording apparatus, comprising the steps of: deflecting a convergent light beam; imaging the convergent light beam on a scanned surface as a spot by an optical system; interposing a reflector mirror between said optical system and the scanned surface; and disposing said optical system so that an angle formed between a symmetrical axis of said optical system with respect to a main-scanning direction and a mirror surface of said reflector mirror in a main-scan cross section has a value other than 90 degrees.
Claim 66
Dependent Claim
19 words
The method of claim 53, wherein the symmetrical axis with respect to the main-scanning direction is an optical axis.
Claim 67
Dependent Claim
13 words
The method of claim 53, wherein said optical system comprises a single lens.
Claim 68
Dependent Claim
29 words
A method according to claim 53, wherein said deflecting step deflects the convergent light beam with a polygon mirror and a mirror surface of said polygon mirror is flat.
Claim 69
Independent Claim
19 words
The method of any one of claims 48, 51 or 55, wherein said single lens is a resin lens.
Claim 70
Independent Claim
26 words
The method of any one of claims 48, 51 or 55, wherein said single lens is designed to be symmetrical with respect to the optical axis.
Claim 71
Independent Claim
25 words
The method of any one of claims 48, 51 or 55, wherein a lens surface of said single lens is shaped into an aspherical surface.
Claim 72
Independent Claim
26 words
The method of any one of claims 46, 50 or 53, wherein said deflecting step comprises deflecting the convergent light beam in the main-scan cross section.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-09-17 | 2000-03-18 | 2000-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-17 | 2004-03-18 | 2004-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-17 | 2008-03-18 | 2008-09-17 | $7700.00 | Window Closed / Lapsed |