Color cathode-ray-tube with electrical and optical coating film

• US 5,200,667 A
• Filed: 05/03/1991
• Issued: 04/06/1993
• Est. Priority Date: 05/10/1990
• Status: Expired due to Term

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Iwasaki, Yasuo, Okuda, Hiroshi
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): Horabik, Michael
• Application Number:
  US07/695,322
• Time in Patent Office: 704 Days
• Field of Search: 313/313, 313/467, 313/480, 313/478, 313/479, 313/473, 313/474
• US Class Current: 313/478
• 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 color cathode ray tube has a coating film formed over an outer surface of a face plate. The coating film prevents a charge-up phenomenon of the face plate and also has a function for improving a contrast performance of the color cathode ray tube. The coating film is composed of a polymer of silicon alkoxide, translucent conductive particles and plural types of dyes or pigments. The absorption peak of the main absorption band of the coating film is set in the range between the main spectrum wavelength of 570 nm of the green luminescence and the main spectrum wavelength of 610 nm of the red luminescence of the color cathode ray tube. The absorption peak of the sub absorption band of the coating film is in at least one of a first range between a wavelength of 380 nm and a wavelength of 420 nm and a second range between a wavelength of 470 nm and a wavelength of 510 nm.

Claims

1. A color cathode ray tube, comprising:

a face plate; and

a coating film including a polymer of silicon alkoxide, translucent and conductive particles, and a plurality of types of dyes or pigments and formed over an outer surface of said face plate;

said coating film having a main absorption band with an absorption peak in a range between a wavelength of 570 nm and a wavelength of 610 nm which is between a main spectrum of green luminescence and a main spectrum of red luminescence;

said coating film further having a sub-absorption band with a maximum sub-absorption peak in a range between a wavelength of 380 nm and a wavelength of 420 nm.

2. The color cathode ray tube according to claim 1, wherein said sub-absorption band has another sub-absorption peak within a range from a wavelength of 470 nm to a wavelength of 510 nm.

3. The color cathode ray tube as claimed in claim 2 wherein said another sub-absorption peak is also a maximum sub-absorption peak.

4. A color cathode ray tube, comprising:

a face plate; and

a coating film including a polymer of silicon alkoxide, translucent and conductive particles and a plurality of types of dyes or pigments and formed over an outer surface of said face plate;

said coating film having a main absorption band with an absorption peak in a range from a wavelength of 570 nm to a wavelength of 610 nm;

said coating film further having a sub-absorption band with a maximum sub-absorption peak in a range from a wavelength of 470 nm to a wavelength of 510 nm.

5. The color cathode ray tube as claimed in claim 4 wherein said sub-absorption band has another sub-absorption peak in a range from a wavelength of 380 nm to a wavelength of 420 nm.

6. A color cathode ray tube comprising:

a face plate; and

a coating film formed on an outer surface of said face plate;

said coating film having a main absorption band such that an absorption peak of said main absorption band is between a main spectrum of red luminescence and a main spectrum of green luminescence;

said coating film further having a sub-absorption band with a maximum sub-absorption peak;

said maximum sub-absorption peak being either between a main spectrum of green luminescence and a main spectrum of blue luminescence or at a wavelength which is shorter than the main spectrum of blue luminescence.

7. A color cathode ray tube comprising:

a face plate; and

a coating film formed on an outer surface of said face plate;

said coating film having a main absorption band such that an absorption peak of said main absorption band is between a main spectrum of red luminescence and a main spectrum of green luminescence;

said coating film further having a sub-absorption band with two maximum sub-absorption peaks;

said two maximum sub-absorption peaks being a first maximum sub-absorption peak positioned between the main spectrum of green luminescence and the main spectrum of blue luminescence and a second maximum sub-absorption peak positioned at a wavelength which is shorter than the main spectrum of blue luminescence.