ELECTRO-OPTIC SHUTTER HAVING A THIN GLASS OR SILICON OXIDE LAYER BETWEEN THE ELECTRODES AND THE LIQUID CRYSTAL

• US 3,700,306 A
• Filed: 09/22/1971
• Issued: 10/24/1972
• Est. Priority Date: 09/22/1971
• Status: Expired due to Term

• Current Assignee: Donald Churchill, Donald E. Koopman, James V. Cartmell
• Original Assignee: Donald Churchill, Donald E. Koopman, James V. Cartmell
• Inventors: Cartmell, James V., Churchill, Donald, Koopman, Donald E.
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Bauer, Edward S.
• Application Number:
  US05/182,819
• Time in Patent Office: 398 Days
• Field of Search: 350/150,16LC
• US Class Current: 349/138
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133784 by rubbing

Abstract

An electro-optic shutter employing nematic liquid crystal material is disclosed. The electrodes of the shutter of this invention are protected with a thin overcoat of an insulating material such as glass. This thin overcoat essentially prevents rapid electrode failure due to conduction of current through the liquid crystal material.

Claims

2. A shutter according to claim 1 wherein the thin overcoat has a thickness ranging from 0.1 to 1.0 micron.

3. A shutter according to claim 1 wherein the two spaced transparent plates are sandwiched between two linear polarizers.

4. A shutter according to claim 3 wherein the polarizers and film are oriented in parallel and perpendicular directions.

5. A shutter according to claim 1 wherein the nematic liquid crystal is characterized by a positive dielectric anisotropy.

6. A shutter according to claim 1 wherein the nematic liquid crystal is p-n-alkoxybenzilidene-p-aminobenzonitrile.

7. A shutter according to claim 1 wherein the nematic liquid crystal material is a mixture by weight of 40 percent methoxybenzilidene-n-butylaniline, 40 percent ethoxybenzilidene-n-butylaniline and 20 percent p-n-butoxybenzilidene-p'"'"''"'"'-aminobenzonitrile.

8. A shutter according to claim 1 wherein the electrically conductive film is indium oxide.

9. A shutter according to claim 1 wherein the voltage gradient is pulsed, unipolar D.C., bipolar D.C. or A.C. potential.

10. A shutter according to claim 1 wherein the voltage gradient is 4 volts for 250 pulses per second unipolar D.C. potential.

11. A shutter according to claim 1 wherein the two spaced transparent plates are glass.

12. A shutter according to claim 1 wherein the nematic liquid crystal material is a mixture by weight of 32 percent methoxybenzilidene-n-butylaniline, 58 percent ethoxybenilidene-n-butylaniline and 10 percent p-n-butoxy-benzilidene-p'"'"''"'"'-aminobenzonitrile.