Apparatus and method for a molded waveguide for use with touch screen displays

• US 7,520,050 B2
• Filed: 12/18/2006
• Issued: 04/21/2009
• Est. Priority Date: 06/04/2004
• Status: Expired due to Fees

• Current Assignee: POA Sana Liquidating Trust
• Original Assignee: POA Sana Liquidating Trust
• Inventors: Graham, David S.
• Primary Examiner(s): ARBES, CARL J
• Application Number:
  US11/612,099
• Publication Number:
  US 20070154133A1
• Time in Patent Office: 855 Days
• Field of Search: 298/25, 298/32, 385/129, 385/132
• US Class Current: 29/825
• CPC Class Codes: G02B 6/124 Geodesic lenses or integrated gratings
• CPC Class Codes: G02B 6/138 by using polymerisation
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

An apparatus and method for an inexpensive, simple to make, self-aligning molded waveguide made of an optically transparent material and that can be used to generate a grid or lamina of light for use with touch screen displays. The molded waveguide substrate includes a plurality of lenses and a plurality of waveguide grooves corresponding to the plurality of integral lenses respectively. After the substrate is molded, the grooves are filled with an optically transparent material to optically couple and align the plurality of lenses and the plurality of grooves respectively. In one application, the molded waveguide substrate is positioned adjacent a touch screen device. A light transmitter and an imaging device are optically coupled to the molded waveguide substrate, and a processing device is coupled to the imaging device. The processing device is configured to determine a data entry to the touch screen by deciphering the coordinates of an interrupt in the light created in the free space adjacent the touch screen device when a data entry is being made to the touch screen device.

Claims

1. A method, comprising;

molding a waveguide substrate, the molding of the waveguide substrate including;

molding a plurality of optical elements integral with the substrate; and

molding a plurality of negative waveguide grooves in the substrate and optically aligned with the plurality of optical elements integrally molded with the substrate respectively; and

filling the negative grooves with an optically transparent material and thereby optically coupling the plurality of optical elements and the plurality of grooves filled with the optically transparent material respectively.

2. The method of claim 1, wherein the molding the plurality of optical elements further comprises molding a plurality of three-dimensional lenses.

3. The method of claim 1, wherein the molding of the plurality of optical elements further comprises molding the optical elements to have a dimension ranging from 50 to 2000 microns in diameter.

4. The method of claim 1, wherein the molding the plurality of negative waveguide grooves further comprises forming the grooves approximately 5 to 50 microns deep into the substrate.

5. The method of claim 1, wherein the molding the plurality of negative waveguide grooves further comprises forming the grooves approximately 5 to 50 microns wide.

6. The method of claim 1, wherein the molding the waveguide substrate further comprises the molding of the substrate with a material having an index of refraction ranging from n=1.0 to 2.0.

7. The method of claim 1, further comprising molding the waveguide substrate from a material having a first index of refraction and filling the grooves with the optically transparent material having a second index of refraction, wherein the second index of refraction is greater than the first index of refraction.

8. The method of claim 1, further comprising molding the plurality of optical elements to have optical properties to create a lamina of light when light is provided to inputs of the waveguides grooves.

9. The method of claim 1, further comprising molding the plurality of optical elements to have optical properties to create a grid of light when light is provided to inputs of the waveguides grooves.

10. The method of claim 1, further comprising molding the waveguide substrate having a first sub-set of the plurality of the negative waveguide grooves extending in a first direction along a first axis.

11. The method of claim 10, further comprising molding the waveguide substrate having a second sub-set of the plurality of the negative waveguide grooves extending in a second direction along a second axis.

12. The method of claim 11, wherein the first axis and the second axis are perpendicular to each other.

13. The method of claim 1, further comprising molding the waveguide substrate such that the plurality of the negative waveguide grooves extend on a first surface of the substrate and a second surface of the substrate, wherein the first surface and the second surface are either perpendicular or parallel to one another.

14. The method of claim 1, wherein a first sub-set of the plurality of waveguide grooves are configured to be optically coupled to a light emitter.

15. The method of claim 1, wherein a second sub-set of the plurality of grooves are configured to be optically coupled to an imaging device.

16. The method of claim 1, wherein the filling of the negative grooves further comprises using capillary action to fill the grooves with the optically transparent material.

17. The method of claim 1, wherein the filling of the negative grooves further comprises over-filling the grooves with the optically transparent material and then removing any excess of the optically transparent material.

18. The method of claim 1, further comprising curing the waveguide substrate after the grooves are filled with the optically transparent material.

19. The method of claim 1, further comprising optically aligning during the molding process the plurality of optical elements and the plurality of the negative waveguide grooves respectively.

20. The method of claim 1, wherein molding the waveguide substrate further comprises molding the waveguide substrate into one of the following shapes:

a one a straight substrate;

square;

L-shaped, rectangle, triangle, round, or an oval shape.

21. The method of claim 1, further comprising:

positioning the molded waveguide substrate adjacent a touch screen device, the molded waveguide being configured to create light in the free space adjacent the touch screen device;

optically coupling a light transmitter to the molded waveguide substrate; and

optically coupling an imaging device to the molded waveguide substrate.

22. The method of claim 21, further comprising connecting a processing device to the imaging device, the processing device configured to determine a data entry to the touch screen by deciphering the coordinates of an interrupt in the light created in the free space adjacent the touch screen device when a data entry is being made to the touch screen device.

23. The method of claim 1, wherein the molding of the waveguide substrate further comprises molding the waveguide substrate using one of the following molding techniques:

injection molding;

compression molding;

embossing;

optical micro-molding.

24. The method of claim 1, wherein the optical elements comprise at least one of, but not limited to the following optical elements:

lenses, gratings, bragg gratings, coupling horns, etc.

25. The method of claim 1, wherein the molding of the negative waveguide grooves further comprises molding the waveguide grooves to have angled walls ranges from 3 to 5 degrees.

26. The method of claim 1, further comprising molding the plurality of negative waveguide grooves to approximately 6 to 8 microns wide and 20 to 25 microns deep.

27. The method of claim 1, further comprising molding the plurality of optical lenses to have a height ranging from 40 to 250 microns.

28. The method of claim 25, further comprising molding the waveguide substrate from a polycarbonate material.

29. The method of claim 1, further comprising molding the plurality of optical lenses to have a diameter ranging from 750 microns to 1 millimeter.

30. The method of claim 1, further comprising molding the waveguide substrate from a light curable material.

31. The method of claim 30, wherein the light curable material comprises an epoxy or urethane.

32. The method of claim 1, wherein the optically transparent material consists of;

a UV curable material, adhesive urethane or an optical epoxy.

33. The method of claim 1, further including treating portions of the waveguide substrate other than those defining the plurality of grooves with a non-stick material that has poor adhesion to optically transparent material;

wherein filling of the negative grooves further comprises over-filling the grooves with the optically transparent material such that the optically transparent material has poor adhesion to said treated portion; and

wherein removing excess portions of the optically transparent material includes removing the material from the treated portions of the substrate.

34. The method of claim 33, wherein treating portions of the waveguide substrate includes forming a layer of Teflon®

on the waveguide substrate such that the Teflon®

material does not extend into the negative grooves.