Patent US4457616A successfully refreshed from Google Patents.
US4457616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable magnification optical apparatus
Assignee: Canon Inc
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Filing: 1982-02-01
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Granted: 1984-07-03
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Expires: 2002-02-01
Abstract
Abstract A variable magnification optical apparatus for projecting an image at a first plane onto a second plane includes an optical system for forming an image of the first plane on the second plane, a first mirror disposed between the image-forming optical system and the first plane and a second mirror disposed between the image-forming optical system and the second plane. When the magnification is changed, the first mirror is rotated by a determined angle of θ and the second mirror is moved in a determined direction while rotating also by the same angle θ. The image-forming optical system is moved in the direction along its optical axis and is rotated by an angle two times larger than the rotation angle θ of the first mirror at the same time.
Inventors
- 👤 Mitsuhiro Tokuhara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:37
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/041
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
144 words
An optical apparatus for projecting an image in a first plane onto a second plane and provided with variable magnification means comprising: an optical system for forming an image of the first plane on the second plane; a first mirror disposed between the first plane and said image-forming optical system and rotatable, at a fixed position, by a determined angle θ upon a change of magnification; a second mirror disposed between said image-forming optical system and the second plane and rotatable by the same rotation angle θ as said first mirror upon a change of magnification while at the same time translationally moving in a determined direction; and wherein said image-forming optical system is rotated by an angle two times larger than the rotation angle θ of said first mirror and is also translationally moved along its optical axis when the magnification is changed.
Claim 2
Dependent Claim
144 words
An optical apparatus for projecting an image in a first plane onto a second plane and provided with variable magnification means comprising: an optical system for forming an image of the first plane on the second plane; a first mirror disposed between the first plane and said image-forming optical system and rotatable, at a fixed position, by a determined angle θ upon a change of magnification; a second mirror disposed between said image-forming optical system and the second plane and rotatable by the same rotation angle θ as said first mirror upon a change of magnification while at the same time translationally moving in a determined direction; and wherein said image-forming optical system is rotated by an angle two times larger than the rotation angle θ of said first mirror and is also translationally moved along its optical axis when the magnification is changed.
Claim 3
Dependent Claim
147 words
An optical apparatus for projecting an image in a first plane onto a second plane and provided with variable magnification means comprising: an optical system for forming an image of the first plane on the second plane; a first mirror disposed between said image-forming optical system and the first plane and rotatable by a determined angle θ upon a change of magnification while at the same time translationally moving in a determined direction; a second mirror disposed between said image-forming optical system and the second plane and rotatable, at a fixed position, by the same angle as the rotation angle θ of said first mirror upon a change of magnification; and wherein said image-forming optical system is rotated by an angle two times larger than the rotation angle θ of said first mirror and is also translationally moved along its optical axis when the magnification is changed.
Claim 4
Dependent Claim
147 words
An optical apparatus for projecting an image in a first plane onto a second plane and provided with variable magnification means comprising: an optical system for forming an image of the first plane on the second plane; a first mirror disposed between said image-forming optical system and the first plane and rotatable by a determined angle θ upon a change of magnification while at the same time translationally moving in a determined direction; a second mirror disposed between said image-forming optical system and the second plane and rotatable, at a fixed position, by the same angle as the rotation angle θ of said first mirror upon a change of magnification; and wherein said image-forming optical system is rotated by an angle two times larger than the rotation angle θ of said first mirror and is also translationally moved along its optical axis when the magnification is changed.
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) | 1987-07-03 | 1988-01-02 | 1988-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-03 | 1992-01-02 | 1992-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-03 | 1996-01-02 | 1996-07-03 | $7700.00 | Window Closed / Lapsed |