JPH0131264B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deflection device used in a color picture tube device, and an object of the present invention is to correct distortion of a reproduced image using only the magnetic field distribution of the deflection device.

The conventional color picture tube device is as shown in Fig. 1.
Red formed on the inner surface of the rectangular face plate 1,
A fluorescent surface 2 having a band-shaped phosphor layer that emits green and blue light, a shadow mask 3 having a rectangular electron beam passage hole provided opposite to the fluorescent surface 2, A color picture tube consists of a net 4 which is connected via a funnel part 6 and houses a plurality of electron guns 5 arranged in a row; It consists of a deflection device 8 for deflecting the emitted electron beam 7.

When the deflection coil of this device is semi-toroidal, the deflection device 8 deflects the electron beam 7 and at the same time automatically converges it on the fluorescent surface 2 and reproduces the electron beam on the fluorescent surface. In order to reduce the image distortion to approximately 0 to 2% in the vertical direction, the vertical magnetic field should be barrel-shaped, and the horizontal magnetic field should be relatively weak pink tension type or uniform type on the electron gun (GUN) side, and a fluorescent surface. Generally, the (SCN) side is designed to have a relatively strong pink tension shape.

In such a deflection device 8, if the vertical magnetic field is made to have a barrel shape on the electron gun side and a pink tension shape on the screen side, the distortion on the left and right sides of the image reproduced on the fluorescent surface will be reduced. It is well known that the vertical deflection coil can reduce the magnetic field, but since the vertical deflection coil is a toroidal type wound around a core, it is said that it is extremely difficult to wind the deflection coil to obtain the magnetic field described above. There are drawbacks.

The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and includes adding a magnetic material to a deflection yoke having a semi-toroidal deflection coil to reduce horizontal distortion of the reproduced image reproduced on the fluorescent surface. The purpose is

Next, an embodiment of the deflection device of the present invention will be described in detail with reference to FIGS. 2 to 4.

That is, in the deflection device of this embodiment, there are four
The magnetic body 13 consisting of rectangular pieces is placed on the horizontal axis (X-
It is characterized by being provided at symmetrical positions with respect to each axis of the vertical axis (X') (Y-Y'). By providing the magnetic body 13 in this manner, it is possible to make the vertical deflection leakage magnetic field distribution near the deflection yoke to which the magnetic body 13 is mounted substantially in the form of a pincushion.

Further explaining the magnetic field distribution with reference to FIG. 3, the leakage portion on the fluorescent surface side due to the magnetic vertical deflection coil also has a barrel shape as shown by the solid line 14, and the lines of magnetic force are parallel to the horizontal axis (X- This is considered to be the same as when there is pole 15 in X'). However, in this embodiment, the magnetic body 13 made of a rectangular piece is arranged so that its longitudinal direction extends to the vicinity of the corner of the effective deflection surface 17 for the rectangular fluorescent surface of the electron beam in the vicinity where the magnetic body 13 is mounted. By having a length of , and arranging the pole 15 so as to sandwich the pole 15, the vertical deflection leakage magnetic field distribution can be substantially shaped into a pincushion shape as shown by the broken line 16. In this case, it is desirable that the spacing between the magnetic bodies 13 disposed to sandwich the horizontal axis (X-X') is such that short-circuiting or deformation of the horizontal deflection magnetic circuit of the deflection yoke is substantially minimized.

Next, the axial distribution of the vertical deflection magnetic field will be explained with reference to FIG. A dashed-dotted line 18 shows the magnetic field distribution of a conventional self-convergence deflection yoke, which has a barrel shape as a whole from the electron gun side (Gun) to the fluorescent surface side (SCN). A broken line 19 shows the magnetic field distribution in the example of the present invention, and the fluorescent surface side (SCN) could be made into a pink tension type. However, when the magnetic field distribution is indicated by the broken line 19, it is indicated by the conventional dashed-dotted line 18. The barrel area is smaller than the magnetic field distribution, which causes a convergence error on the vertical axis (Y-Y'), but this error can be corrected by changing the winding distribution of the vertical deflection coil, as shown by the solid line 20 in Figure 4. This can be solved by creating a strong barrel magnetic field like this. At this time, as is well known, the effect of the vertical magnetic field on the electron gun side on image distortion is small, but the effect on convergence is large, so the electron gun side is made into a strong barrel shape, as shown by the solid line 20 in Figure 4. Even if the convergence error caused by providing a magnetic material on the fluorescent surface side to form a pincushion type is corrected by changing the winding distribution, the effect on image distortion is extremely small.

As mentioned above, according to the embodiment of the deflection device of the present invention, it is possible to simultaneously perform the reduction of left and right image distortion and the convergence correction, and the distortion correction circuit can be omitted or simplified, so its industrial value is extremely high. It is.

In the above embodiment, a case was described in which four rectangular pieces were used as the magnetic bodies, but the present invention is not limited to this. By providing a plurality of circular, square, or other shaped magnetic bodies, these magnetic bodies It goes without saying that the vertical deflection leakage magnetic field distribution in the vicinity of the deflection yoke attached to the body may be made to substantially form a pink tension.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the structure of a color picture tube device, Fig. 2 is a plan view of an embodiment of the deflection device of the present invention, viewed from the fluorescent surface side, and Fig. 3 is a vertical deflection of a conventional deflection device. An explanatory diagram showing a comparison between the leakage magnetic field distribution and the vertical deflection leakage magnetic field distribution of the deflection device of the present invention. Fig. 4 is an explanation of the axial vertical deflection magnetic field distribution from the electron gun side to the fluorescent surface side of the deflection device. It is a diagram. 8, 11...deflection device, 13...magnetic material.

Claims (1)

[Claims] 1. A deflection yoke that is attached to the outer wall of the funnel portion of a color picture tube that houses a rectangular fluorescent screen and a plurality of electron guns arranged in a line that emit electron beams, and that has deflection coils in the horizontal and vertical axis directions, respectively; On the phosphor screen side of the deflection yoke, there are four substantially rectangular pieces arranged so that the ends on the effective surface corner side are close to the vertical axis and are substantially symmetrical with respect to the vertical axis and the horizontal axis. What is claimed is: 1. A deflection device comprising: a magnetic material; the deflection device is characterized in that the vertical deflection leakage magnetic field distribution in the vicinity of the deflection yoke is substantially in the form of a pink tension.