IMAGING SYSTEM

• US 3,655,971 A
• Filed: 08/12/1969
• Issued: 04/11/1972
• Est. Priority Date: 08/12/1969
• Status: Expired due to Term

• Current Assignee: James E. Adams, James H. Becker, Joseph J. Wysocki, Werner E.L. Haas
• Original Assignee: James E. Adams, James H. Becker, Joseph J. Wysocki, Werner E.L. Haas
• Inventors: Haas, Werner E. L., Adams, James E., Becker, James H., Wysocki, Joseph J.
• Primary Examiner(s): Lawrence, James W.
• Assistant Examiner(s): Nelms, D. C.
• Application Number:
  US04/849,418
• Time in Patent Office: 973 Days
• Field of Search: 250/83CD,83.3HP,49.5E,83R,65R,65S 351/60 23/23LC 96/48
• US Class Current: 430/19
• CPC Class Codes: G02F 1/132 Thermal activation of liquid crystals exhibiting a thermo-optic effect
• CPC Class Codes: G03C 1/73 containing organic compounds

Abstract

A system wherein a film of liquid crystalline material is exposed to ultraviolet radiation thereby producing a visible image.

Claims

1. An imaging method comprising:

providing a film comprising a cholesteric liquid crystalline material;

providing said material in its aligned state; and

, exposing in imagewise configuration said film to ultraviolet electromagnetic radiation thereby producing a visible image on the film material and at least in part changing the chemical composition of said film material.

2. The imaging method of claim 1 wherein said ultraviolet radiation comprises radiation of wavelengths of less than about 3,000 A.

3. The method of claim 1 wherein said film is provided on a substrate.

4. The method of claim 1 wherein said film is of a thickness in the range between about 0.1 and about 1,000 microns.

5. The method of claim 1 wherein said film is of a thickness in the range between about 1 and about 50 microns.

6. The method of claim 1 wherein said film is selectively exposed to ultraviolet radiation of a plurality of different total exposures in a plurality of different areas, whereby an image is produced having a plurality of different colors in said different areas of selective exposure.

7. The method of claim 1 wherein the exposure in imagewise configuration is performed using an optical mask.

8. The method of claim 7 wherein the optical mask comprises a transparency having different areas of different transmissivity to ultraviolet radiation.

9. A method comprising the method of claim 1 and physically remixing the material comprising said liquid crystalline film thereby destroying the visible image thereon and thereby providing the film in its aligned state suitable for re-exposure.

10. The method of claim 3 wherein said substrate is sufficiently transparent to view the liquid crystalline material therethrough.

11. The method of claim 1 wherein said liquid crystalline material comprises a material selected from the group consisting of:

cholesteryl iodide, cholesteryl bromide, cholesteryl chloride, cholesteryl nonanoate, and oleyl cholesteryl carbonate.

12. The method of claim 1 wherein the film is exposed under conditions wherein the cholesteric liquid crystalline material is outside of its cholesteric liquid crystalline state, and it is thereafter brought into said liquid crystalline state whereupon the image becomes visible.

13. The method of claim 1 wherein said visible image is a permanently visible image.

14. An imaging method comprising:

providing a film comprising a cholesteric liquid crystalline material;

providing said material in its unaligned state; and

exposing in imagewise configuration said film to ultraviolet electromagnetic radiation thereby producing a latent image on the film material and at least in part changing the chemical composition of said film material; and

developing said latent image into a visible image by heating the exposed film.

15. The imaging method of claim 14 wherein said ultraviolet radiation comprises radiation of wavelengths of less than about 3,000.

16. The method of claim 14 wherein said film is provided on a substrate.

17. The method of claim 16 wherein said substrate is sufficiently transparent to view the liquid crystalline material therethrough.

18. The method of claim 14 wherein said film is of a thickness in the range between about 0.1 and about 1,000 microns.

19. The method of claim 14 wherein said film is of a thickness in the range between about 1 and about 50 microns.

20. The method of claim 14 wherein said liquid crystalline material comprises a material selected from the group consisting of:

cholesteryl iodide, cholesteryl bromide, cholesteryl chloride, cholesteryl nonanoate, and oleyl cholesteryl carbonate.

21. The method of claim 14 wherein said film is selectively exposed to ultraviolet radiation of a plurality of different total exposures in a plurality of different areas whereby an image is produced having a plurality of different colors in said different areas of selective exposure.

22. The method of claim 14 wherein the exposure in imagewise configuration is performed using an optical mask.

23. The method of claim 22 wherein the optical mask comprises a transparency having different areas of different transmissivity to ultraviolet radiation.

24. A method comprising the method of claim 14, and physically remixing the material comprising said liquid crystalline film thereby destroying the visible image thereon and providing the film in its unaligned state suitable for re-exposure.

25. The method of claim 14 wherein the film is exposed under conditions wherein the cholesteric liquid crystalline material is outside of its cholesteric liquid crystalline state, and it is thereafter brought into said liquid crystalline state whereupon the image becomes visible.

26. The method of claim 14 wherein said visible image is a permanently visible image.

27. The method of claim 14 wherein said visible image is a permanently visible image.

28. A deformation imaging process comprising providing a filM comprising a material having a cholesteric liquid crystalline mesophase, exposing in imagewise configuration said film to ultraviolet electromagnetic radiation while said film is in its cholesteric liquid crystalline mesophase, thereby producing a deformation in said film at the boundaries between exposed and unexposed areas.

29. The process of claim 28 wherein the deformation is enhanced by heating the deformation imaged film above the isotropic transition temperature of said film material.

30. The process of claim 28 wherein said deformation imaging is accompanied by a visible change in color of the exposed area of said film.

31. The imaging process of claim 28 wherein said ultraviolet radiation comprises radiation of wavelengths of less than about 3,000. A.

32. The process of claim 28 wherein said film is provided on a substrate.

33. The method of claim 32 wherein said substrate is sufficiently transparent to view the liquid crystalline material therethrough.

34. The process of claim 28 wherein said film is of a thickness in the range between about 0.1 and about 1,000 microns.

35. The process of claim 28 wherein said film is of a thickness in the range between about 1 and about 50 microns.

36. The method of claim 30 wherein said liquid crystalline material comprises a material selected from the group consisting of:

cholesteryl iodide, cholesteryl bromide, cholesteryl chloride, cholesteryl nonanoate, and oleyl cholesteryl carbonate.

37. The process of claim 30 wherein said film is selectively exposed to ultraviolet radiation of a plurality of different total exposures in a plurality of different areas whereby an image is produced having a plurality of different colors in said different areas of selective exposure.

38. The process of claim 28 wherein the exposure in imagewise configuration is performed using an optical mask.

39. The process of claim 38 wherein the optical mask comprises a transparency having different areas of different transmissivity to ultraviolet radiation.

40. A process comprising the process of claim 28 and physically remixing the material comprising said liquid crystalline film thereby destroying the image thereon and providing the film in condition for re-exposure.

41. The method of claim 30 wherein said visible image is a permanently visible image.

42. An imaging method comprising:

providing a film comprising a cholesteric liquid crystalline material;

providing said material in its unaligned state; and

exposing in imagewise configuration said film to ultraviolet electromagnetic radiation thereby producing a latent image on the film material and at least in part changing the chemical composition of said film material; and

developing said latent image into a visible image by contacting the exposed film with organic solvent vapors.

43. The imaging method of claim 42 wherein said ultraviolet radiation comprises radiation of wavelengths of less than about 3,000 Angstroms.

44. The method of claim 42 wherein said film is provided on a substrate.

45. The method of claim 44 wherein said substrate is sufficiently transparent to view the liquid crystalline material therethrough.

46. The method of claim 42 wherein said film is of a thickness in the range between about 0.1 and about 1,000 microns.

47. The method of claim 42 wherein said film is of a thickness in the range between about 1 and about 50 microns.

48. The method of claim 42 wherein said liquid crystalline material comprises a material selected from the group consisting of:

cholesteryl iodide, cholesteryl bromide, cholesteryl chloride, cholesteryl nonanoate, and oleyl cholesteryl carbonate.

49. The method of claim 42 wherein said film is selectively exposed to ultraviolet radiation of a plurality of different total exposures in a plurality of different areas whereby an image is produced having a plurality of different colors in said different areas of selective exposure.

50. The method of claim 42 wherein the exposure in imagewise configuration is performed using an optical mask.

51. The method of claim 50 wherein the optical mask comprises a transparency having different areas of different transmissivity to ultraviolet radiation.

52. A method comprising the method of claim 42, and physically remixing the material comprising said liquid crystalline film thereby destroying the visible image thereon and providing the film in its unaligned state suitable for re-exposure.

53. The method of claim 42 wherein the film is exposed under conditions wherein the cholesteric liquid crystalline material is outside of its cholesteric liquid crystalline state, and it is thereafter brought into said liquid crystalline state whereupon the image become visible.