JPS63108651A - Deflection device for cathode-ray tube - Google Patents

Abstract

PURPOSE:To compensate efficiently the mis-convergence in the vertical direction by providing a roop-state core to the electron gun side of a vertical deflection coil. CONSTITUTION:A ring core 5 is provided to the electron gun side from a bend part 2a of the electron gun side of a horizontal deflection coil 2. The core 5 is composed by divided by two and the gap 5g of 5-10 mm is formed between divided parts. The horizontal deflection coil 2 is wrapped and mounted saddlelikely on a bobbin 1. The magnetic field generated at the back side of the coil 4 is absorbed into the core 5 by providing the core 5 to the electron gun side of the vertical deflection coil 4, and a barrel magnetic field is produced at the core 5 part. On the other hand, a pincushion magnetic field is relatively generated at the back side of the coil 4 as a vertical deflection magnetic field is absorbed. The mis-convergence in the vertical direction is compensated at the faceplate peripheral part as an electron beam from the electron gun deflects as the beam proceeds from the core 5 to the coil 4, then the barrel magnetic field is produced at the central part and the pincushion magnetic field at the outside part, and the barrel magnetic field at the peripheral part is made weaker than the intermediate part.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a deflection device for a cathode ray tube.

[Essentials of invention]

The present invention provides a deflection device for a cathode ray tube in which a horizontal deflection coil is wound in a saddle shape and a straight deflection coil is wound in a toroidal shape, by providing a loop-shaped core on the electron gun side of the vertical deflection coil. , misconvergence is corrected.

[Conventional technology]

For example, a deflection device shown in FIG. 4 has been proposed for use in an in-line color cathode ray tube.

In the same figure, (11 is a bobbin, and this bobbin (1
) is wound with a horizontal deflection coil (2) in a saddle shape.

Further, a vertical deflection coil (4) is wound in a toroidal shape around an annular core (3) on the outside of the bobbin (11).

Here, in order to correct misconvergence in the vertical direction as shown in FIG. 5A, for example, it is known to use a barrel magnetic field as the mounting deflection magnetic field by the vertical deflection coil (4). In FIG. 5, R indicates a red electron beam and B indicates a blue electron beam.

[Problem that the invention seeks to solve]

In this case, if the strength of the barrel magnetic field is determined so that the misconvergence is corrected at the periphery of the screen, the barrel magnetic field is too weak at the center, and the misconvergence is not completely corrected as shown in FIG. 5B.

On the other hand, if the strength of the barrel magnetic field is determined so that the misconvergence is corrected in the middle part of the screen, the barrel magnetic field is too strong in the peripheral part, and the misconvergence is overcorrected as shown in FIG. 5C.

In view of this point, the present invention enables vertical misconvergence to be corrected more effectively.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a loop-shaped, for example, a ring-shaped core (
5).

[Effect]

A ring-shaped core (5) is placed on the electron gun side of the vertical deflection coil (4).
By providing this, the magnetic field generated on the rear side of the vertical deflection coil (4) is absorbed by the core (5), and a barrel magnetic field is generated in this core (5). On the other hand, the vertical deflection coil (
After 4) (μ;), the magnetic field is absorbed and becomes a relative bin cushion magnetic field.

The electron beam deflects as it advances from the core (5) to the vertical deflection coil (4), so relatively speaking, the center becomes a barrel magnetic field and the outside becomes a bottle cushion magnetic field, resulting in opposite distortion between the middle and periphery of the screen. A magnetic field is formed. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In the drawings, parts corresponding to those in FIG. 4 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In this example, as shown in Figure 1, a ring-shaped core (5) is provided closer to the electron gun than the bend portion (2a) of the horizontal deflection coil (2) on the electron gun (not shown) side. This core (5) is formed of a soft ferromagnetic material such as a sintered core, molded core, plastic ferrite, rubber ferrite, permalloy, or iron plate.

The core (5) is divided into two parts as shown in FIG. 2, and a gap (5 g) of 5 to 10 mm is formed between each part.

The rest of the structure is the same as the example shown in FIG.

In this example, by providing the core (5) on the electron gun side of the vertical deflection coil (4), the magnetic field generated on the rear side of the vertical deflection coil (4) is absorbed by the core (5). A barrel magnetic field is generated in the part 5). On the other hand, behind the vertical deflection coil (4)! By absorbing the direct deflection magnetic field, it becomes a relative bin cushion magnetic field. The solid line a in FIG. 3 shows the distribution of the vm direct deflection magnetic field when the core (5) is provided, in correspondence with the positions of the core (5) and the vertical deflection coil (4). The rear portion l of the VX direct deflection coil (4) is relatively a bottle cushion magnetic field.

Incidentally, the broken line in the figure shows the distribution when the core (5) is not provided.

Electronic! The electron beam from Jc (not shown) is directed to the core (5
) to the vertical deflection coil (4), so relatively speaking, the center becomes a barrel magnetic field, the outside becomes a bottle cushion magnetic field, and magnetic fields with opposite distortions are formed in the middle and periphery of the screen. . As a result, the barrel magnetic field at the periphery becomes weaker than at the middle. Therefore, according to this example, when determining the strength of the barrel magnetic field so that the vertical misconvergence is corrected at the periphery of the screen, the barrel magnetic field at the middle part is strong enough to correct the misconvergence as shown in Figure 5. is completely corrected.

In addition, in this example, there is a gap (5g) in the core (5).
is provided, and the vertical deflection magnetic field absorbed by the core (5) is reduced due to this gap (5 g), so that the influence on raster distortion is reduced.

As described above, according to this example, misconvergence in the vertical direction can be almost completely corrected.

In the above embodiment, the core (5) is provided closer to the electron gun than the bend portion (2a) of the horizontal deflection coil (2), but as shown by the broken line in FIG.
It may be provided between the bend portion (2a) and the engineering deflection coil (4). Further, in the above-mentioned embodiments, the core (5) is ring-shaped, but it does not necessarily have to be ring-shaped and may be loop-shaped. Further, in the above embodiment, the core (5) is provided with a gap (5g), but if the influence on raster distortion is not considered, there is no need to provide the gap (5g).

By the way, a deflection device similarly provided with a ring-shaped magnetic body is described in, for example, Japanese Utility Model Application No. 58-64058, but in that device, the vertical deflection magnetic field is converted into a bottle cushion magnetic field on the fluorescent surface (screen) side. This is provided to shift the center of the vertical deflection magnetic field toward the fluorescent surface, and is completely different from the present invention.

〔Effect of the invention〕

As is clear from the embodiments described above, according to the present invention, a loop-shaped core is provided on the electron gun side of the vertical deflection coil,
Relatively speaking, the center part becomes a barrel magnetic field and the outer part becomes a bottle cushion magnetic field, so that magnetic fields with opposite distortions are formed in the middle part and the peripheral part of both sides, so vertical misconvergence can be almost completely corrected. be able to.

[Brief explanation of the drawing]

1 and 2 are configuration diagrams showing one embodiment of the present invention, FIG. 3 is a diagram for explaining the same, and FIG. 4 is a configuration diagram of a conventional example,
FIG. 5 is an explanatory diagram of misconvergence. (1) is a bobbin, (2) is a horizontal deflection coil, (3) is a core, (4) is a world deflection coil, (5) is a ring-shaped core,
(5g) is a gap.

Claims (1)

[Claims] In a cathode ray tube deflection device in which a horizontal deflection coil is wound in a saddle shape and a vertical deflection coil is wound in a toroidal shape, a loop-shaped core is provided on the electron gun side of the vertical deflection coil. A deflection device for a cathode ray tube.