JPH0634153B2 - Driving circuit for thin film EL display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive circuit for an AC drive type capacitive rat matrix display panel, that is, a thin film EL (electroluminescence) display device.

<Prior Art> For example, a double-insulation (or three-layer structure) thin film EL element is configured as follows.

As shown in FIG. 5, a band-shaped transparent electrode 2 made of In ₂ O ₃ is provided in parallel on a glass substrate 1 and, for example, Y
₂ O ₃ , Si ₃ N ₄ , Al ₂ O _{3 and} other dielectric substances 3, Mn and other activator-doped ZnS EL layer 4, and Y ₂ O ₃ , Si ₃ N ₄ , TiO ₂ , and A dielectric material layer 3 ′ such as Al ₂ O ₃ is sequentially laminated to a film thickness of 500 to 10000Å by using a thin film technique such as a vapor deposition method and a sputtering method to form a three-layer structure, and the transparent electrode 2 and the transparent electrode 2 are orthogonal to each other. A strip-shaped back electrode 5 made of Al ₂ O ₃ is provided in parallel in the direction.

Since the thin film EL element has the EL material 4 sandwiched between the dielectric materials 3 and 3 ′ between its electrodes, it can be regarded as a capacitive element in terms of an equivalent circuit. Further, as is clear from the voltage-luminance characteristics shown in FIG. 6, this thin film EL element is driven by applying a relatively high voltage of about 200V. This thin film EL element has the characteristics that it emits light with high brightness due to an AC electric field and has a long life.

Conventionally, the present applicant has proposed the following drive circuit for the purpose of reducing the modulation power consumption for a display device using such a thin film EL element. That is, a high-voltage driver IC having a push-pull function and controlled by a single-potential shift register and a gate logic circuit is connected to the scan-side electrode and the data-side electrode, and the scan-side high-voltage driver IC is commonly used for pull-up. A switching circuit that applies a positive write voltage and 1/2 modulation voltage to the line, and a negative write voltage, 1/2 modulation voltage and 0V to the pull-down common line, and a pull-up common line for the data side high voltage driver. Is a drive circuit for applying an AC pulse to the thin film EL display device to emit light by providing a switching circuit for applying a 1/2 modulation voltage and setting the pull-down common line of the data side high breakdown voltage driver to 0V.

<Problems to be Solved by the Invention> However, since the active type (self-luminous type) display basically consumes a large amount of power, further reduction in power consumption is required.

Therefore, it is an object of the present invention to provide a drive circuit for a thin film EL display device, which can significantly reduce the modulation power consumption and the writing power consumption of the thin film EL display device.

<Means for Solving the Problems> In order to achieve the above object, the thin film EL display device driving circuit of the present invention has an EL layer interposed between a scanning side electrode and a data side electrode arranged in directions intersecting with each other. A high withstand voltage driver I composed of a bidirectional switching element having a push-pull function on at least one of the scanning-side electrode and the data-side electrode in the thin film EL display element to be provided.
A write voltage and a modulation voltage are applied to a pull-up common line or a pull-down common line of the high-voltage driver IC by a bidirectional switching circuit while C is connected, and the bidirectional switching element operates to apply a voltage to the EL layer. In a drive circuit of a thin film EL display device for displaying an image on a thin film EL display device by applying a voltage equal to or higher than a light emission threshold, the thin film EL display device is operated by the operation of the bidirectional switching circuit and the switching device of a high breakdown voltage driver IC. A first switching circuit for taking out the electric charge accumulated in the EL layer after the EL layer emits light, and a capacitor for accumulating the electric charge taken out from the thin film EL display element by the operation of the first switching circuit, The charge accumulated in the capacitor is transferred to the bidirectional switch. A second switching circuit is provided, which is taken out when a write voltage or a modulation voltage is applied to the pull-up common line or the pull-down common line of the high breakdown voltage driver IC by the operation of the circuit and is sent to the bidirectional switching circuit. It has a feature.

<Operation> When displaying an image on the thin film EL display element, the bidirectional switching circuit operates to provide a push-pull function connected to at least one of the scanning side electrode and the data side electrode in the thin film EL display element. The write voltage and the modulation voltage are applied to the pull-up common line or the pull-down common line of the high breakdown voltage driver IC formed of the bidirectional switching element. Then, by the operation of the bidirectional switching element of the high breakdown voltage driver IC, a voltage equal to or higher than the light emission threshold is selectively applied to the EL layer forming the display pixel, and the EL layer emits light.

After that, by the operation of the first switching circuit,
The charges accumulated in the EL layer of the thin film EL display element are taken out to the outside and accumulated in the capacitor.

When the next image is displayed, the high withstand voltage driver I
When the write voltage or the modulation voltage is applied to the pull-up common line or the pull-down common line of C by the operation of the bidirectional switching circuit, the charge accumulated in the capacitor is taken out by the operation of the second switching circuit. It is sent to the bidirectional switching circuit.

In this way, the charge accumulated in the capacitor is reused when the write voltage is applied or when the modulation voltage is applied, and the power consumption is reduced.

<Example> Hereinafter, the present invention will be described in detail with reference to illustrated examples.

In this embodiment, a part of the modulation energy stored in the EL display device is stored in the external capacitor and reused by driving once. Note that the writing energy can be reused similarly, but the description in this embodiment is omitted.

FIG. 1 is a drive circuit block diagram showing an embodiment of the present invention. 10 is a light emission threshold voltage Vth (Vw <Vth <Vw + V
m) shows a thin film EL display device. In this figure, only the electrodes are shown with the X-direction electrode as the data side electrode and the Y-direction electrode as the scanning side electrode. Reference numerals 20 and 30 denote the thin film EL display device 1 described above.
This is a scanning-side high breakdown voltage push-pull bidirectional driver IC (corresponding to a first bidirectional switching circuit, hereinafter referred to as a scanning-side driver IC) corresponding to the odd and even lines of the Y-direction electrode of 0, respectively. Reference numerals 21 and 31 are logic circuits such as shift registers in the scanning side driver ICs 20 and 30, which are "Scan data", "PUP",
By the control signal such as "PDW", the pull-up element or the pull-down element is turned "ON" in response to the "Scan data" in the shift register and "Scan data".
It creates a state in which all pull-up elements or pull-down elements are "ON" regardless of. Reference numeral 40 denotes a data side high breakdown voltage push-pull bidirectional driver IC (corresponding to a second bidirectional switching circuit, hereinafter referred to as a data side driver IC) corresponding to the X-direction electrode of the thin film EL display device 10. Reference numeral 41 is a logic circuit such as a shift register in the data side driver IC 40. FIG. 2 shows an example of the configuration of the above high-voltage push-pull bidirectional driver. In the figure, 501 is a pull-up P
ch high breakdown voltage MOSFET (field effect transistor), 502 is Nch high breakdown voltage MOSF for pull-down
ET and 503 and 504 are diodes for flowing current in the opposite directions to the respective FETs. 501 and 502 are "O" according to input data by a circuit such as a level shifter.
N "and" OFF. "This push-pull type driver can be used as long as it is composed of a switching element having a pull-up function and a switching element having a pull-down function.

Reference numeral 100 denotes a circuit (corresponding to a third bidirectional switching circuit) for switching the pull-down common line potential of the scanning side driver ICs 20 and 30, which has control signals "NVC", NG.
A switch SW for switching between the negative write voltage -Vw, 0V and the modulation voltage 1 / 2Vm by C "and" NM2 ".
1, SW2, SW3, and a switch SW3 'that switches in the opposite direction to the switch SW3 by a control signal "NM2R".

Reference numeral 200 denotes a circuit (corresponding to a fourth bidirectional switching circuit) for switching the pull-up common line potential of the scan side driver ICs 20 and 30. The control signal “PVC” and PM2 ”are used to write the positive polarity write voltage Vw + Vm and the modulation voltage 1 / 2Vm. It is composed of switches SW4 and SW5 for switching to.

Reference numeral 300 is a circuit (corresponding to a fifth bidirectional switching circuit) for switching the pull-up common line potential of the data side driver IC 40, and the modulation voltage 1 is set by the control signal "M1".
A switch SW6 for switching between / 2Vm and a floating state, and a switch SW6 'for switching in the opposite direction to the switch SW6 by a control signal "M1R".

The switch 400 is turned on by the control signal "MDW" 400, and the modulation voltage ¼ Vm is applied to the capacitor Cm.
Circuit for supplying the modulation voltage ¼ Vm and the modulation voltage ½ Vm by supplying the modulation voltage ¼ Vm and the switch SW7 “ON” by the control signal “MUP”. It corresponds to a switching circuit) and is connected to the switches SW3, SW5 and SW6 controlled by the control signals "NM2", "PM2" and "M1". On the other hand, the switch SW3 'or the switch SW6' is turned "O" by the control signal "NM2R" or "M1R".
It is also a circuit for storing a part of the energy stored in the EL display device in the capacitor Cm by setting it to N "and further turning on the switch SW8 by the control signal" MDW ".

Reference numeral 500 is a data inversion control circuit.

Next, the operation of FIG. 1 will be described with reference to the time chart of FIG.

Here, it is assumed that the scanning electrodes of Y ₁ including the picture element A and Y ₂ including the picture element B are selected as the selective scanning electrodes by line sequential driving. Further, in this driving device, the polarity of the write voltage applied to the picture element is inverted for each line to be driven, but the high withstand voltage driver I connected to the scanning side selection electrode is used.
The drive timing of one line in which the pull-down MOSFET of C20, 30 is turned "ON" and the negative write pulse is applied to the picture element on the electrode line is called N drive timing. The drive timing of one line in which the pull-up MOSFET of is turned on and a positive write pulse is applied to the picture element on the electrode line is called P drive timing. In addition, the field (screen) where N drive is performed on the odd line on the scanning side and P drive is performed on the even line is NP
Fields and vice versa are called PN fields.

(A) NP field 1. First modulation voltage charging period (TN ₁ ) in N drive Nch MO of all drivers SDr _{1 to} SDri on the scanning side
By turning on the SFET and turning on the switch SW2 by the control signal "NGC", all electrodes on the scanning side are kept at 0V. At the same time, the switch S is turned on by the control signal "M1".
Turn on W6. At this time, the drivers DDr _{1 to} DDri on the data side turn on the Pch MOSFETs in the case of light emission according to the display data signal “DATA”,
When no light is emitted, the Nch MOSFET is turned "ON". When the display data signal is "H" for light emission and "L" for no light emission, the input display data signal ("DATA") needs to be input to the data side driver IC 40 as it is. The inverted signal "RVC" in 500 is set to "L". (However, the data side driver IC 40 has Pch when the data signal is "H".
The MOSFET is "ON" and the Nch MOSFET is "O".
Pch MOSFET when FF "and data signal is" L "
Is "OFF" and the Nch MOSFET is "ON". Further, since the line sequential driving is performed, the display data "DATA" is transferred at the time of the previous line driving and is held by the latch. ) Furthermore, the control signal "MD
The switch SW8 is turned "ON" by "W" to charge the capacitor Cm with 1/4 Vm. Next, the control signal "MDW".
After the switch SW8 is turned off by the switch SW8 and the switch SW7 is turned on by the control signal "MUP", the first modulation voltage of 1/2 Vm is gradually charged to the data side only in the light emitting pixel. The non-light emitting pixel is not charged and the data side electrode potential of the non-light emitting pixel becomes 0V. When the charging is completed, the switches SW6 and SW7 are turned off.

2. Charging and writing period (TN ₂ ) of the second modulation voltage in N driving Only the driver connected to the selective scan electrode is Nch MO.
Set SFET to "ON", and the other scan side driver is Pch.
Turn on the MOSFET. At the same time, the switch SW5 is turned “ON” by the control signal “PM2” and the modulation voltage ¼ Vm is applied to the pull-up common line of all the scanning side driver ICs 20 and 30, and then the switch SW7 is turned “ON” by the control signal “MUP”. By setting "", the modulation voltage is 1
Apply / 2Vm. In addition, all the scanning side driver IC2
A negative write voltage -Vw is applied to the pull-down common lines of 0 and 30 by turning on the switch SW1 by the control signal "NVC". On the other hand, the data side driver IC 40 continues the driving during the first modulation voltage charging period (TN ₁ ) in the above N driving.

As a result, the light emitting pixel is charged with the modulation voltage 1/2 Vm on the data side during the first modulation voltage charging period (TN ₁ ) in the N drive, so that the data side electrode potential becomes Vm. At the same time, a negative write voltage −Vw is applied to the selective scan electrode.
Is applied, Vm-(-Vw) = Vw +
Vm is applied to emit light. In addition, since the non-light-emitting pixel has a data-side electrode potential of 0V and the negative writing voltage -Vw is applied to the selective scan electrode as described above, the non-light-emitting pixel has 0V-(-Vw). = Vw is applied, but it does not emit light because it does not exceed the emission threshold voltage Vth.

3. After the write voltage discharge in N drive and the second modulation voltage recovery period (TN ₃ ) control signals “NVC”, “PM2”, and “MUP”, the switches SW1, SW5, and SW7 are turned “OFF”.
Scan side all drivers SDr ₁ ~ SDri Nch MOSFE
By turning on T, the write voltage is discharged,
The potential of all electrodes on the scanning side is 1/2 Vm. Therefore, the switch SW is next switched by the control signals "NM2R" and "MDW".
By turning ON 3'and SW8, a part of the electric charges accumulated with the scanning side electrode being positive during the second modulation voltage charging period (TN ₂ ) are accumulated in the capacitor Cm. And
The potential of all electrodes on the scanning side is 1/4 Vm. On the other hand, the electrode potential connected to the light emitting pixel of the data side electrode becomes 3/4 Vm.

4. Second modulation potential discharge in N drive and first modulation voltage recovery period (TN ₄ ) Switch SW by control signals “NM2R”, “MDW”
After turning off 3'and SW8, control signal "NG"
When the switch SW2 is turned "ON" by C ", the scanning side electrode potential becomes 0 V. Also, the electrode potential connected to the data side light emitting pixel becomes 1/2 Vm. Here, the control signal" M1 "
By turning on the switches SW6 'and SW8 by "R" and "MDW", a part of the charges accumulated with the data side electrode being positive in the first modulation voltage period (TN ₁ ) is accumulated in the capacitor Cm. Then, the potential of all electrodes on the data side becomes 1/4 Vm.

5. First modulation voltage charging period in P drive (TP ₁ ) Nch MO of all drivers SDr _{1 to} SDri on the scanning side
By turning on the SFET and turning on the switch SW2 by the control signal "NGC", all electrodes on the scanning side are kept at 0V. At the same time, the switch S is turned on by the control signal "M1".
Turn on W6. In this case the data side driver DDr ₁ ~DDri display data signal "DATA""The Nch MOSFET in the case of a light emitting according to the inverted signal of the O
Set to N ", and turn off Pch MOSFET when not emitting light.
To Here, since it is necessary to input the inverted signal of the input display data signal “DATA” to the data side driver IC 40, the inverted signal “RVC” in the data inversion control circuit 500 is set to “H”. Further, the switch SW8 is turned "ON" by the control signal "MDW" to charge the capacitor Cm with ¼ Vm. Next, after turning off the switch SW8 by the control signal "MDW", the switch SW7 is turned "O" by the control signal "MUP".
By setting it to N ", only non-emission pixels can be gradually reduced to 1/2 V
The first modulation voltage of m is charged on the data side. At this time, the light emitting pixel is not charged and the data side electrode potential of the light emitting pixel is 0.
It becomes V. When charging is completed, SW6 and SW7 turn to "OF".
Set to F ".

6. Charging and writing period (TP ₂ ) of the second modulation voltage in P drive Only the driver connected to the selective scan electrode Pch MO
Turn on the SFET and turn on the other scan side driver Nch
Turn on the MOSFET. At the same time, the write voltage Vw + Vm of positive polarity is applied to the pull-up common line of all the scanning side driver ICs 20 and 30 by turning on the switch SW4 by the control signal "PVC". Further, the switch SW3 is turned "ON" by the control signal "NM2" to the pull-down common line of all the scanning side driver ICs 20 and 30.
Then, the modulation voltage ¼ Vm is applied, and then the modulation voltage ½ Vm is applied by turning on the switch SW7 by the control signal “MUP”. On the other hand, the data-side driver 40 controls the first modulation voltage charging period (T
Continue driving P ₁ ).

As a result, since the data-side electrode potential of the light-emitting pixel is 0 V, the second modulation voltage of 1/2 Vm is gradually charged to the scan side, and at the same time, the positive write voltage Vw + Vm is applied to the selected scan electrode. Since it is applied, (Vw +
Vm) -0V = Vw + Vm is applied to emit light. Further, since the non-luminous pixel is charged with the modulation voltage 1/2 Vm on the data side during the first modulation voltage charging period (TP ₁ ), the data-side electrode potential becomes Vm. At the same time, as described above, since the positive write voltage Vw + Vm is applied to the selective scan electrode, (Vw + Vm) −Vm = Vw is applied to the non-emission picture element, but the light emission threshold voltage Vth. It does not emit light because it is below.

7. Writing voltage discharge and second modulation voltage recovery period in P drive (TP ₃₎ control signal "PVC", "NM2", "MUP" after the switch SW4, SW3, SW7 "OFF" by,
Scan side driver SDr _{1 to} SDri Nch MOSFET
By turning "ON", the writing voltage is discharged, and the potential of all electrodes on the scanning side becomes 1/2 Vm. Therefore, next, the switch SW is turned on by the control signals “NM2R” and “MDW”.
By turning ON 3'and SW8, a part of the electric charges accumulated with the scanning side electrode being positive during the second modulation voltage charging period (TP ₂ ) are accumulated in the capacitor Cm. The potential of all electrodes on the scanning side is 1/4 Vm. On the other hand, the electrode potential connected to the non-emission picture element of the data side electrode becomes 3/4 Vm.

8. Second modulation voltage discharge in P drive and first modulation voltage recovery period (TP ₄ ) Switch SW by control signals “NM2R”, “MDW”
After turning off 3'and SW8, control signal "NG"
When the switch SW2 is turned "ON" by C ", the scanning side electrode potential becomes 0 V. Also, the electrode potential connected to the data side non-light emitting pixel becomes 1/2 Vm. Here, the control signal" M1R ", "MDW" switches SW6 ',
By turning on SW8, the first modulation voltage period (T
Part of the electric charges accumulated in P ₁ ) with the data side electrode being positive is accumulated in the capacitor Cm. The potential of all electrodes on the data side is 1/4 Vm.

(B) PN field 1. First modulation voltage charging period in P drive (TP ₅ ) First modulation voltage charging period in NP field P drive
The same drive as (TP ₁ ) is performed.

2. Second modulation voltage charging and writing period (TP ₆ ) in P driving The same driving as in the second modulation voltage charging and writing period (TP ₂ ) in NP field P driving is performed.

3. Write voltage discharge in P drive and second modulation voltage recovery period (TP ₇ ) The same drive as write voltage discharge and second modulation voltage recovery period (TP ₃ ) in NP field P drive is performed.

4. Second modulation voltage discharge and first modulation voltage recovery period (TP ₈ ) in P drive The same drive as the write voltage discharge and second modulation voltage recovery period (TP ₄ ) in NP field P drive is performed.

5. 1st modulation voltage charging period in N drive (TN ₅ ) 1st modulation voltage charging period in NP field N drive
The same drive as (TN ₁ ) is performed.

6. Second modulation voltage charging and writing period (TN ₆ ) in N driving The same driving as in the second modulation voltage charging and writing period (TN ₂ ) in NP field N driving is performed.

7. Write voltage discharge in N drive and second modulation voltage recovery period (TN ₇ ) The same drive as write voltage discharge and second modulation voltage recovery period (TN ₃ ) in NP field N drive is performed.

8. Second modulation voltage discharge and first modulation voltage recovery period (TN ₈ ) in N drive The same drive as the second modulation voltage discharge and first modulation voltage recovery period (TN ₄ ) in NP field N drive is performed.

As described above, in this drive circuit, NP field and PN
It is composed of field drive timing, and NP
In the field, N for the odd-numbered selection line on the scanning side
Drive, P drive for even-numbered select lines,
In the PN field, the reverse driving is applied to apply an AC pulse necessary for light emission to all the picture elements of the thin film EL display device. FIG. 3 shows a typical example of voltage waveforms applied to the picture elements A and B.

By the way, in the conventional drive circuit, the charge accumulated by the writing voltage and the charge accumulated by the modulation voltage accumulated in the EL display element after light emission are discharged through the resistor in the drive circuit. However, in the drive circuit in this embodiment, a drive circuit capable of reusing this modulation accumulated charge is used (however, although the reuse of the write accumulated charge is omitted, the charge accumulated by the modulation voltage charging is omitted). It can be done in the same way as the reuse method.)
In this drive circuit, the modulation power consumption is reduced by 25% as compared with the conventional drive circuit that discharges the modulation accumulated charge. The reason for this will be described with reference to the model diagram of the circuit shown in FIG.

FIG. 4 (a) is a diagram in which the switch SWa is turned "ON" in the EL element display (capacitance Co) to charge the voltage Vo (corresponding to 1/2 Vm in the embodiment). Here, R represents the resistance in the drive circuit. In this case the energy the energy stored in the EL display device is dissipated in 1/2 CoVo ^2, R becomes 1 / 2CoVO ^2. Next, in this state, the switch SWa is turned "OFF", and the switch SWb is turned "ON" to examine the energy transferred from the EL display element to the external capacitor (capacitance C) when in the equilibrium state. Here, the external capacitor C has a voltage of 1 in advance.
It is assumed that / 2Vo is charged (however, C >> Co).
Further, when the current flowing in the circuit is i, the charge charged in the EL display element Co is qo, and the charge charged in the external capacitor C is q, Therefore, from equations (1), (2), and (3), Is obtained. On the other hand, from the circuit equation, R · i + q / C−qo / Co = 0 (5) holds, so if equations (3) and (4) are substituted into equation (5) and the obtained differential equation is solved. , Is obtained. Therefore, from equation (3) And the energy PR consumed by the resistor R is At t → ∞ Becomes Also, the energy remaining in the EL display element is a voltage of 1/2 Vo between both ends. Becomes Therefore, the energy stored in the external capacitor C from the EL display element Co (recovery energy) is Becomes

Therefore, in the normal charging and discharging of the EL display element Co, Since 25% of energy is required, 25% can be recovered.

In the present embodiment, the bidirectional switching element is connected to each of the scanning side electrode and the data side electrode of the thin film EL display device 10. However, the bidirectional switching element is connected only to the scanning side electrode or only the data side electrode. Then, even if the charge accumulated in the EL display element is reused, the same effect can be obtained, which does not impair the gist of the present invention.

<Effects of the Invention> As is apparent from the above, the driving circuit of the thin film EL display device of the present invention is connected to at least one of the scanning side electrode and the data side electrode in the thin film EL display element by the operation of the bidirectional switching circuit. By applying the write voltage and the modulation voltage to the pull-up common line or the pull-down common line of the high withstand voltage driver IC, by the operation of the bidirectional switching element of the above high withstand voltage driver IC,
A voltage equal to or higher than the light emission threshold is applied to the EL layer forming the display pixel to emit light to display an image, and the charge accumulated in the EL layer of the thin film EL display element is extracted to the outside by the operation of the first switching circuit. The second switching is performed when the write voltage or the modulation voltage is applied to the pull-up common line or the pull-down common line of the high breakdown voltage driver IC by the operation of the bidirectional switching circuit during the next image display. By the operation of the circuit, the charge accumulated in the capacitor is taken out and sent to the bidirectional switching circuit. Therefore, the modulated accumulated charge accumulated in the thin film EL display element after light emission is accumulated in the capacitor, and It can be reused when a write voltage is applied or a modulation voltage is applied during display.

Therefore, according to the present invention, the modulation power consumption, which occupies most of the driving power (about 70%), can be reduced by 25% as compared with the conventional driving without impairing the advantages of the conventional driving. Further, since the same method can be applied to the writing energy, the writing power consumption can be reduced by 25%, and the power consumption can be greatly saved.

[Brief description of drawings]

FIG. 1 is a drive circuit diagram of a thin film EL display device according to an embodiment of the present invention, FIG. 2 is a diagram showing a configuration example of a high breakdown voltage push-pull bidirectional driver, and FIG. 3 shows the operation of FIG. FIG. 4 is a diagram showing a time chart to be described and examples of voltage waveforms applied to picture elements, FIG. 4 is a recovery circuit model diagram of a drive circuit, FIG. 5 is a partially cutaway perspective view of a thin film EL display device, and FIG. FIG. 3 is a diagram showing luminance characteristics with respect to an applied voltage of the thin film EL display device. 10 ... Thin film EL display device, 20, 30 ... Scan side high withstand voltage push / pull driver IC (first bidirectional switching circuit), 40 ... Data side high withstand voltage push / pull driver IC
(Second bidirectional switching circuit), 100 ... Scan side high withstand voltage push / pull driver pull-down common line potential switching circuit and recovery circuit (third bidirectional switching circuit), 200 ... Scan side high withstand voltage push circuit Pull-up common line potential switching circuit (fourth bidirectional switching circuit) of pull driver, 300 ... Data side high voltage push-pull driver pull-up common line potential switching circuit and recovery circuit
(5th bidirectional switching circuit), 400 ... 1/2 modulation voltage step charging circuit and recovery circuit, 500 ... Data inversion control circuit.

Claims (1)

[Claims] 1. A thin film EL display device comprising an EL layer interposed between a scanning side electrode and a data side electrode arranged in a direction intersecting with each other, and is pushed to at least one of the scanning side electrode and the data side electrode. High breakdown voltage driver I composed of bidirectional switching element having pull function
A write voltage and a modulation voltage are applied to the pull-up common line or the pull-down common line of the high-voltage driver IC by a bidirectional switching circuit while C is connected, and the bidirectional switching element operates to apply to the EL layer. In a driving circuit of a thin film EL display device for displaying an image on a thin film EL display element by applying a voltage equal to or higher than a light emission threshold value, the bidirectional switching circuit and high breakdown voltage driver IC
A first switching circuit for taking out the electric charge accumulated in the thin film EL display element by the operation of the switching element to the outside after the EL layer emits light; and the thin film EL by the operation of the first switching circuit.
A capacitor for accumulating the electric charge extracted from the display element to the outside, and an electric charge accumulated in the capacitor are stored in the high breakdown voltage driver I by the operation of the bidirectional switching circuit.
A thin film EL display device comprising a second switching circuit which takes out when a write voltage or a modulation voltage is applied to a pull-up common line or a pull-down common line of C and sends it out to the bidirectional switching circuit. Drive circuit.