Processes for forming a faceplate having a transparent substrate with diffuser surface

• US 6,620,454 B2
• Filed: 08/23/2002
• Issued: 09/16/2003
• Est. Priority Date: 07/29/1994
• Status: Expired due to Fees

• Current Assignee: TPK Touch Solutions (Xiamen) Inc. (TPK Holding Co., Ltd.)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Varaprasad, Desaraju V., Dornan, Craig A., Getz, Catherine A.
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US10/227,109
• Publication Number:
  US 20020197409A1
• Time in Patent Office: 389 Days
• Field of Search: 427/164, 427/165, 427/168, 427/169, 427/387, 427/379
• US Class Current: 427/164
• CPC Class Codes: C03C 17/25 by deposition from the liquid phase
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2217/216 ZnO
• CPC Class Codes: C03C 2217/231 In2O3/SnO2
• CPC Class Codes: C03C 2217/24 Doped oxides
• CPC Class Codes: C03C 2218/11 from solutions or suspensions
• CPC Class Codes: H01J 29/868 Screens covering the input or output face of the vessel, e.g. transparent anti-static coatings, X-ray absorbing layers
• CPC Class Codes: H01J 29/896 Anti-reflection means, e.g. eliminating glare due to ambient light

Abstract

Processes for making a transparent substrate having a glare reducing diffuser surface coating on its surface are disclosed to provide a touchscreen or a faceplate such as for attachment to a screen for a cathode ray tube or other display device. Preferably, the faceplate has at least one of a gloss reading of less than about 80 gloss units, and a resolution of at least about 3 lines per millimeter. The method includes coating at least one layer of a precursor solution onto a functional coating provided on at least one surface of the substrate, and firing the layer to form the faceplate having a diffuser surface coating on the functional coated substrate. Preferably, the precursor solution at least comprises a metal oxide precursor dissolved in an organic solvent. Also, the firing preferably occurs at a temperature of at least 250° C. The functional coating is preferably provided as a transparent conductive coating.

Claims

1. A method of forming an improved coated faceplate, said method comprising:

providing a transparent substrate coated with a functional coating on at least one surface, said functional coating being selected from the group consisting of indium tin oxide, tin oxide, doped tin oxide, and doped zinc oxide;

providing a precursor solution, said precursor solution at least comprising a metal oxide precursor dissolved in an organic solvent;

coating at least one layer of said precursor solution onto said functional coating of said transparent substrate;

firing said at least one layer of said precursor solution at a temperature of at least about 250°

C. to form the faceplate having a diffuser surface coating on said functional coating of said transparent substrate, said coated faceplate having a resolution of at least about 3 lines per millimeter.

2. The method of claim 1 including forming said diffuser surface coating to have a thickness of less than about 3 microns.

3. The method of claim 1 including forming said faceplate to have a gloss reading of greater than about 30 gloss units.

4. The method of claim 1 including forming said faceplate to have a gloss reading in the range of about 30 to about 80 gloss units and a resolution in the range of about 3 lines to about 15 lines per millimeter.

5. The method of claim 1 including forming said faceplate to have a gloss reading of about 30 to about 80 gloss units.

6. The method of claim 1 including forming said faceplate to have a gloss reading in the range of about 40 to about 70 gloss units.

7. The method of claim 1 including forming said faceplate to have a resolution in the range of about 3 to about 15 lines per millimeter.

8. The method of claim 1 including forming said faceplate to have a resolution in the range of about 4 to about 12 lines per millimeter.

9. The method of claim 1 including providing indium tin oxide as said functional coating.

10. The method of claim 1 including providing doped tin oxide as said functional coating.

11. The method of claim 1 wherein said firing is performed by heating said at least one layer of said precursor solution to a temperature in the range of from about 250°

C. to about 600°

C.

12. The method of claim 11 wherein said firing is performed by heating said at least one layer of said precursor solution to a temperature in the range of from about 350°

C. to about 550°

C.

13. The method of claim 12 wherein said firing is performed by heating at least one layer of said precursor solution to a temperature in the range of from about 500°

C. to about 520°

C.

14. The method of claim 11 wherein said firing is performed by heating said at least one layer of said precursor solution for a time period of from about 3 minutes to about 3 hours.

15. The method of claim 1 including partially densifying said precursor solution by exposure to heating prior to firing.

16. The method of claim 1 including selecting said precursor solution from the group consisting of one or more alkoxides, halides, oxyhalides, acetates, peroxyesters, nitrates, and combinations thereof.

17. The method of claim 1 wherein said coating of said precursor solution comprises spraying said precursor solution onto said functional coated transparent substrate.

18. The method of claim 17 wherein said spraying of said at least layer of said precursor solution is performed utilizing an average spray discharge rate of from about 0.01 liters per minute to about 1.0 liters per minute.

19. The method of claim 1 wherein said coating of said at least one layer of said precursor solution is performed while the temperature of said precursor solution and said substrate is at about ambient temperature.

20. The method of claim 1 wherein said coating of said at least one layer of said precursor solution is performed at a relative humidity of from about 25% RH to about 60% RH.

21. The method of claim 1 including forming said precursor solution to include an alkoxide of the formula Si(OR)₄, such that R is a C₁ to C₆ alkyl group.

22. The method of claim 1 including forming said precursor solution to include tetraethylorthosilicate.

23. The method of claim 1 including forming said precursor solution to include an organic solvent selected from the group consisting of alcohols, esters, ethers and anhydrides.

24. The method of claim 1 including providing said transparent substrate with a transparent conductive coating as said functional coating.

25. The method of claim 24 including selecting said transparent conductive coating from the group consisting of said indium tin oxide, said tin oxide said doped tin oxide, and doped zinc oxide.

26. The method of claim 24 including providing said transparent substrate coated with indium tin oxide as said transparent conductive coating.

27. The method of claim 24 including providing said transparent substrate coated with doped tin oxide as said transparent conductive coating.

28. The method of claim 1 including forming said faceplate as a touchscreen.