JP2919822B2 - Display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device having a horizontal deflection circuit capable of responding to input signals having different horizontal frequencies. 2. Description of the Related Art In a horizontal deflection circuit used in general televisions and displays, linearity correction is performed to improve horizontal linearity. FIG. 2 is a circuit diagram of a conventional horizontal deflection circuit that performs linearity correction using a linearity coil. In FIG. 2, 1 is a horizontal synchronization signal input terminal, 2 is a horizontal oscillation circuit, 3 is a horizontal deflection drive circuit, 4 is a horizontal output transistor, 5 is a damper diode, 6 is a resonance capacitor, 7 is a horizontal deflection coil, and 8 is a horizontal deflection coil. Linearity coil, 9 is an S-shaped capacitor, 1
0 is a choke coil (or primary winding of a flyback transformer), and 11 is a power supply terminal. [0003] Using the horizontal deflection circuit shown in FIG.
In order to display an image signal having a different horizontal deflection frequency while keeping the screen size and brightness constant, the current voltage E is adjusted so that the amplitude of the horizontal deflection current becomes constant in accordance with the change in the horizontal deflection frequency. _B can be adjusted automatically. A related art using a saturable reactor is disclosed in Japanese Patent Application Laid-Open No. 58-157260. [0004] However, such a conventional technique has a problem that the horizontal linearity changes with the change of the horizontal deflection frequency. Hereinafter, the cause of such a phenomenon will be described. FIG. 3 shows an equivalent circuit of a horizontal deflection output circuit during a scanning period. In FIG. 3, reference numeral 12 denotes a horizontal deflection coil, 13 denotes an internal resistance (determined by the resistance of the horizontal deflection coil, the on-resistance of an output transistor, a damper diode, and the like), 14 denotes a switch, and 15 denotes a power supply. In the circuit shown in FIG. 3, at time t = 0, switch 1
4, when closed, the current i ₀ flowing in this circuit can be expressed as a function of time t by: [0006] In the equation (1), E is a power supply voltage of the power supply 15, R is a resistance value of the internal resistor 13, and τ is a time constant. From the internal resistance R and the inductance L of the horizontal deflection coil 12, Equation 2 Can be expressed as Therefore, the current i ₀ has a waveform as shown by the dotted line in FIG. On the other hand, when the internal resistance R = 0 (ideal horizontal deflection circuit without deteriorating the horizontal linearity), the current i ₁ flowing through the circuit shown in FIG. [Equation 3] And the waveform is as shown by the solid line in FIG. Therefore, when the scanning period is T _HD , the maximum amplitude I _DY of the ideal horizontal deflection current when the internal resistance R exists and the maximum amplitude I ₁ of the ideal horizontal deflection current when the internal resistance R = 0 are equal to: It can be expressed by the following equation. ## EQU4 ## On the other hand, the horizontal linearity on the screen can be obtained by displaying vertical lines on the screen and calculating the difference between the average interval between the vertical lines and the interval between each vertical line. But,
Here, for convenience, the index LIN indicating the deterioration of the horizontal linearity is given by: Is defined. The index LIN is a value indicating how much the horizontal deflection current decreases when the internal resistance R is present with respect to the ideal horizontal deflection current when the internal resistance R = 0. %, And the lower the horizontal linearity, the larger the numerical value. By substituting equations (4) and (5) into equation (6), the index LIN can be expressed as follows. [Equation 6] From equation (7), it can be seen that the index LIN is determined by the scanning period T _HD , the inductance L of the horizontal deflection coil, and the internal resistance R. Next, FIG. 5 shows a calculation result of how the index LIN changes when the horizontal deflection frequency changes. In this calculation, the resolution is 1000 × 100
For a horizontal deflection coil (inductance L = 120 μH) for non-interlaced color display of about 0 dots, internal resistance R = 1.0Ω, horizontal deflection frequency f _H
= 64 KHz. From the calculation results shown in FIG. 5, when the same horizontal deflection coil is used to vary the power supply voltage to display image signals having different horizontal deflection frequencies, the lower horizontal deflection frequency has It can be seen that the horizontal linearity deteriorates. On the other hand, when the conventional horizontal deflection circuit shown in FIG. 2 is used, the adjustment of the horizontal linearity is performed using the linearity coil 8. The correction amount of the horizontal linearity by the linearity coil 8 is adjusted optimally at a single frequency. Therefore, as described above, as the horizontal deflection frequency changes,
There is a problem that the horizontal linearity changes asymmetrically on the left and right. On the other hand, as a conventional technique for correcting horizontal linearity, a method using a saturable reactor is known as disclosed in Japanese Patent Application Laid-Open No. 58-157260, but it follows changes in the horizontal deflection frequency. Thus, it was not considered until the horizontal linearity was optimally adjusted. An object of the present invention is to provide a display device having a horizontal deflection circuit capable of following a change in the horizontal deflection frequency, wherein the linearity of the horizontal deflection characteristic of the horizontal deflection circuit is changed when the horizontal deflection frequency changes. in keeping the horizontal linearity in a good good to correct the deterioration in the lateral asymmetry due to component. According to the present invention, there is provided a display apparatus having a horizontal deflection circuit capable of responding to input signals having different horizontal deflection frequencies.
The horizontal deflection circuit includes a horizontal deflection coil and the horizontal deflection coil.
To correct the linearity of the horizontal deflection current.
Linearity correction means including coil means for
And the coil means has a horizontal deflection frequency of the first frequency.
The current flowing through the coil means changes from negative to positive.
The first characteristic is that the inductance decreases as
The second deflection, where the horizontal deflection frequency is higher than the first frequency.
At a wave number, the current flowing through the coil means is changed from negative to positive.
The inductance decreases as
The decrease in the conductance is smaller than the first characteristic.
2 and the input of the first characteristic and the second characteristic is
Is the difference in conductance negative for the current flowing through the coil means?
It was made to decrease as it became positive . Further, according to the present invention, in the display device, the second frequency is substantially twice as large as the first frequency. (Operation) The correction signal supply means outputs a correction signal according to the horizontal deflection frequency. The correction signal supply means includes a frequency-voltage conversion circuit, which detects a change in the horizontal deflection frequency and outputs a voltage corresponding to the horizontal deflection frequency as a correction signal. The linearity correction means changes a linearity correction amount of the horizontal deflection current based on the correction signal. Further, when the horizontal deflection frequency is high, the correction signal supply means outputs a correction signal so as to reduce the variable range of the inductance of the linearity coil, and reduces the correction amount of the horizontal linearity. When the horizontal deflection frequency is low, the correction signal supply means outputs a correction signal so as to increase the variable range of the inductance of the linearity coil, and increases the correction amount of the horizontal linearity. Therefore, in response to changes in the horizontal deflection frequency, it is possible to keep the horizontal linearity goodness good. Embodiments of the present invention will be described below with reference to the drawings. In each figure, those that perform the same function are:
Show the same numbers. FIG. 1 is a principle diagram of a horizontal deflection circuit showing a first embodiment of the present invention. In this circuit,
Compared with the conventional horizontal deflection circuit shown in FIG. 2, a correction signal supply circuit 61 including a correction signal generation circuit 16 and a correction signal output circuit 17 and a control winding 21 which is transformer-coupled to the linearity coil 8 are provided. The point provided is different. In the circuit shown in FIG. 1, the correction signal generating circuit 16 responds to a change in the horizontal deflection frequency by
The generated correction signal is changed, and the correction signal output circuit 17 supplies a control current to the control winding 21 based on the correction signal generated by the correction signal generation circuit 16. And
The variable range of the inductance of the linearity coil 8 is changed by the control current flowing through the control winding 21. With this function, the correction amount of the horizontal linearity is changed in accordance with the change in the horizontal deflection frequency, so that good horizontal linearity is always maintained. Next, a specific circuit of the horizontal deflection output circuit 18 surrounded by a dotted line in FIG. 1 will be described. FIG.
FIG. 3 is a circuit diagram of a first specific circuit of a horizontal deflection output circuit 18 in the middle. In this circuit, 21 is a control winding that is transformer-coupled to the linearity coil 8, 22 is a diode,
23 is a capacitor, 24 is a resistor, 25 is a transistor,
Reference numeral 26 denotes a frequency-voltage conversion circuit (hereinafter, referred to as an FV converter). The operation of the circuit shown in FIG. 6 will now be described with reference to FIG. 2 in comparison with a conventional horizontal deflection circuit. First, in the conventional horizontal deflection circuit shown in FIG. 2, when the horizontal deflection current I _DY flows through the damper diode 5, the inductance of the linearity coil 8 increases, and the horizontal deflection current I _DY increases.
_{When DY} flows through the output transistor 4, the inductance is small. The variable range of the inductance is constant even when the horizontal deflection frequency changes. On the other hand, in the circuit shown in FIG. 6, the variable range of the inductance of the linearity coil 8 is increased or decreased by controlling the current flowing through the control winding 21. Specifically, if the current flowing through the control winding 21 is increased, the variable range of the inductance of the linearity coil 8 is reduced. Conversely, if the current flowing through the control winding 21 is reduced, the variable range of the inductance of the linearity coil 8 is widened. According to this principle, in the circuit shown in FIG. 6, a change in the horizontal deflection frequency is detected by the FV converter 26, and the collector current of the transistor 25 is controlled based on the output voltage of the FV converter 26. Therefore, by the operation of the transistor 25,
The value of the control current I _a flowing through the control winding 21 is varied. For example, when the horizontal deflection frequency is high, F-
If the output voltage of the V converter 26 is set to be high, the control current Ia flowing through the control winding 21 at this time (when the horizontal deflection frequency is high) increases. Therefore, the variable range of the inductance of the linearity coil 8 becomes narrow, and the correction amount of the horizontal linearity is small. Conversely, when the horizontal deflection frequency low, the output voltage of the F-V converter 26 becomes lower, the control current I _a flowing through the control winding 21 is small, the variable range of the inductance of the linearity coil 8 becomes wider, horizontal linearity Is large. FIG. 10 is a diagram showing the DC superposition characteristics of the linearity coil 8 in the circuit diagram shown in FIG. In addition,
DC bias characteristics of the linearity coil 8 is a value designed by the horizontal deflection frequency f _H for a compatible horizontal deflection circuit to 32KHz～64KHz. If this in the figure, the dotted line shows the DC superposition characteristics when high horizontal deflection frequency (f _H = 64KHz), the solid line is low horizontal deflection frequency f _H (f _H =
32 KHz). In the circuit shown in FIG. 6, as shown in FIG.
In response to _H change of changing the variable range of the inductance L ₁ of the linearity coil 8, thereby increasing or decreasing the amount of correction of the horizontal linearity. Therefore, in the circuit shown in FIG. 6, even when the horizontal deflection frequency changes, the horizontal linearity can always be kept good correspondingly. FIG. 7 is a circuit diagram of a second specific circuit of the horizontal deflection output circuit 18 surrounded by a dotted line in FIG. In this figure, 27 is a photocoupler, 28 is a transistor,
29 is a resistor. In the circuit shown in FIG. 7, the control current I _a flowing through the control winding 21 is controlled by a photocoupler 27. Also in this case, similar to the circuit shown in FIG.
The correction amount of the horizontal linearity is changed in accordance with the change in the horizontal deflection frequency, and the horizontal linearity can always be kept good. FIG. 8 is a circuit diagram of a third specific circuit of the horizontal deflection output circuit 18 surrounded by a dotted line in FIG. In this figure, 30 is a capacitor, 31 is a variable resistor, and 32 is a resistor. In the circuit shown in FIG. 8, instead of directly detecting the horizontal deflection frequency by F-V converter, it detects the power supply voltage E _B which varies in response to the horizontal deflection frequency, and a correction signal. Even when this circuit is used, similarly to the circuit shown in FIG. 6, the correction amount of the horizontal linearity is changed in accordance with the change in the horizontal deflection frequency, and the horizontal linearity can always be kept good. FIG. 9 is a circuit diagram of a fourth specific circuit of the horizontal deflection output circuit 18 surrounded by a dotted line in FIG. In this figure, 33 is an operational amplifier, and 34, 35, 37, 38
Is a resistor, and 36 is a capacitor. In the circuit shown in FIG. 9, a change in the horizontal deflection frequency is detected by a voltage generated in the S-shaped capacitor 9. However, since the voltage generated in the S-shaped capacitor 9 has a parabolic waveform, the AC component is removed by a low-pass filter including the operational amplifier 33, the resistors 34, 35, 37, 38, and the capacitor 36. Even when the circuit shown in FIG. 6D is used, similarly to the circuit shown in FIG. 6, the correction amount of the horizontal linearity is changed according to the change in the horizontal deflection frequency.
Horizontal linearity can always be kept good. FIG. 11 is a principle diagram of a horizontal deflection circuit showing a second embodiment of the present invention. 11, 39 is a horizontal blanking signal input terminal, 40 is a deflection yoke, 41
Is an auxiliary coil. Hereinafter, the operation of the circuit shown in FIG. 11 will be described. This circuit uses the auxiliary coil 41 when correcting the horizontal linearity. The feature of this circuit resides in that the correction current i _G waveform supplied to the auxiliary coil 41 is changed according to the horizontal deflection frequency to increase or decrease the correction amount of the horizontal linearity. Then, the above correction current i
_G is supplied from the correction signal supply circuit 61. FIG. 12 is a circuit diagram of a specific circuit of the correction signal supply circuit 61. In FIG. 12, 45 is an input terminal, 46 is an output terminal, 49, 53, 54, 58 are transistors,
8, 56 are capacitors, 47, 50, 51, 52, 5
5 and 57 are resistors. The circuit shown in FIG. 12 includes an inverting amplifier circuit including a transistor 49 and a resistor 50, a transistor 53, a transistor 54, a resistor 51, and a
2, a constant current circuit including a resistor 55, a transistor 58,
It comprises a voltage-current conversion circuit comprising a resistor 57. The circuit shown in FIG. 12 inverts and amplifies the horizontal blanking signal input from the input terminal 45 by the inverting amplifier circuit, and then uses the constant current circuit and the capacitor 56 to
It produces a sawtooth wave voltage. And the voltage-
After being converted into a sawtooth current by the current exchange circuit, the current is supplied from the output terminal 46 to the auxiliary coil 41 in FIG. An advantage of the circuit shown in FIG. 12 is that the amplitude of the sawtooth wave generated by the frequency of the horizontal blanking signal input from the input terminal 45 changes. FIG. 13 shows the waveforms of the voltage V ₄₅ , the voltage V ₄₉ and the current i _G in FIG. In this FIG.
(A), (b) and (c) show the case where the horizontal deflection frequency is 6 KHz, and (d), (e) and (f) show the case where the horizontal deflection frequency is 32 KHz. In FIG.
The amplitude of the correction current i _G when the horizontal deflection frequency is 64 KHz is I
_G1, when the horizontal deflection frequency the amplitude of the correction current i _G when the 32KHz and I _G2, I _G2 ≒ 2I _G1 is established. This is because the capacitor 56 is charged with a constant current when the sawtooth wave is generated in FIG. Therefore,
By using the circuit shown in FIG. 11, when the horizontal deflection frequency changes from 64 KHz to 32 KHz, the correction amount of the horizontal linearity increases about twice. On the other hand, from FIG. 5, the horizontal deflection frequency f _H = 3
The horizontal linearity at 2 KHz is the horizontal deflection frequency f _H
It can be seen that the horizontal linearity is about twice worse than in the case of = 64 KHz. Therefore, by using the circuit shown in FIG. 11, the horizontal linearity is changed to the horizontal deflection frequency f _H = 32 KH.
z or the horizontal deflection frequency f _H = 64 KHz, the horizontal deflection frequency f
Even in the case of _H = 32KHz, even when the horizontal deflection frequency f _H = 64 KHz, can be horizontal linearity kept always good. FIG. 14 is a principle diagram of a horizontal deflection circuit according to a third embodiment of the present invention. Hereinafter, the operation of the circuit shown in FIG. 14 will be described. In this circuit, a correction signal is superimposed on the S-time capacitor 9 in order to correct horizontal linearity. The feature of this circuit is that the correction signal waveform applied to the S-shaped capacitor 9 is changed in accordance with the horizontal deflection frequency to increase or decrease the correction amount of the horizontal linearity. The correction signal is supplied from the correction signal supply circuit 61. FIG. 15 is a circuit diagram of a specific circuit of the correction signal supply circuit 61. In FIG. 15, the same correction signal generation circuit 16 as the circuit described in the second embodiment (see FIG. 12) is used as a correction signal generation circuit 16 surrounded by a dotted line. The correction signal output circuit 17 includes transistors 62, 66, 68, 69,
Resistors 63, 64, 65, 70, 71, capacitors 67,
An amplifying circuit composed of 72 is used. This amplifier circuit functions to amplify the correction signal generated by the correction signal generation circuit 16 and drive the S-shaped capacitor 9 in FIG. By using the circuit shown in FIG.
The correction amount of the horizontal linearity is increased / decreased in accordance with the change in the horizontal deflection frequency, so that the horizontal linearity can always be kept good. FIG. 16 is a principle diagram of a horizontal deflection circuit according to a fourth embodiment of the present invention. The circuit shown in FIG.
11 in that the correction signal generation circuit 16 includes a sawtooth wave generation circuit 43 and an integration circuit 74. FIG. 17 is a circuit diagram of a specific circuit of the correction signal supply circuit 61 in FIG. FIG.
7, the sawtooth wave generation circuit 43 is different from the sawtooth wave generation circuit (correction signal generation circuit 16) in FIG.
FV converter 26, transistor 75, resistor 76,
The difference is that 77 is added. Integration circuit 74
Are transistors 78, 82, resistors 79, 80, 83,
It comprises a capacitor 81 and a diode 80 '. This integration circuit 74 is basically a circuit for performing integration by a resistor 80 and a capacitor 81. However, in order to eliminate the influence of the preceding and subsequent stages, transistors 78 and 82 and a resistor 7 are used.
9, 83 are used for impedance conversion. Further, the correction signal output circuit 17 uses the same voltage-current conversion as the circuit shown in FIG. Hereinafter, the effect obtained when the horizontal deflection circuit shown in FIG. 16 is used will be described in comparison with the case where the horizontal deflection circuit shown in FIG. 11 is used. In the second embodiment shown in FIG. 11, a sawtooth wave is approximately used as a waveform of a correction current i _G flowing through the correction coil 41 to correct horizontal linearity. However, the ideal correction current i _G0 waveform is slightly different from a complete sawtooth waveform. Here, when the ideal correction current i _G0 is obtained from the equivalent circuit shown in FIG. 3, from the difference between the equations (3) and (1), the following equation is obtained. Becomes This ideal correction current i _G0 waveform has a waveform shown by a dotted line in FIG. In order to supply the ideal correction current i _G0 to the auxiliary coil 41, the correction signal supply circuit 61 shown in FIG. Hereinafter, the operation of the correction signal supply circuit 61 shown in FIG. 17 will be described. In the circuit shown in FIG. 17, in the sawtooth wave generation circuit 43, the transistor 53,
A sawtooth wave voltage whose slope (I ₀ / C ₀ ) is determined by the constant current I ₀ flowing through the resistor 55 and the capacitor 56 (capacitance C ₀ ) is created. Then, in the subsequent integration circuit 74,
The sawtooth wave voltage generated by the sawtooth wave generating circuit 43 is integrated based on a time constant τ ′ = C ₁ R ₁ determined by the resistor 8 (resistance value R ₁ ) and the capacitor 81 (capacitance C ₁ ). However,
When falling of the sawtooth voltage is accelerated charging of the capacitor C ₁ with a diode 80 'for high speed is required. The correction current i _G ′ supplied by the correction signal supply circuit 61 can be expressed by the following equation. Equation 8 Therefore, in equations (8) and (9), i _G0 = i _G
By selecting each constant so as to satisfy, an ideal corrected current waveform can be obtained. (Equation 9) When the horizontal deflection frequency changes, the current voltage E needs to be changed in proportion to the horizontal deflection frequency in order to keep the horizontal deflection current constant. In the correction signal supply circuit 61 shown in FIG. 17, the value of the current I ₀ is automatically adjusted according to the horizontal deflection frequency so that the expression (10) always holds in this case. This is performed by controlling the base voltage V ₀ of the transistor 53 by the FV converter 26, the transistor 75, and the resistors 76 and 77 in FIG. Based on the above operation, when the correction signal supply circuit 61 shown in FIG. 16 is used, an ideal correction signal waveform can always be supplied to the auxiliary coil regardless of a change in the horizontal deflection frequency. The horizontal linearity can be kept optimal. Further, in the embodiment shown in FIG. 3 (FIG. 11), the correction signal generating circuit 16 may be constituted by a sawtooth wave generating circuit 43 and an integrating circuit 74. The fourth embodiment of the present invention (FIG. 13)
Similar effects can be obtained by using a multiplication circuit instead of the integration circuit 74 described in the fifth embodiment (FIG. 16). The display device of the present invention includes a horizontal deflection circuit capable of responding to input signals having different horizontal frequencies, and the horizontal deflection circuit outputs a correction signal according to the horizontal deflection frequency. Since there is provided a linearity correction means for changing the linearity correction amount of the supply means and the horizontal deflection current, and the correction amount of the horizontal linearity correction means is changed according to the change of the horizontal deflection frequency,
When the horizontal deflection frequency changes, the deterioration of the linearity of the horizontal deflection characteristic caused by the resistance component of the horizontal deflection circuit can be corrected. Further, since the linearity correction means is provided with a transistor to which the output current of the correction signal supply means is input as a base current and the collector current controls the correction amount, the linearity correction range is increased when the horizontal deflection frequency is high. The correction signal is output so as to reduce it, and the correction signal is output so as to increase the linearity correction range when the horizontal deflection frequency is low. This can correct the deterioration of the linearity of the horizontal deflection characteristic that occurs. [0054] Therefore, there is an effect that can keep <br/> horizontal linearity in a good good response to changes in the horizontal deflection frequency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a principle diagram of a circuit showing a first embodiment of the present invention. FIG. 2 is a circuit diagram of a conventional horizontal deflection circuit. FIG. 3 is a circuit diagram showing an equivalent circuit of a horizontal deflection polarization output circuit. FIG. 4 is a waveform diagram of a horizontal deflection current. FIG. 5 is a characteristic diagram showing a relationship between horizontal deflection frequency and horizontal linearity. FIG. 6 is a circuit diagram of a specific circuit according to the first embodiment of the present invention. FIG. 7 is a circuit diagram of a specific circuit according to the first embodiment of the present invention. FIG. 8 is a circuit diagram of a specific circuit according to the first embodiment of the present invention. FIG. 9 is a circuit diagram of a specific circuit according to the first embodiment of the present invention. FIG. 10 is a characteristic diagram showing a DC superposition characteristic of a linearity coil. FIG. 11 is a principle diagram of a circuit showing a second embodiment of the present invention. 12 is a circuit diagram of a specific circuit of the correction signal supply circuit 61 in FIG. FIG. 13 is a waveform chart showing signal waveforms at various parts of the circuit shown in FIG. 12; FIG. 14 is a principle diagram of a circuit showing a third embodiment of the present invention. 15 is a circuit diagram of a specific circuit of the correction signal supply circuit 61 in FIG. FIG. 16 is a principle diagram of a circuit showing a fourth embodiment of the present invention. 17 is a circuit diagram of a specific circuit of the correction signal supply circuit 61 in FIG. FIG. 18 is a waveform chart showing a correction current waveform. [Description of Signs] 8 Linearity 16 Correction signal generation circuit 17 Correction signal output circuit 21 Control winding 26 FV converter 41 Auxiliary coil 43 Sawtooth wave generation circuit 61 Correction signal supply circuit 74 Integration circuit

Continued on the front page (72) Inventor Hitoshi Maekawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi, Ltd. Home Appliances Research Laboratories (72) Koji Kito 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. (56) References JP-A-57-166778 (JP, A) JP-A-58-157260 (JP, A) JP-A-61-206371 (JP, A) Jpn. (Japanese Patent Publication No. 59-48593 (JP, B2)) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 3/23 G09G 1/00 G09G 1/16 H04N 3/27

Claims (1)

(57) [Claims] In a display device provided with a horizontal deflection circuit capable of responding to input signals having different horizontal deflection frequencies, the horizontal deflection circuit includes a horizontal deflection coil and the horizontal deflection coil.
To correct the linearity of the horizontal deflection current.
Linearity correction means including coil means for
And Bei, said coil means, bets horizontal deflection frequency of the first frequency
When the current flowing through the coil means changes from negative to positive,
The first characteristic is that the inductance is reduced.
The second frequency having a deflection frequency higher than the first frequency
The current flowing through the coil means changes from negative to positive
Therefore, the inductance decreases and the inductor
A second characteristic in which the decrease width of the capacitance is smaller than the first characteristic.
Next, the difference in inductance between the first characteristic and the second characteristic
However, when the current flowing through the coil means changes from negative to positive,
A display device characterized in that the display device is reduced by: