JPH022262B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a deflection yoke for use in an in-line color picture tube, and more particularly to means for optimizing residual misconvergence in an in-line color picture tube.

[Prior art]

In the conventional deflection yoke, the residual misconvergence over the entire screen could not be reduced to zero simply by adjusting the winding distribution of the horizontal and vertical coils, resulting in a residual misconvergence pattern as shown in FIG. By using the conventional technology, that is, by adjusting the winding distribution of the horizontal coil and the vertical coil, if the amount of deviation in the Y direction (the amount of deviation in the horizontal line) between the red beam and the blue beam in the middle part 3B of the screen in FIG. The amount of deviation in the Y direction (the amount of horizontal line deviation) between the red beam and the blue beam is as shown in FIG. On the other hand, the peripheral area of the screen 3C
When the amount of deviation in the Y direction (the amount of deviation in horizontal lines) between the red beam and the blue beam is set to zero, the amount of deviation in the Y direction (the amount of deviation in horizontal lines) between the red beam and the blue beam in the middle part 3B of the screen becomes as shown in FIG. In other words, the conventional technology has the disadvantage that this relationship cannot be improved by adjusting the winding distribution of the horizontal coil and the vertical coil.

[Purpose of the invention]

The purpose of the present invention is to design a deflection yoke used in an in-line color picture tube to almost eliminate the residual misconvergence in the entire area on the screen of the in-line color picture tube (particularly to reduce the red beam at the periphery of the screen and the middle part of the screen). The goal is to provide a color picture tube with high image quality, which reduces the amount of horizontal line deviation of the blue beam to zero).

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides a saddle-shaped horizontal coil constituting a deflection yoke in a window portion where no winding is provided in the prior art, and in an intermediate portion between an opening on the screen side and an opening on the electron gun side. An auxiliary horizontal coil is placed in the area approximately 54° to 90° with respect to the horizontal deflection axis, and a horizontal deflection current is applied to form a magnetic field in the same direction as the main horizontal deflection magnetic field, thereby worsening raster distortion at the top and bottom of the screen. In addition, the misconvergence difference between the red beam and the blue beam in the peripheral area 3C of the screen and the middle area 3B of the screen is made almost zero, and the best misconvergence is obtained over the entire screen.

[Embodiments of the invention]

An embodiment of the present invention will be described below.

FIG. 1 shows a conventional deflection yoke, and FIG. 3 shows a deflection yoke according to the present invention. In the window portion (portion where the main horizontal coil winding is not applied) at the center in the tube axis direction between the screen-side opening and the electron gun-side opening of the saddle-shaped horizontal coils 1, 1' constituting the deflection yoke according to the present invention. Auxiliary horizontal coils 4, 4' are arranged. FIG. 5 is a front view of the auxiliary horizontal coils 4, 4', and FIG. 6 is a sectional view of the deflection yoke according to the present invention in the tube axis direction. As shown in FIG. 6, the auxiliary coils 4, 4' according to the present invention are secured to the inner surface of the small inner diameter side of the separator 2 via the insulating separator 2 between the horizontal coils 1, 1' and the vertical coil 6. In addition, this auxiliary coil 4,
4' is a horizontal deflection axis. In this example, the winding is performed in an area of 70 degrees on the screen opening side and 87 degrees on the electron gun opening side with respect to the horizontal deflection axis x-axis, and the main horizontal deflection is as shown in FIG. It is connected in series with horizontal coils 1 and 1' for generating magnetic fields.

The conventional deflection yoke's misconvergence pattern on the picture tube screen is as shown in Figure 2, where the amount of Y-direction deviation (horizontal line misconvergence) between the red beam and the blue beam at the middle part 3B of the screen is inline with a size of 14 inches. Approximately 0.3 to 0.4 mm for picture tubes
It remains as a residual misconvergence.

In order to reduce this misconvergence, as a result of investigating the movement of misconvergence due to the winding distribution of the horizontal coil, we found that the amount of change in the y direction of the blue beam relative to the red beam at the screen periphery 3C is Δy _3C , and the amount of change in the y direction of the blue beam relative to the red beam at the screen periphery 3C is 3B The amount of change in the y direction of the blue beam relative to the red beam at is △y _3B , and the rate of change α is α=
Assuming △y _3B / △y _3C , as shown in Fig. 12, a horizontal coil is applied horizontally in an area of about 30° to about 54° (45° in this example) with respect to the horizontal deflection axis x-axis, as in the conventional horizontal coil. When the coil winding is applied, the magnetic flux density B _x in the x-axis direction due to the horizontal coil winding is as shown in FIG. 11, with respect to the off-axis distance x in the x-axis direction, as shown in FIG.
In this case, α is 0.2 to 0.3 (approximately 0.25 in this example)
It is. If the y-direction shift amount (horizontal line misconvergence) of the screen middle part 3B in FIG. 2 is made zero with this value of α, the misconvergence shift of about 1.2 to 1.6 mm will occur in the screen peripheral part 3C as shown in FIG. becomes. However, the auxiliary horizontal coils 4, 4' of this embodiment
As shown in Fig. 10, with respect to the horizontal deflection axis x-axis,
When the auxiliary horizontal coil winding is applied in the area from about 54° to 90° (70° in this example), the x-axis due to the auxiliary horizontal coil winding is The directional magnetic flux density B _x differs from the case in FIG. 11 because the rate of increase in the x-axis direction magnetic flux density B _x decreases as the off-axis distance x increases, so α is 0.5 to 0.9 (approximately 0.8 in this example). Therefore, if the amount of deviation in the y direction (horizontal line misconvergence) of the screen middle part 3B in FIG.
The misconvergence deviation is approximately 1/3 of that of the conventional deflection yoke, which is a significant improvement. In this example,
For a 14″90° in-line color picture tube, the number of turns of the auxiliary horizontal coil is 20 turns (main horizontal coil 130 turns), the winding angle on the screen opening side is 70°, the winding angle on the electron gun opening side is 87°, and the auxiliary horizontal coil length 22
mm (main horizontal coil 74.5 mm), placed in the window between the screen opening side of the saddle-shaped horizontal coil and the electron gun opening side, and combined with the main horizontal coil and vertical coil as shown in Figure 4. High image quality with almost no misconvergence deviation was obtained.

〔Effect of the invention〕

According to the present invention, the amount of change in misconvergence in the y direction of the red beam and blue beam of the screen middle portion 3B relative to the screen peripheral portion 3C of an in-line color picture tube is increased, and the number of turns, shape, and horizontal direction of the auxiliary horizontal coil are increased. By adjusting the winding distribution of the coil and vertical coil, the deviation in the y direction of the screen middle part 3B and the screen peripheral part 3C (horizontal line misconvergence)
can be reduced to almost zero, and residual misconvergence over the entire screen can be significantly reduced. Therefore, variations in the picture tube and deflection yoke can be absorbed within the misconvergence tolerance range, and it has great effects such as shortening convergence adjustment time and manufacturing costs, making it suitable for display equipment with strict misconvergence specifications. Can be done.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional deflection yoke viewed from the screen opening side, Figure 2 is a diagram of the misconvergence pattern on the screen when a conventional deflection yoke is combined with an in-line color picture tube, and Figure 3 4 is a front view of the deflection yoke according to the present invention as seen from the screen opening side, FIG. 4 is a diagram showing the misconvergence pattern on the screen when the deflection yoke according to the present invention and an in-line color picture tube are combined, and FIG. FIG. 6 is a front view of the auxiliary coil according to the present invention, FIG. 6 is a sectional view in the tube axis direction of the deflection yoke according to the present invention, FIG. 7 is a connection diagram of the auxiliary coil and horizontal coil according to the present invention, and FIG. Misconvergence pattern diagram, Figure 9 is a diagram of the relationship between the horizontal deflection axial magnetic flux density B _x and the off-axis distance when the horizontal coil is placed only at a position of about 70 degrees with respect to the horizontal deflection axis, Figure 10 is a cross-sectional view in the tube axis direction when the horizontal coil is placed at a position of approximately 70° with respect to the horizontal deflection axis.
Figure 11 is a diagram of the relationship between the horizontal deflection axial magnetic flux density _B
The figure is a cross-sectional view in the tube axis direction when the horizontal coil is placed at a position of approximately 45 degrees with respect to the horizontal deflection axis. 1, 1'... Main horizontal coil, 2... Separator,
3C...peripheral area of the screen, 3B...middle area of the screen, R...
...Red beam raster, B...Blue beam raster, 4,
4'...Auxiliary horizontal coil, 5...Core, 6...Vertical coil.

Claims (1)

[Claims] 1. In a deflection yoke equipped with a saddle-shaped horizontal coil used in a color picture tube with an in-line electron gun, an auxiliary horizontal The auxiliary horizontal coil is connected in series with the main horizontal coil so as to generate a deflection magnetic field in the same direction as the main magnetic field generated by the main horizontal coil, and the deflection current is in the same direction as the main horizontal coil. A deflection yoke that is characterized by being made to flow.