JPH024095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color cathode ray tube equipped with a focus correction magnet for making the focus quality on the screen uniform throughout the screen.

In conventional color cathode ray tubes equipped with an in-line integrated electron gun, a convergence speed magnet is attached to the outer circumference of the cathode ray tube neck in order to adjust the static convergence at the center of the color cathode ray tube screen. I came. When adjusting static convergence using this convergence spirit magnet, first of all, the color purity adjustment for the entire screen is done using the convergence spirit magnet's purity magnet, but the tube design Sometimes the design is such that this color purity adjustment is not necessary. However, when manufacturing the tube, there may be a deviation in the exposure of the fluorescent surface, a sealing deviation between the panel surface and the funnel surface, a misalignment between the tube axis and the center axis of the electron gun when the electron gun is inserted, or an inclination of the electron gun with respect to the tube axis. As a result, the phosphor pixels formed by optical exposure on the phosphor surface do not match the beam projection point of the electron gun on the phosphor surface, and the balance of color purity on the entire screen becomes unbalanced. Put it away. Therefore, the electron beam trajectory is corrected using a convergence pulse magnet, and the phosphor picture element formed by optical exposure on the phosphor surface and the impact point of the electron beam on the phosphor surface. match. In this case, since the convergence purity magnet is normally located at a stage before the electron beam inside the electron gun enters the main lens of the electron gun, color purity correction must be performed. , the electron beam trajectory becomes eccentric from the center axis of the electron gun. For this reason, the electron beam is incident on a point shifted from the center axis of the main lens of the electron gun, so the electron beam is affected by the aberration of the electron lens, and on the screen, the electron beam spot nucleus has a tail. It appears as a halo component.
Further, even if the main lens center axis and the electron beam trajectory are misaligned due to problems with assembly accuracy of the electron gun itself, the electron beam will be affected as described above.

Due to the effects of aberrations on the electron beam as described above, a halo component appears on the screen that looks like a tail at one end of the electron beam nucleus, but it is necessary to deflect the electron beam with this halo component to the entire screen. Let's consider the case.

In the case of a self-converging cathode ray tube with a color in-line integrated electron gun, in order to dynamically converge the three electron beams across the screen, a deflection yoke that generates first and second deflection magnetic fields perpendicular to each other is required. Use, but the first
The deflection magnetic field has a strong pink tension type distortion, and the second deflection magnetic field has a strong barrel type distortion. When each electron beam passes through a deflection yoke with such a magnetic field distribution, the magnetic field strength varies greatly depending on the position, so the force received at each point of the electron beam is different, and the shape of the electron beam after deflection is
It becomes a flat shape that is flattened horizontally on the screen.
This phenomenon is a so-called deflection focus shift.

When an electron beam with a halo component passes through the magnetic field, the deflection magnetic field may increase or decrease the halo component depending on the direction in which it is deflected. Power will come into play. Therefore, a halo occurs only in a certain range on the screen, which is unfavorable in terms of focus quality. The above phenomenon becomes a fatal drawback, especially in cathode ray tubes that require high resolution.

An object of the present invention is to provide a beam trajectory correction device for focus correction that eliminates the asymmetry of halo generation on the screen as described above and provides uniform focus quality over the entire screen.

According to the present invention, a first pair of two poles of a convergence spirit magnet conventionally disposed in a color cathode ray tube network having an in-line integrated electron gun, which was conventionally used for color purity adjustment. After adjusting the halo component appearing at the electron beam spot on the screen so that it is uniform over the entire screen using a magnet, a second By adjusting the color purity of the entire screen using a pair of two-pole magnets, it is possible to obtain a cathode ray tube with uniform focus quality over the entire screen and significantly improved resolution.

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an external view of a color cathode ray tube equipped with an in-line integrated electron gun. FIG. 2 shows a cross-sectional view of the in-line integrated electron gun. In the color cathode ray tube 1, a convergence energy magnet 12 is fixed to the outer periphery of the cathode ray tube neck portion 10 for concentrating and correcting a plurality of beams emitted from an inline integrated electron gun 26 on the screen 16. However, Convergence Spirit Magnet 12
In order from the side closest to the screen 16, the purity magnets 1 are installed to adjust the color purity on the screen.
2C, a quadrupole magnet 12B for concentrating both side beams, and a hexapole magnet 12A for concentrating both side beams and a center beam. The magnetic field distribution of the pulley magnet 12C is shown in Figure 3, the magnetic field distribution of the 4-pole magnet 12B is shown in Figure 4, and the magnetic field distribution of the 6-pole magnet is shown in Figure 5.
The distribution is as shown in the figure. A convergence spirit magnet is used to correct the misalignment between the phosphor pixels formed by optical exposure on the phosphor surface and the impact point on the screen of the multiple electron beams emitted from the electron gun. 12 Pyuri Tei Magnets 1
2C corrects the color purity, but the installation position of the purity magnet 12C in the cathode ray tube neck part 10 is the in-line integrated electron gun 26.
It is usually installed near the opposing electrode 23 of the final electrode, which together with the final electrode 24 constitutes the main lens. Assuming that the electron beam trajectory passes through the central axis of the main lens before color purity adjustment,
After color purity adjustment, the electron beam will be incident on a position eccentric to the central axis of the main lens. FIG. 8 illustrates this state. Before color purity adjustment, the electron beam passes through the central axis D-G of the electron gun, but due to deviations when the electron gun is enclosed in the cathode ray tube 1,
Color purity correction is performed because the electron gun central axis D-G does not pass through the exposure center point C, where 16 phosphor pixels on the screen of the cathode ray tube 1 are optically formed, due to inclination, deviation of the exposure center point, etc. Using magnet 12C, D-
Assume that the trajectory has been corrected to C-A. In this way, when the electron beam is incident on a position eccentric from the central axis of the main lens, the electron beam will be subject to aberrations of the main lens in proportion to the amount of eccentricity. FIGS. 6 and 7 show the relationship between the eccentric direction of the electron beam from the central axis of the main lens and the halo generation area on the screen. As shown in FIG. 7a, in the state before color purity correction, the electron beam nucleus 7
It is assumed that the state of the halo 71 that occurs around 0 is symmetrical in the vertical, horizontal, and horizontal directions of the screen. The electron beam impact position on the screen before color purity correction is the 8th
At point G in the figure, when the electron beam is moved from point G upwards on the screen using the magnetic field magnet 12C, a halo is generated significantly at the top of the screen, as shown in Figure 7b. The image becomes almost invisible at the bottom of the screen. Similarly, if you move the electron beam to the bottom, left, and right side of the screen using color purity correction magnets,
It has been confirmed that a halo is significantly generated in the direction in which the electron beam moves, as shown in FIGS. 7c, d, and e, respectively.

The present invention aims to uniformly disperse the halo component on the screen by applying the relationship between the direction of electron beam movement and the direction of halo generation using a color purity correction magnet to a cathode ray tube where a halo is generated asymmetrically on the screen. . That is, it is assumed that a halo is generated only on the upper side of the screen after the color purity correction by the color purity correction magnet as shown in FIG. 6a. This state is shown by the DCA trajectory in FIG. As shown in FIG. 7, in order to balance the halo appearing on the upper side of the screen vertically, the electron beam can be forcibly moved to the lower side of the screen using the color purity correction magnet 12C. in this case,
Assuming that when the electron beam trajectory passes through the electron gun center axis, the halo component is evenly distributed on the screen, the electron beam after the halo component is evenly distributed on the screen by the color purity correction magnet 12C. The beam trajectory is DG. That is, since the electron beam trajectory returns to the one before the color purity correction, the color purity will shift again. In the present invention,
To correct for the shifted color purity, a second pair of bipolar magnets 100 is placed near the final electrode exit of the in-line integrated electron gun 26, as shown in FIG. The electron beam trajectory after arranging the second pair of bipolar magnets 100 and adjusting the color purity across the screen is illustrated in FIGS. 8 and 9. That is, in FIG. 8, the electron beam trajectory after the halo component is evenly distributed over the entire screen is D-
However, as it is, the color purity will remain shifted. Therefore, as shown in FIG. to adjust the color purity. In order to uniformly disperse the halo component over the entire screen, the electron beam only needs to pass through the electron gun center axis DG, so the electron beam passing on the DG axis in FIG. The trajectory can be corrected using a pair of two-pole magnets so that the trajectory passes from point E, which is farther away from the main lens, to the exposure center point C of the cathode ray tube, where the color purity on the screen is corrected. That is, the final electron beam trajectory is D-E-C
−A′.

According to the present invention, as explained above, the first convergence energy magnet, which is conventionally used for color purity adjustment, is disposed in the color cathode ray tube network equipped with an in-line integrated electron gun. Using a pair of two-pole magnets, first, the asymmetric halo component that appears around the electron beam spot is dispersed and adjusted so that it is evenly distributed over the entire screen, and then placed near the final electrode exit of the in-line integrated electron gun. By using the second pair of two-pole magnets to perform the conventional color purity correction, it was possible to modify the cathode ray tube into a cathode ray tube with uniform focus quality across the entire screen and significantly improved resolution quality. I can do it.

[Brief explanation of drawings]

Figure 1 is an external view of a color cathode ray tube equipped with an integrated in-line electron gun, Figure 2 is a cross-sectional view of the integrated in-line electron gun, and Figure 3 is a color cathode ray tube used in a convergence energy magnet. A magnetic field distribution diagram of a magnet for color purity correction. Figure 4 is a diagram showing an example of the magnetic field distribution and operation of a four-pole magnet used in a convergence spirit magnet. Figure 5 is a diagram showing an example of the magnetic field distribution and operation of a four-pole magnet used in a convergence spirit magnet. A diagram showing an example of the magnetic field distribution and operation of a six-pole magnet used in a network. Figures 6a and b are state diagrams in which a halo component appears vertically asymmetrically on the screen, and Figures 7a to e are diagrams showing an example of the operation. , a diagram showing the relationship between the movement direction and halo generation when an electron beam is moved using a color purity correction magnet. Arrows indicate the direction of electron beam movement. FIG. 8 is a trajectory diagram when a beam is moved using a color purity correction magnet of a convergence energy magnet, and FIG. 9 is an electron beam trajectory diagram based on an embodiment of the present invention. 12... Convergence spirit magnet, 10... Cathode ray tube network section, 13... Deflection yoke, 16... Screen (fluorescent surface), 24... In-line integrated electron gun final electrode, 70... Electron beam Nucleus, 71...Halo component, 12C...Color purity correction magnet of convergence spirit magnet, 100...Magnet for color purity correction used in the present invention.

[Claims]

1.Equipped with an outer electrode having a circular concave surface, and an inner electrode having a circular protruding surface facing the circular concave surface at a uniform interval to form a beam path, the outer electrode and the inner electrode are provided with mutual polarity. applying different DC voltages, aligning the tangent at the exit of the beam path with the beam transport path, providing both electrodes rotatably around the tangent, and aligning the rotation direction within the plane of rotation of the tangent at the entrance of the beam path. An electrostatic deflection device comprising a plurality of ion sources or electron sources arranged at intervals.