JPH09102288A - Deflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the focus property of the peripheries of both sides of a self convergence inline type color picture tube. SOLUTION: This deflector has a saddle-type deflecting coil 21 which generates a pin cushion type deflecting magnetic field for deflecting a plurality of beams arranged in a row passing the same plane in the direction of its deflection. Moreover, outside the crossover at the front end of the deflecting coil are provided at least a pair of additional coils 28, which are constituted by winding coils 30, where currents reverse to the deflecting currents flowing to this deflecting coil, synchronizing with the deflection of a plurality of beams by this deflecting coil, flow, around magnetic cores 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflecting device mounted on an in-line type color picture tube which emits three electron beams arranged in a row passing through the same plane.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, a color picture tube has an envelope composed of a panel 1 and a funnel-shaped funnel 2 joined to the panel 1. , A phosphor screen 3 composed of a three-color phosphor layer that emits green and red light is formed, and a shadow mask 4 having a large number of electron beam passing holes formed therein is arranged so as to face the phosphor screen 3. Has been done. On the other hand, in the neck 5 of the funnel 2, three electron beams 6B, 6G, 6R
The electron gun 7 which emits is sealed. Then, the three electron beams 6B, 6G, 6R emitted from the electron gun 7
Is deflected by the horizontal and vertical deflection magnetic fields generated by the horizontal and vertical deflection coils 10H and 10V of the deflection device 9 mounted on the outer side in the vicinity of the boundary between the large-diameter portion 8 of the funnel 2 and the neck 5, and The body screen 3 is formed in a structure for displaying a color image by horizontal and vertical scanning.

In such a color picture tube, the electron guns 7 are arranged in a row so as to pass the electron guns 7 on the same horizontal plane.
An in-line type electron gun that emits B, 6G and 6R is provided, and as shown in FIG. 4, a horizontal deflection coil of a deflection device that deflects the three electron beams 6B, 6G and 6R arranged in a row emitted from the electron gun 7 is used. Horizontal deflection magnetic field 11H generated is pincushion type, vertical deflection magnetic field generated by vertical deflection coil 1
A self-convergence in-line type color picture tube in which 1V is a barrel type and three electron beams 6B, 6G, and 6R are concentrated on a phosphor screen without requiring a special correction circuit has been widely put into practical use.

In general, the horizontal deflection coil for generating the pincushion type horizontal deflection magnetic field 11H is formed in a saddle shape, and the vertical deflection coil for generating the barrel type vertical deflection magnetic field 11V is formed in a toroidal shape.

In such a self-convergence in-line type color picture tube, the main factors that determine the focus characteristics are the control electrode, the acceleration electrode and the focusing electrode that form the electron gun 7, but the deflection device 9 is generated. The inhomogeneous horizontal and vertical deflection magnetic fields 11H and 11V also greatly contribute to the focus characteristics.

That is, the electron beam 6B is generated by the horizontal and vertical deflection magnetic fields 11H and 11V generated by the deflection device 9.
, 6G, 6R are deflected to the peripheral part of the screen, the electron beams 6B, 6G, 6R have their horizontal and vertical deflection magnetic fields 11H.
, 11V due to the axial component of the tube, depending on the strength of the deflection magnetic field, the vertical direction becomes overfocus,
The shape of the beam spot around the screen is distorted. That is,
When the horizontal and vertical deflection magnetic fields generated by the deflecting device deflect the electron beam by the uniform magnetic field, the beam spot 13 on the screen becomes almost a perfect circle as shown in FIG. When the horizontal deflection magnetic field 11H is deflected by a non-uniform magnetic field of pincushion type and the vertical deflection magnetic field 11V is barrel type, the pincushion type horizontal deflection is performed at the screen horizontal axis (X axis) end as shown in FIG. The magnetic field receives the following Lorentz force that presses the upper half of the electron beam downward and the lower half upward, and as shown by 13a, it is distorted into an elliptical shape having the major axis in the horizontal direction. At the screen vertical axis (Y-axis) end, a Lorentz force that presses the right half of the electron beam to the right and the left half to the left is distorted into an elliptical shape with the long axis in the horizontal direction, and This causes deterioration of focus characteristics.

The Lorentz force that distorts the shape of the beam spot 13 can be explained as follows. That is, the charge of electrons is e, the horizontal component of the magnetic flux density B (vector) of the horizontal deflection magnetic field is Bx, the tube axis component is Bz, the horizontal component of the velocity v (vector) of the electron beam is vx, and the tube axis direction is Letting the component be vz, the Lorentz force F (vector) is expressed by F = −e (v × B), and its vertical component Fy is Fy = −e (vz Bx −vx Bz), and its tube axis is The directional component is evx Bz, which is shown in FIG.
As shown in, the electron beam 6 (6B, 6G, 6R) is
By this Lorentz force (tube axis direction component evx Bz),
At the horizontal axis of the screen, the image is distorted into an elliptical shape (solid line) whose horizontal axis is the long axis.

Regarding the deterioration of the focus characteristic due to the deflection magnetic field, regarding the deterioration of the focus characteristic near the long side of the screen (vertical axis end side) due to the vertical deflection magnetic field 11V,
Correction is performed by adding a coma correction coil to the rear end side (neck side) of the deflecting device. However, the horizontal deflection magnetic field 1
Regarding the deterioration of focus characteristics near the short side of the screen (horizontal axis end side) due to 1H, there was no correction means.

[0009]

As described above, the pincushion type horizontal deflection magnetic field generated by the horizontal deflection coil of the deflection device for arranging three electron beams arranged in a row passing on the same horizontal plane,
Regarding the self-convergence in-line type color picture tube which is deflected by the barrel type vertical deflection magnetic field generated by the vertical deflection coil, the focusing characteristics in the peripheral portion of the screen are deteriorated due to the non-uniform deflection magnetic field generated by the deflection device. Among the deterioration of the focus characteristics, the deterioration of the focus characteristics near the long side of the screen due to the vertical deflection magnetic field is
Conventionally, correction is performed by adding a coma correction coil to the rear end side of the deflection device. However, the deterioration of the focus characteristics near the short side of the screen due to the horizontal deflection magnetic field is a problem because there is no conventional correction means.

The present invention has been made in view of the above problems, and the focus characteristics of the self-convergence in-line type color picture tube on the peripheral portion of the screen, particularly near the short side of the screen, can be improved without sacrificing the convergence correction. The purpose is to do.

[0011]

A deflection device having a saddle type deflection coil for generating a pincushion type deflection magnetic field for deflecting a plurality of beams arranged in a line passing through the same plane in the arrangement direction of the plurality of beams, the deflection coil Outside the crossover portion of the front end of the, at least a pair of additional coils are formed by winding a coil in which a current flowing in a direction opposite to the deflection current flowing in the deflection coil in synchronization with the deflection of a plurality of beams by the deflection coil is wound around a magnetic core. A coil is provided.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a deflecting device of a self-convergence in-line type color picture tube which is one form thereof. This deflecting device is composed of a separator 20 made of synthetic resin formed in a substantially trapezoidal shape corresponding to the outer shape in the vicinity of the boundary between the large-diameter portion of the color picture tube funnel and the neck, and disposed inside the separator 20. A pair of upper and lower saddle type horizontal deflection coils 21 for generating a pincushion type horizontal deflection magnetic field and a hollow trapezoidal core 22 made of a magnetic material are wound around the separator 20. It is composed of a pair of upper and lower toroidal vertical deflection coils 23 that generate a magnetic field. The saddle type horizontal deflection coil 21
Is a crossover portion 26 at the front end (the phosphor screen side of the color picture tube) and the rear end (the neck side of the color picture tube) of the deflector with a straight line portion 25 extending in the central axis direction of the deflector interposed therebetween. , 27 (only 26 is shown).

Further, in this deflecting device, a plurality of vertically symmetrical parts are provided outside the connecting line portion 26 on the front end side of the horizontal deflection coil 21 so as to cover the connecting line portion 26 via the separator 20 (illustrated example). In the above, three additional coils 28 are arranged above and below.

Each additional coil 28 is formed by winding a coil 31 around a rectangular parallelepiped magnetic core 30 made of a ferromagnetic material such as ferrite, and the central axis of the coil 31 is in the same direction as the central axis of the deflecting device. In addition, the rear end of the magnetic core 30 is arranged so as to cover the vicinity of the intersection of the crossover portion 26 and the straight portion 25 of the horizontal deflection coil 21. The coil 31 of each additional coil 30 is connected to the horizontal deflection coil 21 so that the current flowing in the direction opposite to the current flowing in the horizontal deflection coil 21 flows.

By the way, if a plurality of additional coils 28 are arranged outside the connecting wire portion 26 on the front end side of the saddle type horizontal deflection coil 21 as described above so as to cover the connecting wire portion 26, the saddle shape is mainly obtained. The leakage magnetic field generated from the crossover line portion 26 on the front end side of the horizontal deflection coil 21 is canceled out, and the oblong shape of the beam spot in the peripheral portion of the screen generated by the conventional electron beam being vertically pressed by the leakage magnetic field is formed. The focus characteristics can be reduced to improve the focus characteristics.

That is, as shown in FIG. 2, when a current flows in the direction indicated by 33 in the saddle type horizontal deflection coil, a leakage magnetic field 34 indicated by a broken line is generated from the crossover portion on the front end side thereof. By arranging a plurality of additional coils 28 outside so as to cover the line portion and connecting to the horizontal deflection coil so that a current in the direction opposite to the current flowing in the horizontal deflection coil flows through each coil 30, the horizontal deflection coil In synchronism with the deflection of the three electron beams, a magnetic field 35 opposite to the leakage magnetic field 34 shown by the solid line is generated around the additional coil 28 to cancel the leakage magnetic field 34. Therefore, the leakage magnetic field 34 can be canceled by adjusting the number of windings of the coil 30 of the additional coil 28 and the current flowing through the coil 30, whereby the leakage magnetic field 34 presses the electron beam in the vertical direction. It is possible to reduce the horizontally elongated shape of the beam spot in the peripheral portion of the screen, which improves the focus characteristics in the peripheral portion of the screen. Moreover, this additional coil 2
The magnetic field 35 generated by 8 can be adjusted so as not to affect the deflection of the 3-electron beam so that the convergence correction of the 3-electron beam is not sacrificed.

In the above embodiment, the three additional coils are arranged vertically symmetrically outside the crossover portion of the saddle type horizontal deflection coil. However, if at least one pair of these additional coils are vertically symmetrically arranged. Of course, three or more additional coils may be arranged vertically symmetrically.

Further, in the above embodiment, the semi-toroidal type deflection device in which the horizontal deflection coil is a saddle type and the vertical deflection coil is a toroidal type has been described, but in the present invention, the horizontal and vertical deflection coils are both saddle type. The same effect can be obtained by applying the present invention to a saddle / saddle type deflection device.

[0020]

In a deflector having a saddle type deflection coil for generating a pincushion type deflection magnetic field for deflecting a plurality of beams arranged in a row passing through the same plane in the arrangement direction of the plurality of beams, the front end portion of the deflection coil is If at least a pair of additional coils are provided outside the connecting wire portion, the coils are wound around a magnetic core in which a current flowing in the direction opposite to the deflection current flowing in the deflection coil is provided in synchronization with the deflection of a plurality of beams by the deflection coil. , It is possible to generate a magnetic field that cancels the leakage magnetic field generated from the crossover part of the front end of the saddle type deflection coil that deteriorates the focus characteristics of the peripheral part of the screen,
As a result, it is possible to improve the focus characteristics near the short sides on both sides in the arrangement direction of the plurality of beams without sacrificing the convergence correction.

[Brief description of the drawings]

FIG. 1 (a) is a front view showing the configuration of a deflector for a self-convergence in-line type color picture tube which is an embodiment of the present invention, and FIG. 1 (b) is a perspective view thereof.

FIG. 2 is a diagram for explaining the operation of the deflection device.

FIG. 3 is a diagram showing a configuration of a color picture tube.

4A is a diagram showing a horizontal deflection magnetic field generated by a deflection device of a self-convergence in-line type color picture tube, and FIG. 4B is a diagram showing a vertical deflection magnetic field.

5A is a diagram showing the shape of a beam spot on the screen of an electron beam deflected by a uniform magnetic field; FIG.
FIG. 6B is a diagram showing the shape of a beam spot on the screen of the electron beam deflected by the nonuniform magnetic field.

6 (a) and 6 (b) are diagrams for explaining the distortion of an electron beam deflected by the non-uniform magnetic field.

[Explanation of symbols]

 20 ... Separator 21 ... Horizontal deflection coil 28 ... Additional coil 30 ... Coil 31 ... Magnetic core 34 ... Leakage magnetic field 35 ... Magnetic field

Claims (1)

[Claims] 1. A saddle type deflection coil for generating a pincushion type deflection magnetic field for deflecting a plurality of beams arranged in a row passing on the same plane in an arrangement direction of the plurality of beams, and a crossover portion of a front end portion of the deflection coil. On the outer side, at least a pair of additional coils formed by winding a coil around which a current flowing in a direction opposite to the deflection current flowing in the deflection coil in synchronization with the deflection of a plurality of beams by the deflection coil is wound. And a deflection device.