JPS58158841A - Color cathode ray tube - Google Patents

Abstract

PURPOSE:To reduce the static convergence due to the focus regulation of the electron beam, by focusing the electron beam through three grids having sequentially higher voltages while controlling the voltage of the central grid. CONSTITUTION:In order to regulate the focus state of the electron beams 16, 17, 18, the voltage of third grid 3 is rised by a focus regulator 21 to rise the voltage ratio V2-3 (third grid voltage/second grid voltage) thereby the electron beams 17, 18 will be bent more between the second grid 2 and the prefocus side grid 9 of third grid 4, while the voltage ratio V3-4 (fourth grid 4 voltage/third grid 3 voltage) is reduced between the main lens side grid 8 and fourth grid 9 thereby it is bent less resulting in the cancellation of the bending due to the variation of the third grid 3 voltage and the variation of the static convergence of the electron beam on the phosphor face can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a cathode ray tube having 98 electron beam guns arranged in a delta arrangement, and more specifically, consists of 8 or more grids and 9 electron lenses. 8
This relates to the reform of an electron gun that focuses and concentrates an electron beam.

Conventionally, the electron gun used in color cathode ray tubes focuses the emitted electron beam from the electron emitting section on the fluorescent surface of the cathode ray tube using a main lens so that the electron beam diameter is the smallest, and also It is configured to focus the beam on one point. As a means of concentrating the latter electron beam, a method is mainly adopted in which the Hatake electron gun is constructed with a separate GSO insulator and each electron gun or two electron guns are tilted so as to concentrate at one point. , and as another means,
3 The electron gun is constructed as a single unit so that parallel electron beams are emitted, and the central axes of the grids forming the electron lens are shifted between the high-voltage side and the low-voltage side. It is generally adopted to concentrate the light by adding an inclination to the surface.

FIG. 1 shows a conventional in-line type 8-beam electron gun such as the latter mentioned above, and in the same figure, the electron gun structure has a 0-circular hole (to be described later) through which three electron beams (to) to (to) pass. It consists of grids 1 to 4 (1) to (4), a cathode body (5) and a cathode part (6), which are fixed by a pair of support rods (7). The 8th grid above (
3) is composed of a main lens side grid (8) and a front focusing lens side grid (9). In the center of the first to eighth clits (1) to (3), there are circular holes (1 heat), (
2m) and (8m), the hole spacing is 1. With side inner hole (1b) %Oc
), (2b), (gc), (3b), (llc) are respectively transparently installed (the hole spacing is the distance from the center of each circular hole 0), the circular hole (1 m)% (2 m), (am), and side holes (1), (2b), (3b), and (lc),
(Ten C) and ($C) are sequentially arranged so as to be coaxial with each other.

The fourth grid (4) is formed with a circular hole (4a) and four holes (4b) and (4c).
4a) is located coaxially with the circular holes (1 m), (2a), and (8 holes) of the first to third grids (1) to (3).
The circular holes (, 4b>, (4c) are formed with a hole interval 44 longer than the hole interval t3 of the first to third grids (1) to (3).

A voltage is applied to the first to #I4 grids (1) to (4) so that a high voltage is applied to each grid in order to accelerate and focus the electron beam. (Since the hole spacing between the hole and the 8th grid (3) is La>Am, the electron beam is concentrated here.
can be lost.

is a focusing adjustment device that is connected to the third grid (3) and adjusts the focusing of the shimiko beam by adjusting the voltage of the eighth grid.

When an electron gun with such a configuration is operated, the cathode body (5)
Nine electron beams (up to), alpha power, saw go straight to the main lens side grid (8) of the 8th grid (3), and the 8th grid (3) and the 4th grid (4) The electron beams (5) and (to) that are focused by the electrostatic lens action of the main lens part and pass through the inner holes (sb) and (8c) on each side are located at the center of the main lens. Each central circular hole (11) to (4) is placed in front of the broom 4 grid (4) and placed on nine fluorescent surfaces (not shown).
Concentrate the electron beam (to) passing through a).

Conventional electron guns like this have a concentrated electron beam.

The hole spacing t is dependent on the difference in hole spacing between the third grid (3) and the fourth grid (4) and the voltage ratio, so the hole spacing is 1. Even if the %L4 difference is constant, if you change it to adjust the focusing of the electron beam (using the electron 4 focusing adjustment parameter in Grirad (3)), the degree of concentration on the fluorescent surface will change, and the state of convergence will change. It has the disadvantage that it changes.

This invention solves the above-mentioned conventional drawbacks by focusing and concentrating the electron beam in 30 grids that increase in height, and by controlling the voltage of the central grid. It is an object of the present invention to provide a polar ray tube that is less affected by static compass due to focusing.

Embodiments of the present invention will be described below with reference to the drawings.

Note that the same parts as in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

In Figure I2, the difference from the conventional example in Figure 1 O is that the front focusing lens side dalid (9) of the 8th grid (3)
) Hole spacing between circular holes (8b) and (8c) on both sides 1
, is 1s! Grid (2) has circular holes (2b) and (2c) on both sides.
) The hole spacing A, y) should be long.

Therefore, assuming the hole spacing of the second to fourth grids (2) to (4), ~L- is As<Ag<4, and the second grid (2) and the third grid (3 ) and Of&ll and due to the potential difference between the eighth grid (3) and the fourth grid (4))
The electron lens consists of a circular hole (2b), (8b)
, and the side inner holes (8b) and (4k) will be misaligned.

With the above configuration, the three electron beams (1!, (5), (to)) emitted from the cathode body (5) are connected to the second grid (2).
Go straight until you reach the second grid (2) and third grid (3).
), the electron beam (1η, -) is bent between the front thread bundle lens side grid (9), and the main lens side grid (8) of the third grid (3) and the fourth grid (4). The electron beam is bent at the threshold of the fourth grid (4) and concentrated onto a central electron beam on a fluorescent surface placed in front of the fourth grid (4).

Kokote, in the ninth stage of adjusting the focusing state of the real child Him (to) (lη, (to)), use the focusing 1111ji device (company).
If the voltage of the grid (3) is increased, the voltage ratio V*-s (8th grid (3) voltage/2nd grid (2) voltage) will increase, so gg grid responsibility 2) and 2nd grid (4)
Between the front focusing lens side grid (9) and the electron beam α? ) (II has a large amount of bending. On the other hand, between the main grid (8) and the fourth grid (4), the voltage ratio Vl-4 (fourth grid (4) voltage/second grid voltage) (3) voltage) becomes smaller, the amount of bending becomes smaller, and as a result, the change in the amount of bending caused by changing the eighth grid (3) voltage is canceled out, so the electron beam on the fluorescent surface It becomes possible to reduce changes in state convergence.

Conversely, when the voltage of the third grid (3) is lowered, the voltage ratio Vl-s becomes smaller, so the amount that the electron beam is bent is smaller. 0,,1 Figure 3 shows another embodiment of the present invention, in which the second grid (3) and the #I4 grid (4) are used. ) A circular hole (19m) between
.

An intermediate grid (to) having several circular holes (19 m) and (19 b) is provided, and the hole interval t16 is set to the fourth grid (4
) is smaller than the hole spacing L4 of the first to eighth grids (2).
) to (4), and the voltage applied to the intermediate grid is also higher than the eighth grid (3) and lower than the fourth grid (4). The focusing state of the electron beam is adjusted by changing the voltage applied to the electron beam. As a result, it is possible to achieve the same effect as in the above embodiment at t1.

In the above embodiment, the case where the electron beam is bent by decentering the central axis of the grid was explained, but it is also possible to bend the electron beam by tilting the facing surface of the grid and decentering the electron lens, or by using an electron gun. The same effect can be obtained by arranging them in a delta type.

As described above, according to the present invention, the eight grids are set so that the voltage increases sequentially from the cathode body side, an electron lens is formed between each grid, and the circular holes facing the electron lens are formed. By decentering the comrades or by tilting the grid facing surface, the eight electron beams passing through it can be focused and concentrated, and the focus of the electron beams can be adjusted above the voltage of the intermediate grid. Furthermore, it is possible to provide a color cathode ray tube in which the influence on concentration caused by adjusting the focus of the electron beam is reduced.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a conventional in-line three-beam electron gun, FIG. 2 is a vertical cross-sectional view showing an embodiment of the present invention, and FIG.
The figure is a longitudinal sectional view showing another embodiment of the present invention. (2), (3), (4), (19...grid, (2)
i) ~ (2c), (11m) ~ (8C), (4m) ~ (
4c), (19m) - (19c) = circular hole, (5) - cathode body, shout - α...electron beam, (2)... focusing device. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 Figure 3

Claims (1)

[Claims] (1) three cathode bodies through which the respective electron beams are emitted in parallel to each other, and an eighth cathode body arranged in order in the ζo6 electron beam row traveling direction and having a circular hole through which the electron beam passes; a first grid, the first and second grids;
, by applying successively higher voltages to the third grid], the first and the third! and between the second and first grids.
An electron lens is formed between the grid of configured to focus and concentrate on; and
A color cathode ray tube comprising a focus adjustment device that adjusts focus of the electron beam by controlling the voltage of the second grid.