Title:
PROJECTOR FOR PROJECTION TELEVISION
Document Type and Number:
Japanese Patent JPH0361904
Kind Code:
A
Abstract:
PURPOSE:To improve the contrast of a picture by means of simple constitution in the projector for a projection television(TV) in which a coupler is filled with a cooling solution and a projection tube is optically coupled with a lens system by adding a light absorbing substance to the cooling solution in the coupler to absorb excess light in the coupler. CONSTITUTION:When the part closed by the CRT projection tube 1, a meniscus lens 3 and the sidewall part 22 is filled with the cooling solution, a front glass 1a is cooled by the cooling solution and optically coupled with the meniscus lens 3. The light absorbing substance for absorbing the full wavelength area of a visible light is added to the cooling solution and a part of light in the cooling solution is absorbed by the light absorbing substance. Thereby, the ratio of the intensity of light made directly incident from the front glass 1a upon the meniscus lens 3 to the intensity of light irregularly reflected by a sidewall part 22 and oriented to the front glass 1a is increased as compared to the case of the light absorbing substance that is unadded. Consequently, the contrast of an image can be improved by means of simple constitution.
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Inventors:
HANIYU MASAAKI
Application Number:
JP19692689A
Publication Date:
March 18, 1991
Filing Date:
July 31, 1989
Export Citation:
Assignee:
PIONEER ELECTRONIC CORP
International Classes:
G02B5/24; G03B21/00; G03B21/16; H01J7/28; H01J31/10; H04N5/74; H04N9/31; (IPC1-7): G02B5/24; G03B21/00; G03B21/16; H01J7/28; H04N5/74; H04N9/31
Domestic Patent References:
| JPS60198503A | 1985-10-08 | |||
| JPS59192209A | 1984-10-31 | |||
| JP30008154A |
Attorney, Agent or Firm:
Hideo Takino (1 outside)
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