Facsimile and static presentation processing – Static presentation processing – Attribute control
Patent
1984-08-27
1987-02-24
Masinick, Michael A.
Facsimile and static presentation processing
Static presentation processing
Attribute control
358237, 358239, 358231, 358251, H04N 574
Patent
active
046461434
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field
The present invention relates to a video projector type television receiver in which an image light from the phosphor screen of a color cathode ray tube is projected through a projection lens onto a picture screen to thereby form on the picture screen a magnified picture image.
2. Background Art
A video projector type television receiver using a color cathode ray tube is constructed in principle as shown in FIG. 1.
In the figure, reference numeral 1 designates a color cathode ray tube in which a phosphor screen 1a is made of, for example, a stripe-shaped color phosphor pattern. The image light from the phosphor screen 1a of the color cathode ray tube 1 is projected through a projection lens 3 onto a picture screen 4 so that a magnified picture image 5 is formed on this picture screen 4. In this case, at the same time when the magnified picture image 5 is formed on the picture screen 4, also the color phosphor pattern of stripe shape (color stripe pattern) which forms the phosphor screen 1a is projected onto the picture screen 4 under being magnified and becomes conspicuous as shown in FIG. 2 so that the magnified picture image 5 on the picture screen 4 becomes difficult to see.
Therefore in the prior art, in order to make the color stripe pattern on the picture screen 4 unconspicuous, as shown in FIG. 3, it is proposed to locate between the projection lens 3 and the color cathode ray tube 1 a prism plate 6 which has a predetermined inclination angle .alpha.. In this case, the image light from a point P on the phosphor screen 1a of the color cathode ray tube 1 is divided into two in its optical path by one prism surface 6a and the other prism surface 6b and projected onto two points Pa and Pb on the picture screen 4. Accordingly, as shown in FIG. 4, on the picture screen 4 are formed two magnified picture images 5a and 5b, each of which is shifted little in parallel in the horizontal direction less than, for example, a pitch Lc of a pair of color stripes. As a result, on the picture screen 4 is formed the magnified picture image 5 which results from mixing these magnified picture images 5a and 5b to each other. Consequently, the number of the color stripes of the magnified picture image 5 is increased twice so that the color stripe pattern becomes not so conspicuous on the picture screen 4.
However, in the example of FIG. 3, air exists in the space between the phosphor screen 1a and the prism plate 6 and in the space between the prism plate 6 and the projection lens 3 so that due to the difference between the refractive indexes of the air and each component, the reflection is easily caused in each boundary surface, thus resulting in a multiple reflected image and a great loss of light.
DISCLOSURE OF INVENTION
Accordingly, it is an object of the present invention to reduce the reflection on the boundary surface. In order to achieve this object, according to the present invention, a video projector type television receiver comprises a prism plate located in front of a color cathode ray tube, a projection lens located in front of the prism plate and transparent liquid respectively injected into the space between the color cathode ray tube and the prism plate and the space between the prism plate and the projection lens.
The present invention is constructed as described above, and the transparent liquid is injected into the space between the color cathode ray tube and the prism plate and the space between the prism plate and the projection lens. Since the difference between the refractive indexes of the transparent liquid and each component is not so large as that between the refractive indexes of air and each component, it is possible to reduce the reflection produced on each boundary surface.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1 and 3 are respectively diagrams each showing an example of a prior art video projector type television receiver,
FIG. 2 is a diagram useful for explaining the example shown in FIG. 1,
FIG. 4 is a diagram useful for explaining the example shown in
REFERENCES:
patent: 2342778 (1944-02-01), Wolff
patent: 3145264 (1964-08-01), Schulz
patent: 3255665 (1966-06-01), Weiher et al.
patent: 3781091 (1973-12-01), Ferguson
patent: 4151554 (1979-04-01), Tucker
patent: 4405949 (1983-09-01), Hockenbrock et al.
patent: 4511927 (1985-04-01), Bauer
patent: 4533850 (1985-08-01), Watanabe et al.
patent: 4563699 (1986-01-01), Watanabe et al.
Ohzeki Minoru
Toyama Takashi
Watanabe Toshiro
Bauer Robert M.
Eslinger Lewis H.
Masinick Michael A.
Sinderbrand Alvin
Sony Corporation
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