JPH02144831A - Color picture tube device - Google Patents

Abstract

PURPOSE:To enhance picture performance by focusing each of three parallel electron beams, given out of a cathode by a common large-aperture electron lens, on a screen in an optimal focused condition and an optimal centralized condition. CONSTITUTION:Components are the first electron lens LL which operates in common on three electron beams BR, BG, BS entered in parallel to a main electron lens portion ML1 and a combined electronic lens which has three individual of the second electron lenses SL1 to SL3 given by an electrode with three beam passing holes in a lens area of the first electron lens LL, and for three individual of the second electron lenses SL1 to SL3 the electron lens at the center is set to be stronger in focusing operation than the electron lenses on both sides and also each of electron beams on both sides is set to be entered into the center beam side of corresponding each of the second electron lenses SL1 to SL3. Each of the electron beams on both sides experiences comatic aberration from the second electron lenses SL1 to SL2, however the comatic aberration is offset because the first electron lens LL then experiences reverse comatic aberration, resulting in good focus on a screen. It is thus possible to enhance picture performance.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a color picture tube device, and particularly relates to a color picture tube device, in which three electron beams arranged in-line are connected to a common large-scale beam. The present invention relates to a color picture tube device having an electron gun focused and concentrated by a diameter electron lens.

(Prior Art) Generally, a color picture tube device is constructed as shown in FIG.
The funnel 4 is formed with a neck 5 joined to the funnel 4.

A film-like screen 2 made of phosphor is formed on the inner surface of the face plate 3, and a shadow mask 9 having a large number of apertures 8 is provided at a predetermined distance from the screen 2.

Further, an electron gun 6 is mounted inside the neck 5.

Further, an internal conductive film 10 is uniformly applied from the inner surface of the funnel 4 to a part of the inner surface of the neck 5.
The outer surface of the external conductive! 111 is uniformly applied, and a part of the outer surface of the funnel 4 is provided with an anode terminal (not shown).

Note that a deflection yoke 7 is attached to the outside from the funnel 4 to the neck 5.

The screen 2 is made up of a large number of red-emitting phosphors, green-emitting phosphors, and blue-emitting phosphors coated in stripes or dots, and receives three electron beams B emitted from the electron gun 6 during operation.
R, , BG and BB are selected by the shadow mask 9 and impact the respective phosphors, causing them to emit light.

The electron gun 6 also includes an electron beam forming section GE for generating, accelerating, and controlling three parallel electron beams B, 1% BG, and SS arranged in-line, and an electron beam forming section GE for focusing and concentrating these electron beams. It has a main electron lens section ML. Then, the three electron beams Bll, Bc, and B are deflected and scanned over the entire surface of the screen 2 by the deflection yoke 7, thereby forming a raster.

By the way, a method of concentrating three electron beams is a technique of concentrating the electron beam emitted from the cathode at an angle from the beginning, as shown in US Pat. No. 2,957,106, for example. There is also a U.S. Patent No.
, 772,554, some of the three electron beam passage openings provided in the electron gun electrode are moved slightly outward from the central axis of the electron gun. There are techniques for concentrating electron beams by decentering them, and all of these techniques are widely used.

The deflection yoke 7 basically includes a horizontal deflection coil for generating a horizontal deflection magnetic field that deflects the electron beam in the horizontal direction, and a vertical deflection coil for generating a vertical deflection magnetic field that deflects the electron beam in the vertical direction. have. In an actual color picture tube device, when the electron beam is deflected,
Since the concentration of the three electron beam spots on the screen 2 begins to deteriorate, measures are taken to prevent this concentration from breaking down.

This is called a convergence free system.
By making the horizontal deflection magnetic field a binction type and the vertical deflection magnetic field a barrel type, the entire area of the screen 2 can be
This is to concentrate the electron beam.

As described above, the quality of color picture tube devices has been improved through the adoption of many developed technologies, but new problems are becoming more common as tubes become larger and higher in quality.

That is, there are (1) a problem with the beam spot diameter of the electron beam on the screen 2, (2) a problem with the distortion of the electron beam spot at the periphery of the screen 2 when it is deflected, and (2) a problem with convergence over the entire surface of the screen 2.

When the tube becomes larger, the distance from the electron gun 6 to the screen 2 becomes longer, and the electron optical magnification of the electron lens increases, increasing the beam spot diameter on the screen 2 and degrading the resolution. It ends up. In order to reduce the beam spot diameter, the performance of the electron lens of the electron gun 6 must be improved.

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

However, since the electron gun 6 of the color picture tube is generally enclosed within the neck 5, which is a thin glass cylinder, first, the aperture of the electrode, that is, the lens aperture is physically restricted. 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 5.

In particular, when three electron guns are integrated in a delta arrangement or in-line arrangement, such as in a shadow mask type color picture tube, the smaller the electron gun spacing Sg is, the more the three electron beams can be screened. 2. It is easy to concentrate on one point near all objects. Furthermore, since there is an advantage that the deflection power is small, the opening of the electrode has to be made even smaller in order to reduce the electron gun spacing Sg.

Therefore, a method can be considered in which three electron lenses arranged on the same plane are completely overlapped to form a large electron lens, and this large-diameter electron lens is used to maximize the electron lens performance.

FIG. 6 is an optical illustration of this.

As shown in the figure, although the core of the projected electron beam becomes smaller, the result is still insufficient when looking at the electron beam as a whole. That is, when three parallel electron beams BRsBa and BB with an electron gun spacing, that is, a beam spacing Sg, pass through one common large-diameter electron lens LEL, the central electron beam B as shown in FIG. is properly focused, the electron beams BRSBB on both sides are overfocused and overconcentrated, with large coma aberration, and the screen 101
Above, three beam spots sp.

spa and SP are widely separated and the beams on both sides are distorted.

In order to match the concentration state of these three electron beams and reduce the coma aberration, if the distance Sg between the three beams is made as small as possible with respect to the lens aperture of the electron lens LEL, there will be no practical problem. , regarding the concentrated state of the three beams on the screen 101, the beam spacing Sg
must be made extremely small, and there are limits to the mechanical arrangement of the electron beam generating section.

Therefore, Japanese Patent Publication No. 49-5591 (U.S. Patent No. 3,
448.316) and U.S. Pat. No. 4,528,
In the specification of No. 476, as shown in FIG.
The three electron beams entering the EL are given an inclination angle in advance, so that the three electron beams simultaneously pass through the center of the electron lens LEL, and the focused state of the three electron beams is adjusted. After that, the divergent electron beams on both sides are strongly directed to φ0 in the opposite direction by the second electron lens LEL2.
The beams are deflected so that the three beams are concentrated on the screen 101.

As a result, the focusing and concentration of the three electron beams is improved.

However, the problem remains that large deflection aberrations or comatic aberrations occur in the electron beams on both sides.

Therefore, as shown in FIG. 8(a), in order to correct the overconcentration of the electron beams, a plate-shaped body having a non-circular aperture 12 common to the three electron beams as shown in FIG. 8(b) is used. A method has been proposed in which the three electron beams are arranged near a large-diameter electron lens and on the side of the electron beam generator, and the three electron beams are allowed to pass through the large-diameter electron lens without intersecting each other.

However, in such a method, since the plate-shaped body 13 has a common aperture for the three electron beams, it is necessary to correct the concentration characteristics caused by the large-diameter electron lens and to completely adjust the focusing state of the three electron beams. It is difficult to match the beam spot, and a large coma aberration remains in the focused beam spot, making it impossible to put it into practical use.

As described above, it is difficult to use a large-diameter electron lens that acts commonly on three electron beams, and it is not possible to maximize the performance of the large-diameter electron lens.

(Problem to be Solved by the Invention a) As mentioned above, in order to further improve the image performance of the color picture tube device, it is possible to It is effective to improve the performance of the image tube and reduce the diameter of the beam spot on the screen 2, but with conventional technology, the performance of the large-diameter electron lens cannot be fully demonstrated, and the image performance of the color picture tube device cannot be improved. There was a problem in that it was difficult to further improve the performance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color picture tube device that makes full use of the performance of a large-diameter electron lens and significantly improves image performance.

[Structure of the Invention] (Means for Solving Department Problems) The present invention includes an in-line electron gun, a deflection yoke, and a screen, and the electron beam emitted from the electron gun section is directed onto the screen by the deflection yoke. In a color picture tube device that deflects and scans vertically and horizontally, the electron gun has an electron beam forming unit including a cathode that generates, accelerates, and controls three electron beams, and a main unit that focuses and focuses the electron beams. The main electron lens section has a common electron lens for the three electron beams, and the common electron lens has three beam passing holes in a lens area on the cathode side. The beam passing holes on both sides have the same size and the central beam passing hole is smaller, and each electron beam on both sides has an electrode with a center beam of the corresponding beam passing hole. This is a color picture tube device configured so that the light is incident on the side.

(Function) According to the present invention, there is provided a first electron lens that acts in common on three electron beams incident parallel to the main electron lens section, and three electron beams within the lens area of the first electron lens. It consists of a composite electron lens having three individual second electron lenses by means of an electrode with a beam passing hole;
The electron lens is set so that the central electron lens has a stronger focusing effect than the electron lenses on both sides, and each electron beam on both sides enters the center beam of the corresponding electron lens at each node 2. It is set as follows.

As a result, each of the electron beams on both sides is subjected to coma aberration by the second electron lens, but then is subjected to coma aberration in the opposite direction by the first electron lens, so the coma aberration is canceled out and well focused on the screen. do.

Furthermore, since the first electron lens can be set to a lens strength that does not cause overconcentration, the three electron beams can be satisfactorily concentrated near the screen.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

This invention is an improved electron gun in order to solve the above problems, and the electron gun will be mainly described.

The electron gun of the color picture tube device according to the present invention is constructed as shown in FIG. 1, and this FIG. 1 shows the vicinity of the neck and the vicinity of the screen.

That is, the same parts as in the conventional example (FIG. 5) are given the same reference numerals, and the electron gun 100 mounted in the neck 5
are a cathode K, a first grid G1, a second grid G2 . 3rd grid G3, 4th grid G4, 5th grid
A grid G5 and a sixth grid 66 are arranged at predetermined intervals and are supported by an insulating support (not shown).

A valve spacer 112 is fixed to the sixth grid G6, and this valve spacer 112 is in contact with the internal conductive film 10 that is uniformly applied from the inner surface of the funnel 4 to a part of the inner surface of the neck 5. Incidentally, such an electron gun 100 is fixed to a stem pin 113 at the lower part of the neck 5.

Each of the above cathodes has a heater inside and generates three electron beams BR, BG, and BB.

In addition, the first grid G1 and the second grid G2 have three relatively small beam passage holes corresponding to the three cathodes K, and in these parts, the electron beams from the cathodes K are controlled and accelerated, so-called electron It constitutes the beam forming section GE.

Next, the third grid G3, the fourth grid G4, and the fifth grid G5 (on the fourth grid G4 side) similarly have three relatively large beam passing holes corresponding to the three cathodes K.

As shown in FIG. 2, three beam passing holes 14.
An electrode G5D with 15.16 is provided. As can be seen from this figure 2, there are three beam passing holes 14.15.1.
6, the beam passage holes 14, 16 on both sides are the same size, but the beam passage hole 15 in the center is smaller than on both sides.

Further, the sixth grid G6 partially overlaps with the fifth grid G5, and is a substantially cylindrical electrode that includes the fifth grid G5, which is a cylindrical electrode, and is similar to the large circular beam passage hole G5T of the fifth grid G5. In between, a large-diameter cylindrical lens is substantially formed.

Further, as described above, a valve spacer 112 is attached to the outer periphery of the tip of the sixth grid G6, and the internal conductive film 10 is uniformly applied from the inner surface of the funnel 4 to a part of the inner surface of the neck 5. They are in contact with each other, and a high voltage is supplied to the anode from the anode terminal provided in the funnel 4. Furthermore, a magnetic field correction element for the magnetic field produced by the deflection yoke 7 can be placed at the tip of the sixth grid G6.

As described above, the first grid G1 to the sixth grid G6 are fixedly supported by the insulating support on the cathode.

Further, as mentioned above, a deflection yoke 7 is attached to the outside from the neck 5 to the funnel 4, and this deflection yoke 7 horizontally directs the three electron beams B, , B, and BB from the electron gun. , consisting of a horizontal deflection coil and a vertical deflection coil for vertical deflection. Further, a multipolar magnet 51 is provided to adjust the trajectory of the electron beam.

A predetermined voltage is applied from the outside to all the electrodes except for the sixth grid G6 through the stem pin 113.

Regarding the voltages applied to each electrode in the above electrode configuration, for example, the cathode has a cutoff voltage of about 150V, a video signal is added to this, the first grid G1 is at ground potential, and the second grid G2 is at ground potential. is 500v~I
KV, 3rd grid G31;! '5~10KV, 4th grid G4 is 500V~3KV, 5th grid G5 is 5~10KV, 6th grid G6 is anode high voltage 25~3KV.
Apply 35KV.

By having such a potential configuration, each cathode K
The electron beam generated in accordance with the modulation signal is transmitted to the cathode by a first grid G1 and a second grid G2, forming a crossover Co as shown in FIGS. , are slightly focused by the prefocus lens PL by the third grid G3, forming a virtual crossover vCO. And the third grid G
Each of the electron beams BR, BG, and B entering the screen 3 is focused in the main electron lens section MLI by the third grid G3 to the sixth grid G6, and the electron beams on both sides are focused on the screen 2. Concentrate on.

In addition, Figures 3 and 4 are respectively '! This is an optical model of the Y-2 cross section and the X-2 cross section of Figure J1.

Next, the lens action of the main electron lens sections MLI from the third grid G3 to the sixth grid G6 will be explained in more detail with reference to FIGS. 3 and 4.

The individual electron beams that form the virtual crossover vCO and enter the third grid G3 are slightly distorted by the individual weak unipotential lenses EL2 formed by the third grid G3, the fourth grid G4, and the fifth grid G5. focused.

The large-diameter electron lens LEL is formed by the fifth grid G5 and the sixth grid G6, and is formed by an electrode G5D having three beam passing holes provided near the sixth grid 66 in the middle of the fifth grid G5. , the penetration of high voltage from the 6th grid G6 side is controlled, so in the end, the tip G5T of the 5th grid G5 (large aperture common to the 3 electron beams) and the cylinder of the 6th grid G6 (the 3rd electron beam One large first electron lens LL is formed by the large aperture common to both. At the same time, within this lens area,
Three separate second electron lenses SL C on its low voltage side
8L+5SLz, SLi) is formed.

Therefore, first, the strength of the electron lens LL is determined so that the three electron beams are concentrated near the screen 2, and the shortfall in focusing is compensated for by three individual second electron lenses SL. ing.

At this time, the beam passing holes 14.15.16 of the electrode G5D are arranged so that the lenses S L + S L3 on both sides are weaker than the center lens SL2, as shown in FIG. 16 is larger than the beam passage hole 15 in the center. With this, the electronic lens LL
The difference between the focusing power for the electron beams on both sides and the focusing power for the central electron beam is canceled out.

Furthermore, the centers of the beam passing holes 14 and 16 on both sides of the electrode G5D are different from the incident positions of the electron beams, that is, the central axes of the beam passing holes on both sides of the first grid 01 to the fourth grid G4. It's off. Therefore, in the horizontal direction (X-Z plane), the electron lenses SL, , SL
In contrast to 3, the electron beams on both sides each pass through the one closer to the solid axis (two wheels) and generate coma aberration, but since this is in the exact opposite direction to the coma aberration caused by the electron lens LL, they cancel each other out and the screen The coma aberration can be ignored in the electron beams on both sides focused on 2, and the electron beams on both sides also form good spots.

Now, the specific dimensions of the above embodiment are as follows, for example.

Spacing Sg between cathodes: 4.92 mm.

Aperture (beam passage hole) diameter of each electrode First grid G1+0.62mm.

0.62mm in second grid G2.

3rd grid G3'p4, 52 m m s
4th grid G4 → 4.52mm.

Electrode G5D *4.52mm.

Electrode G5T ÷25. Qmm.

Electrode D 5 'i'' 25, 0 m m s
6th Grid G6:28. Omm.

Electrode D6 = 23. Qmm.

Center-to-center row of electrode G5D: 4.52mm% opening on both sides*
10.0mm.

Length of each electrode 3rd grid 4th grid 5th grid 6th grid Do G3 4 6.2mm.

G4 ÷ 2, 0 m m s G5'-55,9mm.

G6÷40.0mm, (Length from electrode G5T) Spacing between each electrode First grid G1 Spacing between second grids G2 + 0.35 mm.

With the second grid G2 Interval between third grid G3: 1.2 mm.

Third grid G3 Spacing of the fourth grid G4 -1-0.6 mm.

a+14mm.

[Effects of the Invention] As described above, according to the present invention, the performance of the common large-diameter electron lens is fully demonstrated, and three parallel electron beams generated from the cathode are transmitted by the common large-diameter electron lens. It is possible to focus on the screen in an optimal focusing state and in an optimal concentration state, respectively.

Therefore, a very small beam spot can be realized on the screen, and a color picture tube device with significantly improved image performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing essential parts of a color picture tube device according to an embodiment of the present invention, and FIG. 2 is a plan view showing electrodes forming a main electron lens in the color picture tube device of the present invention.
3 and 4 are optical equivalent diagrams of the electron gun in the color picture tube device of the present invention, FIG. 5 is a schematic sectional view showing the entire general color picture tube device, and FIGS. 6 and 7 are optical configuration diagrams of conventional electron guns (two examples), and Figure 8 (
FIG. 3A is a cross-sectional view showing another conventional electron gun, and FIG. 2... Screen, 100... Electron gun, GE...
Electron beam forming section, MLI...main electron lens section, LE
L...Common large diameter electron lens, LL...First electron lens (common), SL...Second electron lens (individual)
.

Claims (1)

[Claims] A color picture tube comprising an in-line electron gun, a deflection yoke, and a screen, the electron beam emitted from the electron gun section being deflected and scanned in the vertical and horizontal directions on the screen by the deflection yoke. In the apparatus, the electron gun includes 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. has a common electron lens for the three electron beams, and in the lens area on the cathode side of this common electron lens,
It has an electrode with three beam passing holes, the beam passing holes on both sides are the same size, the central beam passing hole is smaller, and each electron beam on both sides corresponds to the electrode. A color picture tube device characterized in that the color picture tube device is configured such that the beam enters the beam near the center of the beam passage hole.