JPH05234534A - Electron gun device - Google Patents

Abstract

PURPOSE:To reproduce an image of high resolution without extending the whole length of a picture tube by providing a magnetic shield part between a shield cup and a deflection yoke. CONSTITUTION:Three electron beams emitted from the cathode of an electrode part 2 and accelerated by the electric field formed by the part 2are passed through an annular magnetic shield part 33 provided between a shield cup 3 and a deflection yoke 5 to scan the phosphor screen of a panel inner surface for reproducing an image by means of the yoke 5. At this time, the part 33 works as to take in the vertical deflecting magnetic field of the yoke 5 to produce a magnetic shielding effect of prohibiting the advance of the vertical deflecting magnetic field into the cup 3. Consequently, the two of the three electron beams positioned on both sides have nearly circular forms above and below a screen lateral width center, and both the lateral positions of the two electron beams are situated on the same side above and below the vertical width center of the screen. An image of high resolution can thus be reproduced without extending the whole length of the picture tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun device used for a high-resolution picture tube used in a terminal of a high-definition TV.

[0002]

2. Description of the Related Art FIG. 6 is a partial schematic view of a conventional high-resolution picture tube excluding an image reproducing section, which is a dish-shaped panel (not shown) having an inner surface coated with a phosphor for reproducing an image by an electron beam. No.) and a funnel-shaped funnel portion 1 connected thereto, and the funnel portion 1 has an electrode portion 2 that has a cathode, which is a source of electron beams, at one end, and that forms and accelerates a plurality of electron beam trajectories. The shield cup 3 is built in and the shield cup 3 is arranged at the other end of the electrode portion 2.

The electrode portion 2 and the shield cup 3 are fixed by welding, and a part of the electrode portion 2 is welded to a conduction terminal embedded in the system portion 7 at the end of the funnel portion 1 on the small diameter side. The shield cup 3 is fixedly supported, and one end of the shield cup 3 is supported by the contactor 4 on the inner surface of the funnel portion 1.
A magnetic field adjusting unit 6 that applies a deflection magnetic field to the electron beam in synchronization is provided on the outer periphery of the shield cup 3, and a deflection yoke 5 that applies a deflection magnetic field to the electron beam is provided on the outer periphery of the funnel-shaped portion of the funnel unit 1. Is provided.

FIG. 7 is a partially enlarged sectional view centering on the shield cup 3. Reference numerals 1, 2, 3, 4 and 6 in the figure show the funnel portion, the electrode portion, the shield cup and the contactor shown in FIG. -A magnetic field adjustment unit. Shield cup 3
A shield pipe 32 is projectingly provided in the central part of the, and the pole piece 31 is arranged around the shield pipe 32. This pole piece 31 is formed by fitting a bent portion of an L-shaped plate material into a slit 34 formed in the shield cup 3 as shown in FIG. 8 as shown in FIG.
Of the three electrode holes 9 formed in line on the
It is arranged so as to sandwich the electrode holes located on both sides. The shield pipe 32 has the same inner diameter as the central electrode hole of the three electrode holes 9, and is arranged so that one end surrounds the periphery of the electrode hole.

FIG. 9 is an enlarged sectional view of the shield cup 3 taken along the line IX-IX in FIG. 6, and the electrode hole 9 arranged in a straight line at the center thereof is irradiated with a blue phosphor. An electron beam 9B, an electron beam 9G for irradiating a green phosphor, and an electron beam 9R for irradiating a red phosphor.
Pass through different electrode holes. Incidentally, 8 is a vertical deflection magnetic field of the deflection yoke 5.

Next, the operation will be described. The three electron beams emitted from the cathode and accelerated by the electric field formed by the electrode 2 are subjected to the following actions in the shield cup 3 portion. That is, the central electron beam 9G passes through the shield pipe 32 without being affected by the surrounding magnetic field due to the magnetic shielding effect of the shield pipe 32, and the other two electron beams 9B and 9R on both sides are pole pieces. The magnetic field adjusting unit 6 receives a magnetic field synchronized with the deflection position from the deflection yoke 5 via 31. The shape of the electron beam irradiation portion on the fluorescent surface on the inner surface of the panel is a circular shape having almost the same area, and the irradiation order of the electron beams on the fluorescent surface on the inner surface of the panel is the same. Three electron beams 9 exiting the shield cup 3
B, 9G, and 9R scan the fluorescent screen on the inner surface of the panel that reproduces an image by the action of the deflection yoke 5.

[0007]

[Problems to be Solved by the Invention] Conventional HDTV
Since the high-resolution picture tube used for the V terminal is configured as described above, the vertical deflection magnetic field 8 from the deflection yoke 5 is added to the magnetic field received by the electron beam at the shield cup 3 by the magnetic field adjustment unit 6. Will be merged. FIG. 9 shows that state. That is, in FIG. 9, the distribution of the vertical deflection magnetic field 8 is attracted by the pole piece 31 and the distribution of the magnetic field is dense.

As a result, the screen 10 of the image reproducing portion scanned by the three electron beams 9B, 9G and 9R of the high resolution picture tube becomes as shown in FIG. In this figure, in particular, the red beam 9R is 10R and the blue beam is blue as shown by enlarging the upper, middle, and lower parts of the widthwise center (C-C) of the screen 10 of the three electron beams 9B, 9G, and 9R. 9B
10B, the shape of the beams on both sides has changed from the original circle to an ellipse. Further, the positions of the red beam 9R and the blue beam 9B are reversed left and right above and below the vertical center (DD) on the screen 10. As a measure for preventing this phenomenon, there is a method of separating the deflection yoke 5 and the pole piece 31 to reduce the influence of the deflection magnetic field, but this causes a problem that the total length of the picture tube becomes long.

The present invention has been made to solve the above problems, and the shape of the beam spots on both sides of the upper and lower sides of the screen are substantially the same without changing the overall length of the picture tube, and the vertical and horizontal intersection points are set. The purpose is to make the area of the beam spot substantially the same.

[0010]

In the electron gun apparatus according to the present invention, a magnetic shield section is provided between the magnetic field adjusting section and the deflection magnetic field generating section.

[0011]

The magnetic shield section of the electron gun apparatus according to the present invention shields the magnetic field from the deflection magnetic field generating section and does not affect the magnetic field adjusting section.

[0012]

【Example】

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial schematic view of a high-resolution picture tube of an electron gun according to a first embodiment of the present invention, excluding a video reproducing section. The funnel 1, the electrode section 2, the shield cup 3, the contactor 4, the deflection yoke 5, and the magnetic field adjustment. The parts 6 and the stem part 7 are the same as the conventional ones, and therefore their explanations are omitted. Reference numeral 33 is an annular magnetic shield portion according to the present invention. 2 is a partially enlarged sectional view centering on the shield cup 3 in FIG. 1, and the shield cup 3 includes a pole piece 31 and a shield pipe 32 as in the conventional device. Further, FIG. 3 is a partially enlarged perspective view of the shield cup 3 in FIG. 2, in which an annular magnetic shield portion 33 having a height of 10 mm is provided at an end portion. Furthermore, FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 1, showing the configuration of the shield cup 3 including the magnetic shield portion 33. Since the structure other than the magnetic shield part 33 is similar to the conventional structure, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

Next, the operation will be described. First electrode part 2
The three electron beams emitted from the cathode and accelerated by the electric field formed by the electrode 2 are subjected to the following actions in the shield cup 3 portion. That is, in FIG. 4, the central electron beam 9G passes through the shield pipe 32 without being affected by the surrounding magnetic field due to the magnetic shielding effect of the shield pipe 32, and the other two electron beams 9B, 9R on both sides are generated. ,
The magnetic field adjusting unit 6 receives the magnetic field synchronized with the deflection position from the deflection yoke 5 via the pole piece 31. The shape of the electron beam irradiation portion on the fluorescent surface on the inner surface of the panel is a circular shape having almost the same area, and the irradiation order of the electron beams on the fluorescent surface on the inner surface of the panel is the same. The three electron beams 9B, 9G, and 9R exiting from the shield cup 3 pass through the annular magnetic shield portion 33 according to the present invention and are reproduced by the action of the deflection yoke 5 on the fluorescent surface inside the panel. To scan.

At this time, as shown in FIG. 4, the annular magnetic shield portion 33 according to the present invention acts so as to take in the vertical deflection magnetic field 8 of the deflection yoke 5 to generate the vertical deflection magnetic field 8 in the shield cup 3. A magnetic shielding effect that prevents entry is created. As a result, the three electron beams 9 of the high-resolution picture tube are
As shown in the enlarged view of the screen 11 of the image reproduction part scanned by B, 9G, and 9R in FIG. 5, the three electron beams 11R, 11G, and 11B of the red beam, the green beam, and the blue beam are at the center of the width (CC- The shape of the beam on both sides above and below (CC) is approximately a circle. Furthermore, the vertical center of the screen 11 (DD-D
The left and right positions of the red beam 11R and the blue beam 11B are on the same side above and below D).

The effect is produced by setting the length of the annular magnetic shield portion 33 in the traveling direction of the electron beam to be about 10 mm. If this length is made too long, it will affect the action of the deflection yoke, so there is a limit to the setting of the length. Further, a stainless material is suitable as a material for the annular magnetic shield portion.

[0016]

As described above, according to the present invention, the magnetic shield portion is provided between the shield cup of the electron gun and the deflection yoke so that the magnetic field of the deflection yoke does not intervene in the shield cup. A high-resolution image can be reproduced without increasing the total length of a high-resolution color picture tube used for a TV terminal. It is possible to provide an electron gun device of a color picture tube.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an electron gun device according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing a configuration of an annular magnetic shield that forms a main part of the electron gun device in FIG.

FIG. 3 is a partially enlarged perspective view showing the configuration of the annular magnetic shield in FIG.

FIG. 4 is a diagram showing a cross section taken along line IV-IV in FIG. 1.

FIG. 5 is a diagram showing a state of electron beams on a screen of an image reproducing unit.

FIG. 6 is a cross-sectional view showing a schematic configuration of a conventional electron gun device.

7 is a partially enlarged cross-sectional view showing a configuration of an annular magnetic shield that forms a main part of the electron gun device in FIG.

8 is a partially enlarged perspective view showing the configuration of the annular magnetic shield in FIG.

9 is a diagram showing a cross section taken along line IX-IX in FIG.

FIG. 10 is a diagram showing a state of electron beams on a screen of an image reproducing unit.

[Explanation of symbols]

 1 Funnel part 2 Electrode part 3 Shield cup 4 Contactor 5 Deflection yoke 6 Magnetic field adjustment part 7 Stem part 8 Vertical deflection magnetic field 9 Electrode hole 9B, 9G, 9R Electron beam 31 Pole piece 32 Shield cup 33 Magnetic shield part

Claims (1)

[Claims] 1. A cathode for generating an electron beam, an electrode portion having the cathode at one end thereof for forming and accelerating a plurality of electron beam trajectories, and another end of the electrode portion provided with a deflection magnetic field for the electron beam. An electron gun device comprising: a magnetic field adjusting section that operates in synchronization; and a magnetic shield section that is provided between the magnetic field adjusting section and the deflection magnetic field generating section and shields the leakage of the deflection magnetic field.