JP2001125526A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the complete ON state and the complete OFF state of a display element which are required in an area gradation system and also to make flicker not to be observed even when a screen scanning frequency is made to be a frequency lower than 60 Hz and moreover to reduce the power consumption of a driving circuit. SOLUTION: Threshold potentials for making a display element to be in ON and OFF states are defined as ON and OFF threshold potentials and control potentials which are to be applied to the ON and OFF states are defined as ON and OFF control potentials. The voltage width between the ON control potential and the OFF control potential is set to be larger than the voltage width between the ON threshold potential and the OFF threshold potential by the extent of widths of anticipated potential variations (dV1, dV2). Then, a screen scanning frequency is made to be lower than 60 Hz within a range that this condition is kepy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device,
The present invention relates to a thin film transistor driven organic electroluminescence display device and a thin film transistor driven liquid crystal display device which realize high image quality and low power consumption.

[0002]

2. Description of the Related Art Recently, an organic electroluminescent display device has been attracting attention as a display realizing the ultimate thin, lightweight, compact and low power consumption in the future. This organic electroluminescence display device is expected to be widely used in a large number in the future.

On the other hand, at present, liquid crystal display devices are already widely and widely used as displays for personal computer monitors, notebook computers, portable information terminals, car navigation systems, portable televisions, wall-mounted televisions, video viewfinders, and the like. It is expected that the range of use will further expand in the future.

One of the driving methods of these displays is an area gradation method (M. Kimura, et al., Proc. E
uro Display '99, to be published, JP 9-23310
7). In the area gray scale method, each display element arranged in a matrix is composed of a plurality of sub-display elements, and the sub-display elements are controlled to one of two states of an on state or an off state by a control potential, and are turned on. This is a method of obtaining a gray scale by changing the total area of the sub-display elements in a state.

An advantage of the area gray scale method over the organic electroluminescence display device is that the uniformity of image quality is improved.
Conventionally used Conductance Control method (T. Shim
oda, M. Kimura, et al., Proc. Asia Display 98, 217
(1998)), the uniformity of light emission luminance when an intermediate voltage is applied is poor. Therefore,
By using only the on-state and off-state with good emission luminance uniformity by the area gradation method, the image quality uniformity is improved (M. Kimura, et al., Proc. Euro Display '99,
to be published, JP-A-9-233107).

An advantage of the area gray scale method over the liquid crystal display device is that the viewing angle is widened. Twist Nemati is widely used
The c-type liquid crystal cell has a large viewing angle dependency when an intermediate voltage is applied. Therefore, a wide viewing angle is realized by using only the on-state and the off-state with little viewing angle dependence by the area gradation method.

[0007]

In an area gray scale method used for a liquid crystal display device or an organic electroluminescence display device, a complete on state and an off state are required. Therefore, a first object of the present invention is to realize a complete on-state and off-state.

One of the characteristics expected of a liquid crystal display device or an organic electroluminescence display device is a reduction in power consumption of a driving circuit. The screen scanning frequency of most current displays is 60 Hz. If the screen scanning frequency can be reduced, the power consumption of the driving circuit can be significantly reduced. However, in the conventional display, when the screen scanning frequency is set lower than 60 Hz, flicker is observed. In addition, flicker at about 30 Hz is known to cause serious health problems through visual perception (Pokemon Syndrome). Therefore, a second object of the present invention is to reduce the power consumption of the drive circuit by preventing flicker from being observed even when the screen scanning frequency is reduced to a frequency lower than 60 Hz.

[0009]

According to the present invention, a display element is formed in each of the pixels arranged in a matrix, and the display element is constituted by a plurality of sub-display elements.
The sub-display element is turned on or off depending on the control potential.
In a display device which is controlled to one of two states and obtains a gray scale by changing the total area of the sub-display elements in the ON state, a threshold potential for the sub-display element to be in the ON state is set to an ON threshold potential, The threshold potential for turning off the display element is an off threshold potential, the lower one of the on threshold potential and the off threshold potential is the lower threshold potential, and the higher one of the on threshold potential and the off threshold potential is the higher threshold potential. High threshold potential,
The control potential applied to the ON state is set to the ON control potential, the control potential applied to the OFF state is set to the OFF control potential, and the lower one of the ON control potential and the OFF control potential is set to the low control potential. When the higher potential of the control potential and the OFF control potential is set to the higher control potential, the change amount of the lower control potential during the screen scanning period is set to dV1, and the change amount of the higher control potential during the screen scanning period is set to dV2, The display device is characterized in that the low control potential is set to be dV1 lower than the low threshold potential, and the high control potential is set to be dV2 higher than the high threshold potential.

According to this configuration, even if the control potential changes during the screen scanning period, each sub-display element can be completely turned on or completely off for the entire screen scanning period. , Becomes possible.

According to a second aspect of the present invention, in the display device of the first aspect, the capacitance holding the control potential is C, the leak current from the capacitance in the on state is I1, and the capacitance in the off state is I1. When the leakage current from the capacitance is I2 and the screen scanning period is T, dV1 = I1T / C, dV2 = I2
A display device characterized by being represented by T / C.

According to this structure, each sub-display element can be completely turned on or completely turned off for the entire period of the screen scanning even if there is a leakage current from the capacitance. , Becomes possible.

According to a third aspect of the present invention, in the display device according to the first aspect, the low control potential is lower than the low threshold potential by dV1.
A display scanning frequency lower than 60 Hz within a range that maintains a condition that the high control potential is lower than the high threshold potential by dV2.

According to this configuration, even if the screen scanning frequency is reduced to a frequency lower than 60 Hz, flicker is not observed and power consumption of the driving circuit can be reduced.

According to a fourth aspect of the present invention, in the display device of the first aspect, a thin film transistor is formed in each of the pixels arranged in a matrix, and a control potential is sampled by the thin film transistor.
A display device.

According to this configuration, the display elements are reliably electrically cut off by the thin film transistors, so that dV1, dV1
V2 can be reduced.

According to a fifth aspect of the present invention, in the display device of the first aspect, the display element is a thin film transistor and an organic electroluminescence element connected in series to the thin film transistor.

According to this structure, even if the control potential changes during the screen scanning period, each sub-display element is completely turned on for the entire period of the screen scanning with respect to the organic electroluminescence display device. Or, it can be completely turned off.

According to a sixth aspect of the present invention, there is provided the display device according to the first aspect, wherein the display element is a liquid crystal display element.

According to this configuration, the liquid crystal display device
Even if the control potential changes during the screen scanning period, it is possible to set each sub-display element to a completely on state or a completely off state for the entire period of the screen scanning.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described.

In this embodiment, a polycrystalline silicon thin-film transistor (low-temperature process) formed by a low-temperature process at 600 ° C. or lower is used.
p-Si TFT). The low-temperature p-Si TFT can be formed on a large and inexpensive glass substrate and can incorporate a drive circuit on a panel, so it is a technology suitable for display manufacturing. In addition, the driving capability is high even in a small size, and a complicated circuit can be incorporated even in one pixel. The present embodiment is an organic electroluminescence element in which a display element is connected in series with a thin film transistor.

The concept of the present invention is also effective for a display using a thin film diode instead of a thin film transistor. Further, the idea of the present invention is also effective for passively driven displays.

FIG. 1 is a pixel equivalent circuit diagram of an embodiment of the present invention. Here, only one pixel is illustrated, but actually, there are a large number of pixels in a plurality of rows and a plurality of columns extending vertically and horizontally.

A plurality of scanning lines 11 and a plurality of signal lines 12 are formed in a matrix. Each scanning line 11 and each signal line 12
Pixel 13 is formed at the intersection of. In the pixel 13,
The switching thin film transistor 14, the storage capacitor 15, and the display element 16 are formed. In this embodiment, a driving thin film transistor 17 and an organic electroluminescence element 18 connected in series to the driving thin film transistor 17 are used as the display elements 16.

While the selection pulse is applied to the scanning line 11, an image signal is applied to the signal line 12, and is held in the storage capacitor 15 through the switching thin film transistor 14. This image signal is applied to the gate terminal of the driving thin film transistor 17, and the organic electroluminescence element
The current and light emission of 18 are controlled. The current used for light emission flows from the current supply wiring 191 to the cathode 192 via the driving thin film transistor 17.

In this embodiment, since the gradation is represented by 2 bits, the signal line 12 includes a low bit signal line 121 and a high bit signal line 122. Corresponding to this, the switching thin film transistor 14 also includes a low bit switching thin film transistor 141 and a high bit switching thin film transistor 142, and the storage capacitor 15 also includes a low bit storage capacitor 151 and a high bit storage capacitor 152. In addition, the display element 16
Also, a low-bit sub-display element 161 and a high-bit sub-display element 162
Consists of The driving TFT 1 corresponds to the low-bit sub-display element 161 and the high-bit sub-display element 162.
7 also includes a low bit driving thin film transistor 171 and a high bit driving thin film transistor 172, and the organic electroluminescence element 18 also includes a low bit organic electroluminescence element 181 and a high bit organic electroluminescence element 182. The area ratio between the low bit organic electroluminescent element 181 and the high bit organic electroluminescent element 182 is 1: 2. This ratio is obtained by arranging one and two organic electroluminescent elements 18 having the same area.
That is, the high-bit organic electroluminescence element 182 has the same area as the low-bit organic electroluminescence element 181 and has a first high-bit organic electroluminescence element 1821 and a second high-bit organic electroluminescence element 1822. Consists of When light is emitted at the same luminance, the light emission amount and the light emission area are in a proportional relationship, so the light emission amount is also 1: 2, and four gradations can be obtained. Note that 3
The concept of the present invention is also effective for gradations of bits or more.

FIG. 2 is a diagram showing a control method of the display element according to the embodiment of the present invention. The horizontal axis indicates the control potential applied to the gate electrode of the driving thin film transistor 17, and the vertical axis indicates the current flowing through the display element 16. Since the current flowing through the display element 16 and the light emission luminance are substantially proportional to each other, the vertical axis may be considered as the light emission luminance.

The display element 16 is controlled by a control potential to one of two states, an on state and an off state. The threshold potential for turning on the display element 16 is the ON threshold potential
The threshold potential for turning off the display element 16 is set to the off threshold potential 22. Here, since the p-type driving thin film transistor 17 is used, (ON threshold potential 2
1) <(off threshold potential 22). When the n-type driving thin film transistor 17 is used, (ON threshold potential 21)
> (Off threshold potential 22), and the same discussion holds if the corresponding parts are replaced in the following discussion. A control potential applied to the ON state is defined as an ON control potential 23, and a control potential applied to the OFF state is defined as an OFF control potential 24. Here again, since the p-type driving thin film transistor 17 is used, (on control potential 23) <(off control potential 24). When the n-type driving thin film transistor 17 is used, (ON control potential 23)> (OFF control potential 24), and the same discussion holds if the corresponding portions are replaced in the following discussion.

Since the switching thin film transistor 14 has a small but finite leak current, the scanning line
The ON control potential 23 or the OFF control potential 24 sampled while the selection pulse is being applied to 11 changes during the screen scanning period, that is, within the holding period. The amount of change in the ON control potential 23 during the holding period is dV1, and the amount of change in the OFF control potential 24 during the holding period is dV2. The ON control potential 23 is set lower than the ON threshold potential 21 by dV1, and the OFF control potential 24 is set higher than the OFF threshold potential 22 by dV2.

According to this configuration, even if the control potential changes during the holding period, the display element 16 can be completely turned on or completely turned off for the entire holding period. . That is, when the on-control potential 23 is sampled while the selection pulse is applied to the scanning line 11,
Even if the potential is increased by dV1 due to the leakage current of the switching thin film transistor 14 during the holding period, the complete ON state is still maintained. If the off-control potential 24 is sampled while the selection pulse is being applied to the scanning line 11, the potential is reduced due to the leakage current of the switching thin film transistor 14 during the holding period.
Even if the voltage drops by dV2, the complete off state is still maintained.

The dV1 and dV2 have dependence on the signal line potential that changes every moment during the screen scanning period and the control potential held in the storage capacitor 15. Therefore, it is desirable to set the maximum value in consideration of these dependencies as the values of dV1 and dV2.

Further, the capacitance holding the control potential, that is, the sum of the holding capacitance 15 and the gate capacitance of the driving thin film transistor 17 is C, the leakage current of the switching thin film transistor 14 in the on state is I1, and the switching thin film transistor in the off state is I. 14 Leakage current
When I2 and the screen scanning period are T, dV1 and dV2
Is represented by dV1 = I1 · T / C and dV2 = I2 · T / C.

According to this configuration, even if a leakage current of the switching thin film transistor 14 exists, the display element 16 can be
A full on state or a full off state can be achieved for the entire period of the screen scanning.

The screen scanning frequency is set to be lower than 60 Hz within a range where the condition that the ON control potential 23 is lower than the ON threshold potential 21 by dV1 and the OFF control potential 24 is higher than the OFF threshold potential 22 by dV2 is maintained. I have. In fact, it is possible to set the frequency to 10Hz or less.
This low frequency is desirable.

According to this configuration, the screen scanning frequency is set to 60 Hz.
Even if the frequency is lowered, the complete off state is still maintained over the entire holding period. Therefore, no problem such as flicker is observed. The power consumption of the driving circuit can be reduced without causing a problem in image quality.

FIG. 3 is a diagram showing a driving circuit according to an embodiment of the present invention. The scan driver clock 331 is applied to the scan driver shift register 311 and the output pulse is transferred. The output pulse has its driving capability increased by the scan driver buffer 312, and the scan line 11 existing in the display area 35 is output.
Is applied to On the other hand, the signal driver shift register 321
Is applied with a signal driver clock 341 to transfer an output pulse. The output pulse has its driving capability increased by the signal driver first buffer 322, and the signal driver first buffer 322 outputs the output pulse.
Applied to latch 323. The digital image signal 342 is applied in synchronization with the output pulse, and the signal driver first latch 3
Sampled at 23. Signal driver latch pulse 34
According to 3, the digital image signal 342 is transferred from the signal driver first latch 323 to the signal driver second latch 324.
The transferred digital image signal 342 is used as a signal driver second signal.
The drive capacity is increased by the buffer 325, and the display area 35
Is applied to the signal line 12 existing at From the peripheral supply wiring 36, a current necessary for causing the organic electroluminescence element 18 to emit light is supplied to the current supply wiring 191 in the display area 35. The cathode contact 37 is connected to the cathode 192, and draws out a current used to cause the organic electroluminescence device 18 to emit light.

In this embodiment, the scan driver and the signal driver are incorporated on the panel by using low-temperature polycrystalline silicon thin film transistor technology. By reducing the screen scanning frequency, the power consumption of these scanning drivers and signal drivers can be significantly reduced. Although not shown in FIG. 3, there is an external controller connected to the panel that generates a timing pulse necessary for the scan driver and the signal driver and a digital image signal 342. By reducing the screen scanning frequency, the power consumption of the external controller can be significantly reduced.

FIG. 4 is a diagram showing a manufacturing process of the thin film transistor according to the embodiment of the present invention. First, amorphous silicon is formed on a glass substrate 41 by PECVD using SiH4 or LPCVD using Si2H6. Amorphous silicon is recrystallized by irradiation with a laser such as an excimer laser or solid phase growth to form polycrystalline silicon 42 (FIG. 4A). After patterning the polycrystalline silicon 42, a gate insulating film 43 is formed, and a gate electrode 44 is formed and patterned (FIG. 4B). Impurities such as phosphorus and boron are self-aligned using polycrystalline silicon
Implanted into 42 and activated, source and drain regions 45 of the CMOS structure are formed. First interlayer insulating film 46
Is formed, a contact hole is opened, and a source electrode and a drain electrode 47 are formed and patterned (FIG. 4C). Further, a second interlayer insulating film 48 is formed,
A contact hole is opened, and a pixel electrode 49 made of ITO is formed and patterned (FIG. 4D).

FIG. 5 is a diagram showing a process of manufacturing an organic electroluminescence device according to an embodiment of the present invention. First, the adhesion layer 51 is formed, and an opening is formed in a region where light emission is desired. The interlayer 52 is formed, and an opening is formed (FIG. 5A). Next, the wettability of the substrate surface is controlled by plasma processing such as oxygen plasma or CF4 plasma. After that, the hole injection layer 53 and the light emitting layer 54 are spin-coated,
A film is formed by a liquid phase process such as squeegee coating or an inkjet process, or a vacuum process such as sputtering or vapor deposition. A cathode 55 containing an alkali metal to reduce the work function is formed into a film, sealed with a sealing agent 56, and completed (FIG. 5B). The role of the adhesion layer 51 is to improve the adhesion between the substrate and the interlayer layer 52 and to obtain an accurate light emitting area. The role of the interlayer 52 is to keep the cathode 55 away from the gate electrode 44 and the source and drain electrodes 47,
It is to reduce the parasitic capacitance and to control the wettability of the surface when forming the hole injection layer 53 and the light emitting layer 54 by the liquid phase process, thereby realizing accurate patterning (T.S.
himoda, M. Kimura, et al., Proc. Asia Display 98,
217 (1998)).

In this embodiment, a display element is formed in each of the pixels arranged in a matrix, and the display element is composed of a plurality of sub-display elements. In the display device, which is controlled to one of two states of an ON state and an OFF state and obtains a gray scale by changing the total area of the sub display elements in the ON state, a threshold potential for the sub display element to be in the ON state in the display device Is the on threshold potential, the threshold potential for turning off the sub-display element is the off threshold potential, the lower one of the on threshold potential and the off threshold potential is the lower threshold potential, the on threshold potential and the off threshold potential Of the higher potential, the higher threshold potential, the control potential applied to the ON state is set to the ON control potential, the control potential applied to the OFF state is set to the OFF control potential,
The lower potential of the on-control potential and the off-control potential is set to the lower control potential, the higher potential of the on-control potential and the off-control potential is set to the higher control potential, and the change amount of the lower control potential during the screen scanning period is calculated. When dV1 and the amount of change in the high control potential during the screen scanning period are dV2, the low control potential is set dV1 lower than the low threshold potential, and the high control potential is set dV2 higher than the high threshold potential. A display device, characterized in that:

According to this configuration, even if the control potential changes during the screen scanning period, each sub-display element can be completely turned on or completely off for the entire screen scanning period. , Becomes possible.

In this embodiment, the capacitance holding the control potential is C, the leakage current from the capacitance in the ON state is I1, and the capacitance in the OFF state is C. The display device is characterized in that when a leak current from the device is I2 and a screen scanning period is T, dV1 = I1 · T / C and dV2 = I2 · T / C.

According to this configuration, even if there is a leak current from the capacitance, each sub-display element can be completely turned on or completely off for the entire screen scanning period. , Becomes possible.

Further, the present embodiment is provided within a range that maintains the condition that the low control potential is dV1 lower than the low threshold potential and the high control potential is dV2 higher than the high threshold potential. And a screen scanning frequency lower than 60 Hz.

According to this configuration, the screen scanning frequency is set to 60 Hz.
Even if the frequency is lowered, flicker is not observed, and power consumption of the driving circuit can be reduced.

According to the present embodiment, a thin film transistor is formed in each of the pixels arranged in a matrix, and a control potential is sampled by the thin film transistor. is there.

According to this configuration, the display elements are reliably cut off electrically by the thin film transistors, so that dV1, dV1
V2 can be reduced.

The present embodiment is a display device characterized in that the display element is a thin film transistor and an organic electroluminescence element connected in series to the thin film transistor.

According to this configuration, even when the control potential changes during the screen scanning period, each sub-display element is completely turned on for the entire period of the screen scanning with respect to the organic electroluminescent display device. Or, it can be completely turned off.

The concept of the present invention is also effective for a display device characterized in that the display element is a liquid crystal display element. Furthermore, for elements driven by voltages other than liquid crystal display elements, elements driven by currents other than organic electroluminescent elements, and light transmittance modulation elements other than liquid crystal display elements, and light emitting elements other than organic electroluminescent elements. Even so, the idea of the present invention is effective.

According to this configuration, even if the control potential changes in the liquid crystal display device or another display device during the screen scanning period, each sub-display element is moved for the entire screen scanning period.
It is possible to have a complete on state or a complete off state.

[0053]

As described above, according to the present invention, even if the control potential changes during the screen scanning period, each sub-display element is completely turned on or completely turned on for the entire screen scanning period. It can be turned off. Therefore, the image quality becomes uniform. Also, even if the screen scanning frequency is reduced to a frequency lower than 60 Hz, flicker is not observed, and power consumption of the driving circuit can be reduced.

[Brief description of the drawings]

FIG. 1 is a pixel equivalent circuit diagram according to an embodiment of the present invention.

FIG. 2 is a diagram showing a control method of the display device according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a drive circuit according to an embodiment of the present invention.

FIG. 4 is a diagram showing a manufacturing process of the thin film transistor according to the embodiment of the present invention.

FIG. 5 is a diagram showing a manufacturing process of the organic electroluminescence device according to the example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Scan line 12 Signal line 121 Low bit signal line 122 High bit signal line 13 Pixel 14 Switching thin film transistor 141 Low bit switching thin film transistor 142 High bit switching thin film transistor 15 Retention capacity 151 Low bit retention capacity 152 High bit retention capacity Reference Signs List 16 display element 161 low bit sub display element 162 high bit sub display element 17 driving thin film transistor 171 low bit driving thin film transistor 172 high bit driving thin film transistor 18 organic electroluminescence element 181 low bit organic electroluminescence element 182 high bit organic Electroluminescent element 1821 First high bit organic electroluminescent element 1822 Second High bit organic electroluminescence element 191 Current supply wiring 192 Cathode 21 ON threshold potential 22 OFF threshold potential 23 ON control potential 24 OFF control potential 311 Scan driver shift register 312 Scan driver buffer 321 Signal driver shift register 322 Signal driver first buffer 323 Signal driver first latch 324 Signal driver second latch 325 Signal driver second buffer 331 Scan driver clock 341 Signal driver clock 342 Digital image signal 343 Signal driver latch pulse 35 Display area 36 Peripheral supply wiring 37 Cathode contact 41 Glass substrate 42 Polycrystalline Silicon 43 gate insulating film 44 gate electrode 45 source and drain regions 46 first interlayer insulating film 47 source electrode and drain Pole 48 second interlayer insulating film 49 pixel electrode 51 adhesion layer 52 interlayer layer 53 a hole injection layer 54 emitting layer 55 cathode 56 sealant

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/30 G09G 3/30 K 3/36 3/36 H05B 33/14 H05B 33/14 A F term ( Reference) 2H093 NA16 NC34 ND10 3K007 AB05 AB17 BA06 CA01 CB01 DA01 DB03 EB00 5C006 AA12 AF51 AF71 BB16 BB17 BC03 BC12 BF03 BF04 FA23 FA47 FA56 GA02 5C080 AA06 AA10 BB05 DD04 DD06 DD26 EE29 FF09 JJ02JJ03

Claims (6)

[Claims] 1. A display element is formed in each of pixels arranged in a matrix. The display element is composed of a plurality of sub-display elements, and the sub-display elements are turned on or off by a control potential. The display device is controlled to any of the above, and obtains a gradation by changing the total area of the sub-display elements in the on-state. In the display device, a threshold potential for the sub-display element to be in the on-state is an on-threshold potential. A threshold potential for causing the sub-display element to be in the off state is an off threshold potential, a lower one of the on threshold potential and the off threshold potential is a lower threshold potential, and the on threshold potential and the off threshold potential are The higher one of the potentials is set to a high threshold potential, the control potential applied to the on state is set to an on control potential, and the control potential applied to the off state is set to off control. And a lower potential of the on-control potential and the off-control potential is a lower control potential, and a higher potential of the on-control potential and the off-control potential is a higher control potential. The change amount of the low control potential is dV1, and the change amount of the high control potential during the screen scanning period is dV1.
When set to 2, the low control potential is d higher than the low threshold potential.
A display device, wherein the display device is set to be lower by V1 and the high control potential is set to be higher by dV2 than the high threshold potential. 2. The display device according to claim 1, wherein a capacitance holding the control potential is C, a leak current from the capacitance in the on state is I1, and the capacitance in the off state is I1. The leakage current from the capacitor is
When the screen scanning period is T, dV1 = I1T / C, d
A display device characterized by being represented by V2 = I2 · T / C. 3. The display device according to claim 1, wherein the low control potential is lower than the low threshold potential by dV1.
A display device, wherein a screen scanning frequency is lower than 60 Hz within a range that maintains a condition that the high control potential is higher than the high threshold potential by dV2. 4. The display device according to claim 1, wherein a thin film transistor is formed in each of the pixels arranged in a matrix, and the control potential is sampled by the thin film transistor. 5. The display device according to claim 1, wherein the display element is a thin film transistor and an organic electroluminescence element connected in series to the thin film transistor. 6. The display device according to claim 1, wherein the display element is a liquid crystal display element.
Display device.