Optical elements and methods for their manufacture

• US 6,310,733 B1
• Filed: 12/31/1996
• Issued: 10/30/2001
• Est. Priority Date: 08/16/1996
• Status: Expired due to Fees

• Current Assignee: Louis Tullo
• Original Assignee: Louis Tullo
• Inventors: Dolgoff, Eugene
• Primary Examiner(s): Sugarman, Scott J.
• Application Number:
  US08/774,569
• Time in Patent Office: 1,764 Days
• Field of Search: 359/742, 359/743
• US Class Current: 359/743
• CPC Class Codes: G02B 30/52 the 3D volume being constructed from a stack or sequence of 2D planes, e.g. depth sampling systems
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: H04N 13/346 using prisms or semi-transparent mirrors
• CPC Class Codes: H04N 13/395 with depth sampling, i.e. the volume being constructed from a stack or sequence of 2D image planes

Abstract

Improved optical elements having rises and faces, which may have annular or linear grooves, such as Fresnel spherical or cylindrical lenses, and methods of making them, are disclosed wherein an opaque coating is imparted to the rises by methods including positioning pre-printed opaque elements on a substrate such that when the optical element is pressed, stamped, embossed or molded from the substrate, rises of the completed element comprise said pre-printed opaque elements. A reflective element is made by imparting a reflective coating onto a substrate and then a non-reflective coating to the rises, e.g. by applying non-reflective material to the element and selectively cleaning it to leave a coat of non-reflective material adhering to the rises but not the faces. Photoresist, photographic emulsion, or ink may be used as the coating. Unwanted light may also be minimized by using circularly polarized light.

Claims

1. A method for minimizing the light scattered by an optical element having rises and faces, said method comprising circularly polarizing the light impinging on said optical element.

2. An improved optical element having rises and faces, wherein light is substantially blocked from being reflected from said rises, whereby it is prohibited from being seen by an observer viewing an image formed by light reflected by said faces.

3. An improved optical element as in claim 2, wherein said optical element is a reflective optical element and said rises are substantially non-reflective.

4. A method of making an improved optical element, comprising the steps of:

(a) producing an optical element having rises and faces, and

(b) imparting an opaque coating to said rises by a step which comprises;

positioning pre-printed opaque coating elements on a substrate material such that when the optical element is pressed, stamped, embossed or molded from said substrate material, rises of the completed element comprise said pre-printed opaque coating elements.

5. The method of claim 4, wherein said optical element has a series of annular grooves.

6. The method of claim 4, wherein said optical element has a series of linear grooves.

7. The method of claim 4, wherein said optical element is a refractive element.

8. The method of claim 7, additionally comprising:

applying an anti-reflective coating to said refractive element to reduce reflection of light.

9. The method of claim 4, wherein said optical element is a reflective element.

10. An improved optical element having rises and faces, wherein an opaque coating has been imparted to said rises by the method of claim 4.

11. The optical element of claim 10, wherein said optical element is a refractive element.

12. The optical element of claim 10, wherein said optical element is a reflective element.

13. A method of making an improved optical element, comprising the steps of:

(a) producing a reflective optical element having rises and faces, and

(b) imparting a coating to said rises which is substantially non-reflective as compared to the faces.

14. The method of claim 13, wherein said optical element has a series of annular grooves.

15. The method of claim 13, wherein said optical element has a series of linear grooves.

16. The method of claim 13, wherein said imparting step (b) is performed by:

(i) applying non-reflective material to said optical element; and

(ii) selectively cleaning said optical element so as to leave a coat of non-reflective material adhering to said rises but not to said faces.

17. The method of claim 13, additionally comprising:

roughening said rises before said imparting step (b), thereby enhancing the adherence of said non-reflective material thereto.

18. The method of claim 13, wherein said imparting step (b) is performed by:

coating a photoresist on said faces, said photoresist being coated by;

applying a coating of photoresist to the optical element so as to coat substantially all faces and rises;

selectively illuminating said coating of photoresist such that when the photoresist is developed, it adheres to said faces but is removable from said rises upon development;

developing said coating to remove said photoresist from said rises, so as to leave photoresist remaining on said faces;

applying to said optical element non-reflective material that is adherent thereto, wherein said non-reflective material is prevented from adhering to said faces because of the photoresist thereon;

removing said photoresist from said faces by rinsing with a developer to

dissolve away the remaining photoresist together with any of said non-reflective substance coated thereon;

whereby an optical element is produced having rises coated with non-reflective material and faces that are reflective.

19. The method of claim 13, wherein said imparting step (b) is performed by:

coating a non-reflective photoresist on said rises, said photoresist being coated by;

applying a coating of photoresist to the optical element so as to coat substantially all faces and rises;

selectively illuminating said coating of photoresist such that when the photoresist is developed, it adheres to said rises but is removable from said faces upon development;

developing said coating to remove said photoresist from said faces, so as to leave photoresist on said rises;

whereby an optical element is produced having rises coated with non-reflective material and faces that are reflective.

20. The method of claim 16, wherein the applying step (i) is performed by dipping or spraying.

21. The method of claim 16, wherein the cleaning step (ii) is performed by subjecting the optical element to a wash.

22. The method of claim 16, wherein grooves are formed in the surface of the rises of the optical element when it is produced, and the cleaning step (ii) is performed by wiping or doctor blading, whereby non-reflective material is left in the grooves.

23. An improved reflective optical element having rises and faces, wherein a coating has been imparted by the method of claim 13.

24. A method of making an improved optical element, comprising the steps of:

(a) producing an optical element having rises and faces, wherein the rises are roughened to facilitate adherence of an opaque light-absorbent coating thereon;

(b) applying a coating to the rises and faces; and

then

(c) removing the coating from the faces;

whereby the coating on the rises prevents light rays from being transmitted through or reflected from the rises.

25. The method of claim 24, wherein the applying step (b) is performed by dipping or spraying.

26. The method of claim 24, wherein the removing step (c) is performed by subjecting the optical element to a wash.

27. The method of claim 24, wherein the rises are roughened by forming grooves in the surface thereof when the optical element is produced, and the removing step (c) is performed by wiping or doctor blading, whereby coating material is left in the grooves.

28. An improved optical element having rises and faces, wherein a coating has been applied to said rises by the method of claim 24.

29. A method of making an improved optical element, comprising the steps of:

(a) producing an optical element having rises and faces, and

(b) imparting an opaque coating to said rises by a process which comprises;

coating a photographic emulsion on the rises and faces;

selectively illuminating the optical element in a manner to cause the photographic emulsion upon development to become dark on rises and clear on faces; and

then developing the photographic emulsion and leaving it in place thereon.

30. The method of claim 29, wherein the optical element is selectively illuminated by scanning it with a laser.

31. The method of claim 29, wherein the optical element is selectively illuminated by exposing it to a pattern that is annular if the rises are circular or is linear if the rises are linear.

32. An improved optical element having rises and faces, wherein an opaque coating has been imparted to said rises by the method of claim 29.

33. A method of making an improved optical element, comprising the steps of:

(a) producing an optical element having rises and faces, and

(b) imparting an opaque light-absorbent coating to said rises by a process which comprises;

coating a photographic emulsion on the rises and faces;

selectively illuminating the optical element by exposing it in a manner to cause the photographic emulsion upon development to become hydrophobic on rises and hydrophilic on faces;

developing the photographic emulsion; and

applying greasy ink and water to the rises and faces, whereby greasy ink adheres to the rises and not the faces.

34. An improved optical element having rises and faces, wherein an opaque light-absorbent coating has been imparted to said rises by the method of claim 33.

35. A method of making an improved optical element, comprising the steps of:

(a) producing an optical element having rises and faces, and

(b) providing opaque markings that are not on the surface of the rises but which are so positioned with respect to the rises that the opaque markings intercept a substantial portion of the light which would pass through or reflect off of the rises.

36. The method of claim 35, wherein the opaque markings are on a transparent element having the opaque markings pre-printed thereon.

37. An improved optical element having rises and faces, wherein opaque markings have been provided by the method of claim 35.

38. A method of making an improved optical element, comprising the steps of:

(a) producing an optical element having a first side with rises and faces and a reverse side without rises and faces, and

(b) providing opaque markings on said reverse side, the markings being so positioned that they intercept a substantial portion of the light which would otherwise pass through or reflect from the rises.

39. An improved optical element having rises and faces, wherein opaque markings have been provided by the method of claim 38.