US4322145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutter device for camera
Assignee: Canon Inc
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Filing: 1980-04-18
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Granted: 1982-03-30
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Expires: 2000-04-18
Abstract
Abstract The present invention relates to an electromagnetically driven shutter device for camera, so designed that a detecting means for detecting the displacement speed of the shutter member and the power supply means for supplying the driving energy to the shutter member are provided in such a manner that the output of the power supply means is varied in accordance with the output of the detecting means so as to maintain the displacement speed of the shutter member constant.
Inventors
- 👤 Tateo Yamada
- 👤 Isao Harigaya
- 👤 Yukio Ogawa
- 👤 Michio Hirohata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:52
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/10; G03B9/18; G03B9/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
116 words
A shutter device for a camera, comprising: magnetic means for forming magnetic fields; conductor means located to be influenced by said magnetic field so that when current is supplied to the conductor means, the relative position of the conductor means and the magnetic field is varied; at least one shutter blade for opening and blocking a photo-taking optical path on the basis of the relative positions of said conductor means and the magnetic means; detecting means for detecting the displacement speed of the shutter blade; and control means for controlling the displacement speed of the shutter blade by controlling the amount of current through said conductor means in response to the output of the detecting means.
Claim 2
Dependent Claim
116 words
A shutter device for a camera, comprising: magnetic means for forming magnetic fields; conductor means located to be influenced by said magnetic field so that when current is supplied to the conductor means, the relative position of the conductor means and the magnetic field is varied; at least one shutter blade for opening and blocking a photo-taking optical path on the basis of the relative positions of said conductor means and the magnetic means; detecting means for detecting the displacement speed of the shutter blade; and control means for controlling the displacement speed of the shutter blade by controlling the amount of current through said conductor means in response to the output of the detecting means.
Claim 3
Dependent Claim
19 words
A shutter device according to claim 1, further comprising a housing, the magnetic means being fixed to the housing.
Claim 4
Dependent Claim
15 words
A shutter device according to claim 1, wherein the magnetic means is a permanent magnet.
Claim 5
Dependent Claim
15 words
A shutter device according to claim 1, wherein the detecting means is an electromagnetic sensor.
Claim 6
Dependent Claim
31 words
A shutter device according to claim 4, wherein the detecting means detects changes in the magnetic field caused by changes in the relative positions of the conductor means and magnetic means.
Claim 7
Dependent Claim
14 words
A shutter device according to claim 4, wherein the detecting means is a conductor.
Claim 8
Dependent Claim
16 words
A shutter device according to claim 1, wherein the conductor means includes a plurality of coils.
Claim 9
Dependent Claim
19 words
A shutter device according to claim 7, wherein the detecting means includes a coil fixed to the conductor means.
Claim 10
Dependent Claim
14 words
A shutter device according to claim 7, wherein the coil is a printed pattern.
Claim 11
Dependent Claim
24 words
A shutter device according to claim 1, wherein the conductor means is fixed to a rotor having a photo-taking optical path at its center.
Claim 12
Dependent Claim
16 words
A shutter device according to claim 10, wherein the shutter blade is connected to the rotor.
Claim 13
Dependent Claim
44 words
A shutter device according to claim 11, further comprising a light measuring arrangement, including means forming a light measuring optical path separate from the photo-taking optical path for controlling the amount of incident light in correspondence to the positional change of the shutter blade.
Claim 14
Dependent Claim
18 words
A shutter device according to claim 1, wherein the control means intermittently supply power to the conductor means.
Claim 15
Dependent Claim
33 words
A shutter device according to claim 13, wherein the control means changes the duty cycle of the intermittent power supply to the conductor means in correspondence to the output of the detecting means.
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) | 1985-03-29 | 1985-09-28 | 1986-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-29 | 1989-09-28 | 1990-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-29 | 1993-09-28 | 1994-03-30 | $7700.00 | Window Closed / Lapsed |