Patent US4653892A successfully refreshed from Google Patents.
US4653892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lens barrel driving apparatus in camera
Assignee: Canon Inc
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Filing: 1986-04-23
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Granted: 1987-03-31
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Expires: 2006-04-23
Abstract
Abstract An apparatus for axially moving a photographic lens barrel in a camera by a corresponding number of steps to the number of driving pulses supplied to a rocking coil in a magnetic field, as motion of the coil is transmitted through a ratchet mechanism with a cam to the barrel. In synchronism with the falling edge of each driving pulse at which the ratchet mechanism starts to return to its initial position by the bias force of a spring, a negative going pulse of shorter duration than that of the driving pulse is applied to the coil to speed up the setting of the barrel.
Inventors
- 👤 Akihiro Namai
- 👤 Akira Egawa
- 👤 Takanori Kodaira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:18
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/02; G02B7/04; G02B7/08; G02B7/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
118 words
A drive device for an optical system in a camera, comprising: (A) an optical system variable in position; (B) drive means for changing in a stepwise manner the position of the optical system, said drive means shifting from an initial position in a predetermined direction by current passage therethrough in a first direction, returning to the initial position by current passage therethrough in a second direction, and repeating the shiftings so as to change in a stepwise manner the position of the optical system; (C) control means for alternately performing the current passage in the first direction and the current passage in the second direction; and (D) elastic means for urging the drive means toward the initial position.
Claim 2
Dependent Claim
118 words
A drive device for an optical system in a camera, comprising: (A) an optical system variable in position; (B) drive means for changing in a stepwise manner the position of the optical system, said drive means shifting from an initial position in a predetermined direction by current passage therethrough in a first direction, returning to the initial position by current passage therethrough in a second direction, and repeating the shiftings so as to change in a stepwise manner the position of the optical system; (C) control means for alternately performing the current passage in the first direction and the current passage in the second direction; and (D) elastic means for urging the drive means toward the initial position.
Claim 3
Dependent Claim
16 words
A drive device according to claim 1, wherein the optical system includes a photographic optical system.
Claim 4
Dependent Claim
23 words
A drive device according to claim 2, wherein the photographic optical system is adjusted in focal point in correspondence to the changed position.
Claim 5
Dependent Claim
55 words
A drive device according to claim 3, which further comprises distance measuring means for measuring the distance of an object and in which the control means determines the number of the current passage in response to the output of the distance measuring means so as to shift the photographic optical system to an in-focus position.
Claim 6
Dependent Claim
39 words
A drive device according to claim 4, wherein the control means includes exposure control means for performing current passage in the second direction after the shifting of the photographic optical system to the in-focus position, thereby performing an exposure.
Claim 7
Dependent Claim
52 words
A drive device according to claim 5, wherein the control means includes return means which performs again the alternate current passage in the first direction and in the second direction to the drive means after the completion of the exposure so as to return the photographic optical system to the initial position.
Claim 8
Dependent Claim
37 words
A drive device according to claim 6, wherein the photographic optical system includes switch means for disabling the operation of the return means in response to the returning of the photographic optical system to the initial position.
Claim 9
Dependent Claim
38 words
A drive device according to claim 1, wherein the control means includes timer means for making the time of the current passage in the second direction shorter than the time of the current passage in the first direction.
Claim 10
Dependent Claim
20 words
A drive device according to claim 1, wherein the drive means includes electromagnetic drive means for driving with electromagnetic force.
References Cited (Backward Citations)
US4021821A
Cited
US4423941A
Cited
US4396267A
Cited
US4401378A
Cited
US4508422A
Cited
US4505567A
Cited
US4505566A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-30 | 1990-09-29 | 1991-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-30 | 1994-09-29 | 1995-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-30 | 1998-09-29 | 1999-03-31 | $7700.00 | Window Closed / Lapsed |