US4314747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light shielding device for automatic focus detecting
Assignee: Pentax Corp
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Filing: 1980-02-05
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Granted: 1982-02-09
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Expires: 2000-02-05
Abstract
Abstract A light-shielding device for a single lens reflex automatic focus camera in which the focus detecting element is normally covered by a shielding plate. The protecting plate is coupled along one edge thereof to a shaft while the end is coupled to one end of an operating lever. The other end of the operating lever is coupled through a U-shaped spring to a mirror operating lever of the camera wherein the U-shaped spring provides a snap action upon release of the shutter curtain which quickly moves the shielding plate to its uncovered position.
Inventors
- 👤 Keisuke Haraguchi
- 👤 Harumi Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:26
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36; G03; G03B; G03B19/00; G03B19/02; G03B19/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
78 words
A light shielding device of an automatic focus detecting element in an automatic focus detecting device of a single-lens reflex camera comprising: an automatic focus detecting element positioned in said camera to receive incoming light; means for shielding said automatic focus detecting element from light before the shutter curtain of said camera is opened and so long as it remains opened; and means for releasing said light shielding means after the shutter curtain of said camera is closed.
Claim 2
Dependent Claim
78 words
A light shielding device of an automatic focus detecting element in an automatic focus detecting device of a single-lens reflex camera comprising: an automatic focus detecting element positioned in said camera to receive incoming light; means for shielding said automatic focus detecting element from light before the shutter curtain of said camera is opened and so long as it remains opened; and means for releasing said light shielding means after the shutter curtain of said camera is closed.
Claim 3
Dependent Claim
74 words
The device of claim 1 wherein said light shielding device further comprises a mirror in which a central portion thereof through which the optical axis passes is a half-silvered mirror and the remaining portion of said mirror is a total reflection mirror; and further comprising a second total reflection mirror and a mirror box, said second reflection mirror and said automatic focus detecting element being provided on the lower portion of said mirror box.
Claim 4
Dependent Claim
56 words
The light shielding device as claimed in claim 1 wherein said shielding means comprises: a shielding plate for covering said automatic focus detecting element in a first position thereof; and a rotatable shaft coupled to an edge of said shielding plate, said, shaft upon rotation, rotating said shielding plate to uncover said automatic focus detecting element.
Claim 5
Dependent Claim
43 words
The light shielding device of claim 4 wherein said releasing means comprises: a lever coupled at one end to an end of said shaft; and a spring coupled between a second end of said lever and a mirror operating lever of said camera.
Claim 6
Dependent Claim
26 words
The light shielding device of claim 4 wherein said spring is disposed to provide a snap action to rotate said shielding plate to the uncovered position.
Claim 7
Dependent Claim
12 words
The light shielding device of claim 5 wherein said spring is U-shaped.
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) | 1985-02-08 | 1985-08-10 | 1986-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-08 | 1989-08-10 | 1990-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-08 | 1993-08-10 | 1994-02-09 | $7700.00 | Window Closed / Lapsed |