JPS63226861A - Color picture tube device - Google Patents

Abstract

PURPOSE:To reduce the distortion of an electron beam deflected in the horizontal direction and improve the resolution by providing the horizontal deflecting magnetic field having the barrel-shaped magnetic field near an electron gun and the pin cushion-shaped magnetic field near a fluorescent screen. CONSTITUTION:The horizontal deflecting magnetic field has a barrel shape on the incident side of an electron beam and a pin cushion shape on the outgoing side of the electron beam. The right and left magnetic field distribution is made asymmetrical, thereby the magnetic field distribution is made similar to the pin cushion magnetic field at the electron beam deflection side, and the good convergence characteristic can be obtained. At this time, the magnetic field distribution is similar to the barrel magnetic field at the opposite side, but little effect is given to the electron beam. The effect of the horizontal deflecting magnetic field on the electron beam spot shape is changed by the strength of the pin cushion or barrel of the magnetic field and the degree of the right and left asymmetry of the magnetic field. Accordingly, when such horizontal deflecting magnetic field is used, the distortion of the electron beam deflected in the horizontal direction is reduced, and the resolution can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a color picture tube device equipped with an in-line electron gun, and more particularly to an in-line color picture tube device equipped with a deflection device.

(Prior art) An in-line color picture tube device is equipped with a panel equipped with a phosphor screen coated with phosphors that emit light in three colors: red, green, and blue, and an electron gun that irradiates an electron beam toward the phosphor screen. The envelope is a funnel that connects the neck and the pulse. Inside the neck, there is an in-line electron gun that emits three electron beams from the center and both sides, and outside the funnel, the electron beam from the electron gun hits the surface area of the phosphor screen. A deflection magnetic field generator is installed to deflect the electron beam in horizontal and vertical directions. In addition, a shadow mask is placed on the inner surface of the panel, close to the phosphor screen, and facing the phosphor screen, so that the electron beams that pass through a number of small apertures in this shadow mask impinge on predetermined positions on the three-color phosphors. There is.

Now, in order for the three electron beams emitted from the electron gun to converge on the phosphor screen, the deflection magnetic field generator has been devised so that the horizontal deflection magnetic field is pincushion-shaped and the vertical deflection magnetic field is barrel-shaped. is being done. This is called a self-convergence type magnetic field.

Such a self-concentrating magnetic field has many advantages, such as eliminating the need for various terminals, convergence yokes, and convergence circuits necessary for beam concentration adjustment. However, since the distortion of the magnetic field is used to self-focus the beam, it has the disadvantage that the shape of the electron beam on the phosphor screen is distorted.

FIG. 4(2) shows the shape of the electron beam deflected to the horizontal end of the phosphor screen, which has a distorted shape divided into a horizontally long bright core part C@ and a vertically long dark halo part OQ. Figure 4 υ shows the shape of the electron beam deflected to the vertical end of the phosphor screen, with a distorted shape divided into a small bright vertically elongated core part O@ and a large dark vertically elongated halo part (B). become.

(Problems to be Solved by the Invention) As described above, in-line cathode ray tube gAl! ! There is a problem that the shape of the deflected electron beam is distorted.
This is one of the causes of resolution deterioration in color picture tubes.

Therefore, the present invention is an in-line type shadow@ray camera that has improved resolution with fewer horizontally deflected electron beams!
! The purpose is to provide equipment.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a vacuum envelope, a phosphor screen disposed inside the envelope, and an in-line electron gun that irradiates three electron beams toward the phosphor screen. The present invention is directed to a color picture tube device comprising: a deflection magnetic field generating device that deflects the electron beam in the horizontal and vertical directions so that the electron beam impinges on a predetermined display area of the phosphor screen.

The present invention is based on the center of the phosphor screen, and when the axis extending in the horizontal direction is the X axis, the axis extending in the vertical direction is the Y axis, and the axis perpendicular to the phosphor screen is the Z axis, a plane including the X axis and the Z axis. ＜X-Z plane) and a pincushion-forming vertical main deflection magnetic field that is almost symmetrical with respect to the electron beam passing region and has mainly horizontal components; It has a vertical auxiliary deflection magnetic field that is almost antisymmetric and has a mainly horizontal component in the electron beam passage region.

The parallel deflection magnetic field is almost symmetrical with respect to the plane (Y-Z plane) that includes the Y axis and two axes, and has mainly vertical components in the electron beam passage area. The magnetic field on the side near the axis is a pincushion magnetic field, and the average of the entire magnetic field on the tube axis is almost antisymmetric with respect to the horizontal main deflection magnetic field, which is the barrel magnetic field, and the plane containing the Y axis and two axes (Y-Z plane). It has a horizontal auxiliary deflection magnetic field with a mainly vertical component in the electron beam passage region.

(Function) According to the present invention, even when an electron beam is deflected by the action of a magnetic field, there is little distortion, and a color picture tube device with good resolution can be realized.

(Example) The present invention will be explained with reference to an example. FIG. 1 shows a preferred magnetic field distribution according to the present invention. In other words, the horizontal deflection magnetic field has a barrel shape on the electron beam incident side, and a pincushion shape on the electron beam exit side, and when averaged as a whole, it has a weak barrel shape, but the barrel magnetic field and the pincushion Both magnetic fields are weak compared to the strength of the pincushion magnetic field or barrel magnetic field of the normally used self-convergence type deflection yoke.

Further, the vertical deflection magnetic field is a weak pincushion magnetic field as a whole, and this pincushion magnetic field is extremely small compared to a normally used self-convergence type deflection yoke. In reality, during the operation of a color picture tube, the horizontal deflection magnetic field is asymmetrical on the left and right, and the vertical deflection magnetic field is asymmetrical on the bottom and top, so the shape is different from the pincushion or barrel shape shown in the conventional concept. are somewhat different.

The magnetic field distribution during operation will be explained using FIG. The horizontal deflection magnetic field has a barrel shape on the electron beam entrance side and a pincushion shape on the electron beam exit side.
By making the left and right magnetic field distribution asymmetrical, on the electron beam deflection side (the side located in the direction in which the I beam is deflected), the magnetic field distribution becomes similar to a pincushion magnetic field, and good convergence characteristics can be obtained. At this time, on the side opposite to the electron beam deflection side, the magnetic field distribution becomes similar to the barrel magnetic field, but the electron beam is rarely affected.

The influence of the horizontal deflection magnetic field on the electron beam spot shape varies depending on the strength of the pincushion or barrel of the magnetic field and the degree of left-right asymmetry of the magnetic field. Further, the degree of horizontal elongation of the electron beam spot shape during horizontal deflection changes depending on the degree of pincushion and barrel when left and right symmetry is achieved, and the stronger the barrel magnetic field, the stronger the degree of vertical elongation of the electron beam spot shape. Therefore, in the case of horizontal deflection, the stronger the barrel magnetic field, the more vertically elongated the beam spot shape and better results can be obtained, but the three color electron beams will be focused in front of the screen, resulting in a so-called overconvergence state. becomes. Therefore, such an overconvergence state can be solved by increasing the degree of left-right asymmetry of the horizontal deflection magnetic field, but in order to increase the degree of asymmetry, it is generally necessary to increase the deflection current, which is not preferable. Furthermore, it has been found that when the horizontal deflection magnetic field is symmetrical and the barrel magnetic field is weak, the shape of the electron beam spot is good and the deflection current can be small.

Furthermore, the influence (weighting function) of the horizontal deflection magnetic field on the electron beam spot shape is expressed by the following formula: %Zs: Stallin surface position, : Inclination of the incident beam, Eq. 8 Pairing position of the two people Also, the influence (weighting function) on convergence is (2kJ(Z-Z@)XHn・dZ)I! becomes a′,
The electron beam entrance side of the horizontal deflection magnetic field has a greater influence on the electron beam shape than the convergence. Therefore, the horizontal deflection magnetic field as a whole has a weak barrel shape, but if the entrance side of the electron beam is a barrel magnetic field and the exit side is a pincushion magnetic field, a good electron beam spot shape can be obtained without causing temperature overconvergence. It will be done.

Such a weighting function is illustrated in FIG.

Further, various methods can be considered to make the horizontal deflection magnetic field bilaterally asymmetrical. An example is shown in FIG. In (c), in order to create a left-right asymmetrical magnetic field, the horizontal deflection coil is divided into left and right parts, and currents of different magnitudes are supplied to each part. The current difference between the left and right coils is adjusted according to the amount of deflection.

In this figure, only the upper half of the horizontal deflection coil is shown, and the actual deflection yoke has a lower half located at a position symmetrical to the horizontal axis.

FIG. 70 shows a toroidal coil 00 for making the horizontal deflection magnetic field bilaterally asymmetrical.

The toroidal coil is wound around the core in a toroidal manner. Such a toroidal coil generates the magnetic field shown in FIG. 7(C), which is generated by the symmetrical saddle magnetic field. superimposed on a symmetrical horizontal deflection magnetic field. In the case of FIG. 7 υ, (C), the degree of asymmetry of the horizontal deflection magnetic field can be obtained to a desired value by changing the number of turns of the toroidal coil 00 and the value of the current flowing through the toroidal coil 0Φ. Further, the pincushion and barrel components of the horizontal deflection magnetic field are determined by the saddle-shaped coil combined with the toroidal coil 0Φ, which is not shown in FIG. The method is the same as in the case of a normal self-convergence type deflection yoke. In addition to the shape shown in Figure 7,
Various examples can be considered, such as making all the horizontal deflection coils toroidal, and it goes without saying that such modifications are also included in the present invention.

Similar to the vertical deflection coil, it is possible to optimize the electron beam spot shape and convergence using a vertically asymmetric magnetic field. An example of a suitable deflection magnetic field according to the present invention is shown in FIG. That is, when the vertical deflection magnetic field is vertically symmetrical, a weak pincushion magnetic field is formed. Further, the asymmetry between the upper and lower deflection magnetic fields is preferably caused by a current difference between deflection currents flowing through a pair of toroidal coils wound around one ferrite core to form an asymmetric magnetic field. It was confirmed that such a magnetic field improves the electron beam spot shape and convergence during vertical deflection. In addition to the above example, the vertical deflection magnetic field of the present invention can be formed in various ways. In other words, when a normal toroidal-wound vertical deflection coil forms a vertically symmetrical magnetic field, the winding distribution is such that the overall magnetic field is a weak pincushion field, and the current values flowing through the upper and lower toroidal coils are differentiated. In addition to the above-mentioned method shown in , similar to the case of the horizontal deflection coil, there are also embodiments such as combining a saddle-wound coil and a toroidal-wound coil, a saddle-wound coil and a saddle-wound coil, or a combination of a toroidal-wound coil and a toroidal-wound coil. However, the effect of improving the convergence of the color picture tube and the shape of the electron beam spot remains unchanged.

As shown in FIG. 10, by the deflection magnetic field according to the present invention, an electron beam spot with a small halo, which is close to a perfect circle, can be obtained at the horizontal axis end of the color picture tube. Furthermore, a nearly perfect circular electron beam spot without a halo was similarly obtained at the vertical axis end.

〔Effect of the invention〕

According to the present invention, the distortion of the electron beam spot shape is small;
A color picture tube with good convergence can be realized.

Therefore, the present invention applies not only to general color picture tubes but also to
It is highly effective in improving the performance of color picture tubes, which require higher definition, and has great industrial value.

[Brief explanation of the drawing]

Fig. 1 is a diagram illustrating the deflection yoke magnetic field distribution of the present invention, Fig. 2 is a sectional view illustrating a conventional color picture tube, Fig. 3 is a schematic diagram of the deflection magnetic field of the conventional example, and Fig. 4. is a diagram showing the shape of the electron beam spot due to the deflection magnetic field in the conventional example;
6 is a diagram showing the horizontal deflection magnetic field of the present invention, FIG. 6 is a diagram showing the weighting function, FIG. 7 is a diagram showing a preferred example of the horizontal deflection winding, and FIG. 8 is a diagram showing the vertical deflection magnetic field of the present invention. FIG. 9 is a diagram showing the deflection magnetic field distribution, FIG. 9 is a diagram showing the vertical deflection magnetic field of the present invention, and FIG. 10 is a diagram showing the electron beam spot shape according to the magnetic field distribution of the present invention. 1... Panel 2... Fluorescent screen 3.
... Funnel 4 ... Neck 5.
...Electron gun 6 ...Electron beam 7
... Stem bin 8 ... Frame 9 ... Shadow mask 10 ... Deflection yoke 11 ... Horizontal deflection ta field 12 ...
... Vertical deflection magnetic field 13 ... Core part 14 ...
...Halo Partial Agent Patent Attorney Nori Ken Chika Yudo Norio Ogo No. 1 Figure 7 Shakuteri Seiki Spot Town 1 Keicho A Direction Spot Y> Figure 4 (b) 1 194 Mukojimata岑 (left)
5 Figure 6 Figure 6 (α) t' + exhaustion (6) (C) Figure 7 Figure 8 (a) 1oL・Ib * 4h Beam spot 9 based on the beam spot 1 on the 7th (α) Figure beam spot 10 diagram

Claims (1)

[Claims] (1) A vacuum envelope, a phosphor screen disposed within the envelope, an in-line electron gun that irradiates three electron beams toward the phosphor screen, and the electron beams are directed toward the phosphor screen. In a color picture tube device equipped with a deflection magnetic field generator that deflects electron beams horizontally and vertically so that they strike a predetermined display area, the X-axis is an axis that extends horizontally with the center of the phosphor screen as a base point. , when the axis extending in the vertical direction is the Y axis and the axis perpendicular to the phosphor screen is the Z axis, the vertical deflection magnetic field from the deflection magnetic field generator is approximately parallel to the plane containing the X axis and the Z axis (X-Z plane). A pincushion-shaped vertical main deflection magnetic field that is symmetrical and has mainly horizontal components in the electron beam passing region, and a vertical main deflection field that is almost antisymmetric with respect to the plane containing the X-axis and Z-axis (X-Z plane) and has mainly horizontal components in the electron beam passing region. The horizontal deflection magnetic field has a vertical auxiliary deflection magnetic field that mainly has a horizontal component, and the horizontal deflection magnetic field is almost symmetrical with respect to the plane (Y-Z plane) containing the Y-axis and the Z-axis, and is mainly vertical in the electron beam passage area. The magnetic field on the side closer to the electron gun is the barrel magnetic field, and the magnetic field on the side closer to the phosphor screen is the pincushion magnetic field.The average of the entire magnetic field on the tube axis is the barrel magnetic field. A color picture tube device characterized by having a horizontal auxiliary deflection magnetic field that is substantially antisymmetric with respect to a plane including the Z axis (YZ plane) and has a mainly vertical component in an electron beam passing region.