JP3335784B2 - Frame error correction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke used in a color cathode ray tube having an in-line type electron gun.

[0002]

2. Description of the Related Art A self-convergence type deflection yoke used for a color cathode ray tube having an in-line type electron gun usually has a horizontal deflection magnetic field in a pincushion shape as shown in FIG. Focus on the horizontal axis vertical line, side beam red (RED) and blue (BLUE) horizontal deviation (XH) on the screen,
Further, by forming the vertical deflection magnetic field into a barrel shape as shown in FIG. 9, a vertical axis vertical line, side beam red (RED) and blue (BL) are displayed on the screen as shown in FIG.
Self-convergence is achieved by focusing the horizontal deviation (YH) between the UEs.

In this case, a vertical deviation (VCR) of a horizontal line called a coma error occurs in the center beam G with respect to the side beams R and B as shown in FIG.

As an apparatus for correcting such a frame error, for example, there is a frame error correction apparatus shown in FIG. The coma error correction device 1 includes U-shaped magnetic poles 2a and 2b.
In FIG. 13, a pair of electromagnets 4a and 4b wound with correction coils 3a and 3b, respectively, are disposed at the rear of a deflection yoke mounted on a color cathode ray tube so as to sandwich a neck portion 5 from above and below. 12 is connected in series to the vertical deflection coil 6 so that a vertical deflection current flows, as shown in FIG.
A coma error is corrected by forming a pincushion-type vertical deflection magnetic field as shown in the inside and applying a vertical deflection force larger than the side beams R and B to the center beam G.

FIG. 14 shows another conventional frame error correction device 7.
The auxiliary coil 9 is attached to the Y-shaped magnetic poles 8a and 8b.
A pair of electromagnets 10a and 10b around which a and 9b are wound are disposed so as to be sandwiched from the left and right sides of the neck portion 5, and a vertical deflection current is supplied to the auxiliary coils 9a and 9b to cause the inside of the neck portion as shown in FIG. A coma error is corrected by forming a deflecting magnetic field as shown and applying vertical deflecting forces in different directions to the center beam G and the side beams R and B.

In the above-mentioned conventional frame error correction device, a sawtooth vertical deflection current shown in FIG. 15A is applied to the auxiliary coil. The waveform of the deflection current is shown in FIG.
And the waveform of the sawtooth-shaped top is dull. Therefore, as shown in FIG. 16, there is a problem that the correction amount is insufficient at the upper and lower ends of the screen, and the frame error is not sufficiently corrected.

FIG. 17 is a diagram showing a frame error correction device disclosed in Japanese Patent Application Laid-Open No. Hei 1-207789, which has been made to solve such a problem. FIG. 18 is a circuit diagram thereof, which is the same as FIG. Reference numerals indicate the same or corresponding parts. In the figure, reference numeral 11 denotes a pair of rod-shaped electromagnets 12a and 12 disposed at positions sandwiching the neck portion 5 from the left and right.
b, the rod-shaped electromagnets 12a and 12b are composed of rod-shaped magnetic poles 13a and 13b and auxiliary coils 14a and 14b.
4b and a series body of a diode group 15 composed of diodes connected in parallel with opposite polarities and an R and L series body 16 are connected in parallel and connected in series to the vertical deflection coil 6.

According to this prior art, the pin cushion magnetic field shown in FIG. 17 is formed in the neck portion 5 by the coma error correction device 1 and the barrel magnetic field is formed by the auxiliary coma error correction device 11 so that the central beam G By applying a stronger vertical deflection force than the side beams R and B, and by generating a barrel magnetic field during the deflection period when the diode group 15 is turned on, that is, during the vertical deflection period at the upper and lower ends of the screen, the vertical and vertical directions of the screen are reduced. The frame error at the end is corrected.

[0009]

However, according to this prior art, an auxiliary coma error correction device is required, and the starting point of energization of the diode group 15 is determined by the voltage of the diode.
There is a problem that it is difficult to improve the accuracy of correcting the coma error because it is determined by the current characteristics.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and has as its object to provide a frame error correction device which has a small number of components and can perform a high accuracy frame error correction. I do.

[0011]

[ MEANS TO SOLVE THE PROBLEMS] A coma according to the present invention
-Correction device is a color cathode with an in-line type electron gun
A pair of electromagnets arranged so as to sandwich the neck of the wire tube
The vertical cathode current is applied to the color cathode ray
Coma errors caused by the deflection yoke attached to the tube
In a coma error correction device that generates a deflection magnetic field to correct
Thus, the coil constituting the pair of electromagnets is a main correction coil.
Main correction coil circuit, and the main correction coil circuit
Connected in parallel with the main correction coil
Sub-correction coil having an L / R value larger than the L / R value of the
And an anti-parallel connection connected in series to the sub-compensation coil
Composed of a sub-compensation coil circuit consisting of a group of diodes
Is what is being done.

The above-mentioned diode group is obtained by connecting a plurality of diodes connected in series in anti-parallel or connecting a plurality of diodes connected in anti-parallel in series. To adjust the conduction voltage. In addition, the above main correction coil circuit
Is a resistor connected in series with the main correction coil.
Between the main correction coil circuit and the sub correction coil circuit.
It is configured so that the impedance ratio can be adjusted.

[0013]

The current flows through the sub-correction coil only while the diode group is conducting, and the L / R ratio of the sub-correction coil is larger than the L / R ratio of the main correction coil. Since the vertical deflection magnetic field of the sub-correction coil is larger than the decrease, the vertical deflection of the center beam G at the upper and lower ends of the screen is increased, and the coma error is corrected.

Further, since the conduction period of the diode group and the current ratio between the main correction coil and the sub correction coil can be adjusted, it is possible to correct a coma error with high accuracy.

[0015]

【Example】

Embodiment 1 FIG. FIG. 1 is a diagram showing a configuration of an embodiment of the present invention,
FIG. 2 is a diagram showing the connection circuit. In the figure, FIG.
2, the same reference numerals as those in FIG. 13 or FIG. 17 indicate the same or corresponding parts, respectively, and 3a and 3b are magnetic poles 2a and 2b.
The main correction coils 3e, 3f wound around
a main correction coil circuit 18a formed of a series body of main correction coils 3a and 3b as shown in FIG. 2, a sub correction coil circuit 18a, and sub correction coils 3e and 3f and a diode group 15. A parallel connection with a sub-correction coil circuit 18b composed of a series body is connected in series to the vertical deflection coil 6 so that a vertical deflection current Ia shown in FIG. 3A is supplied.

FIG. 3B shows a waveform of the main correction current Ib flowing through the main correction coil circuit 18a, and FIG. 3C shows a waveform of the sub correction current Ic flowing through the sub correction coil circuit 18b. T ₁ of the in the figure sub correction current Ic timing turned off, T ₂ is a timing which is turned on.

According to the first embodiment, the vertical deflection current Ia
3 during the period when the diode group 15 is conducting.
The sub correction current Ic shown in (c) flows, and the main correction current Ib
Decreases by that amount. The current ratio between Ib and Ic is
It is determined by the ratio of the impedance of the main correction coil circuit 18a to the impedance of the sub correction coil circuit 18b. Also,
The strength of the deflection magnetic field generated by the main correction coils 3a and 3b and the strength of the deflection magnetic field generated by the sub correction coils 3e and 3f are the value of L / R (inductance / resistance) × Ib of the main correction coils 3a and 3b. And the auxiliary correction coils 3e, 3
It is determined by the value of (L / R) × Ic of f.

Therefore, the vertical deflection magnetic field generated by the sub-correction coils 3e and 3f so that the impedance ratio between the main correction coil circuit 18a and the sub-correction coil circuit 18b becomes a predetermined shunt ratio (shown by a broken line in FIG. 1). ) So that the intensity of the vertical deflection magnetic field generated by the main correction coils 3a and 3b is increased by a predetermined amount.
By setting the values, that is, the number of turns of the main correction coils 3a and 3b and the sub-correction coils 3e and 3f and the wire diameter of each coil, it is possible to accurately correct the frame error generated at the upper and lower ends of the screen.

Embodiment 2 FIG. FIG. 4 is a circuit diagram of a second embodiment of the present invention. The same reference numerals as those in FIG. 2 denote the same or corresponding parts, and a diode group 15a is formed by connecting a series body of three diodes in parallel. The main frame error correction circuit 18a has a resistor R inserted in series. FIG. 5 is a diagram showing current waveforms at various parts in the second embodiment.

According to this embodiment, the rising voltage of the diode string is 3 times the rising voltage of one diode.
As shown in FIG. 5C, the timing T ₃ at which the sub-correction current Ic is turned off and the timing T _{4 at which it} is turned on are as shown in FIG. , The period during which the sub-correction current Ic flows is shortened.

By adjusting the resistance R inserted in the main correction coil circuit 18a, the main correction coil circuit 1
By adjusting the impedance of 8a, the shunt ratio of the main correction current Ib and the sub correction current Ic is adjusted.

According to the second embodiment, the diode group 15
By adjusting the series number of a and the resistance value of the resistor R, the intensity of the deflection magnetic field generated by the main correction coils 3a and 3b, the intensity of the deflection magnetic field generated by the sub correction coils 3e and 3f, and the period thereof Can be adjusted, so that a more accurate frame error correction can be performed.

Embodiment 3 FIG. FIG. 6 is a circuit diagram of Embodiment 3 of the present invention. The same reference numerals as those in FIG. 4 denote the same or corresponding parts, respectively. Reference numeral 15b denotes a series connection of three diodes connected in parallel with opposite polarities. , And operates in the same manner as in the second embodiment, and the same effects are obtained.

In each of the above embodiments, the U-shaped magnetic pole 2
The frame error correction device in which the main correction coils 3a and 3b and the sub correction coils 3e and 3f are wound around a and 2b is shown.
The same can be applied to the frame error correction device shown in FIG. 14, and the same effect can be obtained.

[0025]

According to the present invention, an in-line type electron gun is provided.
Arranged so as to sandwich the neck of a color cathode ray tube having
And a pair of electromagnets.
By the deflection yoke attached to the color cathode ray tube
Coma generating a deflecting magnetic field to correct the coma error that occurs
In the error correction device, a coil forming the pair of electromagnets
The main compensation coil circuit consisting of the main compensation coil
Connected in parallel with the main correction coil of the correction coil circuit,
A supplement having an L / R value greater than the L / R value of the positive coil
An anti-parallel connection connected in series with the positive coil and the secondary correction coil
And a sub-compensation coil circuit consisting of a series of diodes.
Since the L / R values of the two correction coils and the rising voltage of the diode group are adjusted, the magnitude and pattern of the coma error correction magnetic field generated by the coma error correction device can be adjusted. Tona
Thus, there is an effect that a frame error correction device capable of performing highly accurate correction can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a circuit diagram of the first embodiment.

FIG. 3 is a current waveform diagram of each part of the first embodiment.

FIG. 4 is a circuit diagram according to a second embodiment of the present invention.

FIG. 5 is a current waveform diagram of each part of the second embodiment.

FIG. 6 is a circuit diagram according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a pincushion type horizontal deflection magnetic field of the self-convergence type deflection yoke.

FIG. 8 is a diagram showing convergence (XH) in the horizontal direction corrected by a pincushion horizontal deflection magnetic field.

FIG. 9 is a diagram showing a barrel-type vertical deflection magnetic field of a conventional self-convergence type deflection yoke.

FIG. 10 is a diagram showing a horizontal deviation (YH) corrected by a barrel type vertical deflection magnetic field.

FIG. 11 is a view showing a coma error of the self-convergence type deflection yoke.

FIG. 12 is a diagram showing a conventional frame error correction device.

FIG. 13 is a circuit diagram of a conventional frame error correction device.

FIG. 14 is a diagram illustrating another conventional frame error correction device.

FIG. 15 is a current waveform diagram of each part of the conventional example.

FIG. 16 is a diagram showing a frame error correction state according to a conventional example.

FIG. 17 is a diagram showing a frame error correction device according to the prior art.

FIG. 18 is a circuit diagram of a prior art.

[Explanation of symbols]

1 frame error correction device, 2a, 2b U-shaped magnetic pole,
3a, 3b main correction coil, 3e, 3f sub correction coil,
4a, 4b electromagnet, 5 neck, 6 vertical deflection coil, 15 diode group, 18a main auxiliary coil circuit,
18b Secondary auxiliary coil circuit.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 29/76

Claims (3)

(57) [Claims] 1. A color cathode-ray tube having an in-line type electron gun, comprising a pair of electromagnets disposed so as to sandwich a neck portion thereof. in coma error correction device for generating a deflection magnetic field for correcting the generated coma error, the coil constituting the pair of electromagnets includes a main correction coil circuit consisting primarily correction coils, connected in parallel to the main correction coil of the main correction coil circuit
L / R larger than the L / R value of the main correction coil
A sub-correction coil having a value and a
Sub-complement consisting of connected anti-parallel connected diodes
A frame characterized by comprising a positive coil circuit
Error correction device. 2. The method according to claim 1, wherein the diode group includes a plurality of diodes connected in series.
Connect several diodes in anti-parallel or anti-parallel
Are connected in series by a plurality of diodes,
Adjust the conduction voltage by adjusting the number of series-parallel diodes
2. The connector according to claim 1, wherein
Ma error correction device. 3. A main correction coil circuit comprising: a main correction coil;
A resistor is connected in series, and the main compensation is performed by the resistor.
Impedance ratio between coil circuit and sub-correction coil circuit
The contractor is configured to be able to adjust
A frame error correction device according to claim 1 or 2.