US3766841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for extending the exposure range for camera lenses
Assignee: Dymat Photomatrix Corp
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Filing: 1972-12-01
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Granted: 1973-10-23
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Expires: 1992-12-01
Abstract
Abstract The exposure range of a camera lens is extended by positioning a light filter in front of the lens when the amount of light passing into the lens is greater than a given amount of light for which the lens stop would be set at its maximum limit. The filter functions to attenuate the light such that the lens may be set at a proper opening within the stop value range. The filter is removed from in front of the lens when the amount of light passing through the lens is less than a second given amount of light for which the lens stop would be set at its minimum limit. If the filter attenuates the light by at least three stops, the exposure range of the lens is effectively extended by at least three stops.
Inventors
- 👤 R Marsh
- 👤 F Finnegan
- 👤 K Gensike
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:38
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/02; G03B17/12; G03B19/00; G03B19/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
326 words
A device for extensing the exposure range of a camera lens having given maximum and minimum stop limits wherein the lens opening defining the lens exposure is controlled in size by rotation of a lens ring on the lens, said device including: a. a filter; b. mounting means for said filter responsive to rotation of the lens ring to a point at which the maximum stop is set for the lens to move said filter to a first position in front of the lens and responsive to rotation of the lens ring in an opposite direction to a point at which the minimum stop is set for the lens when said filter is in front of the lens, to remove said filter from in front of the lens to a second position, said mounting means for said filter including a stationary mounting plate through which the lens ring extends; radially extending circumferentially spaced first and second actuating pins on said lens ring; a holder for said filter having an off-center arm pivoted on the mounting plate for moving tHe filter between said first and second positions about an axis spaced from and parallel to to the axis of the lens; engaging means on the plate to limit the movement of the filter holder beyond the first and second positions; a filter holder over-center spring connected at one end to the holder at a point between the filter and said pivot axis and at its other end to a stationary point on the plate on the opposite side of the pivot axis so that the filter holder is biased by the spring to hold the filter in either its first or second position; and, c. actuator means mounted on said plate in a position to be engaged by said first and second actuating pins upon rotation of the lens ring in first and second directions respectively to move said filter holder between said first and second positions.
Claim 2
Independent Claim
326 words
A device for extensing the exposure range of a camera lens having given maximum and minimum stop limits wherein the lens opening defining the lens exposure is controlled in size by rotation of a lens ring on the lens, said device including: a. a filter; b. mounting means for said filter responsive to rotation of the lens ring to a point at which the maximum stop is set for the lens to move said filter to a first position in front of the lens and responsive to rotation of the lens ring in an opposite direction to a point at which the minimum stop is set for the lens when said filter is in front of the lens, to remove said filter from in front of the lens to a second position, said mounting means for said filter including a stationary mounting plate through which the lens ring extends; radially extending circumferentially spaced first and second actuating pins on said lens ring; a holder for said filter having an off-center arm pivoted on the mounting plate for moving tHe filter between said first and second positions about an axis spaced from and parallel to to the axis of the lens; engaging means on the plate to limit the movement of the filter holder beyond the first and second positions; a filter holder over-center spring connected at one end to the holder at a point between the filter and said pivot axis and at its other end to a stationary point on the plate on the opposite side of the pivot axis so that the filter holder is biased by the spring to hold the filter in either its first or second position; and, c. actuator means mounted on said plate in a position to be engaged by said first and second actuating pins upon rotation of the lens ring in first and second directions respectively to move said filter holder between said first and second positions.
Claim 3
Dependent Claim
92 words
A device according to claim 1, including, in combination automatic exposure control means for said camera lens for automatically driving said lens ring to provide given correct exposures in response to the amount of light passing through the lens, said driving motion imparted to the lens ring actuating the mounting means automatically when the incoming light exceeds that amount for which the lens is set at its maximum stop and when the incoming light through the filter falls below the minimum amount for which the lens is set at its minimum stop.
Claim 4
Dependent Claim
298 words
A device according to claim 1, in which said actuator means includes an actuator ring rotatably mounted on said pivot axis having circumferentially spaced first and second shoulders; a filter holder pin extending from said filter holder to a position between said shoulders for engagement thereby upon rotation of said actuator ring; an actuator pin on said actuator ring positioned to be engaged by said first and second actuating pins on said lens ring when said lens ring is rotated in said first direction and said second direction respectively; and an actuator ring over-center spring connected at one end to a peripheral portion of the actuator ring and at its other end to a stationary point on the plate spaced on the opposite side of the pivot axis, whereby as said lens ring is rotated towards said point at which the maximum stop is set for the lens, said first actuating pin engages said actuator pin to rotate said actuator ring to bring the first shoulder into engagement with the filter holder pin, the actuator ring spring then passing over-center to drive the actuator ring rapidly in its rotational movement to flip the filter holder to said first position to place the filter in front of the lens, and whereby when said lens ring is rotated in an opposite direction towards said point at which the minimum stop is set for the lens, said second actuating pin engages said actuator pin to rotate said actuator ring in an opposite direction to bring the second shoulder into engagement with the filter holder pin, the actuator spring then passing back over-center to drive the actuator ring rapidly in its rotational movement to flip the filter holder to its second position to remove the filter from in front of the lens.
References Cited (Backward Citations)
US3057279A
Cited
US3584558A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |