JPH0730909A - Lateral mis-convergence correction circuit - Google Patents

Abstract

PURPOSE:To simplify the configuration and to correct lateral mis-convergence while suppressing a power loss. CONSTITUTION:A magnetoresistive element, 35 for X axis lateral mis- convergence and a magnetic reluctance element 40 for Y axis lateral misconvergence are connected in series with a lateral mis-convergence correction coil 17, the magnetoresistive element 35 is arranged in a horizontal deflection magnetic field and the magnetoresistive element 40 is arranged in the vertical deflection magnetic field. Since a parabolic wave correction current for X axis lateral mis-convergence correction and for Y axis lateral mis- convergence correction flows respectively to the correction coil 17, the lateral mis-convergence for X and Y axes is corrected with a simple configuration. Since no saturable reactor nor a resistor to provide a voltage is employed, the power loss is small and a small sized power supply is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lateral misconvergence correction circuit capable of correcting both X-axis lateral misconvergence and Y-axis lateral misconvergence with a simple structure.

[0002]

2. Description of the Related Art In the case of a color cathode ray tube (CRT) in which both a horizontal deflection coil and a vertical deflection coil are toroidally wound, when three electron beams of R, G and B are deflected from the center of the screen toward both left and right ends Misconvergence as shown in 6 occurs.

Since FIG. 6 is a view of the CRT from above,
When this is viewed from the panel (phosphor screen 1) side, a misconvergence as shown in FIG. 7 is obtained. Of the misconvergence, the parallel misconvergence that occurs near the left and right ends of the X axis is called the X axis lateral misconvergence.
The bow-shaped misconvergence that occurs near the upper and lower ends on the Y-axis is called the Y-axis lateral misconvergence.

The X-axis lateral misconvergence is corrected by a correction circuit 10 as shown in FIG.

In the figure, 12 is a horizontal deflection coil,
An upper horizontal deflection coil (upper coil) H arranged in a funnel portion (not shown) on the upper surface side when viewed from the panel side.
It is configured by being divided into U and a lower horizontal deflection coil (lower coil) HD arranged in the funnel portion on the lower surface side.

The horizontal deflection current (IH) flowing through the horizontal deflection coil 12 is also supplied to the saturable reactor 15. The saturable reactor 15 is composed of four reactor coils L1 to L4, the reactor coils L1 and L2 and L3 and L4 are connected in series, and the reactor coils L1 and L4 and L2 and L3 are connected.
And are bifilar wound so that they are closely magnetically coupled. A convergence correction coil LS is connected between the connection midpoints of the series circuit of the reactor coils L1 and L4 and the series circuit of the reactor coils L2 and L3. 16 is S
It is a character correction capacitor.

The correction coil LS is constructed as a quadrupole coil 17, and FIG. 9 shows an example thereof.

The C-shaped cores 18 and 19 are arranged so as to face each other with respect to the CRT 3, and the coils LS1 to LS4 are wound around the respective legs in a winding manner as shown in the drawing so that the panel side to the neck side are wound. When viewed, a magnetic field H as shown in the figure is generated.

Due to this magnetic field H, the R and B electron beams have forces (electromagnetic forces) in the opposite directions as shown by arrows p and q.
Receive. Since these forces p and q act on the electron beams R and B in the horizontal direction of the screen in FIG. 6, both the R electron beam and the B electron beam act so as to approach the G electron beam. . In addition, since a correction current having a parabolic waveform with a horizontal period is flowing through the correction coil LS, the magnetic field H generated at the left and right ends is larger than the center in the horizontal scanning direction. You can correct the convergence.

On the other hand, FIG. 10 shows a conventional example of the Y-axis lateral misconvergence correction circuit 20, in which 22 is a vertical deflection coil and 25 is a convergence correction unit. The convergence correction unit 20 includes four diodes Da to Dd connected in a bridge shape and a convergence correction coil L connected between the middle points m and n of the paired diodes Da to Dd.
A resistor R which has V and is connected in parallel with the pair of diodes Da and Db for applying a potential difference.

A resistor R connects a pair of diodes Da,
By applying a predetermined potential difference between Db, the terminal 21
The vertical deflection current supplied to is modulated into a parabolic wave shape,
This parabolic correction current flows through the correction coil LV.
As a result, the correction magnetic field H, which is maximized in the vicinity of the upper and lower ends of the screen, is added to the R and B electron beams in the tube of the CRT 3, whereby the Y-axis lateral misconvergence is corrected.

[0012]

As described above, in the conventional lateral misconvergence correction circuit 10, the saturable reactor 15 is used to correct the X-axis lateral misconvergence and the Y-axis lateral misconvergence is corrected. For this purpose, a convergence correction coil LV is used. Therefore, in the conventional convergence correction circuit, the convergence correction system is complicated and the cost is increased.

Further, when the saturable reactor 15 is used, since the reactor coils L1 to L4 for the saturable reactor are connected in series to the horizontal deflection coil 12, the ineffective component (ineffective inductance component) of the entire circuit. And the power supply must be increased accordingly.

Correction circuit 2 for Y-axis lateral misconvergence
Even when it is 0, an additional resistance component (resistance component of the resistor R) is added to the vertical deflection coil 22 in series with it, so that the L / R ratio is deteriorated and the power loss due to the resistance component is increased.
Again, a large power source must be used.

Therefore, the present invention solves such a conventional problem, and the horizontal misconvergence requires only a small power supply capacity to correct both the X-axis lateral misconvergence and the Y-axis lateral misconvergence with a simple structure. A correction circuit is proposed.

[0016]

In order to solve the above-mentioned problems, in the present invention, a magnetic resistance element for X-axis lateral misconvergence correction and a Y-axis lateral misconvergence correction are provided in series with a lateral misconvergence correction coil. And a magnetic resistance element for X-axis lateral misconvergence correction is arranged in the horizontal deflection magnetic field.
The magnetoresistive element for axial lateral misconvergence correction is arranged in the vertical deflection magnetic field so that the parabola correction current for X-axis lateral misconvergence and Y-axis lateral misconvergence correction flows in the lateral misconvergence. It is what

[0017]

When the magnetoresistive element 35 is placed in the horizontal deflection magnetic field as shown in FIG. 1, its resistance value is nonlinearly modulated by the horizontal deflection magnetic field. Since the horizontal deflection magnetic field is maximum at the left and right ends and minimum at the center, and since the magnetic flux / resistance characteristic is a non-linear characteristic as shown in FIG. 2, its resistance value changes in a parabolic wave shape in synchronization with the horizontal period. . Therefore, the current flowing in the correction coil LS also becomes a parabolic wave current having a horizontal period, and the same convergence correction magnetic field H as described above is obtained. The X-axis lateral misconvergence is corrected by this correction magnetic field.

For the same reason, the resistance value of the magnetoresistive element 40 arranged in the vertical deflection magnetic field also changes in a vertical cycle and in a parabolic waveform, so that a parabolic correction current is applied to the correction coil LS. The Y-axis lateral misconvergence is corrected by the correction magnetic field generated by the correction current.

Therefore, the lateral misconvergence can be corrected without using the saturable reactor 15 or the convergence correction coil LV.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an example of a lateral misconvergence correction circuit according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a lateral misconvergence correction circuit 30 according to the present invention. Also in the present invention, a convergence correction coil 17 is used, and this is attached to the neck side to form a convergence correction magnetic field H. At the same time, a pair of magnetoresistive elements 35 and 40 are connected in series to the correction coil so that the correction magnetic field H is modulated by the deflection currents of the horizontal and vertical periods.

As the correction coil 17, a quadrupole coil is used, and therefore the same configuration as that shown in FIG. 9 is used, and the coils LS1 to LS1 wound around the U-shaped cores 18 and 19 are used.
A correction magnetic field H as shown in FIG. 9 is formed by the current flowing through LS4.

These four coils LS1 ...
LS4 and a pair of magnetic resistance elements 35 and 40 connected in series to these are connected to the DC power supply 31, respectively.

As the magnetoresistive elements 35 and 40, those having a non-linear characteristic as shown in FIG. 2 and exhibiting a magnetoresistive characteristic (curve 45) in which the resistance value decreases in proportion to the magnitude of the magnetic field are used.

One of the magnetoresistive elements 35 having such characteristics is placed in the horizontal deflection magnetic field.
For example, of the separator 50 around which the horizontal deflection coil 12 as shown in FIG.
1, 52, in this example, is attached on the horizontal deflection coil wire portion wound around the upper bend portion 52 so as to be orthogonal to this coil wire portion.

Since the magnetoresistive element 35 exhibits a pseudo parabolic wave-like change such that the resistance value RH is large when the magnetic field is weak and becomes small when the magnetic field is strong, the magnetoresistive element 35 is placed in the horizontal deflection magnetic field. When placed, the resistance value RH of the magnetic resistance element 35 also changes in a parabolic wave shape as shown in FIG. 4B, and the resistance value RH of the magnetic resistance element 35 is modulated by the horizontal deflection current.

As a result, since the correction current modulated by the horizontal deflection current (see FIGS. 4A and 4B) flows through the correction coil LS, the correction magnetic field H which becomes the strongest at the left and right ends of the screen.
Occurs, which can correct the X-axis lateral misconvergence.

The other magnetoresistive element 40 is placed in a vertical deflection magnetic field. This is attached to a part of a deflection yoke (not shown) around which the vertical deflection coil 22 is wound so as to be orthogonal to the vertical deflection coil 22. Then,
The magnetoresistive element 40 is also modulated by the vertical deflection magnetic field for the reason described above, and the resistance value of the magnetoresistive element 40 is shown in FIG. 5B.
With a vertical period like
The correction current flowing through the correction coil LS is the magnetic resistance element 4
It is also modulated into a parabolic wave shape by 0 (C in the same figure).

After all, the deflection coil LS is shown in FIG.
The correction current modulated by the parabolic wave signal of the horizontal and vertical periods as described above flows, and the correction current of the vertical period can correct the Y-axis horizontal misconvergence that occurs near the upper and lower ends of the screen.

[0030]

As described above, in the present invention, the X-axis lateral misconvergence and the Y-axis lateral misconvergence are corrected only by the pair of magnetoresistive elements connected to the convergence correction coil.

According to this, unlike the conventional case, the X-axis lateral misconvergence can be corrected without using the saturable reactor, and the Y-axis lateral misconvergence can be corrected without using the convergence correction coil, so that the circuit configuration is very large. Besides being simple, the reactive inductance due to the saturable reactor is reduced, and the power loss due to the resistance value R is also reduced, so that the power loss is reduced as a whole of the convergence correction circuit. This has the feature that a small power source can be used as the power source. It is also advantageous in making the circuit into an IC.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a horizontal misconvergence correction circuit according to the present invention.

FIG. 2 is a characteristic curve diagram of a magnetoresistive element.

FIG. 3 is a view showing a mounting state of a magnetic resistance element.

FIG. 4 is an explanatory diagram of X-axis lateral misconvergence correction.

FIG. 5 is an explanatory diagram of Y-axis lateral misconvergence correction.

FIG. 6 is an explanatory diagram of misconvergence.

FIG. 7 is an explanatory diagram of lateral misconvergence.

FIG. 8 is a system diagram of an X-axis lateral misconvergence correction circuit.

FIG. 9 is an explanatory diagram of a quadrupole coil.

FIG. 10 is a system diagram of a Y-axis lateral misconvergence correction circuit.

[Explanation of symbols]

 17 Correction coil (quadrupole coil) 30 Transverse misconvergence correction circuit 35, 40 Magnetoresistive element

Claims (3)

[Claims] 1. A magnetic resistance element for X-axis lateral misconvergence correction and a magnetic resistance element for Y-axis lateral misconvergence correction are connected in series with the lateral misconvergence correction coil, and the X-axis lateral misconvergence correction is performed. And a Y-axis lateral misconvergence correction magnetic resistance element is arranged in the vertical deflection magnetic field, and the X-axis lateral misconvergence and Y-axis are arranged in the lateral misconvergence correction coil. A lateral misconvergence correction circuit characterized in that a parabola correction current for lateral misconvergence correction is made to flow respectively. 2. The lateral misconvergence correction coil is constituted by a quadrupole coil.
Horizontal misconvergence correction circuit described. 3. The lateral misconvergence correction circuit according to claim 1, wherein the X-axis lateral misconvergence correction magnetic resistance element is arranged in an upper bend portion of a separator around which a horizontal deflection coil is wound.