JPS63190232A - color cathode ray tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an in-line color cathode ray tube having convergence characteristics suitable for use at high horizontal deflection frequencies, or at multiple horizontal deflection frequencies.

[Conventional technology]

Currently, there are not many problems when in-line color cathode ray tubes are used in color television receivers of the standard broadcast power type, but for example, when used in high-definition video data terminals (VDT), When using a large number of horizontal scanning lines and therefore a high horizontal deflection frequency, - Of the three electron beams lined up on the horizontal plane, the scanning area by the central beam, that is, the scanning area by the electron beams at both ends of the image area. There was a problem with 11 people sitting together.

The cause of J in this problem is estimated to be first-order.

A cylindrical shield side wall surrounding the three electron beams is installed at the end of the fluorescent screen side of the electron gun that forms three electron beams in-line, in order to shield the electron beams from the electrostatic charge that is charged on the inner wall surface of the glass bulb. A bottomed cylindrical shield electrode made of non-magnetic metal and having an electron beam passage hole for each of the three electron beams on the bottom surface near the l13 pole is disposed.

On the other hand, a deflection yoke for generating a deflection magnetic field for deflecting the electron beam is placed externally near the connection with the neck tube of the funnel of the valve.

Because the end of the deflection magnetic field near the cathode side is in a relative position passing through the shield side wall of the J° shield electrode, eddy currents are induced in the conductive shield side wall by the time-varying deflection magnetic field. , the original deflection magnetic field is weakened by this eddy current. Sign q! At a horizontal deflection frequency similar to that of broadcasting systems, the shadow damage caused by eddy currents is small, and even if the scanning area by the central electron beam and the scanning area by the electron beams 11 at both ends are different, the difference, 1, is small. Not a problem, but high precision for 1 example V D '1'! In an 11-degree display tube, the number of horizontal scanning lines is large, and the time rate of change of the magnetic field for horizontal deflection is much faster than in the case of television broadcasting, so the eddy current generated on the shield side wall of the shield electrode is also much larger. This is thought to be due to the fact that its influence has become more noticeable.

Furthermore, JP-A-56-76145 discloses magnetic field control on the bottom surface of the shield electrode that increases the horizontal deflection magnetic flux density acting on the central electron beam and lowers the horizontal deflection magnetic flux density acting on both side electron beams. For an in-line color cathode ray tube equipped with It is disclosed that an eddy current inducing element is provided that generates an eddy current as a result of the change. And the electronic bee 11 in the center is...
In general, in order to prevent the water deflection angle from becoming small, in the magnetic field control system, +3 (actually a small cylindrical member of high magnetic conductivity magnetic material 14) is placed in one of the central electron beam passage holes. ] This bead 11 is placed in the
The magnetic flux of the deflection magnetic field acting on vP! I'm raising the level.

In addition, an annular body made of a high-permeability magnetic material is placed around the electron beam passage holes on both sides to form a bypass for the magnetic flux that detours around the beam passage holes, so that the horizontal deflection magnetic field that acts on the electron beams on both sides is localized. I'm trying to get weaker. Furthermore, eddy current inducing elements are provided above and below the beam passage holes on both sides, respectively, to protrude like an eave and to be orthogonal to the horizontal deflection magnetic flux. Therefore, four magnetic control elements and four eddy current induction elements are respectively disposed on the bottom surface of the shield electrode by welding or the like.

Next, JP-A No. 0-se73t;, JP-A No. 60-8
6737 - In order to prevent the horizontal deflection magnetic field from being weakened by the foot warming current, the shield side wall is cut out at the part where it intersects with the horizontal deflection magnetic field and an eddy current is generated, and the shield is The height of the shield sidewalls was increased to 6.5mm to reduce the area where the sidewalls intersect with the deflection field. O
It is disclosed that the value is limited to less than ew.

[The gap that the invention attempts to solve]

The present invention stands at 1.1 when an in-line color cathode ray tube is used by increasing the number of horizontal scanning lines and increasing the horizontal deflection frequency in order to obtain high definition.

It sufficiently suppresses convergence defects between the central electron beam and both side electron beams, solves other problems, is simple and easy to manufacture, and fully exhibits not only the original effect of the shield electrode but also secondary effects. The purpose is to provide a color cathode ray tube that is

Means for Solving Problem C] In the present invention, an electron gun is located at the phosphor screen side end of an electron gun that forms three nearly parallel electron beams in one horizontal plane;
A bottomed cylindrical shield electrode made of non-magnetic metal and opening toward the fluorescent screen, consisting of a bottom with three electron beam passage holes and a cylindrical shield side wall that shields the electron beam from charging on the glass bulb wall. , at the top and bottom of each of the electron beam passage holes on both sides inside the cylindrical shield side wall.
A non-magnetic metal wall is installed perpendicularly to the bottom surface, and an eddy current is generated on this projecting wall surface by a horizontal deflection magnetic field to weaken the effect of the horizontal deflection magnetic field on both side beams, and the effect of the horizontal deflection magnetic field on both side beams is reduced. Misconvergence can also be suppressed to a level that causes no problems even when the horizontal deflection frequency is increased.

[Effect]

In the present invention, a wall made of a non-magnetic metal is provided at one end of the electron beam passage hole on both sides in a manner perpendicular to the shield electrode J, so that a weakening magnetic field is generated by an eddy current flowing on this projecting wall surface. Due to the influence of It can be suppressed.

〔Example〕

FIG. 1(a) is a top view of the shield electrode 1 of an embodiment of the color cathode ray tube of the present invention, where La is the shield side wall, lb is the bottom surface, and 2 is the space above and below the beam passage holes on both sides perpendicular to the bottom surface 1b. a non-magnetic metal bent body for protruding the wall surface 2a;
3 is a welding point where the non-magnetic metal bending hole 2 is welded to the bottom surface 1b of the shield electrode 1; 4.6 is a beam passage hole on both sides;
5 is a central beam passage hole. FIG. 1(b) is a side view of the non-magnetic gold plate 2. FIG. In addition, passage holes 4a and 5a for each beam are bored in the bending hole 2.

If holes 68 are made slightly larger than the beam passage holes 4.5 and 6 formed in the bottom surface 1b of the shield electrode 1, there will be some positional error when welding the bent body 2 to the bottom surface 1b. In this way, the strength of the horizontal deflection magnetic field acting on the electron beams on both sides can be adjusted to an appropriate level with respect to the horizontal deflection magnetic field acting on the central electron beam. The three electron beams can be focused with high accuracy both in the center and on both sides of one screen, resulting in a good high-definition image. The folded body 2 shown in FIG. 1(b) can be easily produced by pressing, and it is also extremely easy to weld this folded body 2 to the bottom surface of the shield electrode 1. It is easy to implement regardless of the situation.

〔Effect of the invention〕

As explained above, according to the present invention, using an in-line electron gun, it is possible to easily fabricate 54 high-definition tubes in which electron beam misconvergence is suppressed to the extent that it is practically not a problem.

[Brief explanation of the drawing]

FIG. 1(Q) is a top view of a shield electrode according to an embodiment of the present invention, and FIG. 1(B) is a side view of a bent body for adjusting a deflection magnetic field according to the present invention. 1... Shield electrode, 1a... Shield side wall, lb
...Bottom surface, 2...Bent body, 2a...Protruding wall surface made of non-magnetic metal, 3...Welding point, 4I6...Both side beam passing hole, 5...Central beam passing hole . 1st haze (tb) 1b fullness

Claims (1)

[Claims] 1. In an in-line color cathode ray tube, an electron gun that forms three nearly parallel electron beams in one horizontal plane.
It is located at the end of the phosphor screen, and is made of non-magnetic metal and consists of a bottom surface with three electron beam passage holes and a cylindrical shield side wall that shields the electron beam from charging on the glass bulb wall. A non-magnetic metal wall is provided at the upper and lower portions of each of the electron beam passage holes on both sides of the open bottomed cylindrical shield electrode surrounded by the cylindrical shield side walls, protruding perpendicularly to the bottom surface. Color cathode ray tube.