JPH07225555A - Projection type image receiver - Google Patents

Abstract

PURPOSE:To prevent the cost from greatly increasing and to eliminate color changes with a viewing and listening position by arranging three green projection tubes in array, arranging two red projection tubes on both the sides of the green projection tube arranged in the center, and arranging four blue projection tubes in the four corner. CONSTITUTION:The three green projection tubes 2 are arranged in the intermediate lateral array, one red projection tube 1 is arranged each in the stages above and below the center stage, and one projection tube 3 is arranged each in the four corners. The projection tubes 1-3 of the respective colors are symmetrical about the green projection tube 2 in any direction, so chromaticity variation is in a canceling direction and a hue difference with the viewing and listening position is not generated. Further, the screen luminance of green is dominant, so the three green projection tubes 2 are provided to increase a light output by 1.5 time as large as that of a six-tube system. Thus, the respective color projection tubes 1-3 are arranged symmetrically so as to make the chrominance variation with the viewing and listening position extremely small, so this receiver is adaptive to a large-sized screen, and high luminance and superior cost performance are obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nine-tube type projection receiver capable of displaying a high-luminance projection image on a screen.

[0002]

2. Description of the Related Art A projection type image receiver enlarges and projects primary color images from respective projection tubes of red, green and blue with a lens and synthesizes them to obtain a color image on a screen.
A projection type television receiver (projection television) generally used for home use adopts a three-tube type using one projection tube for each color. However, in a large-screen projection receiver used for business use, since the screen brightness decreases as the screen size increases, in order to secure a practical screen brightness, two projection tubes of each color are used. A 6-tube type, which is used individually, is used.

FIG. 2 shows an example of the arrangement of projection tubes in a 6-tube projection type image receiver. In this arrangement example, the upper rows are arranged from the left side in the order of red, green, and blue, and each color projection tube 1, 2, 3 is arranged.
On the lower side, from the left side, the projection tubes 3, 2, 1 for each color are arranged in the order of blue, green, and red. By changing the arrangement of the projection tubes in the upper and lower stages in this way, it is possible to remarkably improve the chromaticity change caused by changing the viewing position of the screen.

In either a three-tube type or a six-tube type projection image receiver, the projection tubes are arranged at physically separated positions so that images are combined on the screen surface. Therefore, each projection tube is arranged toward the center of the screen. At this time, for example, in a three-tube type projection receiver, a green projection tube is generally arranged at the center, and red and blue projection tubes are arranged on both sides of the projection tube, and the positions of the projection tubes and the screen are different. The relationship and the relationship of the projection angle are different for each projection tube. As a result, the screen may appear bluish or reddish depending on the position at which the viewer views the screen. On the other hand, in the 6-tube type projection receiver, since the arrangement of the projection tubes is switched in the upper and lower stages as described above, the change in chromaticity tends to be offset in the upper and lower stages, and the change in chromaticity is marked. To be improved.

When the screen size is further increased, it is necessary to further increase the number of projection tubes in order to secure the brightness of the screen. However, the projection tube is a nine-tube type and each of the red, green, and blue projection tubes is used. When three tubes are used for each, the tubes are arranged in any order of red, green, blue or blue, green and red above or below the arrangement of the conventional 6 tube type projection tubes shown in FIG. I will add three projection tubes. However, in such a 9-tube type arrangement, the above-mentioned chromaticity change appears, so that a 9-tube type projection receiver has not yet been embodied, and a 6-tube type has a 12-tube type. It was the actual situation.

If the 12-tube type is used, the light output will be twice as high as that of the 6-tube type, and the brightness of the screen will be improved considerably. Adjustment is not easy either. If the screen size is not large enough to require a 12-tube projection tube, it is assumed that the screen is configured as a 12-tube projection receiver.
There is a problem in that it causes a significant increase in cost, and when such a screen size is increased to 12 tubes, the incident angle to the screen of the projection tube arranged outside becomes large, which causes an error. Convergence will also increase significantly, and the power for correcting this will also increase considerably.

[0007]

As described above, in the conventional projection type image receiving apparatus, when the number of projection tubes is increased to accommodate a large screen, a 12 tube type is adopted instead of a 6 tube type. However, there is a problem that the cost becomes very high and the adjustment becomes difficult. In addition, with a screen size that does not need to be a 12-tube type, when the 12-tube type is used, cost performance deteriorates, and further, there is a problem that power consumption increases due to correction of misconvergence.

The present invention has been proposed in order to solve the problems of the prior art, and even if the number of projection tubes is increased in order to cope with a large screen, the cost is significantly increased. It is an object of the present invention to provide a projection type image receiver that can be prevented and that does not cause a change in chromaticity depending on the viewing position.

[0009]

In order to achieve this object, a projection type image receiver according to the present invention comprises three green projection tubes.
It is arranged in a row, two red projection tubes are arranged on both sides of a green projection tube arranged in the center, and four blue projection tubes are arranged at four corners.

[0010]

According to the above-mentioned structure, the projection tubes of the respective colors are symmetrical with respect to the green projection tube in any direction, so that the chromaticity change is offset and the hue difference depending on the viewing position does not occur. . Further, since the screen brightness is dominated by the brightness of green, the light output can be 1.5 times that of the 6-tube type by using three green projection tubes.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a layout of a projection tube used in the projection type receiver of the present invention. In this figure, three green projection tubes 2 are arranged in a horizontal row in the middle row, one red projection tube 1 is arranged in each of the upper and lower middle rows, and one blue projection tube 3 is arranged in each of the four corners. They are arranged one by one. The reason why two red projection tubes 1, three green projection tubes 2, and four blue projection tubes 3 are combined and arranged in this way is as follows.

It is well known that the luminance structure of each primary color for obtaining white luminance 1 on the screen is 0.3R + 0.59G + 0.11B, where red is R, green is G, and blue is B. Looking at this brightness configuration, green is dominant, so if the number of green projection tubes is set to 3 and a conventional beam current is applied, the screen brightness can be increased to 1.5 times that of the 6-tube type. it can.

To obtain a white color under these conditions, the red projection tube 1
Due to the use of two, the red projection tube 1 has a conventional 1.
A beam current of 5 times may be passed. Originally, in the conventional red projection tube, as is clear from the above-described brightness configuration, the required brightness was obtained with about half the beam current of the green projection tube, so that it is easy to increase the beam current to 1.5 times.

Regarding the blue projection tube 3, it is considered that the number of tubes can be reduced only by looking at the luminance configuration for obtaining white, but in practice, the blue phosphor has extremely low luminous efficiency, which is 1/6 of that of the green phosphor. Since only ~ 1/5 efficiency can be obtained,
In the past, the beam current was almost the same as that of the green projection tube. Furthermore, the blue phosphor not only has low luminous efficiency,
Luminance saturation (luminance does not increase with increasing beam current) is easier than other projection tubes. The brightness saturation and poor luminous efficiency hinder the improvement of the brightness of the projection type image receiver, and even if the green projection tube or the red projection tube has a margin, the screen brightness cannot be increased. Therefore, if the number of blue projection tubes is set to 4, the beam current flowing through the blue projection tubes can be 3/4 times that of the conventional one, so that the blue projection tube 3 has 1.5 times as much light as the conventional one. Can be output.

When the green projection tube 2 and the red projection tube 1 have a margin, the light output of the blue projection tube 3 can be further increased. In that case, the screen brightness is 1.5 times that of the 6-tube type. The above can be done.

Further, as shown in FIG. 1, the projection tubes of each color are arranged symmetrically with respect to the green projection tube 2 in any direction, and the chromaticity changes are offset, so that the vertical direction,
No hue difference occurs in the horizontal direction.

As another embodiment, if three green projection tubes are arranged in a line vertically, red projection tubes are arranged on both sides of the central green projection tube, and blue projection tubes are arranged at the four corners, Each color projection tube can be arranged symmetrically.

However, considering that the height of the viewer varies and the frequency of standing and sitting during viewing is low, the viewing position does not vary in the vertical direction, but rather in the horizontal direction. The arrangement of FIG. 1 in which the tubes are arranged in a horizontal row is preferred.

[0019]

As described above, according to the present invention, two red projection tubes, three green projection tubes, and four blue projection tubes are combined so that the chromaticity changes depending on the viewing position. Since the projection tubes of each color are arranged symmetrically so that the number of projection tubes is reduced, it is possible to construct a nine-tube projection type receiver that corresponds to a large screen and has high brightness and excellent cost performance. In addition, the adjustment becomes easier than the 12-tube type.

[Brief description of drawings]

FIG. 1 is a diagram showing an arrangement of respective color projection tubes of a nine-tube type projection receiver according to the present invention.

FIG. 2 is a diagram showing an arrangement of projection tubes of respective colors in a conventional 6-tube type projection image receiver.

[Explanation of symbols]

 1 Red projection tube 2 Green projection tube 3 Blue projection tube

Claims (1)

[Claims] 1. Three green projection tubes are arranged in a row, two red projection tubes are arranged on both sides of a green projection tube arranged in the center, and four blue projection tubes are arranged at four corners. A projection type receiver.