US4097125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming optical system
Assignee: Canon Inc
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Filing: 1976-07-01
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Granted: 1978-06-27
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Expires: 1996-07-01
Abstract
Abstract An optical system for forming an image of an object with extremely small aberrations at unit magnification including a concave mirror and a convex mirror having a smaller radius of curvature than that of the concave mirror and arranged in face-to-face relation to the concave mirror. To minimize the difference between the absolute values of inclination angle of the sagittal image surface and meridional image surface with respect to a common plane parallel to the optical axis at points of intersection therebetween, that is, at points where the astigmatic difference is zero, the center of the convex mirror is spaced from that of the concave mirror toward the concave mirror, whereby a light ray from an object located at a height dependent upon the axial separation between the concave and convex mirrors is reflected from the concave mirror to the convex mirror, then therefrom reflected to the concave mirror and then therefrom reflected again to form an image having a high resolution over a wide range of image width.
Inventors
- 👤 Akiyoshi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:50
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70216; G03F7/70233; G02; G02B; G02B17/00; G02B17/02; G02B17/06; G02B17/0605; G02B17/0615
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
107 words
An image forming optical system comprising; (a) a concave mirror; (b) a convex mirror having a smaller radius of curvature than that of said concave mirror and arranged in face-to-face relation with said concave mirror at a location such that the center of curvature of said convex mirror is spaced from that of said concave mirror toward said concave mirror, and (c) said concave mirror comprising means for reflecting radiation incident on said optical system to said convex mirror and for reflecting said radiation from said convex mirror out of said optical system in a direction generally opposite that of said radiation incident on said optical system.
Claim 2
Dependent Claim
107 words
An image forming optical system comprising; (a) a concave mirror; (b) a convex mirror having a smaller radius of curvature than that of said concave mirror and arranged in face-to-face relation with said concave mirror at a location such that the center of curvature of said convex mirror is spaced from that of said concave mirror toward said concave mirror, and (c) said concave mirror comprising means for reflecting radiation incident on said optical system to said convex mirror and for reflecting said radiation from said convex mirror out of said optical system in a direction generally opposite that of said radiation incident on said optical system.
Claim 3
Dependent Claim
80 words
An image forming optical system according to claim 1, satisfying the following conditions: ##EQU5## where R is the radius of curvature of said concave mirror; r is the radius of curvature of said convex mirror; h is the desired height of an image point of optimum quality from the line passing through the centers of curvature of said convex and said concave mirrors; and Δ is the distance between the centers of curvature of said concave and said convex mirrors.
Claim 4
Dependent Claim
157 words
An image forming optical system comprising; (a) a concave mirror; (b) a convex mirror having a smaller radius of curvature than that of said concave mirror and arranged in face-to-face relation with said concave mirror at a location such that the reflection surface of said convex mirror substantially includes a point at which a light ray parallel to the optical axis of the system after being reflected from said concave mirror at a height equal to the desired height of an image point of optimum quality intersects the optical axis, the center of curvature of said convex mirror being spaced from that of said concave mirror toward said concave mirror, and (c) said concave mirror comprising means for reflecting radiation incident on said optical system to said convex mirror and for reflecting said radiation from said convex mirror out of said optical system in a direction generally opposite that of said radiation incident on said optical system.
Claim 5
Dependent Claim
157 words
An image forming optical system comprising; (a) a concave mirror; (b) a convex mirror having a smaller radius of curvature than that of said concave mirror and arranged in face-to-face relation with said concave mirror at a location such that the reflection surface of said convex mirror substantially includes a point at which a light ray parallel to the optical axis of the system after being reflected from said concave mirror at a height equal to the desired height of an image point of optimum quality intersects the optical axis, the center of curvature of said convex mirror being spaced from that of said concave mirror toward said concave mirror, and (c) said concave mirror comprising means for reflecting radiation incident on said optical system to said convex mirror and for reflecting said radiation from said convex mirror out of said optical system in a direction generally opposite that of said radiation incident on said optical system.
Claim 6
Dependent Claim
64 words
An image forming optical system according to claim 3, satisfying the following conditions: ##EQU6## where R is the radius of curvature of said concave mirror; r is the radius of curvature of said convex mirror; h is the desired height of an image point of optimum quality, and Δ is the distance between the centers of curvature of said concave and said convex mirrors.
Claim 7
Dependent Claim
28 words
An image forming optical system according to claim 3, wherein said convex mirror has a radius of curvature substantially equal to 1/2 times that of said concave mirror.
Claim 8
Dependent Claim
164 words
An image forming optical system comprising: (a) a concave mirror; (b) a convex mirror having a smaller radius of curvature than that of said concave mirror and arranged in face-to-face relation with said concave mirror at a location such that the center of curvature of said convex mirror is spaced from that of said concave mirror toward said concave mirror; and (c) said concave mirror and said convex mirror comprising means for reflecting radiation incident on said optical system from an object positioned at a position deviating from the optical axis of the optical system from said concave mirror to said convex mirror, and reflected from said concave mirror to a location outside said optical system to form an image at an image point at the opposite side of said object point in respect to the optical axis of said optical system, the optical path for the radiation from said object point to the image point being summetrical with respect to said convex mirror.
Claim 9
Dependent Claim
164 words
An image forming optical system comprising: (a) a concave mirror; (b) a convex mirror having a smaller radius of curvature than that of said concave mirror and arranged in face-to-face relation with said concave mirror at a location such that the center of curvature of said convex mirror is spaced from that of said concave mirror toward said concave mirror; and (c) said concave mirror and said convex mirror comprising means for reflecting radiation incident on said optical system from an object positioned at a position deviating from the optical axis of the optical system from said concave mirror to said convex mirror, and reflected from said concave mirror to a location outside said optical system to form an image at an image point at the opposite side of said object point in respect to the optical axis of said optical system, the optical path for the radiation from said object point to the image point being summetrical with respect to said convex mirror.
References Cited (Backward Citations)
US2684015A
Cited
US3748015A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |