JPH02129833A - Color picture tube - Google Patents

Abstract

PURPOSE:To improve a convergence characteristic of three electron beems by providing a cylindrical electron lens common to three electron beems on a main electron lens part while arranging two electrodes of a specific construction inside a focusing electrode of this electron lens. CONSTITUTION:An electro gun part of a color picture tube consists of a cathode K, a first grid to a sixth grid G1 to G6. Of these grids, a first electrode having three beam passage holes 15R, 15G, 15B is present on the side facing to the opening holes 14R, 14G, 14B of the grid G5, while on its opposite side, a second electrode having a horizontally long opening hole 16 which three beems go pass through is present being coaxially arranged inside the grid G6. According to such constitution, the first non-cylindrical lens and the second non-cylindrical electron lens having a large aperture are formed inside the same electric field region of the main electron lens, and both lenses are in the neighboring positions so that a deflection angle can be made extremely small. Accordingly, both side beams come to pass through near the center of the electron lens so as to properly focus and converge on a screen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a color picture tube device, and more particularly to a color picture tube device that converges and concentrates three electron beams arranged in-line.

(Prior Art) As shown in FIG. 7, a color picture tube (100) has a face plate (102) having a screen surface (101) and a funnel (103) connected to a side wall (102') of this face plate. A connected neck (104), an electron gun (105) housed in the neck, a deflection device (106) attached to the outer wall from the funnel to the neck, and a plurality of electron guns disposed opposite to the screen at predetermined intervals. a shadow mask (108) having an aperture (107), a conductive film (109) uniformly applied to the inner wall of the funnel up to a part of the neck, a conductive film (109) applied to the outside of the funnel, and It consists of an anode terminal (not shown) provided in a part of the funnel.

The screen is coated with a large number of red, green, and blue phosphors (110) in stripes, and the three electron beams (BR), (BG), and (Ba) emitted from the electron gun are selected by a shadow mask. This bombards each phosphor, causing it to emit light.

The electron gun has an electron beam generator GE for generating, accelerating, and controlling three parallel electron beams arranged in-line, and a main electron lens ML for converging and concentrating each of these beams on a screen. As a result, three electron beams are focused and concentrated at the center of the screen (111), and these three electron beams are deflected and scanned over the entire surface of the screen by the deflection device to form a raster.

The smaller the distance sD between the three electron beams at the center plane of deflection of the electron beam deflected by this deflection device, the better the degree of concentration (convergence) of the three deflected electron beams, and the more the deflection requires. This has the advantage that less deflection power is required.

In order to improve the image performance of such a color picture tube, it is necessary to improve the performance of the electron gun and reduce the beam spot diameter on the screen.

An effective way to improve the performance of an electron gun is to improve the performance of the main electron lens section.

Generally, the main electron lens portion is formed by coaxially disposing a plurality of electrodes having openings and applying a predetermined potential to each electrode. There are several types of such electrostatic lenses depending on the electrode configuration, but basically, a large-diameter lens is formed by increasing the electrode aperture diameter, or a gradual potential is created by increasing the distance between the electrodes. Lens performance can be improved by changing the focal length to form a long focal length lens.

However, since the electron gun of a color picture tube is generally enclosed within a neck, which is a thin glass cylinder, first, the aperture of the electrode, that is, the lens aperture, is physically controlled. Also, the distance between the electrodes is limited so that the focused electric field formed between the electrodes is not influenced by other undesired electric fields in the neck.

In particular, when three electron guns are integrated in a delta array or inline array, such as in a shadow mask type color picture tube, the smaller the electron beam spacing (Sg) is, the more the three electron beams can be screened. Since it has the advantage that it is easy to concentrate at one point near the entire surface and the deflection power is small, the aperture of the electrode has to be made even smaller in order to reduce the distance between the electron guns.

Therefore, a method was developed in which three electron lenses lined up on the same plane were completely overlapped to form one large electron lens, and this large-diameter electron lens was used to maximize the performance of the electron lens. No. 559 (U.S. Pat. No. 3,
448,316), U.S. Pat. No. 4,528,4
Specification No. 76, Japanese Patent Publication No. 47-43993, Japanese Patent Publication No. 48-14502, U.S. Patent No. 3,011,09
Specification No. 0, U.S. Patent No. 2,861,208,
U.S. Patent No. 2,726,348, Japanese Unexamined Patent Publication No. 1987-
This method has been proposed in Publication No. 69 and Japanese Patent Laid-Open No. 62-217541.

Generally, three parallel electron beams (BR
), (BG), and (BB) pass through one common large-diameter electron lens LEL, when the central electron beam (B6) is properly focused as shown in Figure 8, the electron beams (BR) on both sides ), (BB) are overfocused and overconcentrated states, and the screen (10
1) Above, three beam spots (SPR), (
SPc) + (SPB) are greatly separated and the beams on both sides are distorted.

In order to match the convergence state of these three electron beams and reduce the coma aberration, there will be no practical problem if the distance Sg between the three beams is reduced to a certain extent with respect to the lens aperture of the electron lens LEL. Regarding the concentrated state of the three beams on the screen, Sg must be made extremely small, making mechanical arrangement of the electron beam generating section difficult.

Therefore, Japanese Patent Publication No. 49-5591 (U.S. Patent No. 3.
448,316) and U.S. Pat. No. 4,528,4
In the specification of No. 76, as shown in FIG. 9, the three electron beams incident on the electron lens LEL are given an inclination angle θ in advance so that the three electron beams simultaneously pass through the center of the electron lens LEL. Align the focused state of the three beams,
Thereafter, the diverging beams on both sides are deflected extremely strongly (φ°) in opposite directions so that the three beams are concentrated on the screen.

Therefore, there is a problem in that a large deflection aberration or coma aberration occurs in the beams on both sides.

Further, in Japanese Patent Publication No. 49-5591, this deflection is performed using an electrostatic deflection plate, but this case has the following drawbacks. That is, in a color picture tube, since the current of the electron beam is large, the diameter of the electron beam in the electron lens LEL is also quite large, and the three electron beams overlap in the electron lens. After that, each electron beam is converged by an electron lens and imaged on a screen far away, but the position xd where the electrostatic deflection plate is installed must be placed at a place where these three electron beams are completely separated.) .

For this reason, the electrostatic deflection plate has to be placed quite far from the electron lens, making the total length of the electron gun extremely long. Therefore, the distance from the electron lens to the screen, that is, the image point distance Q becomes longer, the electron optical magnification deteriorates (increases), and the beam spot diameter on the screen worsens (increases). Furthermore, increasing the total length of the electron gun means increasing the total length of the color picture tube, which is extremely undesirable because it significantly impairs the economic efficiency of the color picture tube.

In U.S. Pat. No. 4,528,476, as shown in FIG. 10, three electron beams that pass through the first common electron lens L1 and separate from each other are refocused by the common electron lens L2 at node 2. However, this method also has the following problems.

That is, in general, when one electron beam BG is converged onto a predetermined screen by one electron lens LEL, the beam emitted from the object point on the axis is focused on the image plane (screen) as shown in Fig. 11. If spherical aberration is ignored, the three electron beams BR+BGy BB emitted from the same object point in this state will also be concentrated on the screen. That is, if spherical aberration is ignored, as shown in FIG. 11, (as can be seen, the object point position for focusing and the exit point on the axis for focusing must basically be at the same position.

However, in U.S. Pat. No. 4,528,476, No. The beams are focused by the second electron lenses L□ and L2, but the 0° intersection with the axis of the three beams incident on the second electron lens L2 that causes the focusing action is on the first electron lens. The intersection point (Oo) is very different from the object point position for the focusing action. Therefore, it is easy to see that it is extremely difficult to perfectly match the focusing and concentration of each beam.

Also, U.S. Patent No. 3,011,090, U.S. Patent No. 2
．． No. 861,208, U.S. Patent No. 2,726,348, and Japanese Unexamined Patent Publication No. 53-69, as shown in FIG. 12, a low electrode G4 having three holes is followed by a high electrode G6 having a common hole. By arranging the three electron beams, the electron beams on both sides are bent in directions away from each other, and this is used to aim at concentrating the three electron beams on the screen surface.

Therefore, as shown in Fig. 13, the three parallel electron beams pass through three individual focused electron beams Lc separately, and then immediately pass through a common large diverging electron lens LD, so that the overall While each beam is focused, the electron beams on both sides diverge away from each other.

In this state, the electron beams enter a common large focusing electron lens LEL, and each beam receives a focusing action, and the electron beams on both sides are subjected to a focusing action.

U.S. Patent No. 3,011,090, U.S. Patent No. 2.
No. 861,208 and U.S. Pat. No. 2,726,348 disclose three individual focusing electron lenses L mainly having a focusing effect. The common large-diameter electron lens LEL is mainly designed to perform a concentrated action, whereas the
In Publication No. 3-69, the converging action is mainly performed by the common large-diameter electron lens LEL, so it is thought that the performance of the electron gun will be improved in the latter case.

However, in Japanese Patent Application Laid-Open No. 53-69, if you try to take advantage of the performance of the large-diameter electron lens LEL to improve the focusing performance, the large-diameter electron lens LEL will become stronger, so three beams will be focused on the screen. In order to achieve concentration, the divergence angle α of the beams on both sides must be large. For this reason,
The diverging lens LD formed by the low electrode with three apertures and the high electrode with a common aperture must be strengthened, but at the same time, the first focusing electron lens Lc is also strengthened, so that the beam is focused on the screen. Since the beam is focused (over-focused) in the front and the beam diameter on the screen becomes large, the performance of the large-diameter electron lens cannot be fully demonstrated.

That is, as shown in FIG. 12, when a high potential electrode G5 with a common aperture is placed next to a low potential electrode G4 with three apertures, it is clear from the appearance of the equipotential lines that the aperture is small. A converging lens Lc and a large-diameter diverging lens LD are formed as a pair, and since the function of this converging lens Lc is quite strong, the lens performance of the next large-diameter lens LEL formed by G5lG6 is demonstrated. The problem is that I can't.

(Problems to be Solved by the Invention) An object of the present invention is to provide a color picture tube in which three electron beams are focused and concentrated near the screen, and a large-diameter electron lens that is common to the three electron beams. Problems that arise when trying to reduce the diameter of the beam spot on the screen by using the electron beam; namely, the problem of deflection aberration or coma aberration that occurs when performing a concentrating action, the length of the electron gun, and the problem of the color picture tube. By solving the problems of long lenses, difficulty in converging and concentrating at the same time, and the inability to fully demonstrate the performance of large-diameter electron lenses, we have developed a highly economical and practical product with high resolution and high magnification. The objective is to provide a color picture tube with rich color characteristics.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes an electron gun section, a deflection section, and a screen section, and the in-line array of electron beams emitted from the electron gun section is directed vertically and horizontally by the deflection section. In the deflecting color picture tube device, the electron gun section generates three mutually parallel electron beams;
It is equipped with an electron beam forming part that accelerates and controls the electron beam, and a main electron lens part that converges and concentrates the electron beam. It has a structure with two utility poles inside. The first electrode has three non-circular holes that are longer in the vertical direction than the horizontal direction, corresponding to each of the three electron beams, and the centers of the beam passing holes on both sides are centered in the inline arrangement direction with respect to the centers of the electron beams on both sides. An electrode located away from the center of the beam and within the focused field region of the main electrode lens to form a first non-cylindrical electron lens portion.

The second electrode is an electrode having one non-circular aperture common to the three electron beams, which is longer in the horizontal direction than in the vertical direction,
A second non-cylindrical electron lens portion having a large diameter is formed here.

(Function) With such a structure, a substantial large-diameter electron lens is formed by the tenth non-cylindrical electron lens and the second non-cylindrical electron lens.

In the first non-cylindrical electron lens, both side electron beams are subjected to a deflecting force away from the central electron beam, and when entering the second non-cylindrical electron lens, both side electron beams are subjected to a deflecting force toward the central electron beam. At this time, since the first non-cylindrical electron lens and the second non-cylindrical electron lens are in the same focusing electron lens area and are very close to each other, the amount of deflection of the electron beams on both sides away from the central electron beam is extremely small. The three electron beams travel almost straight and receive a relatively strong deflection force toward the central electron beam by the focusing electric field of the second non-cylindrical electron lens, so that the three electron beams are concentrated on the screen. Therefore, since the electron beams on both sides pass near the center of the large-diameter electron lens, they are hardly affected by comatic aberration or spherical aberration.

Regarding the focusing of each electron beam, due to the structure of the first non-cylindrical electron lens, this lens is a so-called astiglens having a relatively strong focusing power in the horizontal direction.

On the other hand, the second non-cylindrical electron lens is an astiglens that has a relatively strong focusing force in the vertical direction due to its structure.

Therefore, the electron beam can be focused on a small spot on the screen by the focusing action of these two astiglens.

(Example) The present invention will be described in detail below with reference to one drawing.

FIG. 1 shows the neck portion of a color picture tube embodying the present invention. In FIG. 1, the electron gun part (G) disposed in the neck (104) has a cathode K, a first grid G1,
2nd grid G2, 3rd grid G3, 4th grid G
It consists of a fifth grid G5, a sixth grid G6, an insulating support BG and a valve spacer (112) that support them, and the electron gun is fixed to a stem bin (113) at the bottom of the neck. A YZ cross-sectional view and an x-Z cross-sectional view of this electron gun section are shown in FIGS. 2A and 2B, respectively.

Each of the cathodes has a heater (6R) inside.

3 cathodes with (6G), (6B) + KG
y KB, three electron beams BR+ BG+
Generates BB.

In addition, the first grid G1 and the second grid G2 have three relatively small beam passing holes (7R), (7G), (7B) corresponding to the three cathodes KR+KGrKB.
, (8R), (8G).

(8B), and this part controls and accelerates the electron beam from the cathode, forming a so-called electron beam forming part GE. Next, the third grid G3, the fourth grid G, and the fifth grid
Grid G5 also has three cathodes KR+ KGr
Three relatively large beam passing holes (9R
) to (14B).

Furthermore, the opening (14R) of the fifth grid G5, (14
G).

There are three beam passing holes (15R) on the side facing (14B).
).

(15G), (15B),
On the opposite side is a second electrode having a horizontally long aperture (16) through which the three beams pass in common, and is coaxially arranged within the sixth grid G6.

Three beam passing holes (15R), (1,5G), (
15B) is a substantially rectangular opening that is long in the vertical direction as shown in FIG.
15B) is located horizontally further outward from the center beam than the centers of the side beams.

The aperture (16) through which the three beams commonly pass is a horizontally long aperture as shown in FIG.

The 6th grid G is larger than the 5th grid G. It is a cylindrical mold part with an opening (17).

In the above electrode configuration, for example, the cathode has about 15
Set the cutoff voltage to 0■, add a modulation signal to this,
The first grid G1 is connected to the ground potential, and the second grid G2
is about 500 to IKV, and the third grid G3 is about 6 to 9 K.
V, the fourth grid G4 is about 500-3 KV, the fifth grid G5 is about 7-9 KV, and the sixth grid G6 is about 25-3 KV.
Apply an anode voltage of 0 KV.

With such a potential configuration, the beams generated from each cathode K according to the modulation signal are connected to the cathode K,
The first grid G□ and the second grid G2 form a crossover Co as shown in FIG.
The light is slightly focused by the prefocus lens PL of the grid G3, forming a virtual crossover CO, and enters the third grid G3 while diverging. Each beam coming to the third grid G3 is focused in the main electron lens section ML by the third grid G3 to the sixth grid G6, and the beams on both sides are focused and concentrated on the screen (101).

The lens action of the main electron lens sections from the third grid G3 to the sixth grid G5 will be explained in more detail using equivalent optical models shown in FIGS. 5 and 6.

Figure 5 is an electro-optical model of a horizontal cross section, in which the individual electron beams forming a virtual crossover vCO and entering the third grid G8 are transmitted through the third grid G3, the fourth grid G, and the fifth grid G5. Each of the formed weak unipotential lenses (sublens SL) focuses a little, and then the first non-cylindrical electron lens receives an extremely weak focusing action so that only the beams on both sides are deflected by a predetermined angle α. In this state, the electron beams enter the second non-cylindrical electron lens LEL, which has a common large diameter and is formed by the fifth grid G and the sixth grid G6.

A second non-cylindrical electron lens LEL with a common large aperture provides a main focusing effect on the individual beams and a focusing effect on both beams by β.

In other words, for focusing, a system has been established in which the beam emitted from the virtual crossover point vC○ on the axis is focused on the screen surface by the large-diameter electron lens LEL, and for focusing, , when the beams on both sides deflected by the first non-cylindrical electron lens are extended in opposite directions and intersect with the axis, they also coincide with the virtual crossover point vCO of the focusing system, that is, they exit from this virtual exit point vP. A system is established in which three beams are concentrated on the screen surface by a large-diameter lens, and a focusing system that focuses the individual beams and a concentrating system that focuses the three beams are respectively created in the horizontal section. It can be seen that they are established at the same time.

On the other hand, the vertical section will be explained using the electro-optical model shown in FIG.

Due to its structure, the first non-cylindrical electron lens has a focusing force in the vertical direction that is weaker than that in the horizontal direction. Therefore, the object point on the vertical section is located closer to the large aperture lens than the object point on the horizontal section. However, since the focusing power of the large-diameter second non-cylindrical electron lens is weaker than that in the horizontal direction, a system is established in which the electrons are focused on the screen surface even in the vertical section as shown in the model.

Therefore, the three beams can be properly focused and concentrated on one point on the screen.

In order to make it easier to understand the present invention, the diagram of the electron lens system model used in the explanation shows a diagram in which the beams on both sides are largely deflected to the outside by the first non-cylindrical electron lens, but in reality, the first non-cylindrical electron lens Since the non-cylindrical electron lens and the large-diameter second non-cylindrical electron lens are located very close to each other, the first non-cylindrical electron lens receives a force to deflect the beams on both sides to the outside, but the large-diameter second non-cylindrical electron lens It is pulled back inward by the focused electric field of the non-cylindrical electron lens. Therefore, the amount of deflection is very small, and the trajectory is closer to the center beam than shown in the figure, which is almost a straight line. Therefore, the light is focused on the screen with almost no coma aberration.

The effect of the present invention is to fully demonstrate the performance of a large-diameter electronic lens in a snack by comparing it with Japanese Patent Application Laid-open No. 53-69i.

In the case of JP-A-53-69, both beams are deflected outward by a diverging electric field lens, but in this case, the diverging electric field region needs to be placed at a position that does not disturb the electric field region of the large-diameter electron lens. The distance becomes longer. Therefore, since the deflection angle is increased and the electrons are incident on the large-diameter lens and concentrated, they pass around the periphery of the large-diameter lens and are subject to large comatic aberrations and spherical aberrations, making it difficult to fully utilize the performance of the large-diameter electron lens. I can't demonstrate it.

In contrast, the present invention forms a first non-cylindrical electron lens and a large-diameter second non-cylindrical electron lens within the same electric field region of the main electron lens, and since both lenses are located extremely close to each other, the deflection The corners can be made very small. Therefore,
The beams on both sides pass near the center of the large-diameter second non-cylindrical electron lens, and are properly focused on the screen with almost no coma or spherical aberration, fully demonstrating the performance of the large-diameter lens. , can be focused.

As described above, in the embodiments for explaining the present invention, the electrode structure forming the large-diameter lens is an example in which a cylindrical electrode with a relatively low potential is coaxially built inside a cylindrical electrode with a high potential facing each other. However, it goes without saying that the present invention is not limited to this, and the same effect can be obtained even when electrodes having the same diameter are opposed to each other.

In addition, the electrode having a vertically long non-circular hole common to the three beams disposed within the relatively low potential electrode may be plate-shaped as in this embodiment, or the electrode having a relatively low potential It goes without saying that the same effect as the present invention can be obtained even if the opening has a non-circular shape that is long in the vertical direction.

〔Effect of the invention〕

According to the present invention, it is possible to realize a color picture tube device with good three-electron beam concentration characteristics and a small electron beam diameter.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged view of a color picture tube device showing an embodiment of the present invention, and FIGS. 2 (A, ) and (B) are schematic sectional views in the Y direction and 3 is a front view of the first electrode, FIG. 4 is a front view of the second electrode, FIGS. 5 and 6 are optical equivalent model diagrams for explaining the present invention, and FIG. 7 is a conventional model. The schematic sectional views of the color picture tube device, and FIGS. 8 to 13, are optically equivalent model views for explaining the prior art. Agent Patent Attorney Nori Chika Yudo Kikuo Takehana

Claims (1)

[Claims] (1) In a color picture tube device comprising an in-line electron gun section, a deflection section, and a screen section, the electron beam emitted from the electron gun is deflected and scanned in vertical and horizontal directions by the deflection section, wherein the electron gun section is equipped with an electron beam forming section including a cathode that generates, accelerates, and controls three electron beams, and a main electron lens section that focuses and concentrates the electron beams. It has a large-diameter electron lens that acts on the beams in common, and this large-diameter electron lens has a common cylindrical electron lens for the three electron beams, and the three electron beams are located within the converging electric field region of the common cylindrical electron lens. An electrode having three substantially vertically elongated beam passing holes corresponding to the electron beams and an electrode having one substantially horizontally elongated electron beam passing hole common to the three electron beams are arranged. color picture tube device.