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US4274713A Expired / Lapsed US ⏱️ 0.0 years remaining

Device with a scatter-free light valve

Assignee: Siemens AG
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Filing: 1978-07-26
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Granted: 1981-06-23
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Expires: 1998-07-26
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Abstract

Abstract A device with a scatter-free light valve which may be used as a rear view mirror or a sun visor and is characterized by a pair of carrier plates extending parallel to each other to form a cell having a cavity with transparent conductive coatings facing the cavity which receives a layer that can be switched between different optical states, and a light sensitive element, which is electrically connected to the light valve to constantly change the light transmittance of the light valve in response to the intensity of light radiation sensed by the light sensitive element.

Inventors

  • 👤 Hans Krueger

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 06:38
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13725; B; B60; B60R; B60R1/00; B60R1/02; B60R1/08; B60R1/083; B60R1/088; G02F1/133; G02F1/13306; G02F1/13318; G02F1/13731; G02F1/13737

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 176 words
In a device including a scatter-free light valve comprising a cell having two carrier plates which are arranged in parallel to one another to form a chamber therebetween, the surfaces of said plates facing said chamber being provided with electrically conductive, transparent coatings and said chamber receiving a liquid crystal layer, which can be switched between different optical states, the improvement comprising said device being a rear view mirror in a motor vehicle, said device having a reflective mirror layer in direct contact with one of the carrier plates and a circular polarizer being disposed in front of the other carrier plates to circularly polarize light entering the cell, said liquid crystal layer while in a rest state having a twisted homeogeneously orientation and with increasing voltages assumes a homeotropic orientation, and said device including a light sensitive element electrically connected to the transparent coatings of the light valve so that the liquid crystal layer is constantly changing its light transmittance in response to the intensity of the light radiation falling onto the light sensitive element.
Claim 2
Dependent Claim 176 words
In a device including a scatter-free light valve comprising a cell having two carrier plates which are arranged in parallel to one another to form a chamber therebetween, the surfaces of said plates facing said chamber being provided with electrically conductive, transparent coatings and said chamber receiving a liquid crystal layer, which can be switched between different optical states, the improvement comprising said device being a rear view mirror in a motor vehicle, said device having a reflective mirror layer in direct contact with one of the carrier plates and a circular polarizer being disposed in front of the other carrier plates to circularly polarize light entering the cell, said liquid crystal layer while in a rest state having a twisted homeogeneously orientation and with increasing voltages assumes a homeotropic orientation, and said device including a light sensitive element electrically connected to the transparent coatings of the light valve so that the liquid crystal layer is constantly changing its light transmittance in response to the intensity of the light radiation falling onto the light sensitive element.

References Cited (Backward Citations)

DE2158563A1 Cited
GB1372868A Cited
US3694053A Cited
DE2246415A1 Cited
FR2228234B1 Cited
US4025161A Cited
US3837730A Cited
DE2416172A1 Cited
US3912369A Cited
US3961181A Cited
US4088392A Cited
US4093356A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-06-22 1984-12-22 1985-06-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-06-22 1988-12-22 1989-06-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-06-22 1992-12-22 1993-06-23 $7700.00 Window Closed / Lapsed

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