Enhanced light transmission conductive coated transparent substrate

• US 6,787,240 B2
• Filed: 06/18/2001
• Issued: 09/07/2004
• Est. Priority Date: 06/23/2000
• Status: Expired due to Fees

• Current Assignee: TPK Touch Solutions (Xiamen) Inc. (TPK Holding Co., Ltd.)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Getz, Catherine A.
• Primary Examiner(s): Morris, Terrel
• Assistant Examiner(s): Piziali, Andrew T
• Application Number:
  US09/883,654
• Publication Number:
  US 20010055673A1
• Time in Patent Office: 1,177 Days
• Field of Search: 428/428, 428/432, 428/697, 428/699, 428/701, 428/702
• US Class Current: 428/428
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2218/365 Coating different sides of a glass substrate
• CPC Class Codes: G02B 1/116 including electrically conducting layers
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

A reduced glare, conductive coated panel having increased visible light transmission and suitable for use as a touch screen, digitizer panel or a substrate in an information display includes a transparent substrate, one or more thin film interference layers forming a thin film stack on each of the opposite surfaces of the substrate, and a transparent, electrically conductive coating on the outermost layer of one or both of the thin film stacks. The method preferably includes dipping the substrate in a solution of a precursor for the thin film material at an angle to the vertical and the surface of the solution such that the layer of one side of the substrate has a thickness different from that on the opposite side, curing the layers, and applying the transparent electrically conductive coating thereover.

Claims

1. A reduced glare, conductive coated panel comprising:

a transparent substrate having a first surface and a second surface;

a first, multilayer stack disposed on said first surface of said substrate, said first stack comprising at least a first transparent, thin film layer, a second transparent, thin film layer and a third transparent, thin film layer;

a second, multilayer stack disposed on said second surface of said substrate, said second stack comprising at least a first transparent, thin film layer, a second transparent, thin film layer and a third transparent, thin film layer;

each thin film layer in said first stack having a corresponding thin film layer in said second stack;

each of said transparent, thin film layers of said first stack being a wet chemical formed thin film layer and having a refractive index, said first transparent, thin film layer of said first stack being disposed on said first surface of said substrate, said second transparent, thin film layer of said first stack being disposed on said first thin film layer of said first stack, and said third transparent, thin film layer of said first stack being disposed on said second thin film layer of said first stack;

each transparent, thin film layer of said second stack being a wet chemical formed thin film layer and having the refractive index of its corresponding transparent, thin film layer of said first stack;

said first transparent, thin film layer of said second stack being disposed on said second surface of said substrate, said second transparent, thin film layer of said second stack being disposed on said first thin film layer of said second stack, and said third transparent, thin film layer of said second stack being disposed on said second thin film layer of said second stack;

the film thickness of any one of said thin film layers of said second stack being different than the thickness of its corresponding thin film layer of said first stack;

at least one of said thin film layers of said first stack having a thickness greater than the thickness of its corresponding thin film layer of said second stack;

the material composition of said corresponding layers in each of said first and second stacks being the same;

the refractive index of each of said second thin film layers in said first and second stacks being greater than the refractive index of the other thin film layers in said first and second stacks;

the refractive index of said third thin film layer in each of said first and second stacks being less than the refractive index of the other thin film layers in said first and second stacks;

a transparent conductive thin film on said third thin film layer of said first stack, said transparent conductive thin film being a vacuum deposited thin film and comprising a material selected from at least one of indium tin oxide, doped tin oxide, and doped zinc oxide; and

whereby visible light transmission through said coated panel is increased as compared to said substrate coated only with said transparent conductive thin film.

2. The coated panel of claim 1 wherein said transparent substrate is glass.

3. The coated panel of claim 1 wherein said transparent substrate is selected from the group consisting of glass and plastic.

4. The coated panel of claim 1 wherein said first layers in each of said first and second stacks are formed from a combination of silicon dioxide and titanium dioxide, each of said first layers having a refractive index at the sodium D line in the range of from about 1.5 to about 2.0.

5. The coated panel of claim 1 wherein said second layers in each of said first and second stacks are formed from titanium dioxide, said second layers each having a refractive index at the sodium D line of at least about 2.0.

6. The coated panel of claim 1 wherein said third layers in each of said first and second stacks are formed from silicon dioxide, said third layers each having a refractive index at the sodium D line of less than about 1.5.

7. The coated panel of claim 1 wherein said second stack comprises a transparent conductive thin film on said third thin film layer of said second stack, said transparent conductive thin film on said second stack being selected from at least one of indium tin oxide, doped tin oxide, and doped zinc oxide.

8. The coated panel of claim 1 wherein each of said layers of said first stack has a thickness greater than the thickness of said corresponding layer of said second stack on said second surface.

11. The coated panel of claim 4 wherein said second layers in each of said first and second stacks are formed from titanium dioxide, said second layers each having a refractive index at the sodium D line of at least about 2.0.

12. The coated panel of claim 11 wherein said third layers in each of said first and second stacks are formed from silicon dioxide, said third layers each having a refractive index at the sodium D line of less than about 1.5.

13. The coated panel of claim 1 wherein said wet chemical formed thin film layers comprise angle dipped thin film layers wherein said substrate is dipped into a liquid solution of a precursor of the respective first, second or third thin film layers while maintaining said substrate at a predetermined angle to the vertical to simultaneously coat each of said first and second surfaces of said substrate or the previous thin film layers on said first and second surfaces of said substrate, following which said coated layers are cured with at least one of ultraviolet light, air drying and heating/firing.

14. The coated panel of claim 13 wherein said vacuum deposited thin film comprises a sputtered thin film.

9. A reduced glare, conductive coated panel comprising:

a transparent substrate having a first surface and a second surface;

a first, transparent, interference thin film disposed on said first surface of said substrate;

a second, transparent, interference thin film disposed on said second surface of said substrate;

said first thin film corresponding to but having a thickness greater than said second thin film;

a third thin film disposed on said first thin film and a fourth thin film disposed on said second thin film, said third thin film corresponding to but having a thickness greater than said fourth thin film;

a fifth thin film disposed on said third thin film and a sixth thin film disposed on said fourth thin film, said fifth thin film corresponding to but having a thickness greater than said sixth thin film;

the material composition of each of said corresponding thin films being the same; and

a transparent conductive coating on said fifth thin film, said transparent conductive coating being a vacuum deposited coating and selected from at least one of indium tin oxide, doped tin oxide, and doped zinc oxide;

each of said first, second, third, fourth, fifth and sixth thin films being a wet chemical formed thin film and having a refractive index, the refractive index of said third and fourth thin films being greater than the refractive index of the other thin films, said refractive index of the fifth and sixth thin films being less than the refractive index of the other thin films; and

whereby visible light transmission through said coated panel is increased compared to said substrate coated only with said transparent conductive coating.

10. The coated panel of claim 9 also including said transparent conductive coating on said sixth thin film.

15. The coated panel of claim 9 wherein said wet chemical formed thin films comprise angle dipped thin films wherein said substrate is dipped into a liquid solution of a precursor of the respective first and second, or third and fourth, or fifth and sixth thin films while maintaining said substrate at a predetermined angle to the vertical to simultaneously coat each of said first and second surfaces of said substrate or the previous thin films on said first and second surfaces of said substrate, following which said coated layers are cured with at least one of ultraviolet light, air drying and heating/firing.

16. The coated panel of claim 15 wherein said vacuum deposited coating comprises a sputtered coating.