COLOR DISPLAY DEVICES

• US 3,647,279 A
• Filed: 05/27/1970
• Issued: 03/07/1972
• Est. Priority Date: 05/27/1970
• Status: Expired due to Term

• Current Assignee: Edward N. Sharpless, Frederick Davis
• Original Assignee: Edward N. Sharpless, Frederick Davis
• Inventors: Sharpless, Edward N., Davis, Frederick
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Rothenberg, J.
• Application Number:
  US05/040,925
• Time in Patent Office: 650 Days
• Field of Search: 356/32 350/160 40/130
• US Class Current: 349/23
• CPC Class Codes: C09K 19/36 Steroidal liquid crystal compounds
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: G02F 1/13 based on liquid crystals, e.g. single liquid crystal display cells
• CPC Class Codes: G02F 1/1333 Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1341 Filling or closing of cells

Abstract

A display device for exhibiting a color pattern, said device comprising container means having a light-transmitting section and a juxtaposed darker hued or opaque section, a quantity of liquid crystalline material interposed between said container sections and encapsulated within said container means, said material having a characteristic of selective light scattering to exhibit color patterns within a range of temperatures at which said display device is normally utilized, and means for peripherally sealing one of said container sections to the other. Means can also be provided for applying deformational stress to the liquid crystal to vary its color pattern.

Claims

1. A display device for exhibiting a varying color pattern, said device comprising container means having a light transmitting section, a quantity of cholesteric liquid crystalline material encapsulated within said container means, said material having characteristics of selective visual light scattering to exhibit color patterns within a range of temperatures at which said display device is normally utilized, and of transmitting a substantial quantity of impinging visual light, light absorbing means supported by at least one of said liquid crystalline material and said container means for absorbing at least a substantial proportion of said transmitted light, said container means being configured so as to permit substantial volumetric flow of said liquid crystalline material within said container means, said material having an additional characteristic of a selective light frequency scattering which is variable in accordance with applied deformational stresses, the color patterns exhibited by said material being substantially insensitive to a wide range of temperature variations, and means coupled to said container means for displacing said container means to apply said deformational stresses to said material in a direction to induce said volumetric flow, said displacing means comprising a relatively thin portion of said container means adjacent said light-transmitting section, said portion including deformable constriction and expansion areas for displacing and accommodating said flow respectively so that pronounced color changes are effected in said material as a result of said flow.

2. The combination according to claim 1 wherein said displacing means further includes an arm member engageable with an external surface of said container portion, means for retaining said external surface and said arm member in bearing engagement, and means for moving said arm member across said external surface while in bearing engagement therewith.

3. The combination according to claim 1 wherein said light-transmitting section is a substantially flat transparent member of about one-eighth inch in thickness.

4. The combination according to claim 1 wherein said liquid crystalline material includes at least one of the group consisting of alkyl carbonate and alkanoic cholesteric esters of cholesterol, B-sitosterol, stigmasterol, and ergosterol.

5. The combination according to claim 4 wherein said liquid crystalline material is a cholesteryl compound.

6. The combination according to claim 4 wherein a quantity of cholesteryl halide is admixed with said liquid crystalline material.

7. The combination according to claim 6 wherein said halide is selected from the group consisting of cholesteryl chloride, cholesteryl bromide, and cholesteryl iodide.

8. The combination according to claim 6 wherein said halide consists of cholesteryl chloride.

9. The combination according to claim 6 wherein said halide is present in the amount of about 15 to about 40 percent of the resulting composition.

10. The combination according to claim 4 wherein said cholesteric esters include at least one of the group consisting of the oleyl carbonates and the nonanoates, together with a quantity of cholesteryl halide.

11. The combination according to claim 10 wherein said oleyl carbonates include high cholesteryl oleyl carbonate and low cholesteryl oleyl carbonate.

12. The combination according to claim 11 wherein said cholesteryl halide is present in the amount of about 22 percent to about 27 percent, said high cholesteryl oleyl carbonate is present in the amount of about 50 percent to about 75 percent, said low cholesteryl oleyl carbonate is present in the amount of about 0 percent to about 23 percent, and said cholesteryl nonanoate is present in the amount of about 0 percent to about 15 percent.

13. The combination according to claim 1 wherein said light absorbing means are supported on said displacing means.

14. The combination according to claim 1 wherein said displacing means include a flexible membrane sealed to said container means so that a portion thereof can be displaced toward said container means while another portion thereof can be displaced away from said container means.

15. A display device for exhibiting a color pattern, said device comprising container means having a light-transmitting section and containing a thin sandwich of cholesteric liquid crystalline material within said container means, said material having characteristics of selective visual light scattering to exhibit substantially temperature insensitive color patterns within a range of temperatures at which said display device is normally utilized and of transmitting a substantial quantity of impinging visual light, light-absorbing means supported by at least one of said liquid crystalline material and said container means for absorbing at least a substantial proportion of said transmitted light, said container means being configured so as to permit substantial volumetric flow of said material within said container means, said material including a quantity of cholesteryl halide and having an additional characteristic of a selective light frequency scattering which is variable in accordance with applied deformational stresses, and means coupled to said container means for applying said stresses.

16. The combination according to claim 15 wherein said halide is selected from the group consisting of cholesteryl chloride, cholesteryl bromide and cholesteryl iodide.

17. The combination according to claim 15 wherein said halide consists of cholesteryl chloride.

18. The combination according to claim 15 wherein said halide is present in the amount of about 15 percent to about 40 percent of the resulting composition.

19. The combination according to claim 15 wherein said cholesteric material includes at least one of the group consisting of high and low oleyl carbonates and the nonanoates.

20. The combination according to claim 19 wherein said cholesteryl halide is present in the amount of about 22 percent to about 27 percent, high cholesteryl oleyl carbonate is present in the amount of about 50 percent to about 75 percent, low cholesteryl oleyl carbonate is present in the amount of 0 percent to about 23 percent, and cholesteryl nonanoate is present in the amount of 0 present to about 15 percent.