Electronic paper pixel circuit, electronic paper display panel and electronic paper display device

Abstract

The invention discloses an electronic paper pixel circuit, an electronic paper display panel and an electronic paper display device, and relates to the technical field of electronic paper. The electronic paper pixel circuit comprises a first thin film transistor and a second thin film transistor, the grid electrode and the first electrode of the first thin film transistor are connected with each other to access a first grid control signal, and the second electrode is connected with the grid electrode of the second thin film transistor; the second electrode of the second thin film transistor accesses a driving signal, and the first electrode is connected with the pixel electrode; the threshold voltage of the first thin film transistor is greater than that of the second thin film transistor; the first thin film transistor controls the first thin film transistor to be conducted according to the first gate control signal, converts the first gate control signal into an input voltage signal and transmits the input voltage signal to the second thin film transistor; and a second thin film transistor configured to control a voltage of the pixel electrode according to an input voltage signal and a driving signal. According to the invention, driving of the electronic paper pixel can be realized through low voltage, and the purpose of saving power consumption is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic paper, and particularly to an electronic paper pixel circuit, an electronic paper display panel, and an electronic paper display device. Background Art

[0002] Currently, the commonly used driving technology for the backplane of an electronic paper thin film transistor (Thin Film Transistor, abbreviated as TFT) adopts a 2T2C method, that is, a circuit structure of 2 TFTs and 2 capacitors. Figure 1 FIG. is a schematic diagram of an electronic paper pixel driving panel in the prior art, and its pixel circuit is as Figure 2 shown, where 2 TFTs are connected in series to achieve the purpose of reducing the off-state current.

[0003] However Figure 2 For the pixel circuit shown, for example, if it is applied to the driving of an E6 electronic paper, the driving cross-voltage of the gate needs to be greater than or equal to 70V, and the driving cross-voltage of the source needs to be greater than or equal to 40V. In this high-voltage driving environment, problems such as breakdown of thin film transistor (TFT) devices, threshold voltage drift, and device failure caused by the increase in the temperature of TFT devices are likely to occur, and high-voltage driving results in high power consumption of the electronic paper pixel circuit. Summary of the Invention

[0004] In an embodiment of the present invention, an electronic paper pixel circuit is proposed to drive an electronic paper pixel through low voltage, achieve the purpose of saving power consumption, and solve problems such as breakdown of TFT devices, threshold voltage drift, and device failure caused by the increase in the temperature of TFT devices that are likely to occur in the existing pixel circuit under a high-voltage driving environment; the electronic paper pixel circuit includes: a first thin film transistor and a second thin film transistor; the gate and the first pole of the first thin film transistor are connected to each other and receive a first gate control signal; the second pole of the first thin film transistor is connected to the gate of the second thin film transistor; the second pole of the second thin film transistor receives a driving signal; the first pole of the second thin film transistor is connected to a pixel electrode; wherein, the threshold voltage of the first thin film transistor is greater than the threshold voltage of the second thin film transistor; The first thin film transistor is configured to control the first thin film transistor to conduct or turn off according to the first gate control signal, and convert the first gate control signal into an input voltage signal and transmit it to the second thin film transistor when the first thin film transistor is conducting; The second thin film transistor is configured to control the voltage of the pixel electrode according to the input voltage signal and the driving signal.

[0005] In one embodiment, the first thin film transistor is an amorphous silicon thin film transistor; the second thin film transistor is an indium gallium zinc oxide thin film transistor.

[0006] In one embodiment, the electronic paper pixel circuit further includes a third thin-film transistor; The gate of the third thin-film transistor is connected to a second gate control signal; The drain of the third thin-film transistor is connected to a first preset voltage signal; The source of the third thin-film transistor is connected to the gate of the second thin-film transistor; The third thin-film transistor is configured to control the third thin-film transistor to turn on or off according to the second gate control signal, and provide the first preset voltage signal to the gate of the second thin-film transistor when the third thin-film transistor is turned on; Wherein, the second gate control signal lags behind the first gate control signal by one clock cycle in terms of timing.

[0007] In one embodiment, the third thin-film transistor is an amorphous silicon thin-film transistor.

[0008] In one embodiment, the electronic paper pixel circuit further includes a fourth thin-film transistor; The gate of the fourth thin-film transistor is connected to a third gate control signal; The drain of the fourth thin-film transistor is connected to a second preset voltage signal; The source of the fourth thin-film transistor is connected to the gate of the second thin-film transistor; The fourth thin-film transistor is configured to control the fourth thin-film transistor to turn on or off according to the third gate control signal, and provide the second preset voltage signal to the gate of the second thin-film transistor when the fourth thin-film transistor is turned on; Wherein, the third gate control signal is one clock cycle ahead of the first gate control signal in terms of timing.

[0009] In one embodiment, the fourth thin-film transistor is an amorphous silicon thin-film transistor.

[0010] In one embodiment, the first preset voltage signal and the second preset voltage signal are low-level signals.

[0011] In one embodiment, the voltage of the first gate control signal is ±20V.

[0012] An embodiment of the present invention further provides an electronic paper display panel, and the electronic paper display panel includes the above-mentioned electronic paper pixel circuit.

[0013] An embodiment of the present invention further provides an electronic paper display device, and the electronic paper display device includes the above-mentioned electronic paper display panel.

[0014] The electronic paper pixel circuit provided by the embodiment of the present invention includes: a first thin-film transistor and a second thin-film transistor; the gate and the first pole of the first thin-film transistor are connected to each other and are connected to a first gate control signal; the second pole of the first thin-film transistor is connected to the gate of the second thin-film transistor; the second pole of the second thin-film transistor is connected to a driving signal; the first pole of the second thin-film transistor is connected to a pixel electrode; wherein, the threshold voltage of the first thin-film transistor is greater than the threshold voltage of the second thin-film transistor; the first thin-film transistor is configured to control the first thin-film transistor to conduct or turn off according to the first gate control signal, and when the first thin-film transistor conducts, convert the first gate control signal into an input voltage signal and transmit it to the second thin-film transistor; the second thin-film transistor is configured to control the voltage of the pixel electrode according to the input voltage signal and the driving signal. Compared with the prior art, in the embodiment of the present invention, by applying a first gate control signal to the gate of the first thin-film transistor to make the first thin-film transistor conduct, the first gate control signal is converted into an input voltage signal and transmitted to the gate of the second thin-film transistor; the second thin-film transistor controls the conduction of the second thin-film transistor according to the input voltage signal of the gate. Therefore, the first gate control signal does not require a high voltage, only needs to ensure that the first thin-film transistor conducts, and the first thin-film transistor only needs to provide a fixed voltage for the gate of the second thin-film transistor to make it conduct; after the second thin-film transistor conducts, since the threshold voltage of the second thin-film transistor is less than the threshold voltage of the first thin-film transistor, therefore, the second thin-film transistor can also effectively control the voltage between the source and drain of the second thin-film transistor under a relatively low voltage change. In this way, while meeting the requirements of high-quality display, the purpose of saving power consumption can be achieved, and moreover, the driving of the electronic paper pixel can be realized through a low voltage, which also avoids problems such as the breakdown of TFT devices, the drift of threshold voltage, and the failure of devices caused by the increase in the temperature of TFT devices easily caused by high-voltage driving of electronic paper pixels. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] In the drawings: Figure 1 is a schematic diagram of an electronic paper pixel driving panel in the prior art; Figure 2 is Figure 1 a schematic diagram of the pixel circuit corresponding to the electronic paper pixel driving panel in Figure 3Schematic diagram of an electronic paper pixel circuit provided in an embodiment of the present invention; Figure 4 Drive timing diagram of the electronic paper pixel circuit provided in an embodiment of the present invention; Figure 5 Schematic diagram of another electronic paper pixel circuit provided in an embodiment of the present invention; Figure 6 Schematic diagram of another electronic paper pixel circuit provided in an embodiment of the present invention; Figure 7 Provided in an embodiment of the present invention Figure 6 Schematic diagram of the pixel driving panel corresponding to the electronic paper pixel circuit. Detailed implementation manners

[0017] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer and more understandable, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Herein, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but not to limit the present invention.

[0018] In the description of this specification, the terms "include", "including", "have", "containing", etc. are all open-ended terms, that is, they are meant to include but not limited to. The descriptions referring to terms such as "an embodiment", "a specific embodiment", "some embodiments", "for example", etc. mean that the specific features, structures or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. The order of the steps involved in each embodiment is used to schematically illustrate the implementation of the present application, and the order of the steps is not limited and can be adjusted appropriately as needed.

[0019] It has been found through research that in the high-voltage driving environment of the existing electronic paper pixel circuit, problems such as breakdown of TFT devices, threshold voltage drift, and device failure caused by the increase in the temperature of TFT devices are likely to occur, and high-voltage driving results in high power consumption of the electronic paper pixel circuit.

[0020] Based on this, the present invention provides an electronic paper pixel circuit, which can drive the electronic paper pixel through low voltage, meet the requirements of low power consumption and high picture quality display, and can also solve the problems such as breakdown of TFT devices, threshold voltage drift, and device failure caused by the increase in the temperature of TFT devices that are likely to occur in the existing technology in the high-voltage driving environment.

[0021] Figure 3 Schematic diagram of the electronic paper pixel circuit provided in an embodiment of the present invention. As Figure 3As shown, the electronic paper pixel circuit may include: a first thin-film transistor T1 and a second thin-film transistor T2; the gate and the first electrode of the first thin-film transistor T1 are connected to each other and receive a first gate control signal Gate; the second electrode of the first thin-film transistor T1 is connected to the gate of the second thin-film transistor T2; the second electrode of the second thin-film transistor T2 receives a driving signal Source; the first electrode of the second thin-film transistor T2 is connected to a pixel electrode pixel; wherein, the threshold voltage of the first thin-film transistor T1 is greater than the threshold voltage of the second thin-film transistor T2; The first thin-film transistor T1 is configured to control the first thin-film transistor T1 to be turned on or off according to the first gate control signal Gate, and in the case where the first thin-film transistor T1 is turned on, convert the first gate control signal Gate into an input voltage signal and transmit it to the second thin-film transistor T2; The second thin-film transistor T2 is configured to control the voltage of the pixel electrode according to the input voltage signal and the driving signal Source.

[0022] Wherein, the above-mentioned first electrode may be a drain electrode, and the second electrode may be a source electrode, that is, the gate and the drain of the first thin-film transistor are connected to each other, and the source is connected to the gate of the second thin-film transistor; the source of the second thin-film transistor receives the driving signal, and the drain is connected to the pixel electrode; or, the above-mentioned first electrode may be a source electrode, and the second electrode may be a drain electrode, that is, the gate and the source of the first thin-film transistor are connected to each other, and the drain is connected to the gate of the second thin-film transistor; the drain of the second thin-film transistor receives the driving signal, and the source is connected to the pixel electrode.

[0023] In the embodiment of the present invention, the above-mentioned first thin-film transistor T1 is used to turn on or off the second thin-film transistor T2, and the second thin-film transistor T2 is used to drive the pixel electrode pixel. Therefore, in order to avoid breakdown of the TFT device and improve the driving efficiency and display effect, the threshold voltage Vth1 of the first thin-film transistor T1 is greater than the threshold voltage Vth2 of the second thin-film transistor T2, and the electron mobility of the second thin-film transistor T2 is greater than or equal to the electron mobility of the first thin-film transistor T1.

[0024] During specific implementation, as Figure 4 shown, it is a driving timing diagram of the electronic paper pixel circuit provided by the embodiment of the present invention. The voltage of the first gate control signal may be: Gate = ±20V, and the voltage of the driving signal may be: Source = ±20V; when the voltage of the first gate control signal Gate is +20V (high level), it indicates that the gate-source voltage Vgs1 of the first thin-film transistor T1 is greater than the threshold voltage Vth1 of the first thin-film transistor T1, and the first thin-film transistor T1 is turned on, converting the first gate control signal Gate into an input voltage signal and transmitting it to the gate of the second thin-film transistor T2 (that is Figure 3For the G point in [the circuit], the voltage of the gate (G point) of the second thin-film transistor can reach 24V after being coupled through the parasitic capacitance of the TFT. The gate-source voltage Vgs2 of the second thin-film transistor T2 is 24 - 20 = 4V > Vth2, and the second thin-film transistor T2 conducts. Then, according to the input voltage signal and the driving signal, the voltage of the pixel electrode is controlled. Since the Vth2 of the second thin-film transistor is much lower than the Vth1 of the first thin-film transistor, therefore, when the second thin-film transistor T2 is turned on under a relatively low voltage change, it can also effectively control the voltage between the source and drain of the second thin-film transistor T2. In this way, high voltage is not required during the driving process. Only by ensuring that the voltage of the first gate control signal can turn on the first thin-film transistor, and the first thin-film transistor only needs to provide a fixed voltage for the gate of the second thin-film transistor, can low-voltage driving of the electronic paper pixel be achieved.

[0025] During specific implementation, as Figure 3 shown, the above-mentioned electronic paper pixel circuit further includes a first pixel capacitor Cfpl and a second pixel capacitor Cst. Among them, the first end of the first pixel capacitor Cfpl and the first end of the second pixel capacitor Cst are connected to the pixel electrode; the second end of the first pixel capacitor Cfpl and the second end of the second pixel capacitor Cst are connected to a common electrode Vcom, and the common electrode Vcom and the pixel electrode pixel jointly charge the first pixel capacitor Cfpl and the second pixel capacitor Cst.

[0026] Taking the application of the above-mentioned electronic paper pixel circuit to a reader as an example, usually, the conventional pixel circuit of the reader needs high-voltage driving to meet the requirement of the screen refreshing time. By using the above-mentioned electronic paper pixel circuit, the display requirement can be met through low-voltage driving, saving power consumption. Moreover, if all the above-mentioned electronic paper pixel circuits adopt TFT devices with high mobility (mobility) (>=10 cm2 / (V⋅s)), the possibility of the first thin-film transistor T1 being broken down is greater, which is likely to cause the circuit to fail. Therefore, by restricting the threshold voltage of the first thin-film transistor T1 to be greater than the threshold voltage of the second thin-film transistor T2, the stability of the device circuit can be protected more effectively.

[0027] Taking the application of the above-mentioned electronic paper pixel circuit to an electronic price tag as an example, when the electronic price tag is driving for display, the gate-source voltage is about 40V, and the source-drain voltage is about 30V. Under this driving voltage, the above-mentioned electronic paper pixel circuit can work normally. Moreover, due to the characteristics of high mobility and low threshold voltage of the second thin-film transistor T2, the second thin-film transistor T2 can be in a fully open state, which is more conducive to the charging and holding of the pixel voltage.

[0028] It should be noted that the threshold voltage of the first thin-film transistor T1 is greater than that of the second thin-film transistor T2. It can be to select a material with a high threshold voltage as the semiconductor layer material of the first thin-film transistor T1 and a material with a low threshold voltage as the semiconductor layer material of the second thin-film transistor T2; or it can be to increase the thickness of the gate insulating layer of the first thin-film transistor T1 in the manufacturing process to increase its threshold voltage. In the embodiments of the present invention, amorphous silicon thin-film transistors have the advantages of simple process, low cost, high stability, etc. Therefore, the first thin-film transistor can be an amorphous silicon thin-film transistor; the indium gallium zinc oxide IGZO material itself has a high carrier mobility and can generate sufficient driving current at a relatively low voltage, thereby reducing the requirement for the driving voltage. Therefore, the second thin-film transistor can be an indium gallium zinc oxide thin-film transistor, which is beneficial to maintaining the voltage of the pixel electrode.

[0029] In summary, in the embodiments of the present invention, by applying a first gate control signal to the gate of the first thin-film transistor to turn on the first thin-film transistor, the first gate control signal is converted into an input voltage signal and transmitted to the gate of the second thin-film transistor; the second thin-film transistor controls the conduction of the second thin-film transistor according to the input voltage signal of the gate. Therefore, the first gate control signal does not require a high voltage, only needs to ensure that the first thin-film transistor is turned on, and the first thin-film transistor only needs to provide a fixed voltage for the gate of the second thin-film transistor to turn it on (Vgs2>=Vth2); after the second thin-film transistor is turned on, since the Vth1 of the second thin-film transistor is much lower than the Vth2 of the first thin-film transistor, the second thin-film transistor can effectively control the voltage between the source and drain of the second thin-film transistor even under a relatively low voltage change. In this way, while meeting the requirements of high-quality display, the purpose of power saving can be achieved, and moreover, the driving of the electronic paper pixel can be realized through a low voltage, which also avoids problems such as TFT device breakdown, threshold voltage drift, and device failure caused by the increase in the temperature of the TFT device easily caused by high-voltage driving of the electronic paper pixel.

[0030] In one embodiment, as Figure 5 shown, the above-mentioned electronic paper pixel circuit may further include a third thin-film transistor T3; The gate of the third thin-film transistor T3 is connected to a second gate control signal; The drain of the third thin-film transistor T3 is connected to a first preset voltage signal; The source of the third thin-film transistor T3 is connected to the gate of the second thin-film transistor; The third thin-film transistor T3 is configured to control the conduction or cutoff of the third thin-film transistor T3 according to the second gate control signal, and provide a first preset voltage signal to the gate of the second thin-film transistor T2 when the third thin-film transistor T3 is conducting; Among them, the second gate control signal lags behind the first gate control signal by one clock cycle in terms of timing.

[0031] In one embodiment, the first preset voltage signal Vdc can be a low-level signal.

[0032] In one embodiment, the third thin-film transistor can be an amorphous silicon thin-film transistor.

[0033] During specific implementation, refer to Figure 5 and Figure 4 , the above-mentioned first preset voltage signal can be: Vdc = -15V; the second gate control signal Gate+1 lags behind the first gate control signal Gate by one T time in terms of timing (that is, the Gate signal controls the first thin-film transistor T1 to conduct, and after one clock cycle T, the Gate+1 signal controls the third thin-film transistor T3 to conduct). Therefore, when the third thin-film transistor T3 conducts, the access of the negative voltage (low level Vdc) can quickly pull down the voltage of point G, realizing the quick turn-off of the second thin-film transistor T2. Moreover, since the material of the second thin-film transistor T2 is IGZO and IGZO has a low off-state current, after the second thin-film transistor T2 is turned off by the access of the negative voltage, the negative gate voltage of the second thin-film transistor T2 will not quickly drop due to a large leakage current. Therefore, the gate of the second thin-film transistor T2 can also stably maintain the negative voltage state, which is more conducive to maintaining the pixel electrode pixel voltage.

[0034] As Figure 6 shown, an embodiment of the present invention further provides an electronic paper pixel circuit, Figure 7 which is Figure 6 a schematic diagram of a pixel driving panel corresponding to the electronic paper pixel circuit. Refer to Figure 7 and Figure 6 , the above-mentioned electronic paper pixel circuit may further include a fourth thin-film transistor T4; The gate of the fourth thin-film transistor T4 is connected to a third gate control signal; The drain of the fourth thin-film transistor T4 is connected to a second preset voltage signal; The source of the fourth thin-film transistor T4 is connected to the gate of the second thin-film transistor T2; The fourth thin-film transistor T4 is configured to control the fourth thin-film transistor T4 to conduct or turn off according to the third gate control signal, and in the case where the fourth thin-film transistor T4 conducts, provide the second preset voltage signal to the gate of the second thin-film transistor T2; Among them, the third gate control signal is one clock cycle ahead of the first gate control signal in terms of timing.

[0035] In one embodiment, the second preset voltage signal Vdc can also be a low-level signal.

[0036] In one embodiment, the fourth thin film transistor may be an amorphous silicon thin film transistor.

[0037] In specific implementation, since the conduction of the first thin film transistor T1 depends on the cross voltage between the G point and the gate of the first thin film transistor T1, if the voltage of the G point is in a random or inappropriate state, the first thin film transistor T1 may not conduct as expected; therefore, the third gate control signal Gate-1 of the fourth thin film transistor T4 can be one clock cycle T earlier than the first gate control signal Gate in terms of timing (that is, the Gate-1 signal controls the fourth thin film transistor T4 to conduct, and after one clock cycle T, the Gate signal controls the first thin film transistor T1 to conduct). When the fourth thin film transistor T4 conducts, a reset operation can be performed on the voltage of the G point by accessing the second preset voltage signal Vdc, so that the voltage of the G point is at the low level VGL. In this way, when the first gate control signal Gate of the first thin film transistor T1 arrives, it can ensure the reliable conduction of the first thin film transistor T1, so that the signal can be smoothly transmitted to the subsequent circuit and ensure the normal operation of the pixel circuit.

[0038] Moreover, the forward and reverse scan functions can be realized through the fourth thin film transistor T4 and the third thin film transistor T3.

[0039] Specifically, the forward scan function is as follows: Gate control signals are applied in the order of Gate-1 --> Gate --> Gate+1. First, the third gate control signal Gate-1 makes the fourth thin film transistor T4 conduct, and some initialization operations (reset operations) may be performed at this time, such as pre-adjusting the voltage of the G point (if there are residual charges, etc.) to ensure that the circuit is in a suitable starting state; then, the arrival of the first gate control signal Gate makes the first thin film transistor T1 conduct, and the input voltage signal can be smoothly transmitted to the G point of the second thin film transistor T2 to provide a conduction signal for the second thin film transistor T2; finally, the second gate control signal Gate+1 signal makes the third thin film transistor T3 conduct, and the access of the low level signal can quickly pull down the voltage of the G point and quickly turn off the second thin film transistor T2.

[0040] Specifically, the reverse scanning function is described as follows: The gate control signals are applied in the order of Gate+1 --> Gate --> Gate-1. First, the second gate control signal Gate+1 turns on the third thin-film transistor T3, and an initialization operation similar to that when the fourth thin-film transistor T4 is turned on during forward scanning is performed. For example, the voltage at point G is set specifically to meet the requirements of the reverse scanning initial state. Then, the arrival of the first gate control signal Gate turns on the first thin-film transistor T1, and the input voltage signal can be smoothly transmitted to the G point of the second thin-film transistor T2, providing a turn-on signal for the second thin-film transistor T2. Finally, the third gate control signal Gate-1 turns on the fourth thin-film transistor T4, and the access of the low-level signal can quickly pull down the voltage at the G point, quickly turning off the second thin-film transistor T2.

[0041] In this way, the above forward and reverse scanning functions can meet different user display requirements, improve the display quality, optimize signal transmission, and are helpful for assisting panel detection and repair during the production and use of the display panel.

[0042] In summary, the electronic paper pixel circuit provided by the embodiment of the present invention does not require a high voltage for driving. It only needs to ensure that the first thin-film transistor is turned on, and the first thin-film transistor only needs to provide a fixed voltage for the gate of the second thin-film transistor to turn it on. After the second thin-film transistor is turned on, since the threshold voltage of the second thin-film transistor is much lower than that of the first thin-film transistor, the second thin-film transistor can effectively control the voltage between the source and drain of the second thin-film transistor even under a relatively low voltage change. In this way, while meeting the high-quality display requirements, the purpose of power consumption saving can be achieved. Moreover, the driving of the electronic paper pixel can be realized through a low voltage, which also avoids problems such as breakdown of TFT devices, threshold voltage drift, and device failure caused by the increase in the temperature of TFT devices easily caused by high-voltage driving of electronic paper pixels. At the same time, the second thin-film transistor can be quickly turned off through the third thin-film transistor; and through the fourth thin-film transistor, the reset operation of the gate voltage of the second thin-film transistor can be realized before the arrival of the first gate control signal, and the forward and reverse scanning functions can be realized.

[0043] It should be noted that the above first thin-film transistor, second thin-film transistor, third thin-film transistor, and fourth thin-film transistor are all manufactured and designed using the n-TFT process.

[0044] It should be noted that the above electronic paper pixel circuit can be applied to the driving and display scenarios of E6 electronic papers such as the above-mentioned readers and electronic price tags, and can also be applied to the driving and display scenarios of other types of electronic papers according to actual needs, which are not specifically limited here.

[0045] An embodiment of the present invention further provides an electronic paper display panel, which includes the above-mentioned electronic paper pixel circuit. The implementation of the electronic paper display panel refers to the description of the above-mentioned electronic paper pixel circuit, and will not be elaborated here.

[0046] An embodiment of the present invention further provides an electronic paper display device, which includes the above-mentioned electronic paper display panel. The implementation of the electronic paper display device refers to the description of the above-mentioned electronic paper display panel, and will not be elaborated here.

[0047] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electronic paper pixel circuit, characterized in that: include: A first thin film transistor and a second thin film transistor; the gate and the first electrode of the first thin film transistor are connected to each other and receive a first gate control signal; The second electrode of the first thin film transistor is connected to the gate of the second thin film transistor; the second electrode of the second thin film transistor is connected to the driving signal; The first electrode of the second thin film transistor is connected to the pixel electrode; wherein the threshold voltage of the first thin film transistor is greater than the threshold voltage of the second thin film transistor; The first thin film transistor is configured to control the first thin film transistor to be turned on or off according to the first gate control signal, and when the first thin film transistor is turned on, convert the first gate control signal into an input voltage signal and transmit it to the second thin film transistor; The second thin film transistor is configured to control the voltage of the pixel electrode according to the input voltage signal and the driving signal.

2. The electronic paper pixel circuit according to claim 1, characterized in that: The first thin film transistor is an amorphous silicon thin film transistor; the second thin film transistor is an indium gallium zinc oxide thin film transistor.

3. The electronic paper pixel circuit according to claim 1, characterized in that: The electronic paper pixel circuit further includes a third thin film transistor; The gate of the third thin film transistor is connected to the second gate control signal; The drain of the third thin film transistor is connected to a first preset voltage signal; The source of the third thin film transistor is connected to the gate of the second thin film transistor; The third thin film transistor is configured to control the third thin film transistor to be turned on or off according to the second gate control signal, and to provide a first preset voltage signal to the gate of the second thin film transistor when the third thin film transistor is turned on; The second gate control signal lags behind the first gate control signal by one clock cycle in terms of timing.

4. The electronic paper pixel circuit according to claim 3, characterized in that: The third thin film transistor is an amorphous silicon thin film transistor.

5. The electronic paper pixel circuit according to claim 3, characterized in that: The electronic paper pixel circuit further includes a fourth thin film transistor; The gate of the fourth thin film transistor is connected to the third gate control signal; The drain of the fourth thin film transistor is connected to a second preset voltage signal; The source of the fourth thin film transistor is connected to the gate of the second thin film transistor; The fourth thin film transistor is configured to control the fourth thin film transistor to be turned on or off according to the third gate control signal, and to provide a second preset voltage signal to the gate of the second thin film transistor when the fourth thin film transistor is turned on; The third gate control signal is one clock cycle ahead of the first gate control signal in terms of timing.

6. The electronic paper pixel circuit according to claim 5, characterized in that: The fourth thin film transistor is an amorphous silicon thin film transistor.

7. The electronic paper pixel circuit according to claim 3 or 5, characterized in that: The first preset voltage signal and the second preset voltage signal are low level signals.

8. The electronic paper pixel circuit according to claim 1, characterized in that: The voltage of the first gate control signal is ±20V.

9. An electronic paper display panel, characterized in that: Comprising the electronic paper pixel circuit as described in any one of claims 1-8.

10. An electronic paper display device, characterized in that: Comprising the electronic paper display panel as claimed in claim 9.

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