US4592622A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-beam scanning apparatus
Assignee: Koki Holdings Co Ltd
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Filing: 1984-02-08
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Granted: 1986-06-03
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Expires: 2004-02-08
Abstract
Abstract A light-beam scanning apparatus is disclosed in which a mirror surface of a metal having a characteristic that the reflectance of the mirror surface increases as the incident angle of light incident on the mirror surface is larger, is used as a reflecting surface, the optical thickness nd of a transparent protective film formed on the reflecting surface is made substantially equal to mλ/2 (where n, d, m and λ indicate the refractive index of the protective film, the thickness of the protective film, an integer, and the wavelength of the incident light, respectively), the incident light is linearly-polarized light, and the direction of vibration of the linearly-polarized light is inclined at an angle of about +40° to -40° to a direction perpendicular to the plane of incidence of the linearly-polarized light.
Inventors
- 👤 Akira Hashimoto
- 👤 Susumu Saito
- 👤 Akira Arimoto
- 👤 Kenji Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:01
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/08; G02B5/09
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
175 words
A light-beam scanning apparatus comprising: a reflecting surface made of a metal and having a characteristic that the reflectance of said reflecting surface increases as the incident angle of light incident on said reflecting surface is larger, said incident light being linearly-polarized light, the direction of vibration of said linearly-polarized light being inclined at an angle of about +45° to -45° to a direction perpendicular to the plane of incidence of said linearly-polarized light; a transparent protective film formed on said reflecting surface and having an optical thickness nd substantially equal to mλ/2 (where n, d, m, and λ indicate the refractive index of said transparent protective film, the thickness of said transparent film, an integer, and the wavelength of said incident light, respectively); and means for deflecting said reflecting surface, the incident angle of said light incident on said transparent protective film being varied in an angular range less than 70°, to provide scanning light so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 2
Dependent Claim
175 words
A light-beam scanning apparatus comprising: a reflecting surface made of a metal and having a characteristic that the reflectance of said reflecting surface increases as the incident angle of light incident on said reflecting surface is larger, said incident light being linearly-polarized light, the direction of vibration of said linearly-polarized light being inclined at an angle of about +45° to -45° to a direction perpendicular to the plane of incidence of said linearly-polarized light; a transparent protective film formed on said reflecting surface and having an optical thickness nd substantially equal to mλ/2 (where n, d, m, and λ indicate the refractive index of said transparent protective film, the thickness of said transparent film, an integer, and the wavelength of said incident light, respectively); and means for deflecting said reflecting surface, the incident angle of said light incident on said transparent protective film being varied in an angular range less than 70°, to provide scanning light so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 3
Dependent Claim
26 words
A light-beam scanning apparatus according to claim 1, wherein said transparent protective film is an oxide film which is formed on said metal by anodic oxidation.
Claim 4
Dependent Claim
15 words
A light-beam scanning apparatus according to claim 2, wherein said metal is an aluminum-magnesium alloy.
Claim 5
Dependent Claim
154 words
A light-beam scanning apparatus comprising: a mirror with a reflecting surface made of metal for reflecting a light incident at an incident angle of not more than 70°, an anodic oxide film formed on said reflecting surface and having an optical thickness n d substantially equal to mλ/2 (wherein n, d, m, λ indicate the refractive index of said oxide film, the thickness of said oxide film a positive integer, and the wavelength of said incident light, respectively), and means for deflecting said reflecting surface, said incident light being near polarized light and the direction of vibration of said linear polarized light being inclined at an angle of about +40° to -40° to a direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 6
Dependent Claim
154 words
A light-beam scanning apparatus comprising: a mirror with a reflecting surface made of metal for reflecting a light incident at an incident angle of not more than 70°, an anodic oxide film formed on said reflecting surface and having an optical thickness n d substantially equal to mλ/2 (wherein n, d, m, λ indicate the refractive index of said oxide film, the thickness of said oxide film a positive integer, and the wavelength of said incident light, respectively), and means for deflecting said reflecting surface, said incident light being near polarized light and the direction of vibration of said linear polarized light being inclined at an angle of about +40° to -40° to a direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 7
Dependent Claim
14 words
A light-beam scanning apparatus according to claim 5, wherein said metal is aluminum-magnesium alloy.
Claim 8
Dependent Claim
16 words
A light-beam scanning apparatus according to claim 5, wherein said mirror is a rotating polygonal mirror.
Claim 9
Dependent Claim
27 words
A light-beam scanning apparatus according to claim 5, wherein said reflecting surface has a fine mirror surface obtained by a very fine cutting using a diamond tool.
Claim 10
Dependent Claim
33 words
A light-beam scanning apparatus according to claim 5, wherein said anodic oxide film is formed by growing aluminum oxide from said fine mirror surface of Al-Mg alloy using sulfuric acid as an electrolyte.
Claim 11
Dependent Claim
55 words
A light-beam scanning apparatus according to claim 5, wherein said direction of vibration of said linear polarized light is inclined at an angle of about +40° to +45° or -40° to -45° to the direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film.
Claim 12
Dependent Claim
159 words
A light-beam scanning apparatus comprising: a rotating polygonal mirror with a plurality of reflecting surfaces made of metal for reflecting a light incident at an incident angle of not more than 70°, an anodic oxide film formed on said reflecting surface and having an optical thickness n d substantially equal to mλ/2 ( where n, d, m, λ indicate the refractive index of said oxide film, the thickness of said oxide film, a positive integer, and the wavelength of said incident light, respectively), and means for deflecting said reflecting surface, said incident light being linear polarized light and the direction of vibration of said linear polarized light being inclined at an angle of about +40° to -40° to a direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 13
Dependent Claim
159 words
A light-beam scanning apparatus comprising: a rotating polygonal mirror with a plurality of reflecting surfaces made of metal for reflecting a light incident at an incident angle of not more than 70°, an anodic oxide film formed on said reflecting surface and having an optical thickness n d substantially equal to mλ/2 ( where n, d, m, λ indicate the refractive index of said oxide film, the thickness of said oxide film, a positive integer, and the wavelength of said incident light, respectively), and means for deflecting said reflecting surface, said incident light being linear polarized light and the direction of vibration of said linear polarized light being inclined at an angle of about +40° to -40° to a direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 14
Dependent Claim
14 words
A light-beam scanning apparatus according to claim 10, wherein said metal is aluminum-magnesium alloy.
Claim 15
Dependent Claim
27 words
A light-beam scanning apparatus according to claim 11, wherein said reflecting surface has a fine mirror surface obtained by a very fine cutting using a diamond tool.
Claim 16
Dependent Claim
34 words
A light-beam scanning apparatus according to claim 12, wherein said anodic oxide film is formed by growing aluminum oxide from said film mirror surface of said Al-Mg alloy using sulfuric acid as an electrolyte.
Claim 17
Dependent Claim
55 words
A light-beam scanning apparatus according to claim 11, wherein said direction of vibration of said linear polarized light is inclined at an angle of about +40° to +45° or -40° to -45° to the direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film.
Claim 18
Dependent Claim
173 words
A light-beam scanning apparatus of a laser printer for providing substantially constant beam intensity of a scanning light for various angles of incidence, comprising: a mirror with a reflecting surface made of metal for reflecting a light-beam incident at an incident angle of not more than 70°, an anodic oxide film formed on said reflecting surface and having an optical thickness n d substantially equal to mλ/2 (wherein n, d, m, λ indicate the refractive index of said oxide film, the thickness of said oxide film a positive integer, and the wavelength of said incident light, respectively), and means for deflecting said reflecting surface, said incident light being linear polarized light and the direction of vibration of said linear polarized light being inclined at an angle of about +40° to -40° to a direction perpendicular to the palen of incidence of said linear polarized light in response to the thickness of said oxide film so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 19
Dependent Claim
173 words
A light-beam scanning apparatus of a laser printer for providing substantially constant beam intensity of a scanning light for various angles of incidence, comprising: a mirror with a reflecting surface made of metal for reflecting a light-beam incident at an incident angle of not more than 70°, an anodic oxide film formed on said reflecting surface and having an optical thickness n d substantially equal to mλ/2 (wherein n, d, m, λ indicate the refractive index of said oxide film, the thickness of said oxide film a positive integer, and the wavelength of said incident light, respectively), and means for deflecting said reflecting surface, said incident light being linear polarized light and the direction of vibration of said linear polarized light being inclined at an angle of about +40° to -40° to a direction perpendicular to the palen of incidence of said linear polarized light in response to the thickness of said oxide film so that the intensity of light reflected from said reflecting surface is maintained substantially constant in a scanning range.
Claim 20
Dependent Claim
18 words
A light-beam scanning apparatus of a laser printer according to claim 15, wherein said metal is aluminum-magnesium alloy.
Claim 21
Dependent Claim
31 words
A light-beam scanning apparatus of a laser printer according to claim 16, wherein said reflecting surface has a fine mirror surface obtained by a very fine cutting using a diamond tool.
Claim 22
Dependent Claim
16 words
A light-beam scanning apparatus according to claim 15, wherein said mirror is a rotating polygonal mirror.
Claim 23
Dependent Claim
38 words
A light-beam scanning apparatus of a laser printer according to claim 15, wherein said anodic oxide film is formed by growing aluminum oxide from said fine mirror surface of said aluminum-magnesium alloy using sulfuric acid as an electrolyte.
Claim 24
Dependent Claim
59 words
A light-beam scanning apparatus of a laser printer according to claim 15, wherein said direction of vibration of said linear polarized light is inclined at an angle of about +40° to +45° or -40° to -45° to the direction perpendicular to the plane of incidence of said linear polarized light in response to the thickness of said oxide film.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-02 | 1989-12-02 | 1990-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-02 | 1993-12-02 | 1994-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-02 | 1997-12-02 | 1998-06-03 | $7700.00 | Window Closed / Lapsed |