US3860943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrooptical-calibrated variable neutral density filter with split area control
Assignee: Individual
•
Filing: 1973-05-15
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Granted: 1975-01-14
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Expires: 1993-05-15
Abstract
Abstract As an attachment to cameras or other optical equipment there are provided two transparent plate sets in series. Each set includes spaced transparent plates provided with a conductive coating on their inside faces and defining therebetween a chamber filled with dipole particles. When an electric field is applied across the transparent plate set the particles line up and permit passage of light; otherwise the particles are randomly arranged and light does not pass. The conductive area of each set is subdivided, one plate being subdivided into semi-circles and the other lens being divided into a circle and annular ring. Circuitry is provided to control the electric field to each of the four sub-divided areas separately and variably so pictures can be taken with haloes of light or dark, and light or dark halves, or combinations thereof. The trigger for the filter is connected to the camera trigger so starting from viewing the object normally, partial depressing of the trigger shows the operator the filtered image so adjustment can be made, and further depressing actuates the camera.
Inventors
- 👤 Patrick W Tague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:58
CPC Classifications
G; G03; G03B; G03B11/00; G02; G02F; G02F1/00; G02F1/01; G02F1/17; G02F1/172; G03B17/00; G03B17/02; G03B17/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
178 words
A variable neutral density optical filter with split area control comprising first and second transparent plates, means holding said plates spaced from one another and defining a chamber therebetween, an electrically conductive coating on the facing faces of said plates defining said chamber, the electrically conductive coating on at least one of said faces being sub-divided into at least two independent areas, and the electric conductive coating on the other of said faces constitutes at least one independent area a plurality of electrical conductors each connected with a respective independent area of said plates, a fluid containing elongated dipole particles disposed within said chamber, and variable current means for independently establishing a variable potential from each independent area of one plate to the other plate across the fluid-containing chamber thereby to cause said dipole particles to align themselves perpendicularly to said plates, the extent of alignment and the amount of light passing through the plates being dependent upon the potential, the independence of said areas permitting the amount of light passing through said areas to be independently controlled.
Claim 2
Dependent Claim
178 words
A variable neutral density optical filter with split area control comprising first and second transparent plates, means holding said plates spaced from one another and defining a chamber therebetween, an electrically conductive coating on the facing faces of said plates defining said chamber, the electrically conductive coating on at least one of said faces being sub-divided into at least two independent areas, and the electric conductive coating on the other of said faces constitutes at least one independent area a plurality of electrical conductors each connected with a respective independent area of said plates, a fluid containing elongated dipole particles disposed within said chamber, and variable current means for independently establishing a variable potential from each independent area of one plate to the other plate across the fluid-containing chamber thereby to cause said dipole particles to align themselves perpendicularly to said plates, the extent of alignment and the amount of light passing through the plates being dependent upon the potential, the independence of said areas permitting the amount of light passing through said areas to be independently controlled.
Claim 3
Dependent Claim
20 words
A filter according to claim 1, wherein said independent areas of said one face are complementary sections of a circle.
Claim 4
Dependent Claim
17 words
A filter according to claim 2, wherein said independent areas of said one face are substantially semi-circles.
Claim 5
Dependent Claim
24 words
A filter according to claim 2, wherein said independent areas of said one face are a circle substantially and at least one annular ring.
Claim 6
Dependent Claim
90 words
A filter according to claim 1, including at least two sets of first and second transparent plates as defined, the sets being mounted in spaced relationship so that at least one set is rotatable relative to another, the independent areas of one plate of one set being assymmetrical relative to the independent areas of one plate of another, whereby the pattern of light filtration can be varied, and the other plate of each set having only a single conductive area, whereby the demarcation between portions of the pattern is diffused.
Claim 7
Dependent Claim
40 words
A filter according to claim 5, wherein the independent areas said one plate of one set of lenses are substantially semi-circles and the independent areas said one plate of another set are a circle and at least one annular ring.
Claim 8
Dependent Claim
26 words
A filter according to claim 6 in combination with a camera having an optical opening, the filter being aligned with the optical opening of said camera.
Claim 9
Dependent Claim
113 words
A filter in combination with a camera according to claim 7, and further including flash attachment on said camera, a lens attachment connecting said camera with said filter, a focusing lever for said lens attachment, means operatively connecting said focusing lever with said filter so that the operating lever position controls the overall filtration of light, whereby upon focusing upon an object through said lens attachment the distance to said object will automatically control the overall filtration of light thereby to adjust the amount of light entering the camera depending on the distance to said object, all this occurring independently of the selective filtration of light through selected independent areas of the plates.
Claim 10
Dependent Claim
26 words
A filter according to claim 1 in combination with a camera having an optical opening, the filter being aligned with the optical opening of said camera.
Claim 11
Dependent Claim
83 words
A combination according to claim 9, said camera having a shutter control means and including means for controlling the flow of current to said filter, said current control means being operatively connected with the shutter control means of said camera so that, after viewing an image through said camera, displacement of said current control means first actuates said filter so that the camera and operator see the filtered image and continued displacement actuates said camera to take a picture of the filtered view.
References Cited (Backward Citations)
US3572907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |