JPS5856590A - Projection type television receiver - Google Patents

Abstract

PURPOSE:To correct an optical distortion due to the shift in installed position of each CRT, by providing an independent correction coil in response to an angle with a screen, for a deflection coil of each CRT, in a projection type TV receiver using three-CRT. CONSTITUTION:Linearity correction coils 9R, 9G and 9B provided independently are connected in series with deflection coils 2R, 2G and 2B deflecting R, G and B driven with a deflection output circuit 1. In the characteristics of the coils 9R, 9G and 9B, the amount of correction of the coil 9R to a CRT4 is taken larger and that of the coil 9B to a CRT4B is taken small by taking the characteristics of the coil 9G to a CRT4G located at the center as a center. That is, the amount of correction is adjusted corresponding to an angle of the coils 9R, 9B to a vertical line to the projecting direction of the CRT4R and CRT4B and a screen. Thus, the optical shift to the projecting pattern of each CRT can also be adjusted, allowing to minimize the dynamic convergence.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a projection type teleconvex receiver (commonly known as a video projector), and particularly to horizontal linearity correction of a video projector using three cathode ray tubes.

For example, a video projector has three
The enlarged color me is reproduced by arranging book cathode ray tubes (hereinafter referred to as ORTs) inline and projecting enlarged images onto a common screen and compositing them.

In this case, in a general ORT, linearity deteriorates at the beginning of horizontal deflection scanning because there is a loss in the horizontal deflection coil.

As a result, when playing Sanada's picture 1 Elephant, the left side of the screen shrinks and the screen layout extends to 4, creating an oval shape, as shown in Figure 1. In the projector, as shown in Fig. 2, the ill linearity correction coil 3 is commonly connected to the deflection coils 212G and 2B responsible for R, G, and B driven by the deflection output circuit l. This performs linearity correction.

However, in a video projector using a 3-tube 01'LT, the three ORTARs, 4G, and 4B responsible for R, G, and B are arranged inline in the horizontal direction, as shown in Figure 3. Since 0RT4B and 4B are shifted left and right from the center, when a perfect circular pattern is projected onto the screen 5 at an elevation angle of 0 degrees, the projected pattern by 0RT4G becomes a perfect circle as shown by the solid line 6, but 0RT4R.

In the projection pattern by ORT AB, optical distortion occurs due to positional deviation as shown by the dotted line 7 and the dotted line 1f14B. In other words, the projection pattern by ORT4B located on the left side of the center causes optical distortion.

The left side is narrower than the center, and the right side is elongated. In addition, OI'LT4 located on the right side of the center
The projected arm turn according to B is extended on the left side of the center and narrowed on the right side. As described above, in a video projector using a 3-tube ORT, even if the horizontal linearity due to the loss of the horizontal deflection coil is corrected, there is a problem that color shift occurs due to optical distortion. , this is corrected by adding dynamic convergence.

Therefore, one object of the present invention is to prevent color shift in a projection type television receiver 1c by arranging three tubes 0T in an infin.

In order to achieve this purpose, the three-pipe OR according to the present invention
A projection type television receiver using T is provided with an independent IJ linearity correction coil for each ORT deflection coil, and the characteristics of each linearity correction coil are used to calculate the horizontal linearity characteristics and the on-screen linearity characteristics. optics.

The amount of dynamic correction can also be reduced by setting each according to the distortion. Hereinafter, a video projector according to the present invention will be explained in detail using the drawings.

FIG. 4 is a partial circuit diagram of a deflection circuit portion showing an embodiment of a projection type television receiver according to the present invention, and the same parts as in FIG. 2 are indicated using the same symbols. In the same figure, 9R#9G-9B represents each deflection coil 2R, 2G, -
The linearity correction coils are provided independently for each deflection coil 2B, and are connected in series to each deflection coil. Then, each flat arity correction coil 9
R.

The characteristics of 9G and 9B are shown in Figure 5. As shown in Figure 5, the linearity correction coil 9 for qORT4G is placed in the center.
Focusing on the characteristics of G, the correction amount of linearity correction coil 9R for 0RT4B is increased, and
The correction amount of the duality correction coil 9B is set to be small. In other words, the linearity correction coil 9B,
For 9BK, the linearity correction amount is adjusted in accordance with the angle formed between the projection direction of ORT0n and 0RT4B and II@ of the screen surface.

In this way, the fica tube 0RT4B is arranged inline.
By setting the IJ nearness characteristics of , 4G, and 4H independently, it is possible to adjust the optical deviation for each 0RTO projection pattern, and accordingly, the amount of dynamic correction can be reduced to an extremely small amount. ,
Furthermore, if the values match accurately, dynamic correction itself is not necessary.

As explained above, the projection type television receiver according to the present invention has cathode ray tubes in charge of red, green, and blue arranged in an in-line manner, and the deflection coil of each cathode ray tube is provided with an independent or a proximity correction coil. The characteristics of each linearity and correction coil are set corresponding to the angle that each cathode ray tube makes with the screen relative to the horizontal direction.In order to correct the horizontal linearity of the deflection coil and the installation of each cathode ray tube. It has various excellent effects, such as being able to correct optical deviations due to differences in position, and thereby eliminating dynamic confluence in extreme cases.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a pattern caused by horizontal linearity defects, Fig. 2 is a circuit diagram showing an example of a conventional linearity correction circuit, and Fig. 3 is a diagram showing optical distortion of a projection nosetan by three cathode ray tubes. 4 is a circuit diagram showing an embodiment of a linearity correction circuit used in a projection type television receiver according to the present invention, and FIG. 5 is a characteristic diagram of each linearity correction coil shown in FIG. 4. 1... Deflection output circuit, 2R, 2G, 2B... Deflection coil, 919G, 9B... Linearity correction coil. Figure 1 Figure 2 Cusp 3 (2)

Claims (1)

[Claims] (1) A projection television receiver in which three cathode ray tubes for blue, green, and blue are arranged in-line in a screen and separated in the horizontal scanning direction, and the deflection of each cathode ray tube is The installation position of each cathode ray tube can be adjusted by connecting independent or linearity correction coils to each coil, and by varying the characteristics of each linearity correction coil according to the angle that each cathode ray tube makes with the screen. A projection television receiver aircraft characterized by correcting optical distortion caused by misalignment.