Patent US5657147A successfully refreshed from Google Patents.
US5657147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical scanner
Assignee: Panasonic Holdings Corp
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Filing: 1995-07-24
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Granted: 1997-08-12
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Expires: 2015-07-24
Abstract
Abstract The optical scanner of this invention includes a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned. The second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned. A refractive power in the sub-scanning direction at the center of the correction lens in the scanning direction is different from that at the periphery thereof.
Inventors
- 👤 Motonobu Yoshikawa
- 👤 Yoshiharu Yamamoto
- 👤 Kazutake Boku
- 👤 Hironori Nakashima
- 👤 Akinori Yusa
- 👤 Ken Morishima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:25
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/125; G02B26/126
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
187 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an incident surface of the correction lens is a saddle toroidal surface having a profile defined by a circular arc which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and present in the plane including the optical axis.
Claim 2
Dependent Claim
187 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an incident surface of the correction lens is a saddle toroidal surface having a profile defined by a circular arc which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and present in the plane including the optical axis.
Claim 3
Dependent Claim
16 words
An optical scanner according to claim 1, wherein the curved mirror has an axial-symmetric aspherical surface.
Claim 4
Dependent Claim
35 words
An optical scanner according to claim 1, wherein, when a displacement of a vertex of the curved mirror from an optical axis is x m (mm), conditional formula (2) below is satisfied: 0.5<x.sub.m <5.0 (2)
Claim 5
Dependent Claim
76 words
An optical scanner according to claim 1, wherein, when a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and an incident surface of the-correction lens is M (mm), and the focal length of the second image formation optical system in the scanning direction is f m (mm), conditional formula (3) below is satisfied: ##EQU19##
Claim 6
Dependent Claim
47 words
An optical scanner according to claim 1, wherein a focal length of the second image formation optical system in the scanning direction is f m (mm), and an effective scanning width of the surface to be scanned is W (mm), conditional formula (6) below is satisfied: ##EQU20##
Claim 7
Dependent Claim
28 words
An optical scanner according to claim 1, wherein an emergent surface of the correction lens is a cylindrical surface having a refractive power only in the scanning direction.
Claim 8
Dependent Claim
47 words
An optical scanner according to claim 6, wherein an emergent surface of the correction lens is a aspherical cylindrical surface which has a refractive power only in the scanning direction and the section of the surface in the scanning direction has fourth or higher order development terms.
Claim 9
Dependent Claim
98 words
An optical scanner according to claim 7, wherein, when a focal length of the second image formation optical system in the scanning direction is f m (mm), an effective scanning width of the surface to be scanned is W (mm), a distance between a deflection point of the optical deflector and a reflection point of the curved mirror is L (mm), and a distance between an effective outermost position of the curved mirror in the scanning direction and a tangent plane of a vertex of the mirror surface is zm (mm), conditional formula (1) below is satisfied: ##EQU21##
Claim 10
Dependent Claim
35 words
An optical scanner according to claim 8, wherein, when a displacement of a vertex of the curved mirror from an optical axis is x m (mm), conditional formula (2) below is satisfied: 0.5<x.sub.m <5.0 (2)
Claim 11
Dependent Claim
77 words
An optical scanner according to claim 9, wherein, when a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and an incident surface of the correction lens is M (mm), and the focal length of the second image formation optical system in the scanning direction is f m (mm), conditional formula (3) below is satisfied: ##EQU22##
Claim 12
Dependent Claim
136 words
An optical scanner according to claim 10, wherein an angle formed by a plane vertical to a reflection surface the optical deflector and parallel to the scanning direction and an optical axis of the first image formation optical system is β p (deg.), a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and the incident surface of the correction lens is M (mm), a focal length of the second image formation optical system in the scanning direction is f m (mm), and a displacement of a center of the incident surface of the correction lens from the optical axis in the sub-scanning direction is x L (mm), conditional formula (4) below is satisfied: ##EQU23##
Claim 13
Dependent Claim
133 words
An optical scanner according to claim 11, wherein an angle formed by a plane vertical to a reflection surface of the optical deflector and parallel to the scanning direction and an optical axis of the first image formation optical system is β p (deg.), a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and an incident surface of the correction lens is M (mm), a focal length of the second image formation optical system in the scanning direction is f m (mm), and an angle formed by a normal to a vertex of the curved mirror and the optical axis is β m (deg.), conditional formula (5) below is satisfied: ##EQU24##
Claim 14
Dependent Claim
47 words
An optical scanner according to claim 12, wherein a focal length of the second image formation optical system in the scanning direction is f m (mm), and an effective scanning width of the surface to be scanned is W (mm), conditional formula (6) below is satisfied: ##EQU25##
Claim 15
Dependent Claim
12 words
An image formation apparatus using the optical scanner according to claim 1.
Claim 16
Dependent Claim
194 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an incident surface of the correction lens is a saddle toroidal surface having a profile defined by a curve having fourth or higher order development terms which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and is present in the plane including the optical axis.
Claim 17
Dependent Claim
194 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an incident surface of the correction lens is a saddle toroidal surface having a profile defined by a curve having fourth or higher order development terms which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and is present in the plane including the optical axis.
Claim 18
Dependent Claim
147 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an emergent surface of the correction lens is a cylindrical surface having a refractive power only in the scanning direction.
Claim 19
Dependent Claim
147 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an emergent surface of the correction lens is a cylindrical surface having a refractive power only in the scanning direction.
Claim 20
Dependent Claim
166 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an emergent surface of the correction lens is an aspherical cylindrical surface which has a refractive power only in the scanning direction and the section of the surface in the scanning direction has fourth or higher order development terms.
Claim 21
Dependent Claim
166 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an emergent surface of the correction lens is an aspherical cylindrical surface which has a refractive power only in the scanning direction and the section of the surface in the scanning direction has fourth or higher order development terms.
Claim 22
Dependent Claim
194 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an emergent surface of the correction lens is a barrel toroidal surface having a profile defined by a curve having fourth or higher order development terms which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and is present in the plane including the optical axis.
Claim 23
Dependent Claim
194 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an emergent surface of the correction lens is a barrel toroidal surface having a profile defined by a curve having fourth or higher order development terms which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and is present in the plane including the optical axis.
Claim 24
Dependent Claim
217 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein, when a focal length of the second image formation optical system in the scanning direction is f m (mm), an effective scanning width of the surface to be scanned is W (mm), a distance between a deflection point of the optical deflector and a reflection point of the curved mirror is L (mm), and a distance between an effective outermost position of the curved mirror in the scanning direction and a tangent plane of a vertex of the mirror surface is zm (mm), conditional formula (1) below is satisfied: ##EQU26##
Claim 25
Dependent Claim
217 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein, when a focal length of the second image formation optical system in the scanning direction is f m (mm), an effective scanning width of the surface to be scanned is W (mm), a distance between a deflection point of the optical deflector and a reflection point of the curved mirror is L (mm), and a distance between an effective outermost position of the curved mirror in the scanning direction and a tangent plane of a vertex of the mirror surface is zm (mm), conditional formula (1) below is satisfied: ##EQU26##
Claim 26
Dependent Claim
256 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an angle formed by a plane vertical to a reflection surface of the optical deflector and parallel to the scanning direction and an optical axis of the first image formation optical system is β p (deg.), a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and the incident surface of the correction lens is M (mm), a focal length of the second image formation optical system in the scanning direction is f m (mm), and a displacement of a center of the incident surface of the correction lens from the optical axis in the subscanning direction is x L (mm), conditional formula (4) below is satisfied: ##EQU27##
Claim 27
Dependent Claim
256 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an angle formed by a plane vertical to a reflection surface of the optical deflector and parallel to the scanning direction and an optical axis of the first image formation optical system is β p (deg.), a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and the incident surface of the correction lens is M (mm), a focal length of the second image formation optical system in the scanning direction is f m (mm), and a displacement of a center of the incident surface of the correction lens from the optical axis in the subscanning direction is x L (mm), conditional formula (4) below is satisfied: ##EQU27##
Claim 28
Dependent Claim
252 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an angle formed by a plane vertical to a reflection surface of the optical deflector and parallel to the scanning direction and an optical axis of the first image formation optical system is β p (deg.), a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and an incident surface of the correction lens is M (mm), a focal length of the second image formation optical system in the scanning direction is f m (mm), and an angle formed by a normal to a vertex of the curved mirror and the optical axis is β p (deg.), conditional formula (5) below is satisfied: ##EQU28##
Claim 29
Dependent Claim
252 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an angle formed by a plane vertical to a reflection surface of the optical deflector and parallel to the scanning direction and an optical axis of the first image formation optical system is β p (deg.), a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and an incident surface of the correction lens is M (mm), a focal length of the second image formation optical system in the scanning direction is f m (mm), and an angle formed by a normal to a vertex of the curved mirror and the optical axis is β p (deg.), conditional formula (5) below is satisfied: ##EQU28##
Claim 30
Dependent Claim
194 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an incident surface of the correction lens is a saddle toroidal surface having a profile defined by a curve having fourth or higher order development terms which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and is present in the plane including the optical axis.
Claim 31
Dependent Claim
194 words
An optical scanner comprising a light source, an optical deflector for scanning a light flux from the light source, a first image formation optical system disposed between the light source and the optical deflector, and a second image formation optical system disposed between the optical deflector and a surface to be scanned, wherein the second image formation optical system includes a curved mirror for reflecting a light flux from the optical deflector and a correction lens for converging the light flux from the curved mirror on the surface to be scanned, a refractive power in a sub-scanning direction at a center of the correction lens in a scanning direction being different from a refractive power in a sub-scanning direction at a periphery of the correction lens, wherein an incident surface of the correction lens is a saddle toroidal surface having a profile defined by a curve having fourth or higher order development terms which is present in a plane parallel to the scanning direction and including an optical axis, and is rotated around a rotational symmetric axis which is parallel to the scanning direction and is present in the plane including the optical axis.
Claim 32
Dependent Claim
16 words
An optical scanner according to claim 22, wherein the curved mirror has an axial-symmetric aspherical surface.
Claim 33
Dependent Claim
35 words
An optical scanner according to claim 22, wherein, when a displacement of a vertex of the curved mirror from an optical axis is x m (mm), conditional formula (2) below is satisfied: 0.5<x.sub.m <5.0 (2)
Claim 34
Dependent Claim
77 words
An optical scanner according to claim 22, wherein, when a distance between a reflection point of the optical deflector and a reflection point of the curved mirror is L (mm), a distance between the reflection point of the curved mirror and an incident surface of the correction lens is M (mm), and the focal length of the second image formation optical system in the scanning direction is f m (mm), conditional formula (3) below is satisfied: ##EQU29##
Claim 35
Dependent Claim
47 words
An optical scanner according to claim 22, wherein a focal length of the second image formation optical system in the scanning direction is f m (mm), and an effective scanning width of the surface to be scanned is W (mm), conditional formula (6) below is satisfied: ##EQU30##
Claim 36
Dependent Claim
12 words
An image formation apparatus using the optical scanner according to claim 22.
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