JPH0436044Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a deflection device used in an in-line color cathode ray tube. The present invention relates to a deflection device that corrects convergence deviation.

<Prior art> By having a pair of horizontal deflection coils and a pair of vertical deflection coils, and changing the circuit impedance of the pair of horizontal deflection coils with the vertical deflection period,
In this type of deflection device that corrects convergence deviation, as a means for differentially changing the circuit impedance of the horizontal deflection coils in the vertical deflection period, as shown in FIG. Horizontal auxiliary coils 1, 1' and 2, 2' connected in series with the ferrite core 3 are wound on the ferrite core 3, and
A pair of vertical deflection coils 9 above 1' and 2,2'
Vertical auxiliary coil 1 connected in series with and 9′
4, 14' and 15, 15' are wound respectively,
A magnet 4 is disposed to apply a magnetic bias to this to form an erodible sum reactor, and a vertical deflection current is passed through the vertical auxiliary coils 14, 14' and 15, 15'.
By changing the impedance of 1' and 2, 2' in the vertical deflection period, the magnitude of the horizontal deflection current flowing through the horizontal deflection coils 8 and 8' is differentially changed. In addition, as another means, as shown in FIG. In addition to being connected in series with the horizontal deflection coils 8 and 8', these horizontal auxiliary coils 1, 1' and 2, 2' are arranged in close proximity to the annular core 13 of the deflection device, and the vertical deflection emitted from the annular core 13 is By using the deflection magnetic flux to change the impedance of the horizontal auxiliary coils 1, 1' and 2, 2' in the vertical deflection period, the horizontal deflection coils 8 and 8'
The magnitude of the horizontal deflection current flowing through the wafer was differentially changed.

<Problem to be solved by the invention> However, in the conventional deflection device described above, in the former case, in order to change the circuit impedance of the horizontal deflection coil with the vertical deflection period, the vertical deflection device corresponding to each horizontal auxiliary coil is In addition to requiring an auxiliary coil, in order to wind the horizontal auxiliary coil and vertical auxiliary coil, which have a large potential difference, on the same ferrite core, it is necessary to provide sufficient insulation between the two coils, so the ferrite core is In addition, it is necessary to take measures similar to the latter to deal with the unbalanced cross misconvergence at the top and bottom of the screen (Figure 3), which is mentioned in the latter. It had the following drawbacks. In addition, in the case of the latter method, the impedance of the horizontal auxiliary coil is changed in the vertical deflection period by using the vertical deflection magnetic flux emitted from the annular core of the deflection device, so the vertical auxiliary coil required in the former method is However, the size of the vertical deflection magnetic flux emitted from the annular core of the deflection device is automatically determined by the screen size of the cathode ray tube used. Therefore, there is a limit to the amount of change in the circuit impedance of the horizontal deflection coil that changes with the vertical deflection period, in other words, there is a limit to the amount of change in the horizontal deflection current, which has a major drawback in that it imposes large restrictions on correction of convergence deviation. In particular, with conventional deflection devices, even if the trilemma could be corrected to almost zero, a screen such as the one shown in Figure 3 with positive cross-misconvergence at the top and negative cross-misconvergence at the bottom of the screen. It has been difficult to correct the unbalanced convergence shift between the top and bottom. Conventionally, in order to correct this kind of convergence shift, magnetic material pieces made of permalloy or the like are attached to the deflection yoke and the cathode ray tube, so that the magnetic field distribution that tends to pink at the top of the screen is directed toward the barrel, and the magnetic field distribution at the bottom of the screen is shifted toward the barrel direction. Measures have been taken to change the barrel-oriented magnetic field distribution toward the pink tension direction. However, this means needs to be performed for each combination of a deflection yoke and a cathode ray tube, and the correction requires experience, is extremely time consuming, and is extremely inefficient.

<Means for Solving the Problems> The present invention is capable of correcting the various drawbacks of the conventional deflection device described above, especially the unbalanced convergence shift at the top and bottom of the screen as shown in FIG. This is intended to provide a small-sized deflection device, in which a pair of set coils each connected in series with a pair of horizontal deflection coils and given a magnetic bias by a magnet are stored in an insulating case, and A coil unit is formed by winding a coil for generating a magnetic flux that changes with the vertical deflection period, and the coil for generating the vertical deflection magnetic flux has diodes arranged in parallel with opposite polarities. connected in parallel with a current control circuit in which a variable resistor is connected in series to each of the diodes, and connected in series with the pair of vertical deflection coils so that the current flows to the vertical deflection magnetic flux generating coil. By freely controlling the current using the current control circuit,
The horizontal deflection magnetic field distribution in the upper half and lower half of the screen can be controlled independently.

<Operation and Embodiments> The present invention will be described below with reference to the embodiments shown in FIGS. 1 and 2. Fig. 1 shows an embodiment of the deflection device according to the present invention; Fig. 1a is an external side view of the deflection device, Fig. 2b is a circuit diagram of the deflection coil, and Fig. 2 is a cross section of the coil unit of the present invention. FIG. In the figure, coils 1 and 1' are horizontal auxiliary coils connected in series with the upper horizontal deflection coil 8, and coils 2 and 2' are connected in series with the lower horizontal deflection coil 8'. The upper horizontal auxiliary coils 1 and 1' are connected in series so that their magnetic directions are opposite to each other. The side horizontal auxiliary coils 2 and 2' are connected in the same way. the horizontal auxiliary coils 1, 1' and 2;
A magnet 4 for applying a magnetic bias is disposed at each of the terminals 2'. Horizontal auxiliary coils 1 and 1' and 2 and 2' formed in this way
The upper horizontal auxiliary coils 1 and 1' are placed almost parallel to each other,
Similarly, lower horizontal auxiliary coils 2 and 2' are arranged almost parallel, and upper horizontal auxiliary coils 1 and 1',
Each of the drum-shaped ferrite cores 3 of the lower horizontal auxiliary coils 2 and 2' is arranged such that the collar surfaces on one side thereof face each other and housed in an insulating case 6. On the outer periphery of the insulating case 6 in which the horizontal auxiliary coils 1, 1' and 2, 2' are housed, a coil is wound to form a coil unit for generating a magnetic flux that changes with the vertical deflection period. In order to control the current flowing through the coil 5,
A current control circuit 10 in which diodes are connected in parallel with opposite polarities and a variable resistor is connected in series to each diode is connected in parallel, and a pair of vertical deflection coils 9 and 9' are connected in parallel. connected in series. The feature of the present invention is that the current flowing through the coil 5 is controlled by a diode so as to correct the unbalanced convergence shift at the top and bottom of the screen, which was difficult to correct conventionally as shown in FIG. 11 and 11' and variable resistors 12 and 12', it is possible to control the magnitude of the magnetic flux that changes with the vertical deflection period generated from the coil 5, thereby controlling the vertical deflection. By shaping the magnetic field distribution so that when the screen is deflected upward, the magnetic field distribution tends to be pink at the top of the screen, and when the screen is deflected downward, the magnetic field distribution, which tends to barrel at the bottom of the screen, is shaped toward the pink tension. be. Figure 1b is
FIG. 2 is a circuit diagram of a deflection coil showing such an embodiment;
A series circuit consisting of a diode 11 and a variable resistor 12 is a circuit for controlling the current flowing through the vertical deflection magnetic flux generating coil 5 when the screen is deflected to the upper side.
When the voltage across the coil 5 exceeds the forward voltage of the diode 11, a current Iс begins to flow through the diode 11, but the current Id flowing through the diode 11 can be freely controlled by adjusting the resistance value of the variable resistor 12. be done. Further, the series circuit consisting of the diode 11' and the variable resistor 12' is a circuit for controlling the current flowing through the coil 5 when the screen is deflected toward the bottom side, and the voltage across the coil 5 is controlled as in the case when the screen is deflected toward the top side. When exceeds the forward voltage of diode 11', diode 11' becomes conductive and the diode current
However, by adjusting the resistance value of the variable resistor 12', the current Id' of the diode 11' can be freely controlled. In this way, the current flowing through the coil 5 when the screen is deflected upward and downward can be controlled independently and arbitrarily, so that it is possible to flow a current through the coil 5 as shown by the broken line in FIG. 4a. By passing such a current through the coil 5, the vertical deflection magnetic flux applied to the horizontal auxiliary coils 11' and 22' increases when the screen is deflected to the upper side, and decreases when the screen is deflected to the lower side, so that the circuit of the upper horizontal deflection coil The inductance L _T and the circuit inductance L _B of the lower horizontal deflection coil change as shown by the broken line in Figure 4b, and when the screen is deflected to the upper side, the circuit inductance L _T and L _B of the upper and lower horizontal deflection coils change. The difference becomes even larger, and when deflecting to the bottom of the screen, the difference changes to become smaller. Therefore, the magnetic field distribution with a pink tension tendency on the top side of the screen is transformed into the barrel direction, and the magnetic field distribution with a barrel tendency on the bottom side of the screen is transformed into the pink tension direction. Since the desired magnetic field distribution can be obtained arbitrarily, the unbalanced convergence shift at the top and bottom of the screen as shown in FIG. 3 can also be corrected.

<Effect of the invention> As described above, the deflection device according to the invention is provided with a coil for generating a magnetic flux that changes with the vertical deflection period, and in order to control the current flowing through the coil, the polarity of the diodes is set in opposite directions. By providing a current control circuit in which the diodes are connected in parallel and a variable resistor is connected in series, the upper half of the screen and the screen can be adjusted by simply adjusting the resistance value of the variable resistor in the current control circuit. It is now possible to independently and arbitrarily control the vertical deflection magnetic flux for each lower half, making it possible to extremely easily and efficiently correct complex convergence deviations that were difficult to correct in the past. .
Furthermore, each horizontal auxiliary coil is housed in one insulating case, and the vertical deflection magnetic flux generating coil is wound on the outer periphery of this insulating case and integrated as a coil unit. The withstand voltage has improved, making it possible to downsize.

[Brief explanation of the drawing]

FIG. 1 shows a deflection device according to the present invention, FIG. 1a shows a side view of the deflection device, FIG. 1b shows a circuit diagram of a deflection coil, and FIG. FIG. 3 is a state diagram of convergence deviation, FIG. 4a shows the current flowing through the vertical deflection magnetic flux generating coil, and FIG. Figures 5 and 6, which show changes in the circuit inductance of the deflection coil, show examples of conventional deflection devices, and Figure 5a shows a cross-sectional side view of a coil in which a horizontal auxiliary coil and a vertical auxiliary coil are wound around a magnetic core. Figure, same figure b
6A is a plan view of another conventional deflection device, and FIG. 6B is a circuit diagram of the horizontal deflection coil. 1, 1'...Paired coil (upper horizontal auxiliary coil),
2, 2'...Paired coil (lower horizontal auxiliary coil), 3
...Magnetic core, 4...Magnet, 5...Vertical deflection magnetic flux generating coil, 6...Insulation case, 7...Coil unit, 8...Upper horizontal deflection coil, 8'...
Lower horizontal deflection coil, 9, 9'... Vertical deflection coil, 10... Current control circuit, 11, 11'... Diode, 12, 12'... Variable resistor, 13...
...Annular core of the deflection device.

Claims (1)

[Scope of utility model registration request] In a color picture tube deflection device that includes a pair of horizontal deflection coils and a pair of vertical deflection coils, the two coils are wound around a magnetic core and given a magnetic bias by a magnet, so that the magnetic directions are opposite to each other. A pair of assembled coils connected in series such that The coil is connected in series with each of the pair of horizontal deflection coils, and the coil for generating the vertical deflection magnetic flux is connected in parallel with the diodes with polarities opposite to each other, and is connected in series with each of the diodes. A deflection device characterized in that the deflection device is connected in parallel with a current control circuit connected to a variable resistor and in series with the pair of vertical deflection coils.