JPH01248437A - Color picture tube device - Google Patents

Abstract

PURPOSE:To provide an image with good convergence characteristic by forming a barrel type magnetic field as a whole using two sets of deflection coils, forming a barrel mag. field by one of these sets of deflection coils, and by forming a pin cushion mag. field by the other set of deflection coils. CONSTITUTION:A horizontal deflection coil is formed from a saddle type coil, while a vertical deflection coil is composed of a trocoidal coil 15 and saddle type coil 16, wherein the trocoidal coil generates a pin cushion mag. field while saddle type coil produces barrel mag. field. When deflecting in the central part of the screen, the current flowing through the saddle type vertical deflection coil 16 is greater than the current flowing through the trocoidal vertical deflection coil 15, and positive cross pattern is corrected. When deflecting in the perimeter of the screen, the current flows oppositely situated, and negative cross pattern is corrected. This accomplishes good convergence characteristic over the whole screen.

Description

[Detailed description of the invention] [Purpose of the invention] This relates to a picture tube device.

The mainstream is one equipped with an in-line electron gun and a slot-type shadow mask. This will be explained based on FIG.

A face plate (2) has a phosphor screen (2) adhered thereon, which has a phosphor layer regularly arranged in dots or strips that emit light in R, G, and B colors when struck by an electron beam.

A plurality of panel pins (0) installed on the inner wall of the side wall (1-1) of this face plate (2) are connected to the phosphor screen (2) at a predetermined distance via springs (0, A shadow mask (1) with a large number of openings (12), an inner shield (14) provided as necessary, and a funnel support part (8-1) on the side wall (1-1).
1) and the deflection device (c) attached via a wedge (8-2) between the funnel and the outer wall.
In such a color video tube, which is composed of a neck and an adjustment magnet (11) attached to the outer wall, the electron beam (13) emitted from the electron gun (10) is transmitted through the opening (13). to cause a predetermined phosphor layer of the phosphor screen (1) to emit light.

The electron gun (10) normally has three electron gun image tubes called an in-line electron gun, in which R, G, and 83 electron beams are emitted from phosphor layers that emit light in R, G, and H, respectively.
The electron beams that cause the R, G, and B color phosphor layers to emit light are designed to be focused at one point on the phosphor screen by the dimensions of the focusing electrode of the electron gun (10) when the deflection yoke (c) is not operated and the electron beams are not deflected. has been done.

Furthermore, in an in-line electron gun, by appropriately designing the magnetic field of the deflection yoke (2), it is possible to simultaneously cause the three R, G, and B beams to pass through one point of the shadow mask (2) during deflection.

Such a magnetic field is well known as shown in Japanese Unexamined Patent Publication No. 57-1857, and is generally employed. That is,
By using a pincushion type magnetic field for the horizontal deflection magnetic field as shown in Figure 3(,) and a barrel type magnetic field for the vertical deflection magnetic field as shown in Figure 3(b), it is possible to eliminate the need for a special correction device. Good convergence characteristics of the three electron beams (hereinafter referred to as convergence characteristics) can be obtained over the entire screen. However, the following convergence errors become noticeable. This is generally called the horizontal line cross characteristic, and cannot be corrected by changing the characteristics of the pincushion and barrel magnetic fields of the horizontal and vertical magnetic fields. This is shown in the document ``Pineline SST Deflection Yoke for High Definition Color Tube'' (Iwasaki et al., Television Society Technical Report ED619).In other words, the commonly used saddle-toroidal deflection yoke has a positive cross pattern (positive difference). directional astigmatism).

A negative cross pattern (negative anisotropic astigmatism) occurs in the saddle-saddle deflection yoke. This development is mainly due to the difference in the position of the deflection center between the horizontal coil and the vertical coil, and generally a saddle toroidal deflection yoke is used for horizontal deflection. The position of the saddle coil is optimized by shifting it from the position of the toroidal coil in the direction of the deflection yoke axis. This will be explained based on FIG. If the deflection center of the toroidal coil that generates the vertical magnetic field is almost the same as the deflection center of the saddle coil that generates the horizontal magnetic field, a convergence error generally called a positive cross pattern will occur as shown in Figure 4 (a). arise. In order to correct such a positive cross pattern, the horizontal deflection saddle coil is shifted toward the electron gun, so that the cross pattern is corrected as shown in FIG. 4C. When the horizontal deflection saddle coil is further shifted toward the electron gun, a negative cross pattern appears as shown in FIG. 4(b). Therefore, generally, the cross pattern can be corrected by appropriately assembling the relative positions of the horizontal deflection coil and the vertical deflection coil.

(Problem M to be Solved by the Invention) However, with this method, the cross pattern can only be corrected at, for example, one point on the diagonal, and at other points, a loss pattern occurs as shown in FIG. Such reversal of the cross pattern between the middle part and the outermost diagonal becomes more noticeable as the deflection angle and screen size increase. Conventionally, therefore, a method has been adopted to reduce the outermost cross pattern by attaching a magnetic plate or the like to the deflection yoke, but this method still provides insufficient characteristics.

The inventors previously applied for the following patent in order to improve these defects.

That is, by forming the vertical deflection coil with two sets of coils, a saddle-shaped coil and a toroidal-shaped coil, and changing the ratio of currents flowing through each coil in synchronization with the vertical deflection signal, the -layer This is a deflection method with good convergence characteristics and little cross-bang error.

In this system, the deflection centers of the two sets of vertical deflection coils are different in the direction of the central axis of the picture tube, but the difference between the two deflection center positions should not be too large for the following reason.

The first reason is that in such a system, the deflection center position of the vertical deflection magnetic field is changed in synchronization with the vertical deflection, but if the difference between the two deflection center positions is large, the deflection center will move toward the electron gun when the amount of vertical deflection is large. When the electron beam is moved to the picture tube, the deflected electron beam collides with the funnel (2) of the picture tube, which tends to cause so-called neck shadow development in which the four corners of the image are missing.

The second reason is that when two coils are arranged with different deflection centers, the length of the entire deflection yoke in the axial direction of the picture tube is limited by the size and shape of the picture tube. However, reducing the length of the coil in the picture tube axis direction increases the deflection current to form the necessary deflection magnetic field, which reduces the heat generation of the coil. The problem arises of increasing

Therefore, it is preferable that the difference between the deflection center positions of the two sets of vertical deflection coils is not too large.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a vacuum envelope, a phosphor screen disposed within the envelope, and an in-line electron gun that irradiates three electron beams toward the phosphor screen. In a color picture tube device equipped with a deflection device that deflects the electron beam horizontally and vertically so that the electron beam impinges on a predetermined display area of the phosphor screen, the vertical deflection device includes two sets of deflection coils,
The two sets of deflection coils collectively form a barrel-shaped magnetic field.

One set of deflection coils collectively forms a barrel magnetic field, the other set of deflection coils forms a pincushion magnetic field, and the deflection centers of the deflection coils of these two sets are in the direction along the tube axis. This color picture tube device is characterized in that these two sets of deflection coils are driven by different deflection currents synchronized with a horizontal deflection signal and a vertical deflection signal entering the deflection device.

(for production) Hereinafter, the effects of the present invention will be explained.

First, let's assume that the horizontal coil is A coil, and the vertical coil is B coil.
There are two types: coil and C coil. FIG. 6 shows the magnetic field distribution and deflection center due to these coils. That is, it is assumed that the positions of the deflection centers of the respective coils are located in the order of B coil, A coil, and C coil from the electron gun side toward the screen direction. When the A coil and B coil are combined, as shown in Fig. 6, the deflection center of the vertical deflection coil is closer to the electron gun than the deflection center of the horizontal deflection coil, so as shown in Fig. 4 (a). This results in positive cross-convergence characteristics. In addition, when the A coil and the C coil are combined, as shown in Fig. 6, the deflection center of the horizontal deflection coil is closer to the electron gun than the deflection center of the vertical deflection coil. ) has a negative cross-convergence characteristic. In such a case, the above 3
When all the deflection coils of a set are combined, it is preferable to configure the cross convergence characteristic shown in FIG. 5. That is, the cross pattern is positive in the middle of the screen, the cross pattern is negative in the outermost part of the screen, and the cross pattern is zero near the diagonal point of the screen. At this time, when deflecting to the middle part of the screen, change the deflection current of the C coil to B
If it is made larger than the deflection current of the coil, the positive cross pattern will be corrected. Similarly, if the deflection current of the B coil is made larger than the deflection current of the C coil when deflecting to the outermost part of the screen, the negative cross pattern can be corrected.

Therefore, the deflection current of the B coil is set to 1. , When the deflection current of the C coil is defined as IC, the current waveform of -IBy IC is the 12th
As shown in the figure, when the screen is deflected in the middle part, In < Ic, and when the screen is deflected near the diagonal, valve IC1 is when the screen is deflected at the outermost part.
If a>Ic is satisfied, good loss convergence characteristics can be obtained over the entire color picture tube as shown in FIG.

However, in such a case, since the center of deflection of the vertical coil is shifted toward the electron gun when deflecting the outermost part of the screen, the deflected electron beam collides with the funnel cone part of the picture tube, resulting in the so-called chipping of the four corners of the image. Neck shadow phenomenon is more likely to occur.

Also, to shift the deflection centers of the two sets of deflection coils.

A problem arises in that the length of each deflection coil in the picture tube axis direction becomes smaller, the necessary deflection current increases, and the heat generated by the coil increases. Therefore, the difference in the deflection center positions of the two sets of vertical deflection coils cannot be made very large. Therefore, in the present invention, one set of vertical deflection coils forms a barrel magnetic field, the other set of deflection coils forms a pincushion magnetic field, and the two sets of deflection coils as a whole form a barrel magnetic field. It shall be. Here, the deflection magnetic field produced by the B coil is defined as a pincushion, and the deflection magnetic field produced by the C coil is defined as a barrel. As a result, the barrel magnetic field becomes stronger when deflecting the middle part of one screen, and the positive cross pattern is corrected by the negative anisotropic astigmatism as shown in FIG. 9Cb). Further, when the screen is deflected to the outermost part, the pincushion magnetic field becomes strong, and the negative cross pattern is corrected by the positive anisotropic astigmatism as shown in FIG. 9(a). However, although FIG. 9 shows the case where the beam is deflected to the first quadrant on the screen, the cross pattern is similarly corrected when the beam is deflected to other quadrants. Therefore, B coil is a pincushion magnetic field, C
If the coil is made into a barrel magnetic field, cross convergence can be corrected without increasing the difference in the deflection center position between the B coil and the C coil, and problems such as the neck shadow phenomenon and the heat generation of the coil can be improved.

(Example) The present invention will be explained in detail based on the drawings.

FIG. 8 is a diagram showing a preferred embodiment of the present invention.

An electron gun (1o) is enclosed within the neck part (2) of the vacuum envelope, and irradiates an electron beam (not shown) toward a fluorescent screen (not shown) inside the vacuum envelope. In the case of this embodiment, the deflection device is composed of a saddle-toroidal structure, the horizontal deflection coil is formed by a saddle-shaped coil, and the vertical deflection coil is formed by a toroidal-shaped coil (15) and a saddle-shaped coil (16).
Consisted of. The toroidal-shaped vertical deflection coil and the saddle-shaped vertical deflection coil each form different magnetic field distributions in the tube axis direction, and the deflection center of the toroidal coil is closer to the electron gun than the saddle-shaped coil. The shaped coil forms a pincushion magnetic field, and the saddle shaped coil forms a barrel magnetic field. In addition, when a toroidal type vertical deflection coil and a horizontal deflection coil are combined, Fig. 4 (a)
), and when a saddle type vertical deflection coil and a horizontal deflection coil are combined, a negative cross convergence characteristic as shown in FIG. 4(b) is obtained.

When a toroidal-type vertical deflection coil, a saddle-type vertical deflection coil, and a horizontal deflection coil are combined and the same deflection current is applied to the toroidal-type and saddle-type vertical deflection coils, the cross convergence shown in Figure 5 occurs. Configure to obtain the characteristics.

For the deflection device having such a configuration, a current IB shown in FIG. 12 is applied to the toroidal vertical deflection coil,
By applying a current IC shown in FIG. 12 to the saddle-shaped vertical deflection coil, the cross convergence characteristic is corrected. That is, when the screen is deflected at the center of the screen, the current flowing through the toroidal vertical deflection coil is 1. The current IC flowing through the saddle-type vertical deflection coil is larger than that of the current IC, thereby correcting the positive cross pattern. Furthermore, when the screen is deflected to the outermost part of the screen, the current Ib flowing through the toroidal vertical deflection coil becomes larger than the current Ic flowing through the saddle vertical deflection coil, thereby correcting the negative cross pattern. Therefore, good convergence characteristics can be obtained over the entire screen. This situation is shown in FIG.

The current waveform as shown in Fig. 12 can be obtained by connecting toroidal type and saddle type vertical deflection coils as shown in Fig. 14 and using the nonlinear current vs. voltage characteristics of the diode.
Form. In Fig. 14, when the screen is deflected in the middle part,
Since the current flowing through the diodes D1 to D4 is small, the current flowing through the saddle-type vertical deflection coil is larger than the current flowing through the toroidal-type vertical deflection coil. When the outermost part of the screen is deflected, a large amount of current flows through the diode drawer D4, so the current flowing through the toroidal vertical deflection coil is larger than the current flowing through the saddle type vertical deflection coil.

Therefore, the current waveform shown in FIG. 12 can be obtained.

Note that since the current value of each vertical deflection coil can be easily changed by adjusting the values of the resistors R1 to R4, the correction amount of the cross pattern can be adjusted according to the cross convergence characteristics on the screen.

In this embodiment, the vertical deflection coils are a toroidal type coil and a saddle type coil, but two sets of saddle type coils as shown in FIG. 10 or FIG. 11 may be used.

Furthermore, the two sets of vertical deflection magnetic fields formed by the present invention are
As shown in FIG. 13, a strong barrel magnetic field and a weak barrel magnetic field may be used. Even in this case, the two sets of vertical deflection magnetic fields can achieve the same effect as the pincushion magnetic field and barrel magnetic field, correcting cross convergence while solving problems such as neck shadow and coil heat generation. An image of convergence characteristics can be obtained.

Further, although the two sets of vertical deflection magnetic fields of the present invention have different deflection centers, they may be defined by the center of gravity of the coil, or may be defined by the position of the maximum value of the deflection magnetic fields. If these values are different, the deflection center will also be different, so in normal cases these positions can be substituted.

Further, in this embodiment, in order to form the vertical deflection current shown in FIG. 12, a diode is used and a vertical deflection coil is connected as shown in FIG. 14, but the output of the deflection circuit is made into two series, The current waveform shown in FIG. 12 may be formed in the deflection circuit.

〔Effect of the invention〕

The present invention provides an image with good convergence characteristics across the screen of a color picture tube while solving the problems of neck shadow and coil heat generation, and has great industrial utility value.

[Brief explanation of the drawing]

Figure 1 is a diagram for explaining the deflection magnetic field of the present invention, Figure 2 is a diagram for explaining the deflection magnetic field of the present invention.
The figure is a cross-sectional view to explain a conventional color picture tube device.
Fig. 3 is a diagram for explaining the deflection magnetic field used in a conventional color picture tube device, Fig. 4 is a diagram for explaining cross convergence error, and Fig. 5 is a diagram for explaining cross convergence error. , FIG. 6 is a diagram for explaining the deflection magnetic field according to the present invention, FIG. 7 is a diagram showing the state of convergence according to the present invention, FIG. 8 is a sectional view for explaining the present invention in detail, and FIG. 9 is a diagram for explaining the present invention. FIGS. 10 and 11 are diagrams showing the effect of the deflection magnetic field of the invention on the electron beam, FIG. 12 is a diagram showing the deflection current of the invention, and FIG. 13 is a diagram showing the deflection current of the invention. FIG. 14 is a diagram showing an embodiment of the vertical deflection magnetic field, and FIG. 14 is a diagram showing a method of connecting the deflection coils of the present invention. 1... Face plate 2... Fluorescent screen 3...
・Shadow mask 4...Mask frame 5・
...Panel pin 6...Spring 7...
・Funnel 8...Deflection yoke 9...
Neck 10... Electron gun 11... Adjustment magnet 13... Electron beam 14... Inner shield 15... Vertical deflection toroidal coil 16... Vertical deflection saddle coil 17... Saddle coil horizontal Deflection 18... Ferrite core 19.
...Horizontal deflection saddle coil 20...First vertical deflection saddle coil 21...Second vertical deflection saddle coil Agent Patent attorney Noriyuki Chika Yudo Kikuo Takehana Figure 1 B Figure 2 (a) Said dto*〜Ribai-艷(t5%Avn) (b
) * LiA self-V moshi (I comb) Fig. 3 (a) Positive hefu ℃λ””' (C)
70 Souvetantle (bt!e7''''゛'''' Figure 45 Figure 6 Figure 7 (a) (b) Figure 9 Figure 10 Figure 11 Figure 12 Figure 13

Claims (2)

[Claims] (1) A vacuum envelope, a phosphor screen disposed inside the envelope, an in-line electron gun that irradiates three electron beams toward the phosphor screen, and a phosphor screen in which the electron beams are directed to a predetermined position on the phosphor screen. In a color picture tube device equipped with a deflection device that deflects an electron beam in horizontal and vertical directions so as to impinge on a display area, the vertical deflection device consists of two sets of deflection coils, and the two sets of deflection coils collectively form a barrel. One set of deflection coils collectively forms a barrel magnetic field, the other set of deflection coils forms a pincushion magnetic field, and the deflection centers of the deflection coils of these two sets of deflection coils form a barrel magnetic field. are mutually offset in the direction along the tube axis, and these two sets of deflection coils are driven by different deflection currents synchronized with a horizontal deflection signal and a vertical deflection signal entering the deflection device. tube device. (2) Vertical deflection magnetic field formed by two sets of deflection coils The two sets of deflection coils that form the deflection magnetic field are characterized in that the position of the maximum value of the magnetic field strength distribution on the picture tube symmetry axis of the deflection magnetic fields generated by each set is different. A color picture tube device according to claim 1.