US3997906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm device in a camera lens
Assignee: Nikon Corp
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Filing: 1975-08-14
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Granted: 1976-12-14
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Expires: 1995-08-14
Abstract
Abstract A diaphragm device for a camera having a movable lens barrel has a diaphragm blade fixedly positioned with respect to a lens mount portion, the blade being stopped down upon occurrence of shutter release. An aperture diameter setting ring is provided for presetting the rest position of the diaphragm blade when stopped down for stopping the operation of the diaphragm blade when shutter release occurs and the blade reaches a position corresponding to the aperture preset operation. Correcting means is provided for changing the rest position of the diaphragm blade in response to axial movement of the lens barrel so that the quantity of light reaching a film surface which is determined by the stopped down position of the diaphragm blade preset by the aperture diameter setting ring assumes a predetermined value irrespective of the axial movement of the lens barrel.
Inventors
- 👤 Toshio Kashiwase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:52
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/02; G03B9/07; G03B17/00; G03B17/02; G03B17/12; G03B17/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
173 words
A diaphragm device for a camera having a movable lens barrel comprising: a diaphragm blade having its position in the direction of the optical axis fixed with respect to a mount portion for mounting a lens to the body of the camera, the diaphragm blade being stopped down when shutter release occurs in response to the shutter mechanism of the camera; an aperture diameter setting member for presetting the rest position of the diaphragm blade when stopped down and for stopping the operation of the diaphragm blade when shutter release occurs and the blade reaches a position corresponding to the aperture preset operation; and correcting means for changing the rest position of the diaphragm blade preset by the aperture diameter setting member in response to axial movement of the lens barrel so that the quantity of light reaching a film surface which is determined by the stopped down position of the diaphragm blade preset by the aperture diameter setting member assumes a predetermined value irrespective of the axial movement of the lens barrel.
Claim 2
Dependent Claim
173 words
A diaphragm device for a camera having a movable lens barrel comprising: a diaphragm blade having its position in the direction of the optical axis fixed with respect to a mount portion for mounting a lens to the body of the camera, the diaphragm blade being stopped down when shutter release occurs in response to the shutter mechanism of the camera; an aperture diameter setting member for presetting the rest position of the diaphragm blade when stopped down and for stopping the operation of the diaphragm blade when shutter release occurs and the blade reaches a position corresponding to the aperture preset operation; and correcting means for changing the rest position of the diaphragm blade preset by the aperture diameter setting member in response to axial movement of the lens barrel so that the quantity of light reaching a film surface which is determined by the stopped down position of the diaphragm blade preset by the aperture diameter setting member assumes a predetermined value irrespective of the axial movement of the lens barrel.
Claim 3
Dependent Claim
47 words
A device according to claim 1, wherein the correcting means includes: movement direction converting means for converting the rectilinear movement of said lens barrel along the optical axis into rotational movement about the optical axis and for transmitting the rotational movement of the aperture diameter setting member.
Claim 4
Dependent Claim
16 words
A device according to claim 2, wherein the movement direction converting means is a cam mechanism.
Claim 5
Dependent Claim
89 words
A device according to claim 3, wherein the movement direction converting means comprises: a first correcting means operatively associated with one of said aperture diameter setting member and said aperture ring and having a first cam groove; a second correcting member operatively associated with the other of said aperture diameter setting member and said aperture ring and having a second cam groove; and a rotatable member having a pin cooperable with the first and second cam grooves and mounted for rotation in a circumferential direction about the optical axis.
Claim 6
Dependent Claim
54 words
A device according to claim 4, wherein the first correcting member is a cam lever connected to the aperture diameter setting member and the first cam groove is curved; and wherein the second correcting member is a lever connected to the aperture ring and the second cam groove extends parallel to the optical axis.
References Cited (Backward Citations)
FR1285734A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-12-14 | 1980-06-14 | 1980-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-14 | 1984-06-14 | 1984-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-14 | 1988-06-14 | 1988-12-14 | $7700.00 | Window Closed / Lapsed |