JPS59141154A - Miss-convergence correction method of picture tube - Google Patents

Abstract

PURPOSE:To perform the correction with high precision and a wide range by arranging a predetermined number of magnetic pole pieces beforehand on a deflection yoke or at predetermined positions nearby, detecting the miss-convergence on a phosphor screen, and energizing necessary magnetic pieces to the necessary strength from the outside. CONSTITUTION:A picture tube 1 is composed of a panel 2 formed with a phosphor screen 3 inside, a neck 6 housing an electron beam 5, and a funnel 4 connecting the panel 2 and the neck 6. A color purity correction magnet 7A and static convergence magnets 7B, 7C are provided on the outside of the neck 6, and a deflection yoke 9 is coupled outside the cone section 8 of the funnel 4. Storage ribs 11 are provided at a uniform distance at eight positions, for example, along the outer periphery of the york 9, and an unenergized magnetic piece 10 is stored in each rib 11. An optional picture tube 1 and a york 9 are combined together, the miss-convergence on the phosphor screen 3 is detected with a sensor, and necessary ones among the magnetic pieces stored in the ribs 11 are energized to the necessary strength.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a misconvergence correction method particularly suitable for high-quality picture tubes.

While recent computer-applied equipment has been trending toward mass adoption, it has also seen remarkable progress in becoming more sophisticated. Color picture tubes used as displays for computer terminals are no exception.

For example, when three electron beams for red, blue, and line are focused on the entire surface of a phosphor screen, the misconvergence, or misconvergence, is 0.5 to 0.6 for a 14-inch picture tube.
th=m (hereinafter, this level will be referred to as the B1 level for convenience), but picture tubes for computer terminals have even stricter requirements than this, and the misconvergence limit is 0.6 to 0.4. It is a cage (hereinafter, this level will be referred to as the B2 level for convenience). However, in reality, even when achieving the above-mentioned level B1, extraordinary consideration must be given to manufacturing variations in deflection yokes, variations in picture tubes, and the like.

FIG. 1 shows the structure of a conventional color picture tube for realizing the level 1 as described above. In the figure, a picture tube (1) is a panel (2) with a fluorescent screen (3) formed on its inner surface.
), a neck (6) with a built-in electron gun (5) that emits an electron beam that makes the fluorescent screen (3) emit light, and a panel (2).
) and the neck (6) are connected to the funnel (4) or □
It will be. On the outside of the neck (6), there is an assembly (hereinafter referred to as OP) (7) consisting of a two-pole color purity correction magnet G'A) and a four-pole and six-pole static convergence magnet (7B) (70). A deflection yoke (9) is fitted onto the cone (8) of the funnel (4). Note that 03) is a shadow mask placed opposite the phosphor screen (3).

Next, convergence adjustment of the picture tube configured as described above will be explained. First, in order to match the light source position when printing the phosphor screen (3) with the center of deflection by the electron beam, use a two-pole color purity correction magnet (7A).
Move the six electron beams to match the imaginary light source position. At this time, adjustments are made using static convergence magnets σB) and (70) so that the electron beam of the filter is correctly focused at the center of the phosphor screen (3). If necessary, adjustment may be made once again to align the deflection center of the electron beam with the imaginary light source position. Next, the deflection yoke (9) is moved along the picture tube axis in order to align the imaginary light source position with the electron beam over the entire surface of the phosphor screen (3). Once the tendency yoke (9) is fixed at the optimum position, in order to obtain even better convergence over the entire surface of the fluorescent W1 (3), slightly adjust the opening of the deflection yoke (9) on the fluorescent screen (3) side. Shake the head, so-called "shaking the head."

In this way, convergence optimization is performed.

By the way, when we consider the causes of misconvergence, the burning of the phosphor screen (3) is caused by the subsequent movement of the shadow mask α, deformation of the shadow mask 13, misalignment between the panel (2) and the funnel (4), and the electron gun. (5) assembly error, electron gun (
Is the sealing error etc. to the neck (6) of 5) the image? The main causes on the (1) side and the causes on the deflection yoke (9) side are variations in the distribution of the horizontal coil and vertical coil, errors when combining the horizontal coil and vertical coil,
There is also the precision of the separator that separates the horizontal and vertical coils. Considering these points, the picture tube (1
) and the deviation in the deflection yoke (9), it can be seen how difficult it is to achieve the above-mentioned B1 level even with a 1.14-inch picture tube.

However, this level of B1 has been managed to be achieved by the following methods. Simply put, this method is a method in which convergence adjustment is performed using a combination of a picture tube (1) and a deflection yoke (9). In other words, rather than thinking about reducing variations in the picture tube (1) or deflection yoke (9) alone,
t. Bring the picture tube (1) you are going to use and attach it to the deflection yoke (
It is much more efficient and accurate to achieve the level of B1 by attaching 9) and OP(7) and adjusting the magnetic field created by the deflection 'a-ri (91).

Figure 2 (B) shows a conventional deflection yoke (9) used in such convergence adjustment.The end of the deflection yoke (9) has a ferrite sheet, permalloy, or rubber magnet, etc. A magnetic piece a [ is attached to adjust the magnetic field distribution, thereby making it possible to achieve the level B1.Although not shown, the inner surface of the deflection yoke (9), that is, the cone part (8) A magnetic piece (101) is also attached to the abutting surface of the phosphor screen (3).
) Depending on the tendency of misconvergence mentioned above, it is pasted on the inner surface of the deflection yoke (9), the creeping area near the opening, or a part of the molded product at the rear without determining the pasting location, as appropriate by trial and error. Ta. However, this method has the disadvantage that it takes a very long time to achieve a certain level of convergence.

This invention was made to eliminate the above-mentioned conventional defects, and aims to provide a correction method that can efficiently obtain high-quality convergence characteristics in a short time.

Embodiments of the present invention will be described below based on the drawings.

FIGS. 6A and 6B show an example of a deflection yoke used in the miscomparison correction method of the present invention. In this figure, the same or corresponding parts as in FIG. 2 are given the same reference numerals. (11) is a storage lip provided along the outer periphery of the deflection yoke (9), and in this embodiment, storage lips I are provided at eight equally spaced locations. An unmagnetized magnetic piece αα is stored within this storage lip α force. This magnetic piece α0) may be stored in all storage lips (11), or may be stored only in necessary storage lips α1). , magnetized to correct misconvergence.

FIG. 4 shows the state in which the magnetization is being performed. That is, any picture tube (1) and any deflection meter (9)
The resulting misconvergence on the phosphor screen (3) is detected by a sensor (not shown), and the deflection and
- Calculate with a computer or the like, or determine based on experience which locations and how much magnetized single heads are required among the eight storage lip 0υ provided in the cage (9). , magnetize the magnetic piece αα directly or indirectly from the outside using the magnetizing head ①. According to such a method, there is no need to repeatedly attach the magnetic piece a@ by trial and error, and optimal convergence can be achieved in an extremely short time. In addition, in the conventional method, the magnetic piece α
Since α is pasted at random, there was a drawback that the appearance was impaired, but this drawback can be overcome by providing storage lips 0D for the magnetic pieces 00) at predetermined locations as in the above embodiment.

In the above embodiment, an example was shown in which the storage lip OD was provided on the opening side of the deflection yoke (9), but the storage lip (1υ) may also be provided on the electron gun (5) side. ).Furthermore, the storage lip circle does not necessarily have to be provided on the deflection yoke (9), but on the deflection yoke (9).
9) may be provided separately. In addition, in the above practical example, the storage lips (111) are arranged at equal intervals, but the storage lips (111) may be formed continuously and the magnetic pieces 0■ may be arranged over the entire circumference of the deflection yoke (9). .

Note that when magnetizing the magnetic piece αα, if strong local magnetization is performed, undesirable results such as raster distortion and deterioration of electron beam focusing characteristics may occur, so the amount of magnetization should be small and done gradually. is desirable.

As described above, according to the present invention, necessary magnetic pieces among pre-arranged magnetic pieces are externally magnetized with the required strength according to the degree of misconvergence, which makes it extremely efficient and highly efficient. Accurate convergence adjustment can be performed, and as a result, it is possible to realize a high-quality picture tube not only at the B1 level but also at the B2 level.

In addition, in the conventional method, there was a limit where correction was impossible depending on the combination of the picture tube and the deflection loaf, but with this invention, the range that can be corrected can be expanded, so the yield of adjustment can be improved. be able to.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway side view showing the configuration of a conventional color picture tube; Figure 2 is a side view showing a conventional deflection meter;
FIG. 6(B) is a rear view of the same, FIG. 6(A) is a side view showing an embodiment of the deflection yoke used in the present invention, and FIG.
B) is a rear view of the same, and FIG. 4 is a side view showing the magnetized state. (1)... picture tube, (2)... panel, (3)...
- Fluorescent screen, (4)...7 annular, (5)...electron gun, (6)...neck, (8)...cone part, (9
)...deflection yoke, yoke...magnetic piece, yoke...magnetizing head. In addition, the same reference numerals in the figures indicate the same or equivalent parts.0 Agent Shin Kuzuno - (1 other person)

Claims (2)

[Claims] (1) A panel with a phosphor screen formed on its inner surface, a neck with a built-in electron gun that emits an electron beam that causes the phosphor screen to emit light, a funnel connecting the panel and neck, and a cone portion of this funnel. A method for correcting misconvergence in a picture tube equipped with a deflection yoke externally fitted on the phosphor screen. A method for correcting misconvergence in a picture tube, characterized in that the misconvergence of the picture tube is detected, and necessary ones of the magnetic pieces are externally magnetized with a necessary strength according to the degree of the misconvergence. (2) A misconvergence correction method for a picture tube according to claim 1, wherein the magnetic piece is housed in a housing rib provided along the outer periphery of the deflection yoke.