JPH06113344A - Focus adjustment method for television receiver - Google Patents

Abstract

PURPOSE:To adjust the focus of the television receiver simply in an excellent way. CONSTITUTION:In the focus adjustment method for a television receiver 1 in which a color picture is displayed on a screen of a cathode ray tube 2, the picture displayed on the screen is picked up by a camera 5 having a color filter 7 colored by a beam passing through its center and the picked-up picture is adjusted to be in a prescribed state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus adjusting method for a television receiver using a cathode ray tube.

[0002]

2. Description of the Related Art In a television receiver using a cathode ray tube, the focus of the electron beam is adjusted so that the image displayed on the surface of the cathode ray tube is good before being manufactured and shipped from the factory. There is a need to do. This conventional focus adjustment is performed, for example, as shown in FIG. That is,
As the television receiver 1, the volume 3 for adjusting the focus of the electron beam of the cathode ray tube 2 is exposed, and the mirror 4 is placed so as to face the front surface 1a of the television receiver 1. The image displayed on the cathode ray tube 2 is reflected by the mirror 4 to be confirmed by the coordinator m on the back side of the television receiver 1. In this state, the adjuster m operates the focus adjusting volume 3 to judge the degree of focus of the image viewed through the mirror 4 and adjust so that a good image is displayed. The image displayed on the mirror 4 is reflected so that the image displayed on the television receiver can be seen at a position where the volume 3 can be operated.

[0003]

However, in such an adjusting method, since the adjuster makes a judgment by directly looking at the image, the accuracy of focus adjustment is determined by the judgment of the adjuster, and the accuracy is likely to be non-uniform. was there.

It is an object of the present invention to enable focus adjustment of this type of television receiver to be favorably performed by a simple operation.

[0005]

The present invention is, for example, as shown in FIG. 1, in a focus adjusting method for a television receiver 1 in which a color image is displayed on the tube surface of a cathode ray tube 2 and is displayed on the tube surface. The image is captured by a camera 5 having a filter 7 of a color that is colored by a beam passing through the center, and the captured image is adjusted so as to be in a predetermined state.

In this case, the horizontal line is displayed on the television receiver and the display width of the horizontal line is adjusted to be constant.

In this case, the filter is a green filter.

[0008]

With respect to the focus of the cathode ray tube of the television receiver, the beam passing through the center is most dominant, and only the color developed by the beam passing through the center is imaged by the camera, and this captured image is appropriate. Good adjustment can be easily performed by adjusting so that.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4, parts corresponding to those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a diagram showing a system configuration of the adjusting method of this example. In this example, the front surface 1 of a television receiver 1 is shown.
The video camera 5 is arranged so as to face a, and the cathode ray tube 2
The image displayed on the tube surface is captured. In this case, a green filter 7 is attached to the imaging lens 6 of the video camera 5 so that only the green component is imaged. Then, the video signal obtained by imaging is supplied to the monitor receiver 8 and displayed on the monitor receiver 8. In addition, it is preferable that the video camera 5 picks up an image in synchronization with a video signal supplied to the television receiver 1.

Then, a person who adjusts the focus of the television receiver 1 operates the focus adjustment volume 3 of the television receiver 1 while watching the image displayed on the monitor receiver 8 to make an adjustment. Adjust so that the image displayed in is the best.

With this configuration, the image displayed on the monitor receiver 8 is as shown in FIG. That is,
The tube surface of the cathode ray tube 2 has, for example, red, green, and blue fluorescent surfaces R, G, and B formed with carbon stripes C formed between the respective colors. Only the part where is emitted is highlighted as shown by hatching, and the emission of the phosphor screens R and B of other colors can be discriminated only slightly.

As the focus adjustment here, adjustment is made so that the boundary of the light emitting portion becomes clear while observing the image displayed on the monitor receiver 8 in this way.

Here, a video signal for displaying a line having a constant width in the horizontal direction as shown in FIG. 3A is supplied to the television receiver 1, and this horizontal line is supplied to the cathode ray tube 2. To be displayed on the screen. This displayed line is
The color of red, green, and blue is displayed in a relatively good balance (for example, white). Then, this display image is picked up by the video camera 5 and adjusted so that a similar line is displayed on the monitor receiver 8. Here, if the focus adjustment of the television receiver 1 is not appropriate, the width of each horizontal line becomes non-uniform as shown in FIG. 3B, and the width of each horizontal line becomes as shown in FIG. Optimum adjustment can be made by adjusting so as to be uniform as shown.

The principle of good adjustment by such an adjustment will be described. In the case of the television receiver 1 adjusted here, the electrons emitted from the electron gun toward the tube surface of the cathode ray tube 2. As shown in Fig. 4, the beam is a green beam (G beam) at the center and a red beam (R beam).
The incident angles of the blue beam and the blue beam (B beam) are shifted by + θ and −θ with respect to the green beam, and reach the phosphor screen of the cathode ray tube 2. Therefore, the ideal just focus range of each beam is Red R ₀ , green G ₀ , blue B ₀
The red and blue just focus ranges R ₀ and B ₀ are inclined with respect to the green just focus range G ₀ .

Therefore, the green beam (G
By appropriately adjusting the beam), the beams of the three colors are most favorably adjusted, and the focus of the beams of the three colors is optimally adjusted only by adjusting the focus of the green. It will be. In addition, the green phosphor is 3
Among the color phosphors, it has the property of being saturated the fastest, so green is dominant in terms of the clarity of the displayed image.From this point as well, the overall focus is better than the focus adjustment of green. It is preferable to make the adjustment.

It should be noted that although it seems that the same adjustment is performed by just changing the image displayed on the television receiver 1 to a monochromatic image of only green, the actual monochromatic image is received by the television receiver. When it is displayed on the machine, it tends to be adjusted in the overfocus direction due to a change in the high-voltage system of the circuit, and it is not possible to perform the same appropriate adjustment as in the above-described embodiment.

In the television receiver to be adjusted in the above embodiment, since the beam passing through the center is green,
The green filter is used for imaging, but when adjusting a television receiver with a configuration in which beams of other colors pass through the center, use the filter that matches the color of the beam passing through the center. It should be done.

Further, although the horizontal line is adjusted so as to have a constant width in the above-mentioned embodiment, another image may be displayed and adjusted.

[0020]

According to the present invention, only the color developed by the beam passing through the center is picked up by the camera, and the picked-up image is adjusted so that it can be adjusted properly.

In this case, by adjusting the display width of the horizontal line to be constant, the adjustment state can be easily known, and uniform adjustment is possible regardless of who makes the adjustment.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a display example of an image captured according to an embodiment.

FIG. 3 is an explanatory diagram showing an adjustment state according to an embodiment.

FIG. 4 is an explanatory diagram showing a focus state according to an embodiment.

FIG. 5 is a configuration diagram showing a conventional focus adjustment method.

[Explanation of symbols]

 1 Television Receiver 2 Cathode Ray Tube 3 Focus Adjusting Volume 5 Video Camera 6 Imaging Lens 7 Green Filter 8 Monitor Receiver

Claims (3)

[Claims] 1. A focus adjustment method for a television receiver in which a color image is displayed on the surface of a cathode ray tube, wherein the image displayed on the surface of the cathode ray tube is a filter of a color developed by an electron beam passing through the center. A focus adjustment method for a television receiver, which is configured to capture an image with a camera having the above and adjust the captured image to be in a predetermined state. 2. The focus adjusting method for a television receiver according to claim 1, wherein a horizontal line is displayed on the television receiver, and the display width of the horizontal line is adjusted to be constant. 3. The focus adjusting method for a television receiver according to claim 1, wherein the filter is a green filter.