High contrast, moisture resistant antistatic/antireflective coating for CRT display screen

• US 6,746,530 B2
• Filed: 08/02/2001
• Issued: 06/08/2004
• Est. Priority Date: 08/02/2001
• Status: Expired due to Term

• Current Assignee: CPT Technology (Group) Co., Ltd.
• Original Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Inventors: Wang, Shi-Sheng
• Primary Examiner(s): BRUNSMAN, DAVID M
• Application Number:
  US09/921,342
• Publication Number:
  US 20030029357A1
• Time in Patent Office: 1,041 Days
• Field of Search: 313/479, 106/287.11, 106/287.14, 160/287.16
• US Class Current: 106/287.16
• CPC Class Codes: C03C 17/28 with organic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 17/30 with silicon-containing compounds
• CPC Class Codes: H01J 2211/446 Electromagnetic shielding means; Antistatic means
• CPC Class Codes: H01J 2229/8632 characterised by the material
• CPC Class Codes: H01J 2229/8635 Antistatic shielding
• CPC Class Codes: H01J 2229/8636 Electromagnetic shielding
• 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

Abstract

In general, increased video image contrast is achieved by reducing light transmission through an antistatic/antireflective (ASAR) coating disposed on the surface of the display screen of a cathode ray tube (CRT) by adding an organic dye to the coating. A silane coupling agent is added to the coating to prevent diffusion of the dye out of the coating which gives rise to undesirable water marks on the display screen. However, the silane coupling agent at the required concentrations weakens the mechanical strength of the coating, reduces its electrical conductivity, and changes its light reflective index. To avoid this, two or more different silane coupling agents are added to the ASAR coating with the plural silane coupling agents having an additive, or combining, effect which allows for the use of reduced amounts of the coupling agents and avoids the aforementioned problems. One agent is hydrophobic, while the other bonds to the organic dye.

Claims

1. For use on an outer surface of a glass faceplate of a self-emitting display device, wherein the glass faceplate includes a phosphor coating on an inner surface thereof, and wherein the phosphor coating is responsive to energetic electrons incident thereon for providing light for presentation of a video image on the glass faceplate, a coating comprising:

an antireflective layer disposed on the outer surface of the faceplate;

an organic dye disposed in said antirefiective layer for increasing color purity and contrast of the video image presented on the glass faceplate;

a first silane binding agent disposed in the antireflective layer for bonding to the dye and preventing diffusion of the dye out of the antireflective layer; and

a second silane binding agent disposed in and bonded to the antireflective layer for providing the antireflective layer with increased water resistance for preventing washing out of the dye from the antireflective layer.

2. The coating of claim 1 wherein said organic dye is acidic and said antireflective layer includes TES, and wherein said first silane binding agent has a structure of:

3. The coating of claim 2 wherein the ratio of said first silane binding agent to organic dye is 6:

100.

4. The coating of claim 1 wherein said second silane binding agent is a hydrophobic silane binding agent.

5. The coating of claim 4 wherein said second silane binding agent reduces moisture permeation in said antireflective layer in high humidity conditions.

6. The coating of claim 5 wherein said second silane binding agent has a structure of:

7. The coating of claim 6 wherein the ratio of said second silane binding agent to said organic dye is 1:

10.

8. The coating of claim 1 wherein said antireflective layer is also antistatic in composition.

9. The coating of claim 1 further comprising an antistatic layer disposed intermediate and in contact with the glass faceplate and said antireflective layer.