JP2003208127A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the occurrence of visual persistence phenomenon when high luminance data being set in an optical element are rewritten into low luminance data. <P>SOLUTION: When a scanning line SL becomes high and a first transistor Tr1 is turned on to write luminance data, the luminance data of an organic light emitting diode OLED are set onto the gate electrode of a second transistor Tr2. At the same time, a fourth transistor Tr4 provided on a bypass is turned on and electric charges of the anode of the diode OLED are drawn into a ground potential. At the same time, a third transistor Tr3 is turned off and the generation of a penetrating current from a power supply supplying line Vdd is suppressed. Thus, the luminance data of the diode OLED are initialized. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a technique for improving the display quality of an active matrix display device.

[0002]

2. Description of the Related Art The spread of notebook personal computers and portable terminals has been rapidly increasing. Currently, liquid crystal displays are mainly used for these display devices.
Organic E is expected as a next-generation flat display panel
It is an L (Electro Luminescence) display. The active matrix drive system is central to the display method of these displays. A display using this method is called an active matrix type display, and a large number of pixels are arranged vertically and horizontally to show a matrix shape, and a switching element is arranged in each pixel. Video data is sequentially written for each pixel by the switching element.

Research and development of organic EL displays are in their infancy, and various pixel circuits have been proposed. An example of such a circuit will be briefly described with reference to FIG. 9 (see Patent Document 1).

This circuit includes first and second transistors Tr11 and Tr12 which are two n-channel transistors.
An organic light emitting diode OLED which is an optical element, a storage capacitor SC11, a scanning line SL, and a power supply line Vdd.
And a data line DL for inputting luminance data.

The operation of this circuit is as follows:
In order to write the luminance data of the LED, the scanning line SL becomes high, the first Tr11 is turned on, and the luminance data input to the data line DL is set in the second transistor Tr12 and the storage capacitor SC11. . When the scanning line SL becomes low at the timing of light emission, the first transistor Tr11 is turned off, and the second transistor Tr12 is turned off.
The gate voltage of is maintained and light is emitted with the set brightness data.

[0006]

[Patent Document 1] Japanese Patent Laid-Open No. 11-219146

[0007]

When the brightness data of the optical element is large, even if an attempt is made to set a small brightness data by rewriting the brightness data, charges corresponding to the previous large brightness data remain without being removed from the optical element. In some cases, the afterimage phenomenon cannot be seen because the luminance data cannot be set accurately. In particular, the image becomes very difficult to see when displaying a moving image.

The present invention has been made in view of such circumstances, and an object thereof is to propose a new circuit for reducing the above-mentioned afterimage phenomenon. Another object is to reduce the power consumption of the display device. Another object is to propose a new circuit that suppresses the progress of deterioration of the optical element.

[0009]

One aspect of the present invention relates to a display device. This apparatus includes a current bypass element in parallel with the optical element, and controls the current bypass element according to the operation of setting the brightness data in the optical element to initialize the voltage generated across the optical element. In addition, a switch may be provided to shut off the path for supplying a current to the optical element when the current bypass element is turned on.

The data update instruction signal for setting the brightness data and the signal for controlling the current bypass element may be made common to initialize the voltage generated at both ends of the optical element and simultaneously set the brightness data. . Here, the data update instruction signal is generally a scanning signal and is input to the scanning line. Further, a data update instruction signal for setting the brightness data and a signal for controlling the current bypass element may be separately provided so that the timing of initializing the voltage generated at both ends of the optical element can be set. That is, a wiring different from the scanning line is prepared to control the current bypass element and the switch for supplying the current to the optical element. As a result, the voltage generated at both ends of the optical element can be initialized without being restricted by the scanning timing.

Assuming an active matrix type display device, one pixel is generally composed of an optical element, a driving circuit, a data line, a scanning line and a power supply line. Also,
A path connected in series with the drive circuit, the optical element, and the ground potential is formed from the power supply line, and a current having a desired value is supplied to the optical element. Here, a bypass including a switching element is provided from the anode of the optical element to the ground potential. Further, a switching element for cutting off the power supply from the power supply line to the optical element is provided between the drive circuit and the power supply line or between the drive circuit and the optical element.

When the switching element provided in the bypass is turned on, the anode of the optical element is short-circuited to the ground potential and has the same potential as the ground potential. At the same time, by turning off the switching element provided between the power supply line and the drive circuit,
The through current that flows from the power supply line to the ground potential is suppressed.

When the voltage generated at both ends of the optical element is initialized, a reverse voltage is applied to both ends of the optical element when the voltage to be applied when the optical element emits light is a positive voltage. Good. That is, a reverse bias application state may be applied when the optical element is caused to emit light.

Here, an organic light emitting diode can be assumed as the optical element, but the invention is not limited to this. Moreover, as a current bypass element and a switching element, a MOS (Metal Oxide Semicond
uctor) transistor and thin film transistor (TFT: Th)
in Film Transistor), but not limited to this. The "luminance data" is data relating to the luminance information set in the driving transistor, and is distinguished from the light intensity emitted by the optical element.

Another aspect of the present invention also relates to a display device. This apparatus has an optical element having a first terminal that is an entrance of a current and a second terminal that is an exit of the current, and a change of the current to be passed through the optical element, for a predetermined period, the first terminal And an initialization element for actively discharging electric charges from the side. Here, the initialization element is a switching element provided in parallel with the optical element, and when the switching element is turned on, the charge of the anode of the optical element is drawn to the ground potential via the switching element.

Yet another aspect of the present invention also relates to a display device. This apparatus has an optical element having a first terminal which is an entrance of an electric current and a second terminal which is an exit of an electric current, and a predetermined period when changing an electric current to be passed through the optical element,
An initialization element that stores electricity on the side of the first terminal. In addition, the initialization element may operate such that the second terminal has a higher potential than the first terminal during a predetermined period.

It should be noted that any combination or rearrangement of the above components is also effective as an aspect of the present invention.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the following embodiments, an active matrix type organic EL display is assumed as a display device. The embodiment proposes a new circuit that reduces the above-mentioned afterimage phenomenon. For this reason, a bypass including a switching element is provided in parallel from the anode of the optical element to the ground potential, and the switching element is turned on / off at a predetermined timing to release the electric charge of the optical element to the ground potential, and the brightness data of the optical element initialize.

First Embodiment FIG. 1 shows a circuit of one pixel of the display device according to the first embodiment. This pixel includes an organic light emitting diode OLED, which is an optical element, and a driving circuit 10.
, First and second storage capacitors SC1 and SC2, and third and fourth transistors Tr3 functioning as switching elements,
Equipped with Tr4. The drive circuit 10 further includes first and second transistors Tr1 and Tr2.

The data line D to which the brightness data is input
L, a power supply line Vdd for supplying a current to the organic light emitting diode OLED, and a scanning line SL to which a signal for updating the brightness data is input. The data line DL, the power supply line Vdd, and the scanning line SL are shared with other pixels.

In addition, the first, second and fourth transistors Tr
1, Tr2, Tr4 are n-channel transistors,
The third transistor Tr3 is a p-channel transistor.

First, third and fourth transistors Tr1 and Tr
Gate electrodes of 3 and Tr4 are connected to the scanning line SL. The drain electrode (or source electrode) of the first transistor Tr1 is on the data line DL, and the source electrode (or drain electrode) of the first transistor Tr1 and the gate electrode of the second transistor Tr2 are one of the second storage capacitors SC2. Connected to the electrode. A source electrode of the second transistor Tr2 and an anode of the organic light emitting diode OLED;
The other electrode of the storage capacitor SC2 is connected to the drain electrode (or source electrode) of the fourth transistor Tr4. The cathode of the organic light emitting diode OLED and the source electrode (or drain electrode) of the fourth transistor Tr4 are connected to the ground potential. The drain electrode of the second transistor Tr2 and one electrode of the first storage capacitor SC1 are connected to the drain electrode (or source electrode) of the third transistor Tr3. First storage capacity S
The other electrode of C1 is connected to ground potential. The source electrode (or drain electrode) of the third transistor Tr3 is connected to the power supply line Vdd.

Therefore, the third and second transistors Tr3 and Tr2 and the organic light emitting diode OLED are serially connected in this order from the power supply line Vdd to the ground potential to form a main path. Further, a bypass including the fourth transistor Tr4 is formed from the anode of the organic light emitting diode OLED.

The operation of this circuit will be described. When the scanning line SL goes high to turn on the first transistor Tr1 for writing the brightness data, the second transistor Tr1 is turned on.
A potential corresponding to the luminance data of the organic light emitting diode OLED is set to the second gate electrode and the second storage capacitor SC2. At the same time, the fourth transistor Tr4 is turned on and the charge of the anode of the organic light emitting diode OLED becomes the fourth
Is pulled out to the ground potential via the transistor Tr4. At the same time, since the third transistor Tr3 is turned off, generation of a through current from the power supply line Vdd is prevented. As a result, the anode of the organic light emitting diode OLED becomes the same potential as the ground potential.

Then, at the timing of light emission, the scanning line SL becomes low, so that the first and fourth transistors Tr.
1, Tr4 is turned off, and the third transistor Tr3 is turned on. As a result, a current corresponding to the brightness data set in the second transistor Tr2 flows from the power supply line Vdd to the organic light emitting diode OLED.

According to the first embodiment, since the brightness data of the optical element is initialized at the time of writing the brightness data, it is possible to reduce the afterimage phenomenon which is seen when the large brightness data is rewritten to the small brightness data. . Further, at that time, the current supply from the power supply line to the drive circuit is cut off, so that the consumption current is reduced.

Second Embodiment: FIG. 2 shows a pixel circuit of a display device according to a second embodiment. This pixel includes an organic light emitting diode OLED, which is an optical element, and a driving circuit 10.
And the first and second storage capacitors SC1 and SC2 and the third and fourth transistors Tr3 and T functioning as switching elements.
r4, the data line DL, the power supply line Vdd, the first,
Two scanning lines SL1 and SL2 are provided. The drive circuit 10 further includes first, second, fifth and sixth transistors Tr1, Tr2,
It includes Tr5 and Tr6. First and fourth transistors Tr
1, Tr4 is an n-channel transistor, and the second, third,
Transistors Tr2, Tr3, Tr5, Tr6 of 5 and 6
Is a p-channel transistor.

First, third and fourth transistors Tr1 and Tr
3, the gate electrode of Tr4 is connected to the scanning line SL1, and the gate electrode of the sixth transistor Tr6 is connected to the scanning line SL2. The drain electrode (or source electrode) of the first transistor Tr1 is connected to the data line DL. The source electrode (or drain electrode) of the first transistor Tr1 and the drain electrode of the fifth transistor Tr5 are connected to the drain electrode (or source electrode) of the transistor Tr6. The gate electrodes of the second and fifth transistors Tr2 and Tr5 and the source electrode (or drain electrode) of the transistor Tr6 are connected to one electrode of the second storage capacitor SC2. The source electrodes of the second and fifth transistors Tr2 and Tr5, the drain electrode (or source electrode) of the third transistor Tr3, and the other electrode of the second storage capacitor SC2 are one electrode of the first storage capacitor SC1. Connected to. The source electrode (or drain electrode) of the third transistor Tr3 is connected to the power supply line Vdd with the first storage capacitor S
The other electrode of C1 is connected to ground potential. The drain electrode of the second transistor Tr2 and the drain electrode (or source electrode) of the fourth transistor Tr4 are connected to the anode of the organic light emitting diode OLED. The cathode of the organic light emitting diode OLED and the source electrode (or drain electrode) of the fourth transistor Tr4 are connected to the ground potential.

The operation of this circuit will be described. The first scanning line SL1 is high for writing the luminance data, and the second scanning line SL is
When 2 goes low, the first, fourth, and sixth transistors Tr
1, Tr4, Tr6 are on, and the third transistor Tr3
Turns off. The gate electrode and the drain electrode of the fifth transistor Tr5 are short-circuited, and the fifth transistor Tr5
Operates in the unsaturated region, and the gate electrode of the fifth transistor Tr5 and the gate electrode of the second transistor Tr2 have the same potential. As a result, the brightness data is set in the second transistor Tr2. At this time, since the path from the power supply line Vdd is cut off by turning off the third transistor Tr3 and the fourth transistor Tr4 is turned on, the charge of the anode of the organic light emitting diode OLED is set to the fourth transistor Tr4. It is pulled out to the ground potential via and the potential of the anode of the organic light emitting diode OLED drops to the ground potential.

At the timing of light emission, the first scanning line S
L1 is low, the second scanning line SL2 is high, and
Transistors Tr1, Tr4, Tr6 of 4 and 6 are off,
The third transistor Tr3 is turned on. This allows
A current corresponding to the brightness data set in the second transistor Tr2 flows through the organic light emitting diode OLED.

According to the second embodiment, the same effect as that of the first embodiment can be obtained.

Third Embodiment: FIGS. 3 and 4 show a third embodiment.
2 shows a circuit of one pixel of the display device according to. Embodiment 1,
In the second example, the third transistor Tr3 that functions as a switching element is provided between the power supply line Vdd and the drive circuit 10, but in the third embodiment, it is provided between the drive circuit 10 and the organic light emitting diode OLED. Therefore, the circuit illustrated in FIG. 3 is a circuit in which the connection order of the third transistor Tr3 and the second transistor Tr2 in the circuit illustrated in FIG. 1 of Embodiment 1 is switched, and similarly the circuit illustrated in FIG. The third transistor T of the circuit shown in FIG. 2 of the second embodiment
This is a circuit in which the connection order of r3 and the second transistor Tr2 is exchanged.

The operation of these circuits is the same as in the first embodiment.
Since the operation is the same as that of the circuits of 2 and 2, the description thereof is omitted. Further, the same effect can be obtained. However, in the first and second embodiments, when the third transistor Tr3 is turned off,
The first storage capacitor SC1 is provided to suppress the influence given to the luminance data, that is, the influence given to the gate electrode of the second transistor Tr2. In the third embodiment, since the third transistor Tr3 is provided between the second transistor Tr2 and the organic light emitting diode OLED, the gate electrode of the second transistor Tr2 is turned off even when the third transistor Tr3 is turned off. You can eliminate the effect of giving.

The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that this embodiment is an exemplification, and that various modifications can be made to the combinations of the respective constituent elements and the respective processing processes, and that such modifications are within the scope of the present invention. . An example of such a modification will be given.

In the embodiment, the drive circuit 10 shown in FIGS. 1 to 4 is assumed as the drive circuit, but the present invention is not limited to this. Since there are many such drive circuits, the circuit to which the present invention is applied can be generalized as shown in FIGS. The circuit of FIG. 5 is a circuit that generalizes the first and second embodiments, and the circuit of FIG. 6 is a circuit that generalizes the third embodiment.

In the embodiment, the third and fourth transistors Tr3 and Tr4 are turned on / off using the scanning line SL connected to the drive circuit of the same pixel, but even if they are connected to the scanning line SL one scan before in time. Good. By doing so, the coupling noise due to the operation of the scanning line SL to the write data can be reduced. Furthermore, the third and fourth transistors Tr3,
A dedicated wiring may be separately provided to turn on / off Tr4. The circuits shown in FIGS. 7 and 8 are the control lines CS for turning on / off the third and fourth transistors Tr3 and Tr4 as described above by using the generalized circuits shown in FIGS. 5 and 6, respectively.
This is a circuit provided with L. As a result, there is no time restriction on the scanning line SL, and the light emission of the pixel can be controlled at any time. That is, by controlling the control line CSL, the light emission time can be adjusted, and the white balance and the brightness can be adjusted.

In the embodiment, the escape port for the current flowing through the bypass, that is, the source electrode of the fourth transistor Tr4 is connected to the ground potential, but the present invention is not limited to this. For example, this may be equal to the threshold voltage of the organic light emitting diode OLED. This improves the light emission response of the organic light emitting diode OLED.

In the embodiment, the organic light emitting diode OL is used.
Fourth transistor T bypassed to ED
The source electrode of r4 is connected to the ground potential and is set to the same potential as the cathode of the organic light emitting diode OLED, but the invention is not limited to this. Besides, for example, the source electrode of the fourth transistor Tr4 may be the organic light emitting diode OL.
It may be connected to a lower potential than the cathode of the ED. Such a pixel circuit is illustrated in FIGS. 10 and 11.

FIG. 10 shows a fourth transistor Tr4 connected to the ground potential in the pixel circuit shown in FIG.
Is a circuit in which the source electrode of is connected to a negative potential Vee lower than the ground potential to which the cathode of the organic light emitting diode OLED is connected. Similarly, in FIG. 11, in the pixel circuit shown in FIG. 8, the source electrode of the fourth transistor Tr4 connected to the ground potential is set to a negative potential Vee lower than the ground potential to which the cathode of the organic light emitting diode OLED is connected. It is a circuit to connect. In these pixel circuits, when the control line CSL becomes high, the third transistor Tr3 turns off and the fourth transistor Tr4 turns on.
At this time, the potential of the anode of the organic light emitting diode OLED is the negative potential V of the source electrode of the fourth transistor Tr4.
It becomes ee. Since the cathode of the organic light emitting diode OLED is at the ground potential and has a higher potential than the anode, the organic light emitting diode OLED is in the reverse bias applied state during the light emitting period.

By thus applying the reverse bias to the organic light emitting diode OLED, the electric charge remaining in the anode of the organic light emitting diode OLED can be extracted and the afterimage phenomenon can be suppressed, and at the same time, the organic light emitting diode OL can be suppressed.
The characteristics of the organic film that constitutes the ED can be recovered. As a general problem, the organic light-emitting diode OLED has a problem that deterioration of an organic film, that is, a decrease in brightness due to long-term use is remarkable as compared with an optical element using a liquid crystal. As described above, the deterioration of the organic film can be recovered while preventing the deterioration of the display quality by setting the organic light emitting diode OLED in the reverse bias applied state during the update period of the brightness data.

Here, the third and fourth transistors Tr3 and Tr4, which are the initialization elements, are on / off controlled by the control line CSL different from the scanning line SL, but the invention is not limited to this. 4 transistor Tr
On / off control of 3 and Tr4 may be performed. For example, in FIG.
The fourth transistor Tr4 as shown in FIG.
Also in the circuit controlled by L, the potential of the source electrode of the fourth transistor Tr4 is set to the organic light emitting diode OL.
You may connect to the negative electric potential Vee lower than the electric potential of the cathode of ED.

Generally, in the laminated structure of the organic light emitting diode OLED, as shown in FIG. 12, an anode layer 110, a hole transport layer 120, an organic EL layer 130, and a cathode layer 140 are laminated in order on an insulating substrate such as a glass substrate 100. Has been done. The laminated structure of the organic light emitting diode OLED is shown in FIG.
Not only the structure shown in FIG. 13 but also as shown in FIG.
The L layer 130, the hole transport layer 120, and the anode layer 110 may be sequentially stacked. When the laminated structure of the organic light emitting diode OLED is the structure shown in FIG. 12,
Although the cathode of the organic light emitting diode OLED is connected to the ground potential which is a fixed potential, in the case of the structure shown in FIG. 13, the anode of the organic light emitting diode OLED is connected to the fixed potential. A pixel circuit suitable for an organic light emitting diode OLED having such a laminated structure is shown in FIGS.
For example.

FIG. 14 shows that in the pixel circuit shown in FIG. 10, the anode and cathode of the organic light emitting diode OLED are replaced with each other, and the anode is connected to the power supply potential Vff which is a positive potential and a fixed potential. In addition, the fourth transistor Tr4
Of the electrode connected to the negative potential Vee of
It is connected to a positive potential Vgg which is a potential higher than f. Third transistor Tr connected to the power supply line Vdd
The electrode of 3 is connected to the low potential line Vhh which is at the ground potential.

Further, the third transistor Tr3 is changed from a p-channel transistor to an n-channel transistor, and the fourth transistor Tr4 is changed from an n-channel transistor to a p-channel transistor. During the light emitting period of the organic light emitting diode OLED, the current is changed from the power supply potential Vff to the organic light emitting diode OLED, the driving circuit 10, the third
Low potential line V which is ground potential through the transistor Tr3 of
It flows to hh. At this time, the control line CSL is set to high to turn on the third transistor Tr3 and turn off the fourth transistor Tr4. Organic light emitting diode OLE
When the control line CSL is set low during the update period of the brightness data of D, the third transistor Tr3 is turned off and the fourth transistor Tr4 is turned on. It becomes a high positive potential Vgg, and the organic light emitting diode O
The LED is in a reverse bias applied state.

FIG. 15 shows that in the pixel circuit shown in FIG. 11, the organic light emitting diode OLED has its anode and cathode replaced with each other, and the anode is connected to a ground potential which is a fixed potential. In FIG. 11, the power supply line Vdd having a positive potential to which the drive circuit 10 is connected is referred to as a negative potential line Vii having a negative potential. In addition, the negative potential Vee of the fourth transistor Tr4
The electrode connected to is connected to the positive potential Vgg, which is higher than the ground potential. Organic light emitting diode OLED
When the control line CSL is set to high during the update period of the luminance data, the fourth transistor Tr4 is turned on and the third transistor Tr3 is turned off. At this time, the potential of the cathode of the organic light emitting diode OLED becomes a positive potential Vgg higher than the power source potential Vff which is the potential of the anode, and thus the organic light emitting diode OLED is in the reverse bias applied state.

In the pixel circuit shown in FIGS. 14 and 15, the third and fourth transistors Tr3 and Tr4 are ON / OFF controlled by the control line CSL, but the invention is not limited to this. The ON / OFF control may be performed by the scanning line SL. Good. In that case, when the brightness data is set in the drive circuit 10,
A transistor in which the third transistor Tr3 is off and the fourth transistor Tr4 is on may be used.

[0047]

According to the present invention, the afterimage phenomenon can be reduced or the power consumption can be reduced. From another point of view, the progress of deterioration of the organic light emitting diode OLED can be suppressed.

[Brief description of drawings]

FIG. 1 is a diagram showing a pixel circuit according to a first embodiment.

FIG. 2 is a diagram showing a pixel circuit according to a second exemplary embodiment.

FIG. 3 is a diagram showing a pixel circuit according to a third embodiment.

FIG. 4 is a diagram showing a pixel circuit according to a third embodiment.

FIG. 5 is a diagram showing a generalized circuit of a pixel according to the first and second embodiments.

FIG. 6 is a diagram showing a generalized circuit of a pixel according to a third embodiment.

FIG. 7 is a diagram showing a generalized circuit of a pixel of a modified example.

FIG. 8 is a diagram showing a generalized circuit of a pixel of a modified example.

FIG. 9 is a diagram showing a circuit of a pixel of the related art.

FIG. 10 is a diagram showing a generalized circuit of a pixel of a modified example.

FIG. 11 is a diagram showing a generalized circuit of a pixel of a modified example.

FIG. 12 is a view showing a laminated structure of a general organic light emitting diode.

FIG. 13 is a view showing a laminated structure opposite to that of a general organic light emitting diode.

FIG. 14 is a diagram showing a generalized circuit of a pixel of a modified example.

FIG. 15 is a diagram showing a generalized circuit of a pixel of a modified example.

[Explanation of symbols]

10 Driving circuit, OLED Organic light emitting diode,
SC1 first holding capacity, SC2 second holding capacity,
SL scan line, CSL control line, Tr1 first transistor, Tr2 second transistor, Tr3
Third transistor, Tr4 fourth transistor, Tr5 fifth transistor, Tr6 sixth transistor, Vdd power supply line, Vee negative potential, Vff power supply potential, Vgg positive potential, Vhh
Low potential line, Vii negative potential line.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H05B 33/14 A

Claims (8)

[Claims] 1. A current bypass element is provided in parallel with an optical element, and the current bypass element is controlled according to an operation of setting brightness data in the optical element to initialize a voltage generated across the optical element. Characteristic display device. 2. The display device according to claim 1, further comprising a switch for interrupting a path for supplying a current to the optical element when the current bypass element is turned on. 3. A data update instruction signal for setting the brightness data and a signal for controlling the current bypass element are made common to initialize the voltage generated at both ends of the optical element and at the same time set the brightness data. The display device according to claim 1, wherein the display device is a display device. 4. A data update instruction signal for setting the brightness data and a signal for controlling the current bypass element are separately provided so that the timing of initializing the voltage generated at both ends of the optical element can be set. The display device according to claim 1, wherein the display device is a display device. 5. An optical element having a first terminal corresponding to an entrance of a current and a second terminal corresponding to an exit of the current,
A display device, comprising: an initialization element which actively discharges electric charges from the side of the first terminal for a predetermined period when changing a current to be passed through the optical element. 6. An optical element having a first terminal corresponding to an entrance of a current and a second terminal corresponding to an exit of the current,
A display device comprising: an initialization element that stores electricity on the side of the first terminal for a predetermined period when changing a current to be passed through the optical element. 7. The initialization device operates so that the second terminal has a higher potential than the first terminal during the predetermined period. Display device. 8. When the voltage generated at both ends of the optical element is initialized, a reverse voltage is applied to both ends of the optical element when a positive voltage is a voltage to be applied when the optical element emits light. The display device according to claim 1, wherein the display device is applied.