JPH07226946A - Projection television receiver - Google Patents

Abstract

PURPOSE:To realize the performance of the 6-tube system by using only 5-tubes with respect to the projection television receiver. CONSTITUTION:Three primary color red, blue, green cathode ray tubes and each tube screen of the cathode ray tubes is projected through a lens and a picture is displayed on a screen 6. In the projection television receiver, in order to obtain the picture having a sufficient lightness on the large screen 6, three cathode ray tubes are increased to 6 tubes, and in this case, two red and green cathode ray tubes each are used and only one red cathode ray tube is in use to obtain the same lightness as that by the 6-tube system. Thus, number of the cathode ray tubes is reduced by one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called projection television for projecting images of red, blue and green cathode ray tubes on a screen and displaying a color image on the screen.

[0002]

2. Description of the Related Art As shown in Japanese Utility Model Publication No. 5-5749, "Screen of Rear Projection Television", a conventional projection television has a cathode ray tube which emits three primary colors of light of red, blue and green arranged side by side. , Was composing the image on the screen. When the screen becomes large, the amount of light becomes insufficient, so we used a 6-tube configuration with two red, blue, and green cathode ray tubes.

[0003]

The present invention is effective for a system of three tubes or more used for realizing a large screen of 60 inches or more. The 40 to 50 inch projection television uses a so-called three-tube system in which one CRT is used for each of red, blue and green, and when it is 60 inches or more, there are two tubes for three primary colors for the purpose of ensuring brightness. A 6-tube method using a Braun tube is used. The present invention realizes the performance (brightness) of this 6-tube system with 5 tubes.

[0004]

In the case of the three-tube system, the distribution of the beam current for realizing a practical color temperature is blue 500.
It can be realized with uA, green 550uA and red 250uA. In the case of the 6-tube system, the same beam current ratio is used. On the other hand, the maximum average beam current of the cathode ray tube is about 550 uA. With 6 tubes, green is 550uA + 550uA = 1100u
A, blue is 500uA + 500uA = 1000uA, red is 250uA
A + 250uA = 500uA. In other words, one red CRT will be sufficient for the current, and one CRT can be reduced. In this case, not 6 tubes,
Although it is a five-tube system, it is possible to obtain the same performance in all such as brightness.

[0005]

According to the present invention, one red CRT is eliminated and five tubes achieve the performance of six tubes.

[0006]

FIG. 1 shows an embodiment of the present invention. It is a view of the projection TV as seen from the front, with red (R) at the bottom.
1, green (G) 4 and blue (B) 5 are arranged, and blue (B) 1 and green (G) 2 are arranged in the upper row. 6 is a screen. Further, FIG. 2 is a side view showing 1 to 5
A lens 7 is provided on the front surface of each color cathode ray tube, and the screen 6
Is projected on. This embodiment only shows the principle part. In practice, a mirror is often used to make the depth of the entire set shorter, and the depth is reflected, but this can also be easily realized by the principle shown in FIG. In addition, there is a problem of color shift in which chromaticity changes depending on the viewing direction, and various arrangements of cathode ray tubes have been devised to address this problem. An example thereof is shown in FIG. In FIG. 3, the arrays (a) and (b) are
This is a method of arranging B, G, and R on the upper row and G and B on the lower row. The arrangement of (c) has G, G and R between B and G in the upper row.
B is arranged between the two. In the method (d), the arrangement of the upper stage is changed, R is arranged in the center, and G and B are arranged on the left and right.

[0007]

As described above, according to the present invention, 5
With the tube system, the same performance as the 6-tube system can be obtained, and one CRT can be reduced. Therefore, the economy is good. That is,
One lens, one cathode ray tube, one deflection yoke, and one convergence yoke can be reduced. Therefore,
It consumes less power. Moreover, there is an effect that the arrangement of the cathode ray tubes has flexibility.

[Brief description of drawings]

FIG. 1 is a front view of a projection television of the present invention.

FIG. 2 is a side view of a projection television.

FIG. 3 is a diagram showing an example of a CRT arrangement method according to the present invention.

[Explanation of symbols]

 1 ... Blue, 2 ... Green, 3 ... Red, 4 ... Green, 5 ... Blue, 6 ... Screen, 7 ... Lens.

Claims (1)

[Claims] 1. A cathode ray tube of three primary colors of red, blue and green is used,
In a projection type projection television that projects an image on the surface of a cathode ray tube with a lens and projects an image on the screen, in order to obtain an image with sufficient brightness on a large screen, three to six cathode ray tubes are used. In this case, only two blue and green cathode ray tubes were used at this time,
A projection television that uses only one red cathode ray tube to obtain the same brightness as the six-tube type.