JP2000333034A - Horizontal deflection circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress a power supply voltage even when a high horizontal frequency is employed and to effectively prevent a peak level of a pulse voltage obtained across a resonance capacitor for a horizontal blanking period from being increased. SOLUTION: The horizontal deflection circuit is provided with a series connection of a choke coil 12 connected between both terminals of a power supply, and of 1st switch sections 13, 14 that are on/off-controlled by a horizontal drive signal synchronously with a horizontal synchronizing signal to set a horizontal fly-back period and a horizontal scanning period, a 1st resonance capacitor 15 that is connected in parallel with the 1st switch sections 13, 14, a horizontal deflection coil 16 that is connected in parallel with the 1st switch sections 13, 14, a horizontal deflection coil 16 that is connected in parallel with the 1st switch sections 13, 14, a series connection consisting of a 2nd resonance capacitor 18 and an S-shaped correction capacitor 19, and 2nd switch sections 20, 21 that are substantially connected in parallel with the 2nd resonance capacitor 18 and driven to take an off-state within the horizontal fly-back period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The invention described in the claims of the present application relates to a method of displaying an image according to a video signal using a cathode ray tube for image display. The present invention relates to a horizontal deflection circuit used to cause a directional deflection.

[0002]

2. Description of the Related Art In an image display apparatus for displaying an image in accordance with a video signal using an image display cathode ray tube, for example, in a television receiver, the horizontal and vertical directions of electron beams in the image display cathode ray tube are changed. A horizontal deflection circuit including a horizontal deflection coil and a vertical deflection circuit including a vertical deflection coil are used to cause the deflection of the horizontal deflection coil, and the horizontal deflection coil and the vertical deflection coil are usually combined to form a deflection coil unit. Then, it is engaged with the cathode ray tube for image display. Of such horizontal deflection circuits and vertical deflection circuits used in television receivers and the like, a horizontal deflection circuit including a horizontal deflection coil is basically configured as shown in FIG. 6, for example.

In the basic horizontal deflection circuit shown in FIG. 6, a choke coil 2 and a collector-emitter path of a switching transistor element 3 are formed between both ends of a power supply for supplying a power supply voltage of Vcc. They are connected in series. And, in parallel with the collector-emitter path of the switching transistor element 3, the damper diode element 4, the resonance capacitor 5, and the horizontal deflection coil 6
And the S-shaped correction capacitor 7 are connected in series. The switching transistor element 3 and the damper diode element 4 substantially form one switch unit.

Under these circumstances, a horizontal drive signal DH synchronized with a horizontal synchronizing signal in a video signal used for image display by a cathode ray tube for image display is supplied to the base of the switching transistor element 3, and the switching transistor ON / OFF of the element 3 by the horizontal drive signal DH
Off control is performed. Thereby, the switch section formed by the switching transistor element 3 and the damper diode element 4 is turned off and on according to the horizontal drive signal DH, and the horizontal flyback period and the horizontal scanning period are set. Is set.

FIG. 7A shows the on / off state of the collector-emitter path of the switching transistor element 3, and FIG. 7B shows the on / off state of the damper diode element 4. As shown in FIGS. 7A and 7B, in the horizontal flyback period, both the collector-emitter path of the switching transistor element 3 and the damper diode element 4 are turned off. In the horizontal scanning period, first, The damper diode element 4 is turned on, and then the collector-emitter path of the switching transistor element 3 is turned on.

With the horizontal retrace period and the horizontal scan period set, a horizontal deflection current is supplied to the horizontal deflection coil 6 as a scan current in the horizontal scan period. During the period, the current flows as a retrace current. This horizontal deflection current is passed through the S-correction capacitor 7 throughout the horizontal scanning period and
The waveform has an S-shape over the entire horizontal retrace period. At this time, as shown in FIG. 7C, a voltage in the negative direction is obtained between both ends of the resonance capacitor 5 during the horizontal scanning period, and a relatively high pulse voltage is obtained during the horizontal flyback period. . Then, a voltage as shown in FIG. 7C obtained between both ends of the resonance capacitor 5 is applied between the collector and the emitter of the switching transistor element 3.

As described above, when the horizontal deflection current flows through the horizontal deflection coil 6 as the scanning current and the retrace current, a horizontal deflection magnetic field is formed which extends to the inside of the image display cathode ray tube with which the horizontal deflection coil 6 is engaged. The horizontal deflection magnetic field causes horizontal deflection scanning of the electron beam in the image display cathode ray tube. The width of the horizontal deflection scan of the electron beam in the image display cathode ray tube, that is, the horizontal scan width is determined according to the strength of the horizontal deflection magnetic field, and therefore, the value of the horizontal deflection current flowing through the horizontal deflection coil 6. Is done.

Under these circumstances, the deflection index is used to indicate the strength of the horizontal deflection magnetic field required to obtain a predetermined horizontal scanning width in a cathode ray tube for image display. Assuming that the inductance of the horizontal deflection coil 6 in the horizontal deflection circuit shown in FIG. 6 is Lh and the value of the horizontal deflection current flowing through the horizontal deflection coil 6 is Ih, the deflection index is L
h · Ih ² , that is, the product of the inductance of the horizontal deflection coil 6 and the square of the value of the horizontal deflection current.

In the horizontal deflection circuit shown in FIG. 6 where the power supply voltage value is Vcc, the inductance of the choke coil 2 is L2, the capacitance of the resonance capacitor 5 is C5,
Assuming that the capacitance of the S-shaped correction capacitor 7 is C7, the pulse voltage obtained between both ends of the resonance capacitor 5 in the horizontal retrace period is Tr / 2 = π in the horizontal retrace period, where Tr is the horizontal retrace period. / 2 ・ [｛L2 · Lh
/ (L2 + Lh)} • {C5 • C7 / (C5 + C7)}]
^The peak value Vcp is taken at ^1/2 , and assuming that the horizontal scanning period is Tt, the peak value Vcp is expressed by Expression 1.

[0010]

## EQU1 ## Vcp = Vcc. (1 + .pi. / 2.Tt / Tr)

The peak value Ihp of the horizontal deflection current flowing through the horizontal deflection coil 6 at the end of the horizontal scanning period is expressed by Expression 2.

[0012]

[Equation 2] Ihp = Tt · Vcc / Lh

In an image display device such as a television receiver provided with the horizontal deflection circuit as described above, the horizontal frequency tends to be gradually increased, especially in recent years. The cause is that the horizontal resolution of the image displayed by the image display cathode ray tube is increased, so that a so-called high-resolution image is obtained, and further, the image is displayed by the image display cathode ray tube. The vertical frequency has been increased in order to further suppress flicker-like changes in the image.

When the horizontal frequency is increased, the higher the horizontal frequency is, the shorter the horizontal scanning period Tt and the horizontal retrace period Tr are. On the other hand, the required value of the horizontal scanning width of the electron beam in the image display cathode ray tube is determined by the size of the display surface (front face) of the image display cathode ray tube regardless of the horizontal frequency. . Therefore, when obtaining the peak value Ihp of the horizontal deflection current required to realize the horizontal scanning width required in each image display cathode ray tube, the horizontal deflection coil 6
Assuming that the inductance Lh is constant and the horizontal frequency is increased and the horizontal scanning period Tt is shortened from Equation 2,
The power supply voltage value Vcc is increased.

If the horizontal frequency is increased and the power supply voltage value Vcc is increased, even if Tt / Tr is kept constant, the resonance capacitor 5 in the horizontal flyback period Tr is obtained according to the above equation (1). , The peak value Vcp of the pulse voltage obtained between both ends is increased. The voltage having the peak value Vcp is applied between the collector and the emitter of the switching transistor element 3. Therefore, it is necessary to take care that the peak value Vcp of the pulse voltage obtained between both ends of the resonance capacitor 5 during the horizontal retrace period Tr does not exceed the collector-emitter breakdown voltage of the switching transistor element 3. .

Conventionally, as a measure for preventing the peak value Vcp of the pulse voltage obtained between both ends of the resonance capacitor 5 from exceeding the collector-emitter breakdown voltage of the switching transistor element 3 during the horizontal retrace period Tr,
For example, two measures have been taken. One of them is
Therefore, in obtaining the peak value Ihp of the horizontal deflection current required for realizing the horizontal scanning width required in each image display cathode ray tube, by reducing the inductance Lh of the horizontal deflection coil 6, it means that can suppress an increase in power supply voltage value Vcc due to the horizontal frequency is increased, the inductance Lh of the horizontal deflection coil 6 in the horizontal deflection circuit, while maintaining the deflection index represented as Lh · Ih ² substantially constant , Is to reduce. The other is to use a high breakdown voltage transistor element having an extremely high collector-emitter breakdown voltage as the switching transistor element 3.

[0017]

However, when one of the above two measures, that is, a measure to reduce the inductance Lh of the horizontal deflection coil 6, is taken, the number of turns of the horizontal deflection coil 6 is reduced. Be restricted. That is,
The inductance Lh of the horizontal deflection coil 6 can be reduced by reducing the number of turns of the horizontal deflection coil 6. However, if the number of turns of the horizontal deflection coil 6 is reduced indiscriminately, the image display cathode wire to which the horizontal deflection coil 6 is applied is applied. This will hinder the formation of the convergence correction magnetic field required when the tube is a color cathode ray tube for displaying a color image, and the variation in manufacturing of the horizontal deflection coil 6 is so large that it exceeds an allowable value. Inconvenience that it becomes. Therefore, the inductance L of the horizontal deflection coil 6
In order to achieve the purpose of suppressing the increase of the power supply voltage value Vcc as necessary, it is difficult to sufficiently reduce h.

In the case where a high breakdown voltage transistor element having an extremely high collector-emitter breakdown voltage is used as the switching transistor element 3, which is another one of the above two measures, a high high voltage is required. It is difficult to obtain a high-voltage transistor element. Peak value Vcp of the pulse voltage obtained between both ends of the resonance capacitor 5
For example, when the horizontal frequency is set to 120 kHz, it may reach 1,300 V. In such a case, as the switching transistor element 3, VCBO
A high breakdown voltage transistor element having a breakdown voltage of 1,700 V or more is required. It is extremely difficult to obtain a certain amount of such a high-voltage transistor element at a reasonable price, and even if it is available, the burden on the price becomes excessive and the performance is low. There is a risk of taking too much risk.

In view of the above, the invention described in the claims of the present application is controlled by a coil connected between both ends of a power supply and a horizontal drive signal in synchronization with a horizontal synchronizing signal to perform horizontal return. A series connection with a switch unit for setting a line period and a horizontal scanning period, a resonance capacitor connected in parallel to the switch unit, and a series connection of a horizontal deflection coil and an S-shaped correction capacitor also connected in parallel to the switch unit. With the basic configuration including the following, when obtaining the peak value of the horizontal deflection current required to realize the required horizontal scanning width in the cathode ray tube for image display to which it is applied, Even when the frequency is increased, the increase in the power supply voltage value and the increase in the peak value of the pulse voltage obtained between both ends of the resonance capacitor during the horizontal retrace period are effectively suppressed. It can, thus, for example, to provide a horizontal deflection circuit that will need not use the high-voltage transistor device with difficulties to obtain as a switching transistor elements forming a switch unit.

[0020]

A horizontal deflection circuit according to any one of the first to fifth aspects of the present invention includes a coil connected between both ends of a power supply. A series connection with a first switch unit, which is turned on / off by a horizontal drive signal synchronized with a horizontal synchronization signal to set a horizontal retrace period and a horizontal scanning period, and a second switch unit connected in parallel to the first switch unit 1 resonant capacitor,
A series connection of a horizontal deflection coil, a second resonance capacitor, and an S-shaped correction capacitor connected in parallel to the first switch section, and a substantially parallel connection to the second resonance capacitor for horizontal retrace; And a second switch unit driven to be turned off during the period.

In particular, the horizontal deflection circuit according to the invention described in claim 3 of the present application claims claim 1.
With the basic configuration of the horizontal deflection circuit according to any one of the first to fifth aspects, the second
A switch section, a gate is supplied with a horizontal drive signal or a drive signal synchronized with the horizontal drive signal, and a drain-source path is turned off during a horizontal flyback period. And a damper diode element connected in parallel to the drain-source path of the inductive transistor element.

Further, in particular, the horizontal deflection circuit according to the invention described in claim 4 of the present application is a horizontal deflection circuit according to any one of claims 1 to 5 of the present invention. In the second switch section, a horizontal drive signal or a drive signal synchronized with the horizontal drive signal is supplied to the gate, and the drain-source path is turned off within the horizontal retrace period. A depletion type field effect transistor element,
And a damper diode element connected in parallel to the drain-source path of the depletion type field effect transistor element.

[0023] In the horizontal deflection circuit according to any one of the first to fifth aspects of the present invention, the horizontal deflection circuit has
That is, the second switch unit is turned off over the entire horizontal retrace period or during a part of the horizontal retrace period. Therefore, during the horizontal retrace period in which the second switch section is turned off, the second deflection current flowing through the S-shaped correction capacitor and the horizontal deflection coil is applied to the second deflection section.
And the first resonance capacitor are arranged in series, and during the horizontal retrace period in which the second switch unit is turned off, the horizontal current flowing through the S-shape correction capacitor and the horizontal deflection coil is turned off. The deflection current flows into each of the second resonance capacitor and the first resonance capacitor, and a pulse voltage is generated between both ends of the second resonance capacitor and between both ends of the first resonance capacitor.

As a result, between both ends of the horizontal deflection coil,
During the horizontal retrace period in which the second switch is turned off, there is no second resonance capacitor, and a series connection of a horizontal deflection coil and an S-shaped correction capacitor is connected in parallel to the first switch. A pulse voltage having a larger peak value than the pulse voltage applied in the case is applied. Accordingly, even in the horizontal scanning period in which the second switch unit is turned on, there is no second resonance capacitor between both ends of the horizontal deflection coil, and the horizontal deflection coil and the S-shaped correction are provided in the first switch unit. Compared to the voltage applied when the series connection with the capacitor is connected in parallel,
High voltage is applied. That is, the voltage between both ends of the horizontal deflection coil is increased. Therefore, by appropriately selecting the capacitance value of the second resonance capacitor, the horizontal deflection required for realizing the horizontal scanning width required in the image display cathode ray tube to which the horizontal deflection circuit is applied is realized. The peak value of the deflection current can be obtained without increasing the voltage value of the power supply.

In such a case, the pulse voltage having an increased peak value applied between both ends of the horizontal deflection coil during the horizontal retrace period in which the second switch section is turned off is the first voltage. Since the capacitance is distributed to the resonance capacitor and the second resonance capacitor in accordance with the respective capacitance values, the capacitance value of the second resonance capacitor is appropriately selected, so that the capacitance is obtained between both ends of the first resonance capacitor. The peak value of the applied pulse voltage is reduced as compared to a case where the second resonance capacitor is not provided and the series connection of the horizontal deflection coil and the S-shaped correction capacitor is connected in parallel to the first switch unit.

Therefore, in order to obtain the peak value of the horizontal deflection current required for realizing the horizontal scanning width required for the image display cathode ray tube to be applied, even when the horizontal frequency is increased, the power supply voltage may be increased. The value increase and the increase in the peak value of the pulse voltage obtained between both ends of the first resonance capacitor during the horizontal retrace period can be effectively suppressed. It is not necessary to use a high breakdown voltage transistor element which is difficult to obtain as a switching transistor element to be formed.

In particular, the horizontal deflection circuit according to the invention described in claim 3 of the present application and the horizontal deflection circuit according to the invention described in claim 4 in the claims are provided. Therefore, each of the horizontal deflection circuits according to any one of the first to fifth aspects of the present invention has the basic configuration of the horizontal deflection circuit according to any one of the first to fifth aspects.
Is formed including a static induction type transistor element having a drain-source path connected substantially in parallel with the second resonance capacitor and a damper diode element connected in parallel with the drain-source path. And a horizontal deflection circuit according to any one of the first to fifth aspects of the present invention, wherein the second switch section has a drain-source path having a drain-source path. And a damper diode element connected in parallel to the drain-source path of the depletion-type field effect transistor element connected in parallel to the two resonance capacitors.

Then, the electrostatic induction type transistor element is
With no drive voltage supplied to the gate, the drain-
The source path is maintained in the ON state, and the drain-source path of the depletion type field effect transistor element is maintained in the ON state without supplying a drive voltage to the gate. Therefore, in the drive circuit for the switching transistor element forming the second switch section, for example, when a power supply is turned on, a drive voltage may be supplied to the switching transistor element to turn it on. An extremely simple device that does not require a protection circuit or the like for preventing certain element destruction is sufficient.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a horizontal deflection circuit according to any one of claims 1, 2, 3 and 5 of the present application. .

In the example shown in FIG. 1, the voltage value is V
The choke coil 12 and the collector-emitter path of the switching transistor element 13 are connected in series between both ends of a power supply cc. In parallel with the collector-emitter path of the switching transistor element 13, the damper diode element 14, the first resonance capacitor 15, the horizontal deflection coil 16, the ferrite bead inductor 17, the second resonance capacitor 18, Each of the series connection with the character correction capacitor 19 is connected. The switching transistor element 13 and the damper diode element 14 substantially form a first switch section.

The ferrite bead inductor 17
The drain-source path of the switching transistor element 20 and the damper diode element 21 are connected in parallel to the series connection of the switching transistor element 20 and the second resonance capacitor 18. The switching transistor element 20 is an electrostatic induction type transistor element. Each of the drain-source path of the switching transistor element 20 and the damper diode element 21 is connected to the second resonance capacitor 18 substantially in parallel.
Further, the switching transistor element 20 and the damper diode element 21 which are an electrostatic induction type transistor element
And substantially form the second switch section.

Further, the switching transistor element 2
In the case of 0, the gate is connected to the output terminal of the drive signal forming unit 25.

Under these circumstances, the base of the switching transistor element 13 is synchronized with the horizontal synchronizing signal in the video signal provided for image display by the image display cathode ray tube to which the example shown in FIG. 1 is applied. Horizontal drive signal DH
And the switching transistor element 20
Are supplied with a drive signal DH ′ synchronized with the horizontal drive signal DH formed in the drive signal forming section 25.

The switching transistor element 13 is driven by the horizontal drive signal DH so that the collector-emitter path of the switching transistor element 13 shifts from the off state to the on state and from the on state to the off state. On / off control is performed to perform. Thereby, the first switch section formed by the switching transistor element 13 and the damper diode element 14 is turned off and on in accordance with the horizontal drive signal DH, and the horizontal flyback period and the horizontal scanning are performed. A period is set.

The switching transistor element 20
, The horizontal drive signal D from the drive signal forming unit 25
The drive is performed by the drive signal DH ′ synchronized with H, and the drain-source path of the switching transistor element 20 is turned on and off so as to make a transition from the off state to the on state and a transition from the on state to the off state. Is done. Accordingly, the second switch section formed by the switching transistor element 20 and the damper diode element 21 is turned off during the horizontal flyback period and turned on during the horizontal scanning period according to the drive signal DH ′. In such a case, since the switching transistor element 20 is an electrostatic induction type transistor element, the drive signal DH ′ supplied to the gate of the switching transistor element 20 has the drain-source path of the switching transistor element 20 turned on. In the horizontal scanning period in the state, the signal is a signal that does not substantially apply a voltage to the gate of the switching transistor element 20.

2A, 2B, 2C, and 2D show the on / off state of the collector-emitter path of the switching transistor element 13, the on / off state of the damper diode element 14, and the drain-source state of the switching transistor element 20, respectively. The ON / OFF state of the passage and the ON / OFF state of the damper diode element 21 are shown. These A of FIG.
As shown by D in FIG. 5, during the horizontal retrace period, all of the collector-emitter path of the switching transistor element 13, the damper diode element 14, the drain-source path of the switching transistor element 20, and the damper diode element 21 are turned off. In the horizontal scanning period, first, the damper diode element 14
And the damper diode element 21 are turned on, and then the collector-emitter path of the switching transistor element 13 and the drain-source path of the switching transistor element 20 are turned on.

As described above, during the horizontal scanning period set by turning on the collector-emitter path of the damper diode element 14 or the switching transistor element 13 and turning on the first switch section, A horizontal deflection current flows through the deflection coil 16 as a scanning current.
Collector-emitter path and damper diode element 1
4 is turned off and the first switch section is turned off in a horizontal flyback period,
A horizontal deflection current flows through the horizontal deflection coil 16 as a retrace current. The horizontal deflection current flowing through the horizontal deflection coil 16 has an S-shaped waveform throughout the horizontal scanning period and the entire horizontal retrace period by passing through the S-shaped correction capacitor 19. It is assumed to form.

Under such circumstances, the damper diode element 1
4 or the collector-emitter path of the switching transistor element 13 is turned on, the first switch section is turned on, and the damper diode element 2 is turned on.
1 or during a horizontal scanning period in which the drain-source path of the switching transistor element 20 is turned on and the second switch section is turned on, a horizontal deflection current flowing through the S-shaped correction capacitor 19 and the horizontal deflection coil 16 is switched. Both the collector-emitter path of the transistor element 13 and the damper diode element 14 are turned off, the first switch section is turned off, and the drain-source path of the switching transistor element 20 and the damper diode element 21 are turned off. During a horizontal retrace period in which both are turned off and the second switch section is turned off, the current flows into the second resonance capacitor 18 and the ferrite bead inductor 17 and further flows into the first resonance capacitor 15. .

That is, during the horizontal flyback period, the second resonance capacitor 18 and the first resonance capacitor 18 respond to the horizontal deflection current flowing through the S-shaped correction capacitor 19 and the horizontal deflection coil 16.
Are arranged in series with each other, whereby a pulse voltage is generated between both ends of the second resonance capacitor 18 and between both ends of the first resonance capacitor 15, respectively. As a result, at the connection point P between the horizontal deflection coil 16 and the ferrite bead inductor 17,
A pulse voltage as shown in FIG. 2E is obtained, and a pulse voltage as shown in FIG. 2F is obtained at a connection point Q between the horizontal deflection coil 16 and the choke coil 12.

The ferrite bead inductor 17
Plays a role in suppressing the generation of unnecessary oscillation current when the drain-source path of the switching transistor element 20 shifts from the off state to the on state.

The pulse voltage obtained at the connection point P shown in FIG. 2E and the pulse voltage obtained at the connection point Q shown in FIG. 2F have different polarities from each other. In the horizontal retrace period, the end between the two ends is indicated by E in FIG.
And a pulse voltage corresponding to the sum of the pulse voltage shown in FIG. 2F and the pulse voltage shown in FIG.
The pulse voltage applied between both ends of the horizontal deflection coil 16 is supplied to the first switch unit without the second resonance capacitor 18 and the horizontal deflection coil 16 and the S-shaped correction capacitor 19.
The peak value is increased as compared with the pulse voltage applied in the case where the series connection with is connected in parallel.

Accordingly, even during the horizontal scanning period, the voltage as shown in FIG. 2E obtained at the connection point P and the voltage as shown at F in FIG. Since the polarities are different from each other, there is no second resonance capacitor 18 between both ends of the horizontal deflection coil 16, and the series connection of the horizontal deflection coil 16 and the S-shaped correction capacitor 19 is connected in parallel to the first switch unit. A voltage having a value larger than the voltage applied when connected is applied. Therefore, the voltage between both ends of the horizontal deflection coil 16 is increased. Therefore, by appropriately selecting the capacitance value of the second resonance capacitor 18,
It is possible to obtain the peak value of the horizontal deflection current required to realize the required horizontal scanning width in the cathode ray tube for image display to which the example of FIG. 1 is applied without increasing the voltage value Vcc of the power supply. it can.

Under these circumstances, both the collector-emitter path of the switching transistor element 13 and the damper diode element 14 are turned off, the first switch section is turned off, and the drain of the switching transistor element 20 is turned off. In the horizontal retrace period in which both the source path and the damper diode element 21 are turned off and the second switch unit is turned off, the peak value applied between both ends of the horizontal deflection coil 16 is increased. The pulse voltage is applied between the first resonance capacitor 15 and the second
To the resonance capacitor 18 in accordance with the respective capacitance values. Therefore, by appropriately selecting the capacitance value of the second resonance capacitor 18, the first resonance capacitor 1
5, the peak value of the pulse voltage obtained between both ends of the case where the second resonance capacitor 18 is not provided and the series connection of the horizontal deflection coil 16 and the S-shaped correction capacitor 19 are connected in parallel to the first switch unit. Can be reduced.

Therefore, according to the example shown in FIG. 1, it is necessary to obtain the peak value of the horizontal deflection current required for realizing the horizontal scanning width required in the image display cathode ray tube to which it is applied. Even when the horizontal frequency is increased, it is possible to effectively suppress the increase in the voltage value Vcc of the power supply and the increase in the peak value of the pulse voltage obtained between both ends of the first resonance capacitor 15 during the horizontal flyback period. Accordingly, for example, it is not necessary to use a high breakdown voltage transistor element which is difficult to obtain as the switching transistor element 13 forming the first switch section.

Further, in the example shown in FIG. 1 described above, the switching transistor element 20 forming the second switch section is an electrostatic induction transistor element, and the electrostatic induction transistor element has a gate. The drive signal DH ′ supplied from the drive signal forming section 25 to the gate of the switching transistor element 20 is not During the horizontal scanning period when the source path is in the ON state, the switching transistor element 2
The signal does not apply a voltage to the gate of 0. Therefore, the drive signal forming unit 25 protects, for example, at the time of power-on, protection of the switching transistor element 20 from element destruction that may occur when a drive voltage is supplied to turn on the drain-source path of the switching transistor element 20. A circuit or the like is not required, and an extremely simple circuit is sufficient.

FIG. 3 shows a specific configuration example of the drive signal forming section 25. A specific configuration example of the drive signal forming unit 25 shown in FIG. 3 includes a drive power transformer 31, a forward bias resistor 32, a reverse bias diode 33, a reverse bias resistor 34, and a feedback resistor 35. Have been. In the drive power transformer 31, one end of the primary winding is connected to a connection point Q between the horizontal deflection coil 16 and the choke coil 12, and the other end has a voltage value of Vcc '. The secondary winding is connected at one end to a connection point P between the horizontal deflection coil 16 and the ferrite bead inductor 17, and the other end is connected to a forward bias resistor 32. And one end of the reverse bias resistor 34 are connected to a common connection point. Then, a pulse voltage synchronized with the horizontal drive signal DH, which is obtained by transforming the pulse voltage as shown in FIG. 2F obtained at the connection point Q, is generated in the secondary winding of the transformer 31 for the drive power supply. , The pulse voltage is
It is added between the connection point P and a common connection point between one end of the forward bias resistor 32 and one end of the reverse bias resistor 34.

A specific configuration example of such a drive signal forming section 25 has a floating configuration because the electrostatic induction type transistor element as the switching transistor element 20 has a floating configuration.
Then, a drive signal DH ′ synchronized with the horizontal drive signal DH based on a pulse voltage synchronized with the horizontal drive signal DH obtained on the secondary winding of the drive power transformer 31 is:
The forward bias resistor 32 and the reverse bias diode 3 to which the gate of the switching transistor element 20 is connected.
3 and the feedback resistor 35 at a common connection point R at one end. FIG. 4 shows a drive signal DH ′ obtained at the common connection point R.
Here is an example.

Under such circumstances, the forward bias to the switching transistor element 20 is determined by the forward bias resistor 32, and the resistance of the switching transistor element 20 in the ON state in the drain-source path is determined. The value (ON resistance) is sufficiently reduced. Further, the reverse bias to the switching transistor element 20 includes a reverse bias diode 33, a reverse bias resistor 34, and a forward bias resistor 3.
2, the drain-source path of the switching transistor element 20 is rapidly shifted from the on state to the off state.

FIG. 5 shows an example of the horizontal deflection circuit according to any one of the first, second, fourth and fifth aspects of the present invention.

The example shown in FIG. 5 differs from the example shown in FIG. 1 in that a switching transistor element which is a depletion type field effect transistor element is used instead of the switching transistor element 20 which is an electrostatic induction transistor element. 40 correspond to those used, and the other configuration is the same as the example shown in FIG. In FIG. 5, portions corresponding to the respective portions in the example shown in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and redundant description thereof will be omitted.

In the example shown in FIG. 5, in parallel with the series connection of the ferrite bead inductor 17 and the second resonance capacitor 18, a switching transistor element 40 which is a depletion type field effect transistor element is connected. The drain-source path is connected to the damper diode element 21, and the drain-source path of the switching transistor element 40 and the damper diode element 21 are each substantially parallel to the second resonance capacitor 18. It is connected to the. The switching transistor element 40 and the damper diode element 21, which are depletion-type field effect transistor elements, substantially form a second switch section. The gate of the switching transistor element 40, which is a depletion-type field-effect transistor element, is connected to a drive signal supply unit 25 that supplies a drive signal DH ′ synchronized with the horizontal drive signal DH.

Under such circumstances, the switching transistor element 40 which is a depletion type field effect transistor element is similar to the switching transistor element 20 which is an electrostatic induction type transistor element in the example shown in FIG. Operating and its drain-source path is
It is turned off in the horizontal retrace period and turned on in the latter half of the horizontal scanning period. At this time, since the drain-source path of the depletion type field effect transistor element is maintained in an on state without supplying a driving voltage to its gate, the depletion type field effect transistor The drive signal DH ′ supplied to the source of the switching transistor element 40 is substantially the switching transistor element 4 during the horizontal scanning period when the drain-source path of the switching transistor element 40 is in the ON state.
It is a signal that does not apply a voltage to the gate of 0.

In the example shown in FIG. 5, FIG.
The same operation as the example shown in FIG. 1 is performed, and the same operation and effect as those obtained by the example shown in FIG. 1 are obtained. Further, the drive signal forming unit 2 in the example shown in FIG.
5, a specific configuration example as shown in FIG. 3 is applied.

In the examples shown in FIGS. 1 and 5 described above, the switching transistor element 20 and the damper diode element 21 which are the electrostatic induction transistor elements, or the depletion type field effect transistor element Switching transistor element 40
And the second formed by the damper diode element 21
Is in an off state over the entire horizontal flyback period and is in an on state during the horizontal scanning period. The on / off state of the second switch unit is as described above. The present invention is not limited to this. For example, the second switch unit may be turned off in a part of the horizontal flyback period and turned on in another period including the horizontal scanning period. It is sufficient that the second switch unit is turned off during the horizontal flyback period. In the example shown in FIGS. 1 and 5 described above, the series connection including the horizontal deflection coil 16 connected in parallel to the collector-emitter path of the switching transistor element 13 is performed in series. Ferrite bead·
Although the inductor 17, the second resonance capacitor 18, and the S-shaped correction capacitor 19 are formed in an arrangement order, the arrangement order in a series connection including the horizontal deflection coil 16 is not limited to this example.

[0055]

As is clear from the above description, according to the horizontal deflection circuit according to any one of the first to fifth aspects of the present invention, the horizontal deflection period can be reduced. In other words, the second switch section is turned off during the entire horizontal retrace period or during a part of the horizontal retrace period, and the second switch section is turned on during other periods. Put in the state. As a result, there is no second resonance capacitor between both ends of the horizontal deflection coil during the horizontal retrace period in which the second switch is turned off, and the first switch has a horizontal deflection coil and an S-shape. In comparison with the pulse voltage applied when the series connection with the correction capacitor is connected in parallel, a pulse voltage having a larger peak value is applied, and accordingly, the second switch unit is turned on. Even during the horizontal scanning period, there is no second resonance capacitor between both ends of the horizontal deflection coil, and a series connection of the horizontal deflection coil and the S-shaped correction capacitor is connected in parallel to the first switch unit. In this case, a large voltage is applied as compared with the voltage applied in the step (1), and the voltage between both ends of the horizontal deflection coil is increased. Therefore, by appropriately selecting the capacitance value of the second resonance capacitor, the horizontal deflection required for realizing the horizontal scanning width required in the image display cathode ray tube to which the horizontal deflection circuit is applied is realized. The peak value of the current can be obtained without increasing the voltage value of the power supply.

The pulse voltage having an increased peak value applied between both ends of the horizontal deflection coil during the horizontal flyback period in which the second switch section is turned off is:
The first resonance capacitor is distributed to the first resonance capacitor and the second resonance capacitor in accordance with the respective capacitance values. Therefore, by appropriately selecting the capacitance value of the second resonance capacitor, the voltage between both ends of the first resonance capacitor can be increased. The peak value of the pulse voltage obtained in step (b) is lower than when the second resonance capacitor is not provided and the series connection of the horizontal deflection coil and the S-shaped correction capacitor is connected in parallel to the first switch unit. Can be.

Therefore, in order to obtain the peak value of the horizontal deflection current required for realizing the horizontal scanning width required for the image display cathode ray tube to be applied, even when the horizontal frequency is increased, the power supply voltage may be increased. It is possible to effectively suppress the increase in the value and the increase in the peak value of the pulse voltage obtained between both ends of the first resonance capacitor during the horizontal retrace period, thereby forming, for example, the first switch section. It is not necessary to use a high breakdown voltage transistor element which is difficult to obtain as a switching transistor element. In other words, the horizontal frequency can be increased while suppressing an increase in the power supply voltage value and an increase in the peak value of the pulse voltage obtained between both ends of the first resonance capacitor during the horizontal flyback period. become.

Further, according to the horizontal deflection circuit according to the invention described in claim 3 of the present application, and to the horizontal deflection circuit according to the invention described in claim 4 of the present application, For example, with the basic configuration of the horizontal deflection circuit according to any one of the first to fifth aspects of the present invention, the second switch section includes the drain-source path having the second configuration. Formed including a static induction type transistor element connected substantially in parallel to the resonance capacitor and a damper diode element connected in parallel to the drain-source path thereof; and
With the basic configuration of the horizontal deflection circuit according to any one of the first to fifth aspects of the present invention, the second switch section includes a drain-source path having a second path.
Depletion-type field-effect transistor element connected substantially in parallel to the
And a driving circuit for the switching transistor element forming the second switch section, for example, when the power supply is turned on, the switching transistor element is formed. A protection circuit or the like for preventing element destruction that may occur when a driving voltage is supplied to turn on the device is unnecessary, and an extremely simple device is sufficient.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an example of a horizontal deflection circuit according to any one of the first, second, third, and fifth aspects of the present invention.

FIG. 2 is a timing chart for explaining the operation of the example shown in FIG. 1;

FIG. 3 is a circuit configuration diagram showing a specific configuration example of a drive signal forming unit in the example shown in FIG. 1;

FIG. 4 is a waveform chart showing a drive signal obtained by a specific configuration example of the drive signal forming unit shown in FIG. 3;

FIG. 5 is a circuit diagram showing an example of a horizontal deflection circuit according to any one of the first, second, fourth, and fifth aspects of the present invention.

FIG. 6 is a circuit configuration diagram showing a basic horizontal deflection circuit.

FIG. 7 is a timing chart for explaining the operation of the basic horizontal deflection circuit shown in FIG. 6;

[Explanation of symbols]

12 ... choke coil, 13, 20, 40 ...
Switching transistor element, 14, 21 ... damper diode element, 15 ... first resonance capacitor, 16 ... horizontal deflection coil, 17 ... ferrite bead inductor, 18 ... second resonance capacitor , 19 ... S-shaped correction capacitor, 25
..The drive signal forming section, 31 ... transformer for drive power supply, 32 ... resistance for forward bias, 33 ...
・ Reverse bias diode, 34 ・ ・ ・ Reverse bias resistor, 35 ・ ・ ・ Feedback resistor

Continuation of the front page (72) Inventor Yoshiaki Inoue 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C068 BA08 BA09 GA16 GB01 JB07 LA01

Claims (5)

[Claims] A first switch connected between both ends of a power supply and configured to set a horizontal flyback period and a horizontal scanning period by being turned on / off by a horizontal drive signal synchronized with a coil and a horizontal synchronization signal; Series connection; a first resonance capacitor connected in parallel to the first switch unit; a horizontal deflection coil, a second resonance capacitor, and an S-shaped correction capacitor connected in parallel to the first switch unit And a second switch unit connected substantially in parallel to the second resonance capacitor and driven to be turned off during a horizontal retrace period. Deflection circuit. 2. The first switch section includes a switching transistor element to which a horizontal drive signal is supplied to a base and a damper diode element connected in parallel to a collector-emitter path of the switching transistor element. The horizontal deflection circuit according to claim 1, wherein: 3. A static induction type wherein a second switch section supplies a gate with a horizontal drive signal or a drive signal synchronized with the horizontal drive signal, and a drain-source path is turned off during a horizontal retrace period. 3. The horizontal deflection circuit according to claim 1, wherein the horizontal deflection circuit includes a transistor element and a damper diode element connected in parallel to the drain-source path of the static induction transistor element. 4. A depletion type wherein a second switch section supplies a gate with a horizontal drive signal or a drive signal synchronized with the horizontal drive signal, and a drain-source path is turned off during a horizontal flyback period. 3. The horizontal structure according to claim 1, wherein the field effect transistor element is formed to include a damper diode element connected in parallel to the drain-source path of the depletion type field effect transistor element. Deflection circuit. 5. The horizontal deflection circuit according to claim 3, wherein a ferrite bead inductor is connected in series with the second resonance capacitor.