Cathode-ray tube and method of producing the same

• US 5,519,282 A
• Filed: 12/21/1993
• Issued: 05/21/1996
• Est. Priority Date: 12/25/1992
• Status: Expired due to Fees

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Okuda, Hiroshi, Takizawa, Tomoki
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): RICHARDSON, LAW
• Application Number:
  US08/170,765
• Time in Patent Office: 882 Days
• Field of Search: 313/478, 313/479
• US Class Current: 313/478
• CPC Class Codes: H01J 2209/012 Coating
• CPC Class Codes: H01J 2229/003 Preventing or cancelling fields entering the enclosure
• CPC Class Codes: H01J 2229/89 Optical components associated with the vessel
• CPC Class Codes: H01J 2229/8915 Surface treatment of vessel or device, e.g. controlled surface roughness
• CPC Class Codes: H01J 2229/8918 by using interference effects
• CPC Class Codes: H01J 29/867 Means associated with the outside of the vessel for shielding, e.g. magnetic shields screens for shielding inside the vessel H01J29/06; magnetic shielding in general H05K9/00
• 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

A cathode-ray tube (CRT) of anti-static-processed type and further a cathode-ray tube which screens a leakage electric field (VLF band width) has a triple coat layer formed on a face plate thereof. The triple coat layer includes a high-refractive transparent conductive layer, a low-refractive smooth transparent layer, and a low-refractive rough transparent layer; and is formed on the face plate to reduce the weight of the CRT, minimize the deterioration of the resolution and contrast of images displayed, diminish the reflection of external light, and provide sufficient film strength for practical use.

Claims

1. A cathode-ray tube provided with a face plate, comprising:

a high-refractive transparent conductive layer formed on an outer surface of said face plate said high-refractive transparent conductive layer having an optical thickness equal to 1/4 of a specified wavelength of incident light to said face plate; and

a low-refractive smooth transparent layer formed on the surface of said high-refractive transparent conductive layer; and

a low-refractive rough transparent layer formed on the surface of said low-refractive smooth transparent layer, and said low-refractive smooth transparent layer and said low-refractive rough transparent layer having a combined optical thickness equal to 1/4 of said specified wave-length.

2. A cathode-ray tube according to claim 1, wherein said specified wavelength is 550 nm.

3. A cathode-ray tube according to claim 1, wherein

said low-refractive rough transparent layer has a glossiness with respect to said face plate of 75 to 85%.

4. A cathode-ray tube provided with a face plate, comprising:

a high-refractive transparent conductive layer formed on an outer surface of said face plate, said high-refractive transparent conductive layer containing carbon black; and

a low-refractive transparent section formed on a surface of said high-refractive transparent conductive layer, said low-refractive transparent section having a low-refractive index relative to said high-refractive transparent conductive layer, and said high-refractive transparent conductive layer having a high-refractive index relative to said low-refractive transparent section.

5. A cathode-ray tube according to claim 4, wherein said low-refractive transparent section comprises:

a low-refractive smooth transparent layer formed on the surface of said high-refractive transparent conductive layer; and

a low-refractive rough transparent layer formed on the surface of said low-refractive smooth transparent layer.

6. A cathode-ray tube provided with a face plate, comprising:

a high-refractive transparent conductive layer formed on an outer surface of said face plate, said high-refractive transparent conductive layer containing indium oxide; and

a low-refractive transparent section formed on a surface of said high-refractive transparent conductive layer, said low-refractive transparent section having a low-refractive index relative to said high-refractive transparent conductive layer, and said high-refractive transparent conductive layer having a high-refractive index relative to said low-refractive transparent section.

7. A cathode-ray tube according to claim 6, wherein said low-refractive transparent section comprises:

a low-refractive smooth transparent layer formed on the surface of said high-refractive transparent conductive layer; and

a low-refractive rough transparent layer formed on the surface of said low-refractive smooth transparent layer.