JPH04237933A - Color picture tube device - Google Patents

Abstract

PURPOSE:To eliminate misconvergence which means that a screen pictured by a center beam at both right and left end portions of the screen slips to the left in relation to a screen pictured by a pair of side beams by installing a three dimensional portion at the annular portion of a magnetic field control element. CONSTITUTION:A magnetic field control element 30 made of a magnetic substance with high magnetic permeability is arranged on the bottom of the convergence cup 2 of an electron gun in such a way that 3 electron-beam passing holes 3B, 3G, 3R are individually surrounded by the element 30, while facing to 3 cathodes respectively. The element 30 is constituted of an annular portion 31 and a three dimensional portion 32, and the pair of three dimensional portions 32 have a plane portion 32a and a side wall portion 32b. When an electron beam scans from the left to the right on a screen, the magnetic field generated in the central part of the screen acts on each electron bean to the same extent because of a projecting form of the pair of 3 dimensional portions 32. The quantity of right drift of a center beam is, therefore, equalized to the quantities of drift of a pair of side beams, so that it is possible to eliminate the right drift of a raster drawn by a center beam on a previously generated screen.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube device, and more particularly to a color picture tube device having an improved magnetic field control element for correcting aberrations due to non-uniformity of deflection magnetic fields in an in-line color picture tube device. Regarding.

0002

2. Description of the Related Art Generally, a color picture tube device has an envelope consisting of panels and funnels that are joined together.
A phosphor screen consisting of a three-color phosphor layer that emits blue, green, and red light is formed on the inner surface of the panel, facing a shadow mask equipped with a large number of electron beam passage holes attached to the inside of the panel. By deflecting three electron beams emitted from an electron gun disposed inside the neck of the funnel by a magnetic field generated by a deflection yoke attached to the outside of the funnel, the phosphor screen is scanned horizontally and vertically. , is formed in a structure that displays a color image on this phosphor screen.

In such a color picture tube device, in particular, the electron gun is an in-line type electron gun that emits three electron beams arranged in a row, consisting of a center beam and a pair of side beams passing on the same plane. A self-convergence type in-line color picture tube device is widely used, which generates a non-uniform magnetic field in which the horizontal deflection magnetic field is pincushion-shaped and the vertical deflection magnetic field is barrel-shaped, and the three electron beams are self-focused by this non-uniform magnetic field. .

However, in this self-convergence type in-line color picture tube device, due to the non-uniformity of the deflection magnetic field, the deflection sensitivity of the center beam is lower than that of the pair of side beams, as shown in FIG. , Raster 1G drawn by the center beam is smaller than raster 1B, 1R drawn by a pair of side beams, and VCR and HCR are placed on the vertical axis (Y axis) and horizontal axis (X axis) at the top, bottom, left and right of the screen, respectively. This results in coma aberration shown in . This coma aberration occurs, for example, in a 14-inch 90-degree deflection color picture tube device, with a VCR of 1.0 to 2.0 mm and an HCR of 1.0 to 2.0 mm.
is approximately 0.5 mm.

Therefore, conventionally, in this type of color picture tube device, a magnetic field control element is installed at the inner bottom of a cylindrical cup (hereinafter referred to as a convergence cup) made of a non-magnetic material attached to the electron beam emitting end of the electron gun. This coma aberration is removed by arranging . That is, as shown in FIG. 6, out of the three electron beam passing holes 3B, 3G, and 3R formed at the bottom of the convergence cup 2, a hole is placed around the pair of side beam passing holes 3B, 3R. A magnetic field control element 4a made of an annular high permeability magnetic material and a magnetic field control element 4b made of a high permeability magnetic material are arranged near the center beam passage hole. By arranging the magnetic field control elements 4a and 4b in this manner, it is possible to weaken the deflection magnetic field exerted on both side beams and strengthen the deflection magnetic field exerted on the center beam. As a result, the raster drawn by the center beam is expanded both horizontally and vertically, while the raster drawn by the pair of side beams is reduced both horizontally and vertically, due to the nonuniformity of the deflection magnetic field. The three-color raster can be made to match by removing comatic aberration.

In addition, in order to eliminate the need for raster distortion correction circuits at the top and bottom of the screen, generally the electron gun sides for the horizontal and vertical deflection magnetic fields are made into a strong barrel shape, and the screen side is made into a strong pincushion shape. As for the magnetic field distribution, the horizontal deflection magnetic field is set in a pincushion shape, and the vertical deflection magnetic field is set in a barrel shape. However, the force exerted by the vertical deflection magnetic field on the three electron beams is weaker for the center beam than for both side beams, and at the top and bottom of the screen, the raster drawn by the center beam is located inside the raster drawn by both side beams. Large aberrations occurred.

For this reason, Japanese Patent Application Laid-open No. 57-172636 discloses that, as shown in FIG. A magnetic field control element 7 having a three-dimensional part 6 extending toward the passage hole 3G and having its tip erected is arranged to strengthen the vertical deflection magnetic field exerted on the center beam and reduce the horizontal deflection rear leakage exerted on the center beam. It is shown that the magnetic field is reduced, thereby correcting the deviation of the raster drawn by the center beam.

However, if the magnetic field control element 7 provided with the three-dimensional portion 6 as described above is used in a color cathode ray tube with a horizontal deflection frequency of 31.5 kHz or higher, as in recent color display tube devices, the rear leakage magnetic field of horizontal deflection As a result, the magnetic field control element 7 is magnetized, and as shown in FIG. 8, the raster 1G drawn by the center beam is shifted to the right with respect to the rasters 1B and 1R drawn by the pair of side beams at both the left and right ends of the screen. Misconvergence occurs.

The cause of such misconvergence is residual magnetism remaining in the magnetic field control element due to the deflection magnetic field. That is, when the electron beam is deflected to scan the screen from left to right, the horizontal deflection magnetic field becomes as shown by the solid arrow 8 in FIG. 9(a). When the electron beam moves from the left edge of the screen to the center of the screen, the deflection magnetic field gradually weakens, and when the electron beam is located at the center of the screen, the deflection magnetic field 8 becomes zero. At this time, the magnetic flux density within the magnetic field control element 7 draws a hysteresis curve 9 shown in FIG. 9(b), and when the central part of the screen is scanned, residual magnetism of the magnitude shown by B1 remains. Therefore,
Due to the residual magnetism of the magnetic field control element 7, a magnetic field 10 indicated by broken line arrows is generated near the electron beam passage holes 3B, 3G, and 3R, as shown in FIG. 9(c). The force acting on each side beam 11B, 11R due to this magnetic field 10 is Fs,
If the force acting on the center beam 11G is Fc, then
Fs>Fc, center beam 11G at the center of the screen
The pair of side beams 11B and 11R are deflected to the right, resulting in a misconvergence in which the center beam 11G is relatively shifted to the left. However, since the misconvergence at the center of the screen is usually corrected by a static magnet, it appears as a misconvergence in which the center beam 11G is relatively shifted to the right at both the left and right ends of the screen.

[0010] This amount of deviation increases by increasing the amount of magnetization due to the enlargement of the magnetic field control element due to the attachment of the three-dimensional part, and becomes more than 0.3 mm on the left and right sides. It is a serious problem for.

[0011]

[Problems to be Solved by the Invention] As mentioned above, even if a magnetic field control element provided with a three-dimensional part is used to correct the misconvergence between the center beam and a pair of side beams, the rear leakage of horizontal deflection still occurs. The magnetic field control element is magnetized by the magnetic field and residual magnetism remains, which causes the raster drawn by the center beam to shift to the right at both left and right ends of the screen relative to the raster drawn by the pair of side beams. Convergence occurs. This right-shift phenomenon poses a serious problem for high-resolution color picture tube devices that require high convergence characteristics.

The present invention has been made to solve the above-mentioned problems, and the misconvergence that cannot be solved even if a three-dimensional part is provided for the annular part arranged to surround a pair of side beam passage holes. That is, the purpose is to eliminate misconvergence in which the screen drawn by the center beam at both left and right ends of the screen is shifted to the right with respect to the screen drawn by the pair of side beams, and to provide a high-resolution color picture tube device. . [Structure of the invention]

[0013]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a convergence system at the tip of an electron gun that emits three electron beams arranged in a row, consisting of a center beam and a pair of side beams passing on the same plane. The cup is attached to the convergence cup, and the nonuniformity of the deflection magnetic fields around a pair of said beam passing holes among the three electron beam passing holes arranged in a row through which the three electron beams pass through each formed at the bottom of the convergence cup. In a color picture tube device in which a magnetic field control element is arranged to correct aberrations based on The three-dimensional portion is characterized in that the three-dimensional portion has a shape in which both ends protrude toward the center beam passage hole.

[0014]

[Function] As described above, a three-dimensional portion is provided extending from the side edge of the annular portion of the magnetic field control element that surrounds each of the pair of side beam passage holes to the center beam passage hole, and the three-dimensional portion is provided at both ends. By making the shape protrude toward the center beam passage hole, it is possible to equalize the influence of the magnetizing magnetic field of the magnetic field control element on the pair of side beams and the center beam at the center of the screen. It is possible to correct the phenomenon in which the side beam is deflected to the right more than the center beam and the center beam is insufficiently deflected relative to the pair of side beams, thereby eliminating the shift to the right of the screen drawn by the center beam.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments with reference to the drawings.

FIG. 1 shows an in-line color picture tube device which is an embodiment of the present invention. This color picture tube device is
A shadow mask 22 which has an envelope consisting of a panel 20 and a funnel 21 that are integrally joined, and has a large number of electron beam passage holes formed inside the panel 20.
A phosphor screen 23 consisting of a three-color phosphor layer that emits blue, green, and red light is formed on the inner surface of the panel opposite to the phosphor screen 23 . Further, in the neck 24 of the funnel 21, an in-line electron gun 25 is disposed which emits three electron beams arranged in a row, consisting of a center beam 11G and a pair of side beams 11B and 11R passing on the same horizontal plane. Further, on the outside of the funnel 21, three electron beams 11B, 11G, 11R emitted from this electron gun are provided.
A deflection yoke 26 is attached to generate a deflection magnetic field that deflects the magnetic field in horizontal and vertical directions.

The electron gun 25 includes three cathodes arranged in a row in the horizontal direction, a grid for controlling electron emission from the cathodes, and an electron beam emitted through the grid toward the phosphor screen 23. It has a plurality of grids, such as focusing and accelerating grids, arranged successively adjacent to each other on the three cathodes, and a convergence cup 27 made of a non-magnetic material is attached to the most advanced grid. As shown in FIG. 2(a), the bottom of the convergence cup 27 has high magnetic permeability holes surrounding the three electron beam passage holes 3B, 3G, and 3R corresponding to the three cathodes. A magnetic field control element 30 made of a magnetic material is arranged.

The magnetic field control element 30 consists of an annular portion 31 surrounding each side beam passage hole, and a three-dimensional portion 32 that stands up from the side edge of the annular portion 31 on the side of the center beam passage hole 3G. Center beam passing hole 3G on both ends
It has a shape that protrudes to the side.

The magnetic field control element 30 of this embodiment is specifically shown in FIG. 2(b). That is, N
Internal diameter 3.4 due to FB magnetic material (45% permalloy)
mm, annular part 31 with an outer diameter of 6.7 mm, and a height of 4.0 m.
m three-dimensional parts 32, and the distance between the pair of three-dimensional parts is set to 6.8 mm. Further, the pair of three-dimensional parts 32 includes a flat part 32a with a width W of 5.0 mm, a width L of 1.0 mm and a height provided so that an inclination angle θ is 60 degrees from both ends of the flat part 32a. It consists of a side wall portion 32b of 4.0 mm.

By the way, as mentioned above, if the magnetic field control element is placed in the area covered by the leakage magnetic field at the rear of the horizontal deflection of the deflection yoke, it will be magnetized by the leakage magnetic field at the rear of the horizontal deflection and residual magnetism will remain, causing the electron beam to appear on the screen. When scanning from left to right, a magnetic field 33 indicated by a broken arrow in FIG. 3 is generated even in the center of the screen where the magnetic field of the deflection yoke is zero due to the residual magnetism. In the magnetic field control element 30 of this embodiment, the side wall portion 32
b By providing the three-dimensional portion 32, both ends of the three-dimensional portion 32 are shaped to protrude toward the center beam passage hole.
The magnetic field 33 acts on each electron beam 11B, 11G, 11R to the same extent. As a result, in the conventional magnetic field control element, the force Fs acting on each side beam 11B, 11R due to residual magnetism is changed from the force Fs acting on the center beam 11G.
c, and Fs>Fc, the force Fc acting on the center beam 11G is made larger than before.
s=Fc. As a result, the amount of rightward deviation of the center beam becomes equal to the amount of deviation of the pair of side beams, and it is possible to eliminate the rightward deviation of the raster drawn by the center beam on the screen that has conventionally occurred. In the above embodiment, the side wall portion 32 provided at the tip of the three-dimensional portion 32
By adjusting the inclination θ and width L of b, it is possible to control the magnetic field 33 due to residual magnetism.

Further, the shape of the three-dimensional portion is not limited to that formed by the flat portion 32a and the side wall portions 32b at both ends thereof as in the above embodiment. That is, as shown in FIG. 4, the same effect can be obtained even if the entire three-dimensional portion 32 is curved and both ends thereof protrude toward the center beam passage hole 3G side.

[0022]

As described above, the color picture tube device of the present invention has an annular portion surrounding a pair of side beam passage holes and a center portion of the annular portion at the bottom of the convergence cup attached to the tip of the electron gun. By arranging a magnetic field control element consisting of a three-dimensional part that stands up from the beam passage hole side, and shaping the three-dimensional part so that both ends protrude toward the center beam passage hole side, a pair of side beams and a center beam at the center of the screen can be controlled. It is possible to equalize the influence of the magnetizing magnetic field of the magnetic field control element on By correcting the phenomenon of insufficiency, it is possible to eliminate the right shift of the raster drawn by the center beam.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of a color picture tube device that is an embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of a magnetic field control element disposed at the bottom of a convergence cup in the color picture tube device of FIG. 1;

FIG. 3 is a diagram showing the operation of the magnetic field control element shown in FIG. 2;

FIG. 4 is a diagram showing another embodiment of the magnetic field control element according to the present invention.

FIG. 5 is an explanatory diagram of coma aberration occurring in a self-convergence type inline color picture tube device.

FIG. 6 is a diagram showing the configuration of a magnetic field control element disposed at the bottom of a convergence cup of a conventional color picture tube device.

FIG. 7 is a diagram showing the configuration of a magnetic field control element including an annular portion and a three-dimensional portion disposed at the bottom of a convergence cup of a conventional color picture tube device.

FIG. 8 is a diagram illustrating raster deviation when a magnetic field control element consisting of an annular portion and a three-dimensional portion is used.

FIG. 9 is a diagram illustrating magnetization of a magnetic field control element by a horizontal deflection magnetic field.

[Explanation of symbols]

25...In-line electron gun 27...Convergence Cup 3B, 3R...Side beam passage hole 3G...Center beam passage hole 30...Magnetic field control element 32...Annular part 32...Stereoscopic part 32a...Plane part 32b...Side wall part 33...Magnetic field

Claims (1)

[Claims] Claim 1: A cylindrical convergence cup is attached to the tip of an electron gun that emits three electron beams arranged in a row consisting of a center beam and a pair of side beams passing on the same plane, and a cylindrical convergence cup is attached to the bottom of the convergence cup. Magnetic field control elements for correcting aberrations due to non-uniformity of the deflection magnetic field are arranged around a pair of side beam passing holes among the three electron beam passing holes arranged in a row through which the three electron beams are passed through respectively. In the color picture tube device, the magnetic field control element includes at least an annular portion surrounding each of the pair of side beam passage holes, and a solid portion standing up from a side edge of the annular portion on the side of the center beam passage hole. A color picture tube device characterized in that the three-dimensional portion has a shape in which both ends protrude toward the center beam passage hole.