Solar-powered sun sensitive window

• US 4,475,031 A
• Filed: 04/23/1981
• Issued: 10/02/1984
• Est. Priority Date: 04/23/1981
• Status: Expired due to Fees

• Current Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Original Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Inventors: Mockovciak, John Jr.
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): Hostetter, D.
• Application Number:
  US06/256,850
• Time in Patent Office: 1,258 Days
• Field of Search: 350/331 R, 250/205, 250/201, 250/212, 136/291
• US Class Current: 250/214.0SG
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 3/6722 with adjustable passage of light
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: Y10S 136/291 Applications

Abstract

A self-contained sun sensitive window made up of liquid nematic crystals sandwiched between two transparent conductors is powered directly by a solar cell. An increase in light intensity upon the solar cell reduces the transparency of the window, resulting in a constant intensity behind the window.

Claims

1. A self-contained, sun sensitive window comprising:

a solar cell which outputs an electric current proportional to incident sunlight;

passive voltage regulator means for converting the electric current output by the solar cell to a high DC voltage output;

a pair of transparent plates placed parallel to each other;

a closure placed between the plates such that the plates form a closed cavity;

a pair of transparent, electrically conductive coatings on a pair of facing sides of the plates, said coatings being electrically connected to the output from the voltage regulator means; and

a quantity of electro-optical modulating material filling the cavity between the plates.

2. The device of claim 1 which further comprises a switch means for breaking the electrical connection between the voltage regulator and one of the conductive coatings.

3. The invention of claim 1 wherein the voltage regulator means comprises a blocking oscillator having a transformer with a primary winding connected to the solar cell and a secondary winding having a larger number of turns than the primary winding, said primary and secondary windings being arranged in a circuit such that the current output by the solar cell intermittently flows through the primary winding in a sawtooth wave form, whereby a high voltage is induced in the secondary winding.

4. The invention of claim 1 wherein the electro-optical modulating material comprises a nematic liquid crystal.