JPS61269835A - Convergence correcting device - Google Patents

Abstract

PURPOSE:To make a deflecting magnetic field into an even magnetic field and enable the correction of a convergence, by connecting in series the first and the fourth coils, and the third and the second coils, whose bias magnetic fields are in the reverse directions respectively, and connecting a convergence correcting coil between the both connections. CONSTITUTION:When coils 12 and 13, and, coils 14 and 15, wound on coil bobbins 10 and 11 respectively, are applied with currents in the same direction, the direction of the generated magnetic fluxes are arranged so that one coil is in the same direction and the other in the reverse direction to that of the bias magnetic fluxes from the magnets 7 and 8. Then, coils 12 and 15, and, coils 14 and 14 are connected in series respectively, both series circuited connections are connected in parallel, and terminals 16 and 17 are picked up from this connection, as well as a convergence correcting coil 18 is connected to the connections between the coils 12 and 15, and between the coils 14 and 13. When a horizontal saw tooth wave current is applied between the terminals 16 and 17, a correcting current flows in the coil 18, to correct the active convergence.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a convergence correction device for correcting the convergence of a color cathode ray tube.

[Summary of the Invention] The present invention provides a convergence correction device for correcting the convergence of a color cathode ray tube, in which a correction current equivalent to a parabolic current is applied to the convergence correction coil by passing a horizontal deflection current through the convergence correction coil from one direction. This is to correct misconvergence.

[Conventional technology]

In conventional in-line color cathode ray tubes, convergence is corrected by using a special deflection magnetic field, or by supplying a horizontal parabolic current to a convergence correction coil.

[Problem that the invention seeks to solve]

However, by using a special deflection magnetic field, the cross-sectional shape of the electron beam is no longer circular, and this distortion causes
Focus characteristics deteriorate and image quality deteriorates. Therefore, in graphic displays, high-precision monitor receivers, and the like that require good focus characteristics, it is necessary to make the deflection magnetic field a uniform magnetic field.

When the deflection magnetic field is a uniform magnetic field, misconvergence that changes in the horizontal direction can be corrected by passing a parabolic current with a horizontal period through the convergence correction coil.

However, with this configuration in which convergence is corrected by flowing a parabolic current through the convergence correction coil, an external correction circuit is required to flow the parabolic current through the convergence correction coil, resulting in a complicated and expensive configuration. .

Therefore, an object of the present invention is to provide a convergence correction device that can perform convergence correction by making the deflection magnetic field uniform.

Another object of the present invention is to provide a convergence correction device that does not require a complicated external correction circuit for passing a parabolic current through a convergence correction coil and is simple and inexpensive.

[Means for solving problems]

This invention provides a core to which a bias magnetic field is applied, a bias magnetic field for the first and second coils 12.13, and a third coil for the first and second coils.
The first to fourth coils 12 to 15 are wound so that the bias magnetic field for the second coil 14 and the fourth coil 14 is in the opposite direction, and the first coil 12 and the fourth coil 15 are connected in series. The third coil 14 and the second coil 13 are connected in series, and a convergence correction coil is connected between the connection point of the first and fourth coils 12.15 and the connection point of the third and second coils 14.13. 18, and the series connection of the first and fourth coils and the series connection of the third and second coils are connected in parallel to supply a horizontal sawtooth current.

[Effect]

Regardless of whether the current is passed from the terminal 16 to the terminal 17 or from the terminal 17 to the terminal 16, the current flows in the same direction in the convergence correction coil 18. Therefore, when a horizontal sawtooth current is passed through the terminals 16 and 17, a correction current equivalent to the horizontal parabolic current flows through the convergence correction coil 18. This corrects convergence.

〔Example〕

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

In FIG. 1, 1 is a U-shaped core, and the core 1 has magnetic legs 2 and 3. Reference numeral 4 denotes a T-shaped core, and the bottom portion of the core 4 is provided to shunt leakage of the magnetic field to the outside. A magnetic leg 5 protrudes from the center of the bottom surface of the core 4 and forms a side path for the magnetic paths of the magnetic legs 2 and 3 of the core 1 . A magnet 7 is interposed between the magnetic leg 2 of the core 1 and one end of the core 4.

A coil bobbin 10 is attached to the magnetic leg 2.

As shown in FIG. 2, coils 12 and 13 are wound around this coil bobbin 10 in a bifilar manner.

In this way, since the coils 12 and 13 are bifilar-wound, the magnetic properties of the coils 12 and 13 are equal to each other.

A coil bobbin 11 is attached to the magnetic leg 3.

Coils 14 and 15 are wound around this coil bobbin 11 in a bifilar manner. For this reason, the coil 14
and 15 have the same magnetic properties. coil bobbin 1
0 and 11 are coils 1 wound on the coil bobbin 10
2 and 13 and the coil 14 wound around the coil bobbin 11
and 15 in the same direction, the direction of the generated magnetic flux is the same with respect to the bias magnetic flux from the magnets 7 and 8, and the other is in the opposite direction.

Coil 1 wound around these coil bobbins 10 and 11
2.13 and 14.15 are connected as shown in FIG. That is, the coil 12 and the coil 15 are connected in series, and the coil 14 and the coil 15 are connected in series. The coils 12 and 15 connected in series are connected in parallel, and the coils 14 and 15 connected in series are connected in parallel, and terminals 16 and 17 are led out from the connection point of this parallel connection. coil 12
A convergence correction coil 18 is connected between the connection point of the coil 15 and the connection point of the coil 14 and the coil 13.

As shown in FIG. 4, a pair of convergence yokes 19A sandwich the neck portion 20 from the left and right sides.

19B is provided, and this convergence yoke 19A
, 19B, the coil 18 is wound around them. By passing current through this coil 18 in the direction shown, the side beam 21
A force is generated that moves R121B outward.

Terminals 16 and 17 are connected in series with the horizontal deflection coil. By passing a horizontal sawtooth current between terminals 16 and 17, a correction current equivalent to a parabolic current flows through coil 8. As a result, side beams 21R and 21B
is moved to correct the horizontal motion convergence of the screen. In this embodiment, the convergence in the vertical direction of the screen is corrected by using a barrel magnetic field as the deflection magnetic field.

The following will explain how a correction current equivalent to a parabolic current flows through the convergence correction coil 18 by causing a horizontal sawtooth current to flow through the terminals 16 and 17.

Now, current flows from terminal 16 to terminal 17 in FIG. 3, and at this time, as shown by arrows A and B in FIG. A magnetic flux is generated in the opposite direction to the direction indicated by the dashed arrow, and the coil 14 is wound around the coil bobbin 11.
It is assumed that magnetic flux in the same direction as the bias magnetic flux is generated from and 15.

The inductance of the coil increases as the magnetic flux increases.
, also decreases. The magnetic flux of coils 12 and 13 is
Since it is in the opposite direction to the bias magnetic flux, it decreases, and the coil 14
The magnetic fluxes of 1 and 15 increase because they are in the same direction as the bias direction. Therefore, the inductance of coils 12 and 13 increases and the inductance of coils 14 and 15 decreases.

When the inductance of coils 12 and 13 is large and the inductance of coils 14 and 15 is small, terminal 1
The current from 6 flows through coil 14, through coil 18, and through coil 15 to terminal 17, as shown by the solid arrow in FIG.

Conversely, when current flows from terminal 17 to terminal 16, magnetic flux in the same direction as the bias magnetic flux is generated from coils 12 and 13, and magnetic flux in the opposite direction to the bias magnetic flux is generated from coils 14 and 15. , the inductance of coils 12 and 13 decreases, and the inductance of coils 14 and 15 increases.

Therefore, current from terminal 17 flows through coil 13, through coil 18, and through coil 12 to terminal 16, as shown by the dashed arrow in FIG. As is clear from FIG. 3, the direction of the current flowing through the coil 18 at this time is the same as the direction when the current flows from the terminal 16 to the terminal 17.

In this way, the current flows in the same direction in the coil 18 whether it is passed from the terminal 16 to the terminal 17 or from the terminal 17 to the terminal 16. Therefore, a horizontal sawtooth current as shown in FIG.
6 and 17, a current of the same polarity flows through the coil 18 and becomes larger on both sides of the screen, as shown in FIG.

The current waveform flowing through the coil 18 shown in FIG. 6 is similar to a parabolic current. Therefore, by passing a horizontal sawtooth current through the terminals 16 and 17, convergence correction can be performed using the current flowing through the coil 18.

In addition, in FIG. 6, T, , T2 . Although the current flowing through the coil 18 decreases in the section indicated by T, this does not pose any problem since this is the retrace section.

In this embodiment, the coils 12.13 and 14.15 are bifilar wound around the coil bobbins 10 and 11, but the coils 12.13 and 14.15 may be wound side by side.

This convergence correction device is attached to a color cathode ray tube as shown in FIG.

FIG. 7 shows the entire deflection device for a color cathode ray tube to which the present invention can be applied. In Figure 7, 3
Reference numeral 1 designates a front cover of the separator, 32 a rear cover of the separator, 33 a core, and 34 a mounting portion for two-pole, four-pole, and six-pole magnets. Magnet mounting part 34 and rear cover 32
Convergence yokes 19A and 19B are attached between the two. As shown in FIG. 1, between the front cover 31 and the rear cover 32, a coil bobbin 10 and a coil 14. ．． A convergence correction device 35 constituted by a coil bobbin 11 wound with a coil bobbin 15 is fixed via a holder 36.

A terminal plate for connecting a coil such as a vertical deflection coil is provided on one surface of the holder 36, and a convergence correction device 35 is attached to the other surface. Note that the magnetic field of the convergence correction device 35 is arranged so as to be orthogonal to the vertical deflection magnetic field of the color cathode ray tube, so that the correction magnetic field does not affect the vertical deflection magnetic field.

〔Effect of the invention〕

According to this invention, since the coils 12, 13 and 14° 15 wound around the core 1 to which a bias magnetic field is applied are provided, horizontal sawtooth currents are caused to flow through the terminals 16 and 17 for convergence correction. A correction current equivalent to a parabolic current can be passed through the coil 18. Thereby, convergence correction can be performed while the deflection magnetic field remains a uniform magnetic field. In this way, since the current for convergence correction can be generated without using a complicated external circuit, convergence correction can be performed at low cost without deteriorating focus characteristics.
)

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of this invention, Fig. 2 is a plan view used to explain bifilar winding, Fig. 3 is a connection diagram of an embodiment of this invention, and Fig. 4 is an explanation of convergence correction operation. FIGS. 5 and 6 are waveform diagrams used to explain an embodiment of the present invention, and FIG. 7 is a perspective view showing the installation state of an embodiment of the present invention. 1: Core, 7, 8: Magnet, 10.11: Coil bobbin, 12.13.14, 15: Coil, 18: Coil for convergence correction. Agent Patent Attorney Tadashi Sugiura 47F each. Figure 2. Figure 3. Added phrases to the scene * Figure 4. Figure 5. Corrections. Figure 7.

Claims (1)

[Claims] The first to fourth coils are wound around a core to which a bias magnetic field is applied so that the bias magnetic fields for the first and second coils and the bias magnetic fields for the third and fourth coils are in opposite directions. , the first coil and the fourth coil are connected in series, and the third coil and the second coil are connected in series.
coils are connected in series, a convergence correction coil is connected between the connection point of the first and fourth coils and the connection point of the third and second coils, and the first and fourth coils are connected in series.
A convergence correction device configured to supply a horizontal sawtooth current by connecting in parallel the series connection of the coil and the series connection of the third and second coils.