Claims
- 1. A method of manufacturing a projection cathode ray tube comprising a display window, the method comprising vapour depositing a multilayer interference filter on an inside surface of the display window, characterized by surrounding the display window with an edge having a height above the inside surface which is from about 1/10 to about 1/5 of the minimum distance between the centre and the edge of the display window.
- 2. A method as claimed in claim 1, characterized in that the side of the display window facing the vapour deposition source is curved.
- 3. A method as claimed in claim 1, characterized in that vapour deposition is carried out with a background gas pressure of more than 2*10.sup.-4 mbar.
- 4. A method as claimed in claim 1, characterized in that TiO.sub.2 is vapour deposited.
- 5. A method as claimed in claim 1, characterized in that a short wave pass interference filter is vapour deposited.
- 6. A method as claimed in claim 5, characterized in that a short wave pass filter is vapour-deposited which comprises a stack of at least six layers having alternately a high and a low refractive index, each layer having an optical thickness between 0.2 .lambda..sub.f and 0.3 .lambda..sub.f, an average optical thickness of 0.25 .lambda..sub.f, .lambda..sub.f being equal to px.lambda. and .lambda. being a central wavelength selected from the emission spectrum of the display screen, p being a number between 1.18 and 1.33.
- 7. A method as claimed in claim 1, characterized in that a bandpass interference filter is vapour deposited.
- 8. A method of manufacturing a projection cathode ray tube comprising a display window, the method comprising vapour depositing a multilayer interference filter on an inside surface of the display window, characterized in that the display window comprises a recessive edge.
- 9. A method as claimed in claim 8, characterized in that the side of the display window facing the vapour deposition source is curved.
- 10. A method as claimed in claim 8, characterized in that vapour deposition is carried out with a background gas pressure of more than 2*10.sup.-4 mbar.
- 11. A method as claimed in claim 8, characterized in that TiO.sub.2 is vapour deposited.
- 12. A method as claimed in claim 8, characterized in that a bandpass interference filter is vapour deposited.
- 13. A method as claimed in claim 8, characterized in that a short wave pass interference filter is vapour deposited.
- 14. A method as claimed in claim 13, characterized in that a short wave pass filter is vapour-deposited which comprises a stack of at least six layers having alternately a high and low refractive index, each layer having an optical thickness between 0.2 .lambda..sub.f and 0.3 .lambda..sub.f, an average optical thickness of 0.25 .lambda..sub.f, .lambda..sub.f being equal to px.lambda. and .lambda. being a central wavelength selected from the emission spectrum of the display screen, p being a number between 1.18 and 1.33.
Priority Claims (1)
Number |
Date |
Country |
Kind |
8802210 |
Sep 1988 |
NLX |
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Parent Case Info
This is a continuation of application Ser. No. 07/403,542, filed Sep. 5, 1989 now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0246696 |
Nov 1987 |
EPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
403542 |
Sep 1989 |
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