JPH02123646A - Flat type picture tube device - Google Patents

Abstract

PURPOSE:To prevent a deflection yoke slope and raster strain, and improve deflection efficiency by so forming the internal surface of a horizontal deflection coil along a gun axis as to have a circular arc with the center thereof on the gun axis at the side of an electron gun, and a rectangular form in a length-wise direction with the deflected angle thereof rounded for the gun axis at the side of a phosphor screen. CONSTITUTION:A pair of saddle type horizontal deflection coils 14a and 14b mounted to the funnel part of a flat type picture tube 1 is so formed as to be asymmetric above and below a horizontal plane 15 including a gun axis 9. A coil cross section at a position C at the side of an electron gun within a region along the gun axis 9 has an internal surface along a circular arc having a radius of curvature about the gun axis 9 and a deflected circular arc external surface. Also, the section is so formed as to be asymmetric about the horizontal plane 15. On the other hand, the coil section at a phosphor screen side position (a) is made along a rectangular form in a length-wise direction with the corner part thereof rounded and approximately along the external surface of the funnel. At an intermediate position (b), the cross section is made to have an intermediary form between forms at positions (a) and (c).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flat picture tube device comprising a flat picture tube and a deflection yoke attached to a funnel portion of the picture tube.

2. Description of the Related Art A conventional flat picture tube device is constructed as shown in FIG. 4 and FIG. 4 scans the phosphor screen 7 under the deflection action of a deflection yoke 6 attached to the funnel section 5. The rear panel section 8 supporting the phosphor screen 7 is connected to the gun shaft 9 of the electron gun l.
Since the image drawn on the phosphor screen 7 by the scanning is viewed from the scanning surface side through the transparent front panel section 10, it is possible to obtain a high-luminance image. can. The deflection yoke 6 includes a pair of toroidal vertical deflection coils 11a.

11b1 ferrite core 12. It has a pair of saddle-type horizontal deflection coils 13a, 13b and an insulating coil support frame (not shown).
a and 13b are vertically symmetrical as shown in FIGS. 6 and 7.

Problems to be Solved by the Invention In the flat picture tube device configured as described above, the neck portion 2 is cylindrical, whereas the rear panel portion 8 and the front panel portion 1o are both approximately flat. Therefore, the horizontal deflection coil 12 is attached to the deflection yoke 6 which is attached to surround the funnel portion 5 that connects the two.
The phosphor screen 7gA does not completely follow the outer surface of the picture tube 1, but is inclined perpendicularly to (), which tends to cause raster distortion.

In addition to being difficult to obtain high deflection efficiency, the neck part 2
There is also a problem in that the tolerance for so-called neck shadow, in which the electron beam 4 is caught in the funnel portion 5, is also low.

Means for Solving the Problems According to the present invention, a region along the gun axis of a pair of horizontal deflection coils constituting the deflection yoke has an inner surface shape along an arc centered on the gun axis on the electron gun side. The phosphor screen bond has an inner surface that is eccentric to the gun axis and roughly follows a horizontal rectangle with rounded corners.

Function: In the flat picture tube device constructed in this manner, the inner surface of the horizontal deflection coil is more closely aligned with the outer surface of the picture tube, especially at the funnel portion, so that the large-diameter side of the funnel portion has a substantially rectangular male shape. Even if the deflection yoke is tilted, it is possible to prevent the tilting of the deflection yoke and the resulting raster distortion. In addition, since the effective inner diameter of the coil becomes smaller, the deflection efficiency can be increased, and the mounting position of the deflection yoke α can be further moved toward the phosphor screen side, thereby increasing the margin of neck shadow.

Embodiments Next, the present invention will be explained along with embodiments shown in the drawings.

As shown in FIGS. 1 and 2, the pair of saddle-type horizontal deflection coils 14a and 14b attached to the funnel portion of the flat picture tube 1 are replaced by a pair of toroidal-type vertical deflection coils (not shown). , a ferrite core, an insulating coil support frame, etc. constitute a deflection yoke, which is formed asymmetrically above and below with respect to a horizontal plane 15 that includes the gun shaft 9. That is, the cross-sectional shapes at position a of the phosphor screen in the region along the gun axis, position C of the example electron gun, and a position intermediate thereto are as shown by a + CT b in Fig. 3, respectively. It is formed into a shape.

The cross-sectional shape of the coil at position C in the example electron gun has an inner surface along a circular arc with a radius of curvature centering on the gun axis 9 and an eccentric arc-shaped outer surface, similar to the conventional horizontal deflection coil.
It is symmetrical with reference to 5. On the other hand, the cross-sectional shape of the coil at position a on the phosphor screen side is made to roughly follow a horizontally long rectangle with rounded corners.
Approximately along the outer surface of the funnel section. However, the vertical outer diameter is larger in the lower coil part than in the upper coil part.
The lower coil portion projects slightly inward below. In addition, the cross-sectional shape of the coil at the intermediate position is intermediate between the cross-sectional shapes at positions a and c, and this deformation tendency is not limited to the position, but extends from the vicinity of position C to position a. It is structured so that it occurs gradually according to the following.

Effects of the Invention In the picture tube device of the present invention, since the inner surface of the horizontal deflection coil almost completely follows the outer surface of the funnel portion of the flat picture tube, it is possible to prevent the tilting of the deflection yoke and the occurrence of raster distortion due to the tilt of the deflection yoke. The effective inner diameter of the coil can be reduced and deflection efficiency can be improved. Furthermore, since the mounting position of the deflection yoke can be moved further toward the phosphor screen side, the margin of neck shadow can be increased.

[Brief explanation of drawings]

FIG. 1 is a side view of the main parts of a flat picture tube device embodying the present invention, FIG. 2 is a front view of a pair of horizontal deflection coils of the same device, and FIGS. (C) is a diagram showing the cross-sectional shape of the horizontal deflection coil at three locations in Figure 2, Figure 4 is a side sectional view of a conventional flat picture tube device, Figure 5 is a perspective view of the same device, and Figure 6 The figure is a perspective view of a pair of horizontal deflection coils of the same device, and FIG. 7 is a side view of the same deflection coil. DESCRIPTION OF SYMBOLS 1... Flat picture tube, 3... Electron gun, 5... Funnel part, 7... Phosphor screen, 9... Gun shaft,
14a. 14b...Horizontal deflection coil, 15...Horizontal surface. Name of agent: Patent attorney Shigetaka Awano and one other person Fukuzu diagram

Claims (1)

[Claims] It consists of a flat picture tube with a phosphor screen provided on the rear panel inclined with respect to the gun axis of the electron gun, and a deflection yoke attached to the funnel part of the picture tube. A region of the horizontal deflection coil along the gun axis has an inner surface shape along an arc centered on the gun axis on the electron gun side, but an area that is eccentric to the gun axis on the phosphor screen side. What is claimed is: 1. A flat picture tube device characterized by having an inner surface substantially following a horizontal rectangle with rounded corners.