US4633072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focus apparatus for zoom lens system with distance detection
Assignee: Canon Inc
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Filing: 1985-12-30
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Granted: 1986-12-30
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Expires: 2005-12-30
Abstract
Abstract Focusing optics placed behind the zooms optics of a zoom arrangement are focused by computing the necessary focusing movement in response to the output of a focal length detector and an object distance detector. Comparison is made to the actual position of the focusing optics.
Inventors
- 👤 Muneharu Sugiura
- 👤 Akira Tajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:23
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/282
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
155 words
A focusing apparatus for a zoom lens system comprising: (a) a zoom lens optical system having an object end and image end and defining an optical axis; (b) a focusing optical system arranged behind the image end of said zoom lens optical system for adjusting the focus; (c) means for detecting focal length information by zooming of said zoom lens optical system; (d) distance measuring means for measuring an object distance, said distance measuring means having a range finding element at a position displaced from the optical axis of said zoom lens optical system; (e) means receptive of an output signal from said focal length information detecting means and an output signal from said object distance measuring means for computing an amount of movement of said optical system for adjusting the focus to an in-focus position; and (f) means for driving said focusing optical system on the basis of the signal of said computing means.
Claim 2
Dependent Claim
155 words
A focusing apparatus for a zoom lens system comprising: (a) a zoom lens optical system having an object end and image end and defining an optical axis; (b) a focusing optical system arranged behind the image end of said zoom lens optical system for adjusting the focus; (c) means for detecting focal length information by zooming of said zoom lens optical system; (d) distance measuring means for measuring an object distance, said distance measuring means having a range finding element at a position displaced from the optical axis of said zoom lens optical system; (e) means receptive of an output signal from said focal length information detecting means and an output signal from said object distance measuring means for computing an amount of movement of said optical system for adjusting the focus to an in-focus position; and (f) means for driving said focusing optical system on the basis of the signal of said computing means.
Claim 3
Dependent Claim
35 words
A focusing apparatus according to claim 1, further including: means for detecting the distance which said focusing optical system has moved from a predetermined start point in a range of movement of said focusing optical.
Claim 4
Dependent Claim
151 words
A focusing apparatus for a zoom lens system comprising: (a) a zoom lens optical system having an optical axis; (b) an optical system for focus adjustment arranged in rear of said zoom lens optical system; (c) means for detecting focal length information by zooming of said zoom lens optical system; (d) distance measuring means for measuring an object distance, said distance measuring means having a range finding element arranged on an optical axis coinciding with the optical axis of said zoom lens otpical system at at least one point; (e) means receptive of an output signal from said focal length information detecting means and an output signal from said ojbect distance measuring means for computing an amount of movement of said optical system for focusing adjustment to an in-focus position; and (f) means for driving said optical system for focus adjustment on the basis of the signal of said computing means.
Claim 5
Dependent Claim
151 words
A focusing apparatus for a zoom lens system comprising: (a) a zoom lens optical system having an optical axis; (b) an optical system for focus adjustment arranged in rear of said zoom lens optical system; (c) means for detecting focal length information by zooming of said zoom lens optical system; (d) distance measuring means for measuring an object distance, said distance measuring means having a range finding element arranged on an optical axis coinciding with the optical axis of said zoom lens otpical system at at least one point; (e) means receptive of an output signal from said focal length information detecting means and an output signal from said ojbect distance measuring means for computing an amount of movement of said optical system for focusing adjustment to an in-focus position; and (f) means for driving said optical system for focus adjustment on the basis of the signal of said computing means.
Claim 6
Dependent Claim
64 words
A focusing apparatus as in claim 3, wherein said range finding element incudes a light splitter along the optical axis of said zoom lens optical system for directing light away from the optical system along the optical axis of said range finding element, and detecting means in the path of the light directed out of the optical axis of said zoom lens optical system.
Claim 7
Dependent Claim
25 words
A apparatus as in claim 4, wherein said distance measuring means further includes a lens in the path between said beam splitter and said detector.
References Cited (Backward Citations)
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US4329578A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |