JPS5837655B2 - color picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color picture tube having an in-line electron gun with three electron beam passing holes arranged in a straight line.

A color picture tube with an in-line electron gun has the advantage of not requiring a complicated convergence circuit.

However, for this purpose, it is necessary to distort the horizontal deflection magnetic field into a pincushion shape and the vertical deflection magnetic field into a barrel shape.

However, in the magnetic field distribution by the conventional deflection yoke, the first
As shown in the figure, the size of the raster G' generated on the screen surface of the face panel 1 by the central electron beam among the electron beams emitted from the three electron beam passage holes G, B, and R is different from that of the raster G' generated on the screen surface of the face panel 1. The size of the laser beams B' and R' generated by the electron beam is smaller than that of the laser beams B' and R'.

In order to correct this, two pairs of magnetic pieces 6 and 7 as shown in FIG. 3 are attached to the electron gun 3 of the color picture tube 2 shown in FIG. 2.

FIG. 3 is a view of the electron beam emitting end surface 15 at the tip 13 of the electron gun 3, viewed from the face panel side, with a thickness of 0.2 mm.
~0.5 magnetic material pieces 6, 7 are placed on the electron beam emitting end surface 15
By attaching the deflection magnetic field to the electron gun side, the deflection magnetic field part that extends toward the electron gun side acts more strongly on the central electron beam than on both side electron beams, and the raster size deviation shown in Figure 1 is corrected. .

However, in this case, four fine magnetic pieces 6 and 7 are required.
It takes a lot of effort to handle and weld it.

On the other hand, as shown in FIG. 4, the deflection yoke 10 attached to the color picture tube 2 is provided with a saddle-shaped horizontal deflection coil and a toroidal-shaped vertical deflection coil, and the horizontal deflection coil is shown as a solid line in FIG. This type of magnetic field generates a magnetic field that has a pincushion tendency as a whole, but has an increased barrel component on the electron gun side compared to the conventional pincushion type horizontal deflection magnetic field shown by the broken line in the same figure. , the size relationship shown in Figure 6
/ , B/ , R/ are obtained.

In this case, the raster size could be corrected by attaching two pieces of magnetic material as shown in FIG.

That is, two elongated horizontal wing portions 9 formed on each of the two magnetic material pieces 8 are placed on both sides of the outer electron beam passage hole R (or B) in the vertical force direction, and Since the upright portion 19 is placed between the central electron beam passage hole and the outer electron beam passage hole, the central electron beam immediately after exiting the electron gun is subjected to a vertical deflection magnetic field that is stronger than that of the electron beams on both sides. act.

However, since the horizontal deflection magnetic field acts almost equally on the central electron beam and both side electron beams, it was possible to correct the disparity in raster size as shown in FIG.

However, since the two horizontal wing portions 9 protrude in an elongated manner, there is a drawback that deformation easily occurs during handling or welding.

The present invention has been made with the above-mentioned points in mind, and will be described below along with embodiments shown in the drawings.

In FIG. 8, two magnetic pieces 28 arranged to face each other on the electron beam emitting end surface 15 of the electron gun each have an annular portion 29 surrounding the outer electron beam passage hole R (or B). At the same time, two standing portions 30 stand up in the electron beam passing direction from positions on both sides sandwiching the centrally located electron beam passing hole G from the vertical force direction, and are in a vertical plane.
have.

In this case, the magnetic flux 11 of the vertical deflection magnetic field crosses both magnetic pieces 28 as shown by the arrows, but since the annular portion 29 exists, the vertical deflection magnetic field near the electron beam emission end face is
It has little effect on the outer electron beams and strongly acts only on the central electron beam.

Therefore, the Y-direction size of rask-G' in FIG. 6 can be brought close to the Y-direction size of rasters B/, R/.

On the other hand, the magnetic flux of the horizontal deflection magnetic field is generated as shown by arrow 12 in FIG. It has a strong effect on the target.

This is related to the fact that by providing the standing parts 30 of the magnetic piece 28 on both sides of the central electron beam passage hole in the vertical direction, the interval 31 between the standing parts of both magnetic pieces 28 can be made small. are doing.

Then, the size of rask G' in the X direction is defined as raster B/,
It can be made close to the size of R/ in the X force direction.

Depending on the characteristics of the deflection coil, the rask deviation may differ from the forms shown in FIGS. 1 and 6.

Therefore, the height of the upright portions 30 and the distance between the upright portions 31, which can be adjusted over a wide range, may be set to appropriate values to eliminate the discrepancy in raster size.

In the case of a 110-degree deflection 20-inch color picture tube, the width of the upright portion 30 is 2.0 mm, the height is 3 mm, and the interval 31 is 2 mTf.
L, and 5 pieces of iron with a thickness of 0.25 mm are used as the magnetic material.
An iron-nickel alloy with 50% nickel can be used.

In another embodiment shown in FIG. 10, the outer shape of the annular portion of both magnetic pieces 28 is rectangular.

As described above, in the color picture tube of the present invention, the two magnetic pieces arranged opposite to each other at the electron beam emitting end of the electron gun do not have an elongated welded part, so they are not deformed during handling or welding. Not only is there less risk of causing damage, but one or both of the horizontal and vertical deflection magnetic fields in the vicinity of the electron beam emission surface can be made to act more strongly on the central electron beam than on the outer electron beams, and the degree of has the advantage that it can be changed as appropriate by adjusting the height of the upright parts, the interval between the upright parts, etc., and the size discrepancy between the three rusks can be almost completely eliminated.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the raster size deviation of a conventional color picture tube, Fig. 2 is a cross-sectional view of the color picture tube, Fig. 3 is a plan view of a magnetic piece attached to a conventional electron gun electrode, and Fig. Figure 4 is a sectional view showing the relationship between the color picture tube and the deflection yoke;
Figure 6 and Figure 6 are diagrams showing the characteristics of the deflection yoke shown in Figure 4 and the resulting raster size deviation, and Figure 7 is a conventional magnetic piece for correcting the raster size deviation shown in Figure 6. FIG. 8 and FIG. 9 are diagrams for explaining one embodiment of the present invention, and FIG. 10 is a diagram showing another embodiment of the present invention. 28... Magnetic piece, 29... Annular part,
30... Standing part, G, B, R... Electron beam passing hole.

Claims (1)

[Claims] 1. Each of the two magnetic material pieces arranged to face each other on the electron beam emitting end surface of the electron gun is located at the outer side of the three electron beam passing holes arranged in a horizontal line. It has an annular part surrounding the central electron beam passage hole, and stands up in the electron beam passage direction from both sides vertically sandwiching the electron beam passage hole located in the center.
A color picture tube characterized in that it has two standing parts.