JP2000243317A - Cathode-ray tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve magnetic field generating efficiency of a deflection yoke. SOLUTION: A cross-sectional shape A of a cone part 26 of a CRT is formed in a rectangular shape longitudinally larger than the length and breadth ratio of a screen 22. The cross-sectional shape A is formed in the same shape as an area for receiving force from a magnetic field made by a deflection yoke 25, that is, an electron beam deflecting area M to finally draw a rectangular raster on the screen 22 by an electron beam. An inside surface shape of the deflection yoke 25 arranged around this cone part 26 is also formed in the same shape as a cross-sectional shape of the cone part 26. Thus, an useless space can be eliminated between the deflection yoke 25 and the electron beam deflecting are M, so that magnetic field generating efficiency of the deflection yoke 25 can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube device. Specifically, by improving the inner surface shape of the deflection yoke and the cross-sectional shape of the cone portion of the CRT (cathode ray tube) in which the deflection yoke is disposed, the shape is longer than the aspect ratio of the screen, thereby improving the magnetic field generation efficiency of the deflection yoke. The present invention relates to a cathode ray tube device as designed.

[0002]

2. Description of the Related Art FIG. 3 shows an overview of a general CRT device 10. As shown in FIG. As is well known, the CRT device 10
An RT 17 and a deflection yoke 15 are provided. Then, the CRT 17 is provided with an electron gun 11 for generating an electron beam.
, A panel having a screen 12 for drawing a raster (image), and a funnel connecting the two. The funnel deflects the electron beam to secure a space for electrons to travel. The deflection yoke 15 is arranged around a portion of the CRT 17 from the neck to the funnel. The portion 16 of the CRT 17 where the deflection yoke 15 is provided is called a cone portion. The electrons emitted from the electron gun 11 at the neck are
A deflection action is given by a magnetic field generated from a deflection yoke 15 provided around the entrance of the funnel portion, and a raster is formed by scanning on a screen 12 having a predetermined aspect ratio (for example, 3: 4, 9:16, etc.). To be done.

[0003]

As shown by the shape C in FIG. 4, the cross-sectional shape of the cone 16 is generally circular. In FIG. 4, a region indicated by a mesh is a region required for electron beam deflection (hereinafter, “electron beam deflection region”).
M). This region M is a region in the deflection magnetic field where the electron beam emitted from the electron gun 11 receives a force from the magnetic field generated by the deflection yoke 15 to finally draw a rectangular raster on the screen 12. .

As is clear from the drawing, the cross-sectional shape of the cone portion 16 is larger than the region M in a portion including the electron beam deflection region M. For example, regions C1 to C shown in the drawing
4. These areas C1 to C4 are useless spaces from the viewpoint of the efficiency of the magnetic field for applying the deflection effect, and generate an invalid magnetic field. Therefore, there is a limit in improving the magnetic field generation efficiency by this method.

Therefore, the sectional shape of the cone 16 is shown in FIG.
As shown by a shape B in FIG. In this case, since the cross-sectional shape of the cone 16 is rectangular, the deflection yoke 15 can be brought closer to the electron beam deflection area M. The cross-sectional shape of the cone portion 16 is generally a shape having the same aspect ratio as the screen 12, or the three-dimensional (red, blue, and green) electron beams are arranged side by side, so that the aspect ratio of the screen 12 is increased. It has a slightly longer shape.

As described above, the electron beam emitted from the electron gun 11 is swept up, down, left, and right by the magnetic field generated by the deflection yoke 15 to create a raster on the screen 12, but the screen is particularly flat. Then, as shown in FIG. 5, the pincushion distortion at the top and bottom of the raster becomes large.
In order to reduce the pincushion distortion, the vertical magnetic field is increased on the electron gun side among the deflection magnetic fields. For this reason, the electron beam deflection area M is vertically longer than the aspect ratio of the screen 12 even though it is not described above. Therefore, as described above, in the case where the cross-sectional shape of the cone portion 16 is the same as the aspect ratio of the screen 12 or a rectangular shape longer than that, the efficiency of the generation of the magnetic field is still left and right of the cone portion 16. There is useless space from the point of view.

Accordingly, an object of the present invention is to provide a cathode ray tube device which further improves the efficiency of generating a magnetic field of a deflection yoke.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to deflecting an electron beam around a cone portion of a cathode ray tube having a cone portion having a substantially rectangular cross section so as to scan on a screen of the cathode ray tube. Wherein the cross-sectional shape of the cone portion of the cathode ray tube and the inner surface shape of the deflection yoke are longer than the screen aspect ratio of the cathode ray tube.

In the present invention, the sectional shape of the cone portion of the cathode ray tube and the inner shape of the deflection yoke are made longer than the aspect ratio of the screen of the cathode ray tube. As a result, there is no need to interpose a useless space between the electron beam deflecting region and the electron beam deflecting region which is longer than the screen aspect ratio, and it is possible to further improve the magnetic field generation efficiency of the deflection yoke. It becomes possible.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an overview of a CRT device 20 according to an embodiment of the present invention. As with the conventional CRT device 10 shown in FIG. 3, the CRT device 20 includes a CRT 27 and a deflection yoke 25.
And has a neck portion, a panel portion having a screen 22, and a funnel portion connecting both of them. The deflection yoke 25 is disposed around a cone 26 extending from the neck of the CRT 27 to the funnel. The electron beam emitted from the electron gun 11 at the neck is deflected by the magnetic field generated from the deflection yoke 25, and scans on the screen 22 having a predetermined aspect ratio (for example, 3 to 4, 9 to 16, etc.). To form a raster.

Here, the cone portion 2 of the CRT device 20
6 and the inner surface shape of the deflection yoke 15 are longer than the aspect ratio of the screen 22, and the size is the same as the size of the electron beam deflection area M required to draw an appropriate raster on the screen 22. It is said. Next, the shape and size of the cone portion 26 and the deflection yoke 25 will be described with reference to FIG.

FIG. 2 shows the cross-sectional shape A1 of the cone 26 of the CRT device 20 and the shape A of the inner surface of the deflection yoke.
2 is shown. The shapes A1 and A2 have a slightly longer aspect ratio than the aspect ratio of the screen 12. Around the cone portion 26, a deflection yoke 25 having a similar inner surface shape is disposed so as to extend along the outer peripheral surface of the cone portion 26 without any gap. Further, for comparison with the cross-sectional shape of the conventional cone portion, the shapes B and C in the conventional method shown in FIG. 4 are indicated by broken lines.

The meshed portion is a region M necessary for deflecting the electron beam, that is, the sectional shape A of the cone portion 26 has the same size as the electron beam deflecting region M. Therefore, no useless space exists between the deflection yoke 25 and the electron beam deflection area M, and generation of an invalid magnetic field is eliminated.

As described above, in the embodiment of the present invention, by bringing the deflection yoke 15 closer to the electron beam deflection area M, it is possible to eliminate a useless space.
The magnetic field generation efficiency of the deflection yoke 25 can be improved. Further, since the coil of the deflection yoke 25 can be brought closer to the electron beam deflection area M, a more complicated magnetic field can be generated in the electron beam deflection area M, and convergence and image distortion can be improved.

The power consumption of the deflection yoke 25 can be reduced by improving the magnetic field generation efficiency. This reduction in power consumption suppresses a temperature rise due to the heat generated by the coil of the deflection yoke 25, so that the size of the deflection yoke 25 can be reduced as a whole.

[0016]

According to the present invention, the shape of the inner surface of the deflection yoke and the cross-sectional shape of the cone of the CRT on which the deflection yoke is arranged are made to be longer than the aspect ratio of the screen. The efficiency of generating a magnetic field can be improved, and power consumption can be reduced. Further, a complicated deflection magnetic field can be generated, and convergence and image distortion can be improved.

[Brief description of the drawings]

FIG. 1 shows an overview of a CRT device of the present application.

FIG. 2 is a diagram showing a cross section of a cone portion and an inner surface shape of a deflection yoke.

FIG. 3 shows an overview of a conventional CRT device.

FIG. 4 is a diagram showing a cross-sectional shape of a conventional cone portion.

FIG. 5 is a diagram for explaining pincushion distortion.

[Explanation of symbols]

10, 20 ... CRT device, 11, 21 ... electron gun, 1
2, 22 ... screen, 15, 25 ... deflection yoke, 1
6, 26 ... cone part, 17, 27 ... CRT

Claims (1)

[Claims] 1. A deflection yoke for deflecting an electron beam and scanning on a screen of the cathode ray tube is disposed around the cone portion of the cathode ray tube having a cone portion having a substantially rectangular cross section. A cathode ray tube device comprising: a cathode ray tube; wherein a sectional shape of a cone portion of the cathode ray tube and an inner surface shape of the deflection yoke are longer than an aspect ratio of a screen of the cathode ray tube.