US3750136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for controlling light patterns with a high contrast
Assignee: Siemens AG
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Filing: 1971-02-22
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Granted: 1973-07-31
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Expires: 1991-02-22
Abstract
Abstract A system to produce a visual presentation on a screen such as alpha-numeric indications characterized by a switching element which is a matrix of individually controlled liquid crystals, a converging lens system, a plane filter located at the focal point of the lens system, and a screen. The matrix of liquid crystals includes means to render discrete liquid crystals in a condition to diffuse and scatter the light beams being projected therethrough. By selectively rendering specific liquid crystals of the matrix in the scattering condition, a source of parallel light can be converted to a specific pattern which is passed through a convergent lens system, through the plane filter such as an iris or aperture in a partition extending perpendicular to the parallel light beams and projected on a screen to produce the desired indication. Preferably, the source of light is obtained from a laser.
Inventors
- 👤 D Roess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:48
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133526; G02F1/1313
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
An arrangement for producing a pattern in a beam of directional light rays projecting on a screen to create an image thereon, comprising a screen, a light beam switching element with selectively controllable areas along a plane extending transverse to the axis of said beam for scattering portions of the directional rays of the beam to create a pattern of scatter rays and unscatter rays in the beam, and a filter means disposed between said switch element and said screen for blocking the scatter rays as it passes the unscatter rays to improve the contrast between the image and background illumination on said screen, said filter means consisting of means for converging the unscatter directional rays to a focal point and a plane filter comprising a partition with means forming an iris therein, said plane filter being disposed with the iris means at said focal point and the partition extending transversely to the axis of the beam whereby the filter means reduces background illumination of the screen which is caused by the scattered rays being projected on the screen.
Claim 2
Dependent Claim
179 words
An arrangement for producing a pattern in a beam of directional light rays projecting on a screen to create an image thereon, comprising a screen, a light beam switching element with selectively controllable areas along a plane extending transverse to the axis of said beam for scattering portions of the directional rays of the beam to create a pattern of scatter rays and unscatter rays in the beam, and a filter means disposed between said switch element and said screen for blocking the scatter rays as it passes the unscatter rays to improve the contrast between the image and background illumination on said screen, said filter means consisting of means for converging the unscatter directional rays to a focal point and a plane filter comprising a partition with means forming an iris therein, said plane filter being disposed with the iris means at said focal point and the partition extending transversely to the axis of the beam whereby the filter means reduces background illumination of the screen which is caused by the scattered rays being projected on the screen.
Claim 3
Dependent Claim
33 words
An arrangement according to claim 1, characterized in that the switching element is a matrix of individual liquid crystals each of which is selectively controlled between a light-transmitting condition and a light-scattering condition.
Claim 4
Dependent Claim
18 words
An arrangement according to claim 1 wherein the means forming an iris is an aperture in the partition.
Claim 5
Dependent Claim
31 words
An arrangement according to claim 1 wherein the means forming an iris is a transparent member with a center fully permeable to light surrounded with an outer area impermeable to light.
Claim 6
Dependent Claim
36 words
An arrangement according to claim 4, wherein the means forming an iris has an immediate area between the center and outer area to provide a gradual transition from said permeable center to the impermeable outer area.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |