DIPOLAR ELECTRO-OPTIC STRUCTURES AND METHOD

• US 3,841,732 A
• Filed: 03/04/1970
• Issued: 10/15/1974
• Est. Priority Date: 03/04/1970
• Status: Expired due to Term

• Current Assignee: Alvin M. Marks
• Original Assignee: Alvin M. Marks
• Inventors: Marks, Alvin M.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): McGraw, V. P.
• Application Number:
  US05/016,280
• Time in Patent Office: 1,686 Days
• Field of Search: 350/267,160,16R,16LC
• US Class Current: 359/296
• CPC Class Codes: G02F 1/172 based on a suspension of orientable dipolar particles, e.g. suspended particles displays

Abstract

Methods and electro-optical panels are disclosed for controlling the transmission, absorption, and reflection of light and related forms of electro-magnetic radiation by the electrical orientation, and the disorientation of submicron asymmetrical dipolar particles in an ionic or nonionic suspending transparent fluid medium.

Claims

1. A light controlling device comprising in combination a transparent suspending medium, a plurality of submicron dipole members rotatably carried within the medium to form a suspension, spaced transparent sheets to contain the suspension, opposed electrodes disposed on each side of said suspension, one of said electrodes being a transparent conductive film and the other of said electrodes being reflective, and means to apply an electric field across said electrodes to control the disposition of the dipole suspension from light absorptive in a random state to transparent in an aligned state.

2. A device according to claim 1 in which the reflective electrode is specularly reflective.

3. A device according to claim 1 in which at least one of the electrodes is a light absorptive conductor and the dipolar suspension is reflective in the random state and light transmissive in the aligned state.

4. A device according to claim 1 in which the electrodes are in direct contact with the dipole suspension and the suspending medium is substantially free of ions.

5. A device according to claim 4 in which the fluid is selected from the class consisting of aromatics, such as, toluol, benzene;

esters such as, di iso amyl adipate, dimethyl phthalate;

silicone oils;

aliphatics such as hexane, decane;

chlorinated organics, such as chlorinated diphenyls, and the dipoles are selected from the class consisting of metals, semiconductors and dichroic crystals.

6. A light controlling device according to claim 1, wherein the suspending medium is in the form of a layer having a thickness of at least 10 3 cms and not more than 10 1 cms.

7. A light controlling device comprising in combination a transparent suspending medium a plurality of submicron dipole members rotatably carried within the medium to form a suspension, spaced transparent sheets to contain the suspension, opposed electrodes disposed on each side of said suspension, at least one of said electrodes being a transparent conductive film, means to apply an electric field across said electrodes to control the disposition of the dipole suspension from light absorptive in a random state to transparent in an aligned state, wherein a transparent insulating layer is disposed between each of the electrodes and the dipole suspension, the suspending medium contains free ions, and the electric field is non-constant.

8. A device for forming an electro-optic iris comprising in combination, a transparent suspending medium, a plurality of submicron dipoles in said medium, spaced sheets for containing said suspension, at least one of said sheets being transparent, opposed electrodes on each side of the suspension, at least one of said electrodes being a point electrode, and means to apply an electric field across the said electrodes.

9. A device according to claim 8 in which both the spaced electrodes comprise point electrodes disposed along the same axis, normal to the plane of the spaced sheets.

10. A device according to claim 8 in which the dipole suspension contains free ions, is contained between transparent insulating sheets and the electric field is non-constant.

11. A device according to claim 8 in which the electrodes are in contact with the mediun and the medium is substantially free of ions.

12. A light controlling device comprising a suspension of submicron dipoles in which the electrodichroic ratio is at least 10, for an electric field intensity exceeding 3kv/cm for a frequency in excess of 1KHz.

13. An electro-optic panel comprising spaced sheets, a spacer peripherally separating said sheets to form a thin large area cell having a thickness in the order of from 10 3 cms to 10 1 cms, electrode layers on said shEets, a dipole fluid suspension layer within said cell, leads attached to said electrodes, at least one sheet and electrode layer being transparent, and at least one transparent insulating layer separating said dipole suspension from at least one of said electrode layers.

14. An electrooptical panel according to claim 13 in which the transparent electrode coatings are connected to bus bars inserted into the panel circumferentially a short distance from the edge

15. A device according to claim 13 in which at least one layer is nontransparent and light absorbing.

16. A electro-optic panel comprising spaced sheets, a spacer peripherally separating said sheets to form a thin large area cell having a thickness of the order of from 10 3 cms to 10 1 cms, electrode layers on said sheets, a dipole fluid suspension layer within said cell, leads attached to said electrodes, one of said sheets and one of said electrode layers being transparent, the other of said electrode layers being reflecting, and said electrode layers being in contact with the surface of said dipole fluid suspension layer.

17. An electrooptic specular mirror according to claim 16 in which the dipole suspension is absorbing in the random state, the reflecting layer is specularly reflecting, and whose transparency may be electrically varied to provide a variable reflectivity.

18. An electrooptical mirror according to claim 17 in which the dipole fluid suspension is substantially opaque-absorbing at no voltage with the dipoles in the random state, and in which the specular reflectance is about 50 percent when voltage is applied and the dipoles are aligned substantially normal to the sheet surface.

19. An electrooptical mirror according to claim 17 in which a specular reflection is substantially entirely from the surface of the device closest to incident light on the device and is of the order of 4 percent, at no voltage.

20. An electro-optic panel which may be varied from diffuse-reflective to absorbent, comprising spaced sheets, a spacer peripherally separating said sheets to form a thin large area cell having a thickness in the order of from 10 3 cms to 10 1 cms, electrode layers on said sheets, a dipole fluid suspension layer within said cell, leads attached to said electrodes, at least one sheet and electrode layer being transparent, at least one electrode layer being nontransparent and light absorbing, said dipolar suspension being diffuse-reflective with dipoles in the random state at no voltage and being transmissive with the dipoles in the aligned state with voltage applied, and the inner face of the sheet furthest from the incident light being light absorbing.

21. An electro-optic panel which varies from absorbing black to diffuse-reflective, comprising spaced sheets, a spacer peripherally separating said sheets to form a thin large area cell having a thickness in the order of from 10 3 cms to 10 1 cms, electrode layers on said sheets, a dipole fluid suspension layer within said cell, leads attached to said electrodes, at least one sheet and electrode layer being transparent, said dipole suspension becoming transparent when voltage is applied and light is diffuse-reflected from the inner face of the sheet furthest from the incident light.