JPS63188646U

JPS63188646U -

Info

Publication number: JPS63188646U
Application number: JP1987077708U
Authority: JP
Priority date: 1987-05-22
Filing date: 1987-05-22
Publication date: 1988-12-02

Description

[Brief explanation of the drawing]

第１図は、本考案による透過形スクリーンを構
成するフレネルレンズを示した断面図である。第
２図は、レンズの入光角と出光角の関係を示した
図、第３図は、フレネルレンズの場合の入光角と
出光角の関係を示した図である。第４図は、本考
案による透過形スクリーンが適用されるプロジエ
クシヨンＴＶの一例を示した図である。第５図〜
第９図は、反射率と観察側集光点の関係を説明す
るための図である。第１０図は、本考案による透
過形スクリーンの実施例を示した図である。第１
１図は、プロジエクシヨンＴＶの従来例を示した
図、第１２図は、同従来例プロジエクシヨンＴＶ
の問題点を説明するための図である。１……フレネルレンズ、２……レンチキユラー
レンズ、Ｂ……青色光のブラウン管、Ｇ……緑色
光のブラウン管、Ｒ……赤色光のブラウン管。 FIG. 1 is a sectional view showing a Fresnel lens constituting a transmission screen according to the present invention. FIG. 2 is a diagram showing the relationship between the incident light angle and the light exit angle of a lens, and FIG. 3 is a diagram showing the relationship between the light incidence angle and the light exit angle in the case of a Fresnel lens. FIG. 4 is a diagram showing an example of a projection TV to which the transmissive screen according to the present invention is applied. Figure 5~
FIG. 9 is a diagram for explaining the relationship between reflectance and observation-side focal point. FIG. 10 is a diagram showing an embodiment of a transmission type screen according to the present invention. 1st
Figure 1 is a diagram showing a conventional example of Projection TV, and Figure 12 is a diagram showing the conventional example of Projection TV.
FIG. 2 is a diagram for explaining the problem. 1... Fresnel lens, 2... Lenticular lens, B... Braun tube for blue light, G... Braun tube for green light, R... Braun tube for red light.

Claims

[Claims for Utility Model Registration] (1) Used in a three-tube projection TV,
In a transmission type screen having a Fresnel lens arranged so that the Fresnel surface faces the light exit side, the Fresnel lens is configured such that the viewing side condensing point distance gradually increases from the center toward the outer periphery. A transparent screen characterized by: (2) The focal point distance on the viewing side of the Fresnel lens is such that the projector is near the optical axis, the distance between the lens and the screen is 500 mm to 1200 mm, and the focal point distance of the three cathode ray tubes for red, green, and blue light is the same. 500mm if the angle is between 5 degrees and 15 degrees, the difference in reflection loss between red and blue light does not exceed 30%, and the maximum reflection loss of red or blue light does not exceed 50%.
The transmission type screen according to claim 1, which is a utility model registered and is characterized in that the screen increases in the range of (center) to 30,000 mm (periphery). (3) The transmission screen according to claim 1, wherein the Fresnel lens has a lens angle that increases monotonically from the center toward the outer periphery.