JPH03208238A - Color image receiving tube - Google Patents

Abstract

PURPOSE:To enhance convergence grade as the whole of a face plate by disposing a plurality of magnetic field generating elements which generate eddy current magnetic fields in the neighborhood of magnetic field control elements within an anode. CONSTITUTION:Magnetic field control elements 3A and 3B are mounted in the neighborhood of electron beams 4a and 4c at the both sides within a convergence cup disposed at the tip end section of an electron gun 12. When a color image receiving tube is in operation, eddy current magnetic fields 2 are generated by the horizontal deflecting magnetic field 1 of a deflecting yoke, this exerts an influence on a center electron beam 4b, and concurrently generates eddy current 16A and 16B over respective magnetic field generating elements 5A, 5A, 5B and 5B, accompanied by which, magnetic fields 2 and 2 which exert an influence on the electron beams 4a and 4c at the both sides, are generated. Namely, the disposition of the elements 5A, 5A, 5B and 5B makes it possible to equalize influences which are exerted to beams 4a through 4c by the magnetic fields 2 and 2. This thereby enables symmetry from right to left on the face plate to be actualized, thereby making it possible to obtain stable convergence.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color picture tube commonly used in displays, monitors, etc., and more specifically, relates to an improvement in convergence quality during operation of a color picture tube. It is something.

[Prior Art] Fig. 3 is a vertical cross-sectional view of a conventional common color picture tube.
In the figure, (6) is a rectangular face plate panel, (7) is a rectangular funnel part, and both (6), (
7) are connected together. The face plate panel (6) has an observation face plate (8), the inner surface of which is coated with three colors of phosphors (9).

(10) is a porous color selection electrode, ie, a shadow mask, which is attached to the phosphor (9) at a predetermined distance. (11) is the neck part, and the funnel part (
7), and an in-line electron gun (12) is installed in the center of the interior thereof.

This in-line electron gun (12) has a hot cathode, an electrode for controlling an electron beam, an electrode for extracting an electron beam, a focusing electrode, and an anode, but the specific structure thereof is well known, so illustration thereof is omitted.

(14) is a scratch yoke, which is attached to the outer periphery of the joint between the funnel part (7) and the neck part (11);
83 R, G, electron beams (4a), (4b) emitted from the electron gun (12). (4c) is deflected to pass through the shadow mask (10) and collide with the phosphor (9). (15) is the convergence cup, and the electron gun (12) is the convergence cup.
) is placed at the tip of the convergence cup (15), and the electron beams (4a) and (4c) on both sides of the convergence cup (15)
), there are magnetic field control elements (3^), respectively, as shown in Fig. 4. (3B) is installed.

Next, the operation of the above configuration will be explained.

When operating a color picture tube, the deflection yoke (+4)
The horizontal deflection magnetic field (1) causes the convergence cup (1
5) An eddy current (16) is generated above in the direction of the arrow in Figure 4,
This generates an eddy electric 'a magnetic field (2).

At this time, the electron beams on both sides (4a), (4c
) has its magnetic field cut off by the magnetic field control elements (3A) and (3[1), so it is hardly affected by the eddy current magnetic field (2), and only the center electron beam (4b) is affected by the eddy current magnetic field (2). The side electron beam (4a) will be affected by the side electron beam (4a). (4c) The deflection sensitivity to (4c) is slow.

Also, the retrace period of horizontal scanning is 1/5 to 1/6 of the scanning period.
The eddy current magnetic field (2) generated during the flyback period is large. Therefore, the eddy current magnetic field (2) generated during the retrace period immediately after the start of the horizontal scanning period, that is,
It has a large effect on the convergence on the left side of the screen, and also affects the convergence on the center of the screen and the right side of the screen.

To be more specific, as shown in Fig. 5(a), on the left side of the screen, side electron beams (4a) and (4c)
The landing line (18) of the center electron beam (4b) is largely displaced to the right with respect to the landing line (l7) of , and at the center and right side of the screen,
The center landing line (l8) is slightly displaced to the left with respect to the side landing line (17).

Generally speaking, static convergence adjustment is performed to deal with such deviations in the landing line.
Through this static convergence adjustment, Figure 5 (
As shown in b), the entire screen will move to the right, and the ? On the right, there is a difference in distance (HCRIl, HCRr) between the side landing line (17) and the center landing line (18).

[Problem to be solved by the invention] Since the conventional color picture tube is configured as described above, static convergence adjustment also causes a difference in the distance between the landing line between the left and right sides of the screen and the center. Therefore, there was a problem in that the convergence between the left and right sides of the screen became asymmetrical, and the convergence quality of the screen as a whole deteriorated.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a color picture tube that can improve the convergence quality of the entire screen.

[A Thousand Steps to Solve the Problems] The color picture tube according to the present invention generates an eddy current magnetic field in the vicinity of the magnetic field control element in the anode that causes a center electron beam and electron beams on both sides to resonate, respectively. It is characterized by a plurality of magnetic field generating elements arranged in an upright position.

[Function] According to the present invention, when the color picture tube is in operation, an eddy current magnetic field that affects the center electron beam is generated by the horizontal deflection magnetic field of the deflection yoke, and an eddy current is also generated in the magnetic field generating element itself. This forcibly generates eddy current magnetic fields on the electron beams on both sides. This makes it possible to have the same effect on the electron beams at the center and both sides, and to obtain stable convergence over the entire screen.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 is an enlarged schematic perspective view of the main parts of a color picture tube according to an embodiment of the present invention, and since the overall structure of the color picture tube is the same as that shown in FIG. 3, illustration and explanation are omitted. However, in the following explanation, the symbols used in FIG. 3 are used for components that are not shown in FIG. 1.
explain.

In Figure 1, (4a), (4b), (4c
) are three electron beams emitted from the in-line electron gun (12), and the electron beams (4a), ( Magnetic field control elements (3A) and (3B) are respectively attached near 4C).

(5A). (5A). (5B) , (5B
) are magnetic field generating elements, and these magnetic field generating elements (5
A). (5A) (5B) (5B) is 9.2mm long
．． It is formed into a rectangle with a width of 7.0 mm and a plate thickness of 0.5 mm.
Made of non-magnetic material and conductor, electron beam (4a)
．． (4b). The magnetic field control element (3^) is placed in an upright position along the radial direction of (4c). It is placed near (3B).

Next, the operation of the above configuration will be explained.

When the color picture tube is in operation, the deflection yoke (14)
An eddy current magnetic field (2) is generated by the horizontal deflection magnetic field (1), which affects the center electron beam (4b) and also causes the magnetic field generating elements (5A), (5A), (5
B), eddy current (16A) on (5B). (16
B) and, along with this, an eddy current magnetic field (
2) , (2) is generated.

That is, the above magnetic field generating element (5^'). (5A
) (5B) and (5B), the eddy current magnetic field (
2). The influence of (2) on the center and both side electron beams (4b), (4a), (4c)
Both can be made almost the same.

Therefore, on the left and right sides of the screen, the distance between the side and center landing lines is 1i (HCRIl., HCRr
) can be made the same, that is, symmetrical on the screen, such as HCRn=HCRc, and stable convergence can be obtained.

FIG. 2 is a schematic perspective view of the main parts shown in another embodiment of the present invention, and the difference from the embodiment shown in FIG. 1 is that two magnetic field generating elements (5A) and (5B) are installed. The rest of the configuration is the same as in FIG. 1. The embodiment shown in FIG. 2 also provides the same effects as the embodiment described above.

[Effects of the Invention] As described above, according to the present invention, it is possible to forcibly generate an eddy current magnetic field in each of the electron beams on both sides that has almost the same effect as the center electron beam. Also, the landing deviation of the side electron beams can be made symmetrical on the left and right sides of the screen.

Therefore, it is possible to obtain stable convergence quality over the entire screen by static convergence adjustment.

[Brief explanation of drawings]

FIG. 1 is an enlarged schematic perspective view of the main parts of a color picture tube according to an embodiment of the present invention, FIG. 2 is an enlarged schematic perspective view of the main parts showing another embodiment of the invention, and FIG. 3 is a general view of the main parts. FIG. 4 is an operational explanatory diagram showing how a vortex magnetic field is generated during operation of a conventional color picture tube;
FIG. 5 is a front view of a screen showing the results of conventional convergence. (1)...Horizontal deflection magnetic field, (2)...Eddy current magnetic field,
(3A). (3B-)...Magnetic field control element, (4
a) , (4b) . (4C)-electron beam, (5
A), (5B)...Magnetic field generating element, (12)...
- In-line electron gun, (14)...deflection yoke. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a color picture tube equipped with an in-line electron gun having a hot cathode, an electron beam control electrode, an electron beam extraction electrode, a focusing electrode, and an anode, a center electron beam is placed near the magnetic field control element in the anode. and a color picture tube characterized in that a plurality of magnetic field generating elements that generate eddy current magnetic fields that respectively influence electron beams on both sides are arranged in an upright position.