JPS6244937A - Color picture tube - Google Patents

Abstract

PURPOSE:To make good focus characteristic and convergence characteristic compatible by arranging a double stage electrostatic side beam deflector between main electron lens of electron gun and deflection yoke thereby reducing the inclination angle of side beam thus realizing reduction of the caliper of main electron lens and the inclination angle simultaneously. CONSTITUTION:A side beam deflector 7 is arranged at the tip section of fourth electrode 6 of bipotential inline electron gun comprising three cathodes 2r, 2g, 2b and first to fource electrodes 3-6. The side beam deflector 7 is constructed with a planar electrostatic deflection electrode board parallel with double stage y-z plane and produces electrostatic field sin X-direction for deflecting respective side beam 11r, 11b. First stage deflector is formed with the electrode boards 8, 10 while second stage deflector is formed with electrode boards 9, 10 where the supply voltage to the electrode board 10 is the voltage of fourth electrode 6 or the anode voltage Eb is applied while Eb-V1 is applied onto the electrode board 8 and Eb+V2 is applied onto the electrode 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a color picture tube, and more particularly to an in-line dot type high resolution color display tube device.

[Technical background of the invention]

First, an example of an inline dot type high resolution color display tube device will be explained with reference to FIG.

That is, there is a panel (13) on which a phosphor screen (12) is formed by regularly arranging circular phosphor dots of three colors (usually red, green, and blue), and this phosphor screen (12).
a shadow mask (15) having a circular electron beam aperture (14) opposite to the center beam (2); a funnel (16); l1g), side beam (ll
r) An in-line electron gun (18) arranged along the X-axis that electrostatically focuses and emits (llb), and a deflection yoke (18) which is a deflection system provided on the outer wall of the cone part of the funnel (16). 19).

The feature of this in-line type is that the deflection yoke (19) has a non-uniform magnetic field, so that the center beam can be spread across the entire screen using only the combination of the color picture tube and the deflection yoke (19) without using any circuit correction means. (l1g), side beams (llr) and (llb) can be made substantially coincident, which is what is called dynamic convergence free.

In color display tubes, focus characteristics and convergence characteristics are important, unlike general color picture tubes. The biggest factor that determines the focus characteristics is the aperture (D) of each electron gun, but the currently mainstream neck outer diameter is 29.1. +nm, the aperture (D) is 5.
Generally, the thickness is about 5 nn.

On the other hand, the biggest factor that influences convergence characteristics is the inclination angle of the side beam with respect to the tube axis, which is determined by the distance between the center beam and side beam A in the electron gun (Sg) and the distance between the electron gun and the phosphor screen (Sg). Ls
g). This center distance (Sg) is 29
．． In the case of 1 nyn net, approximately 6.6 fields are common.

Next, a conventional pi-potential in-line electron gun (υ) will be explained with reference to FIG.

That is, the main structure consists of three cathodes (2r) (2g) (2b), a first electrode (3), a second electrode (4), a third electrode (c), and a fourth electrode (0). The third electrode (c)
Up to the center beam (11,g) and each side beam (
llr) (llb) interval (Sg) is the distance between the centers of the center gun and side gun, and the third electrode (c)
By off-centering the electrode aperture center of each side gun with the fourth electrode (0) and the fourth electrode (0) on the high voltage side outward from the third electrode (0) on the low voltage side, the main electron lens is distorted and the side beam ( 1,1r) (llb) and center beam (l1
g) A general structure in which static convergence is obtained at an inclination angle (θ) on the phosphor screen (12) (actually the electron beam passage part of the shadow mask) having a distance (Lsg) from the main electron lens. It is.

[Problems with background technology]

However, the aperture (D) for obtaining dual focus characteristics and the beam spacing (Sg) for obtaining convergence characteristics are in a contradictory relationship. In other words, for focusing characteristics, the aperture (D) needs to be as large as possible.
For this reason, it is better to have a larger beam spacing (Sg), and if possible, it is desirable to enlarge the neck diameter, but for convergence characteristics, it is desirable that the beam spacing (Sg) be small and, as a result, the inclination angle be small.

Particularly in the case of large 20-inch ultra-high resolution color display tubes, this relationship has reached its limit and sufficient performance cannot currently be achieved.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and
It is an object of the present invention to provide a color picture tube that can achieve both good focus characteristics and convergence characteristics.

[Summary of the invention]

The color picture tube of the present invention reduces the inclination angle of the side beam by arranging a two-stage electrostatic side beam deflector between the electron beam focusing system, that is, the main electron lens of the electron gun, and the deflection system, that is, the deflection yoke. This allows the main electron lens aperture and inclination angle to be reduced at the same time.

[Embodiments of the invention]

Next, a pi-potential in-line electron gun (21) used in an embodiment of the color picture tube of the present invention will be explained with reference to FIGS. 1 and 2. However, the same amount as in the conventional example indicates the same part, and the color picture tube is the same as that shown in FIG. 3, so the explanation will be omitted.

That is, in this example, three cathodes (2r) (2g)
(2b), a first electrode 0, a second electrode 0), a third electrode 0, and a fourth electrode (0). ■The feature is that it is equipped with.

This side beam deflector (■) is composed of flat electrostatic deflection electrode plates parallel to the y-z plane in two stages, each of which has a static deflection in the X direction to deflect the side beams (11r) (llb). Generates an electric field.

At this time, no effect is exerted on the center beam (l1g).

The first stage deflector is formed by electrode plates (8) and (10), and the second stage deflector is formed by electrode plates 0 and (10). Among these electrode plates (8), (9), and (10), the voltage supplied to the electrode plate (10) is the voltage of the fourth electrode 0, that is, the anode voltage (
Eb) is applied, and (Eb-vl) is applied to the electrode plate (to),
(Eb+V2) is applied to each electrode (9).

The distance between the electrode plate (10), the electrode plate (8), and the electrode plate ■ is (
di) (d2), the strength of the deflection electric field is E1=V□/d□ and E2=v2/d2, respectively.

Generally, in the case of an electron beam that is parallelly incident on a parallel plate electrode at a velocity v0, the electric field of the plate electrode is E and the length is Q.

When the specific charge of electrons is (e/m), 0 from the center of the electrode
The amount of deflection d8 at a point separated by a distance of 8 is d8ヱ (noni)
The velocity in the direction of the electric field E after leaving the electrode is given by .

Now, the neck diameter of the 20-inch tube for the second stage deflector is 29.
Assuming the case of 1mm, 5g1=6.6mm Ls,
::3o.

If mm Eb=25KV, SKz=5.0v
In order to obtain substantial static convergence with an and phosphor screen, d1 = d2 = 8 books 1
121”20rffIl, n 2 =3.43mm,
It is calculated that Vl'' 2 KV, V2''=I KV is one solution. However, in this case, disturbances in the electric field between both deflectors and at the ends of the electrodes are ignored.

As a result, S3□ = 6.6 mm and aperture D = 5.5 nwn are maintained in the main electron lens part, and the final side beam inclination is equivalent to that of the conventional tube when S = 5.0 mm, which is a good result. Focus characteristics and convergence characteristics can be obtained.

In the above example, the neck diameter is 29.1 mm, but it is more effective when the neck diameter is large, such as a neck diameter of 36.5+nm. This increase in neck diameter results in an increase in deflection power, but in high-resolution color display tubes where performance is important, the increase in deflection power is not a major problem. Furthermore, the present invention is more effective with large pipes such as 20 inches.

In addition, in the case of the present invention, since there is no need to deflect the side beam in the main electron lens section, there is no need to decenter the side beam passage hole of the fourth electrode 0 as in the conventional case, and the focus characteristics deteriorate due to this. horizontal smearing) can be avoided.

The embodiment described above is a typical one, and the electrode configuration and supply voltage are not limited to this embodiment. If the electrode configuration is devised, the supply voltage (V,..., V2) can be reduced to one. It is possible.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to achieve both good focus characteristics and good convergence characteristics, and in particular, it is possible to provide a large-sized ultra-high resolution display tube.

[Brief explanation of drawings]

1 and 2 are diagrams showing an electron gun used in an embodiment of the color picture tube of the present invention. FIG. 1 is an explanatory cross-sectional view, and FIG. Explanatory diagram: Figure 3 is a partially cutaway perspective view of an inline dot type color picture tube;
The figure is an explanatory cross-sectional view of an electron gun used in a conventional color picture tube. 1, 18.21--electron gun 2 r, 2 g,
2 b-Cathode 7...Side beam deflector 8, 9, 1
0...electrode plate 1, 1. g... Center beam 1.1r, llb... Side beam 12... Phosphor screen 15... Shadow mask 19... Deflection yoke

Claims (1)

[Claims] a panel with a phosphor screen formed on its inner surface; a shadow mask placed opposite to the phosphor screen; a neck connected to the panel via a funnel; In the color picture tube, the color picture tube includes an in-line electron gun including a focusing system that electrostatically focuses and emits a beam and both side beams, and a deflection system including a deflection yoke provided on the outer wall of the cone portion of the funnel. A first stage and a second stage side beam deflector are disposed between the focusing system and the deflection system from the focusing system side, the first stage deflects the side beam toward the center beam, and the first stage deflects the side beam toward the center beam. A color picture tube characterized in that, in the second stage, static convergence is obtained by deflecting the side beams and the center beam so that they form a predetermined inclination angle.