Electronic paper display panel and display device

Abstract

The embodiment of the present invention provides an electronic paper display panel and a display device, including: a plurality of pixel circuits and a control circuit; the control circuit is connected to the common electrode through a first electrostatic ring circuit; the first electrostatic ring circuit includes: a first thin film transistor, a second thin film transistor, a third thin film transistor and a fourth thin film transistor. In the embodiment of the present invention, by connecting the gate and the drain of the fourth thin film transistor, the voltage difference between the gate and the drain of the fourth thin film transistor is zero. When a large voltage passes through the control circuit, the voltage will be significantly reduced through the first electrostatic ring circuit. In addition, since the gates of the second thin film transistor and the third thin film transistor are suspended, the current cannot pass through, which can avoid the leakage current of the control circuit flowing into the common electrode to affect the voltage of the common electrode, thereby improving the display quality of the electronic paper display panel and retaining the release of static electricity by the first electrostatic ring circuit.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to an electronic paper display panel and a display device. Background Art

[0002] Electronic paper (EPD) is a display panel commonly used in electronic readers and electronic tags. The display effect of electronic paper is close to that of paper, and it is more convenient to carry, environmentally friendly and energy-saving than paper.

[0003] Reference Figure 1 , is the pixel circuit of the electronic paper in an ideal state; wherein, it includes a plurality of pixel unit circuits 01, each pixel unit circuit 01 is connected to a common electrode Vcom, and the function of Vcom is to offset the voltage difference ΔVp generated inside the pixel unit circuit during the electronic paper display process, so that the black, white and red microspheres sandwiched between the two ends of the pixel capacitor of the pixel unit circuit can all be at a normal target display voltage. At present, since the electronic paper does not have a positive or negative frame flickering frame, it is impossible to adjust the voltage value of the common electrode when the positive or negative frame is good as the optimal Vcom value like an LCD (liquid crystal) display panel. Therefore, the voltage value of the common electrode of the current electronic paper is set after being sensed by an IC (chip), that is, when the common electrode is not connected to the external control circuit and other control circuits are normally turned on, the voltage value variation range of the electronic paper common electrode is tested by the IC, which is the optimal voltage value variation range, and then the optimal voltage value variation range of the common electrode Vcom is set. At this time, the voltage value of the common electrode should be within the set optimal voltage value variation range, and the optimal voltage value variation range of the common electrode Vcom is usually between -1V and 0.

[0004] However, the electronic paper display panels currently used all need to be connected to the control circuit through an electrostatic ring. Figure 2 This is a current control circuit access method, wherein the electrostatic ring circuit is 02, the control circuit is 03, and includes multiple control circuits 03, each control circuit 03 is connected to the common electrode Vcom through an electrostatic ring circuit 02. Figure 2 In the circuit diagram shown, IC and capacitor C1 are connected to detect the voltage of Vcom. The detected voltage value of Vcom deviates from the set optimal voltage value variation range, and the detected voltage value fluctuates severely, which leads to poor display effect of the electronic paper display panel.

[0005] On this basis, the data in Table 1 below are obtained through experimental measurement. The detection of the Vcom values ​​of the common electrodes of three different display panels (x, y and z) under different circuits shows that when the common electrode is not connected to the electrostatic ring circuit 02 and the control circuit 03, the absolute value of the Vcom value is the smallest, which is most consistent with the optimal voltage value set by Vcom. The more external control circuits 03 are connected, the greater the absolute value of the Vcom value is, and the more it deviates from the set optimal voltage value range. It can be seen that the external electrostatic ring circuit 02 and the control circuit 03 will cause leakage current in the display panel during use, which will lead to the problem of large fluctuation of the voltage value of the common electrode.

[0006] Voltage / V x types of display panels y types of display panels Types of display panels Before tangent -4.0 -4.1 -2.6 Cut off circuit A -2.8 -2.4 -2.0 Cut off the B and C circuits -1.7 -1.5 -1.6 Cut off the A, B and C circuits 0 -0.1 0

[0007] Table 1

[0008] In addition, the circuit structure of the electrostatic ring circuit 02 currently used is as follows Figure 3 , in the electrostatic loop circuit, and Figure 2 In the connection mode, the current electronic paper display panel has leakage problems in the external control circuit and the electrostatic ring circuit, which leads to unstable voltage value of the common electrode and large fluctuation, which ultimately leads to low display quality of the display panel. Summary of the invention

[0009] The present invention provides an electronic paper display panel to solve the problem that the voltage of the common electrode of the existing electronic paper display panel deviates from the optimal voltage value and has a large fluctuation.

[0010] In a first aspect, the present invention provides a method comprising: a plurality of pixel circuits and a control circuit; the plurality of pixel circuits are connected to a common electrode; the control circuit is connected to the common electrode via a first electrostatic ring circuit; the first electrostatic ring circuit comprises: a first thin film transistor, a second thin film transistor, a third thin film transistor and a fourth thin film transistor;

[0011] Wherein, the gate of the first thin film transistor is connected to the source of the first thin film transistor and the common electrode; the drain of the first thin film transistor is connected to the source of the second thin film transistor;

[0012] The gate of the second thin film transistor is respectively connected to the drain of the second thin film transistor, the gate of the third thin film transistor and the source of the third thin film transistor;

[0013] The drain of the third thin film transistor is connected to the source of the fourth thin film transistor;

[0014] The gate of the fourth thin film transistor is connected to the drain of the fourth thin film transistor and the control circuit.

[0015] Optionally, a plurality of the control circuits are included; the plurality of control circuits are connected in series via a second electrostatic ring circuit.

[0016] Optionally, the second electrostatic ring circuit has the same circuit structure as the first electrostatic ring circuit; the gate of the first thin film transistor in the second electrostatic ring circuit is connected to one of the control circuits; and the gate of the fourth thin film transistor in the second electrostatic ring circuit is connected to another adjacent control circuit.

[0017] Optionally, the control circuit includes: a switch control circuit and at least one pixel voltage circuit.

[0018] Optionally, the control circuit further includes: at least one data signal circuit.

[0019] Optionally, one of the data signal circuits is connected to the common electrode via the first electrostatic ring circuit.

[0020] Optionally, it includes a plurality of data signal circuits, the plurality of data signal circuits are connected to each other through the second electrostatic ring circuit, the pixel voltage circuit is connected to the data signal circuit through the second electrostatic ring circuit, and the switch control circuit is connected to the pixel voltage circuit through the second electrostatic ring circuit at the end away from the common electrode.

[0021] Optionally, the first thin film transistor, the second thin film transistor, the third thin film transistor and the fourth thin film transistor all have a source-drain homologous structure.

[0022] Optionally, the pixel circuit includes: a fifth thin film transistor, a coupling capacitor, and a storage capacitor; the drain of the fifth thin film transistor is connected to the first electrode of the pixel capacitor and the first electrode of the storage capacitor, and the second electrode of the pixel capacitor is connected to the common electrode; the second electrode of the storage capacitor is connected to the common electrode.

[0023] A second aspect of the present invention provides a display device, comprising any one of the electronic paper display panels described above.

[0024] An embodiment of the present invention provides an electronic paper display panel, comprising: a plurality of pixel circuits and a control circuit; the plurality of pixel circuits are all connected to a common electrode; the control circuit is connected to the common electrode via a first electrostatic ring circuit; the first electrostatic ring circuit comprises: a first thin film transistor, a second thin film transistor, a third thin film transistor and a fourth thin film transistor; wherein the gate of the first thin film transistor is connected to the source of the first thin film transistor and the common electrode; the drain of the first thin film transistor is connected to the source of the second thin film transistor; the gate of the second thin film transistor is respectively connected to the drain of the second thin film transistor, the gate of the third thin film transistor and the source of the third thin film transistor; the drain of the third thin film transistor is connected to the source of the fourth thin film transistor; the gate of the fourth thin film transistor is connected to the drain of the fourth thin film transistor and the control circuit. In the embodiment of the present invention, since the gate and drain of the fourth thin film transistor are connected, the voltage difference between the gate and drain of the fourth thin film transistor is zero. When a large voltage passes through the control circuit or static electricity is released on the first electrostatic ring circuit, the voltage will be significantly reduced through the first electrostatic ring circuit. In addition, since the gates of the second thin film transistor and the third thin film transistor are suspended, current cannot pass through the second thin film transistor and the third thin film transistor, which can prevent the leakage current of the control circuit from flowing into the common electrode, thereby affecting the voltage of the common electrode, thereby improving the display quality of the electronic paper display panel and retaining the release of static electricity by the first electrostatic ring circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0026] Figure 1 It is a schematic diagram of the circuit structure of an electronic paper display panel in the prior art;

[0027] Figure 2 It is a schematic diagram of the circuit structure of another electronic paper display panel in the prior art;

[0028] Figure 3 It is a circuit structure schematic diagram of an electrostatic ring circuit in the prior art;

[0029] Figure 4 is a schematic diagram of a circuit structure of an electronic paper display panel provided by an embodiment of the present invention;

[0030] Figure 5It is a circuit structure schematic diagram of an electrostatic ring circuit provided by an embodiment of the present invention;

[0031] Figure 6 is a schematic diagram of a circuit structure of another electronic paper display panel provided by an embodiment of the present invention;

[0032] Figure 7 is a performance detection diagram of a first electrostatic ring circuit provided by an embodiment of the present invention;

[0033] Figure 8 This is another performance detection diagram of the first electrostatic ring circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Reference Figure 4 , showing a schematic diagram of an electronic paper display panel provided by an embodiment of the present invention, comprising: a plurality of pixel circuits 10 and a control circuit 30; the plurality of pixel circuits 10 are all connected to a common electrode Vcom; the control circuit 30 is connected to the common electrode Vcom via a first electrostatic ring circuit 20.

[0036] Reference Figure 2 , the first electrostatic ring circuit 20 includes: a first thin film transistor T1, a second thin film transistor T2, a third thin film transistor T3 and a fourth thin film transistor T4;

[0037] Wherein, the gate electrode W1 of the first thin film transistor T1 is connected to the source electrode of the first thin film transistor and the common electrode; the drain electrode of the first thin film transistor T1 is connected to the source electrode of the second thin film transistor T2;

[0038] The gate of the second thin film transistor T2 is respectively connected to the drain of the second thin film transistor T2, the gate of the third thin film transistor T3 and the source of the third thin film transistor T3;

[0039] The drain of the third thin film transistor T3 is connected to the source of the fourth thin film transistor T4;

[0040] The gate of the fourth thin film transistor T4 is connected to the drain of the fourth thin film transistor T4 and the control circuit 30 .

[0041] Specifically, the pixel circuit 10 includes: a fifth thin film transistor T4; a pixel capacitor C2; a storage capacitor C3; the drain of the fifth thin film transistor T4 is connected to the first electrode of the pixel capacitor C2 and the first electrode of the storage capacitor C3, the second electrode of the pixel capacitor C2 is connected to the common electrode Vcom; the second electrode of the storage capacitor C3 is connected to the common electrode Vcom.

[0042] The working principle of the pixel circuit 10 is as follows: three kinds of charged particles, black, white, red or black, white and yellow, are sandwiched between the first electrode (pixel electrode) and the second electrode (common electrode) of the pixel capacitor C2. When a voltage is applied between the first electrode and the second electrode, the charged particles move in a directional manner. By controlling the direction of the electric field between the first electrode and the second electrode, the moving directions of different charged particles can be controlled accordingly, thereby controlling the display of the electronic paper display panel. When a voltage is applied to the gate of the fifth thin film transistor T5 to turn on the fifth thin film transistor T5, a voltage Vsource is applied to the source of the fifth thin film transistor T5, and the voltage value of the first electrode of the pixel capacitor is Vsource, and the voltage value of the common electrode Vcom is maintained between -1V-0V, a voltage difference is formed between the first electrode and the second electrode of the pixel capacitor, and the charged particles move to display; the storage capacitor C3 starts to store charge, and after the fifth thin film transistor T5 is turned off, the storage capacitor C3 releases the charge, so that the charged particles between the first electrode and the second electrode of the pixel capacitor move slowly, and finally stop displaying.

[0043] Reference Figure 5 The first electrostatic ring circuit W1 end is connected to the common electrode Vcom, and the first electrostatic ring circuit W2 end is connected to the control circuit 30 .

[0044] In the embodiment of the present invention, refer to Figure 4 , when there is only one control circuit 30, the control circuit 30 is connected to Vcom through the first electrostatic ring circuit 20. Since the gate and drain of the fourth thin film transistor are connected in the first electrostatic ring circuit, the voltage difference between the gate and drain of the fourth thin film transistor is zero. Therefore, when a large voltage passes through the control circuit or static electricity is released on the first electrostatic ring circuit, the voltage will be significantly reduced through the first electrostatic ring circuit. In addition, since the gates of the second thin film transistor and the third thin film transistor are suspended, the current cannot pass through the second thin film transistor and the third thin film transistor. Therefore, it is possible to avoid the leakage current of the control circuit from flowing into the common electrode, thereby affecting the voltage of the common electrode, improving the display quality of the electronic paper display panel, and retaining the release of static electricity by the first electrostatic ring circuit. Therefore, the first electrostatic ring circuit 20 can release static electricity, and can reduce the large voltage generated by the control circuit 30, and prevent leakage from affecting the common electrode Vcom.

[0045] In addition, multiple control circuits may be included, which correspondingly include multiple first electrostatic ring circuits, and each control circuit is connected to the common electrode Vcom through a first electrostatic ring circuit.

[0046] Specifically, the control circuit may be one or more, wherein the control circuit includes: a switch control circuit SW 30(a), a pixel voltage circuit GO / GE 30(b) and a data signal circuit DO / DE 30(c); wherein the switch control circuit 30(a) is used to control whether to apply a voltage to the gate of the fifth thin film transistor in the pixel circuit 10, that is, to control whether the fifth thin film transistor T5 is turned on or off. The pixel voltage circuit 30(b) is used to control whether to apply a voltage to the source of the fifth thin film transistor in the pixel circuit 10 to control the voltage difference of the pixel capacitor C2; the data signal circuit 30(c) is used to obtain the content to be displayed on the display panel, and then determine the voltage value applied to the source of the fifth thin film transistor.

[0047] When the control circuit 30 has only the switch control circuit SW, the switch control circuit SW applies a voltage of -20V to the gate of the fifth thin film transistor T5, and detects the voltage values ​​of the common electrodes of the display panels of different electrostatic ring circuits. Referring to Table 2, the electrostatic ring circuits AD are various electrostatic ring circuits used in the prior art, and the first electrostatic ring circuit is the electrostatic ring circuit used in the embodiment of the present invention.

[0048] It can be seen from Table 2 that when the switch control circuit SW is in the working state, the currently used electrostatic ring circuits will have leakage current, which will affect the common electrode Vcom. However, when the first electrostatic ring circuit provided in the embodiment of the present invention is used, no static current will be generated. In addition, when the switch control circuit SW is not connected to the common electrode, no leakage current will be generated. Therefore, it can be known that the electrostatic ring circuit on the display panel is the main source of leakage of the switch control circuit SW to Vcom. The purpose of designing the electrostatic ring circuit in the electronic paper display panel and connecting it to the common electrode is to prevent the display panel from being electrostatically acted during the manufacturing process or during user use. However, the static electricity cannot be released and flows into the pixel circuit to cause electrostatic breakdown. Therefore, it is necessary to set an electrostatic ring circuit in the display panel. By setting the first electrostatic ring circuit provided in the embodiment of the present invention, on the one hand, the leakage current of the control circuit can be prevented from flowing into the common electrode, and on the other hand, the static electricity can be released to avoid the influence of static electricity on the pixel circuit.

[0049]

[0050] In the embodiment of the present invention, refer to Figure 6 , including multiple control circuits 30; the multiple control circuits 30 are connected in series through a second electrostatic ring circuit 40.

[0051] Specifically, connecting the control circuits 30 in series can prevent the leakage current of each control circuit 30 from acting more directly on the common electrode compared to connecting them in parallel, thereby reducing the impact of the leakage current on the common electrode.

[0052] In an embodiment of the present invention, the circuit structure of the second electrostatic ring circuit 40 is the same as that of the first electrostatic ring circuit 20; the gate W1 of the first thin film transistor in the second electrostatic ring circuit 40 is connected to one of the control circuits 30; the gate W2 of the fourth thin film transistor in the second electrostatic ring circuit 40 is connected to another adjacent control circuit 30.

[0053] Reference Figure 5 , which is also a schematic diagram of the circuit structure of the second electrostatic ring circuit 40, wherein the W1 end of the second electrostatic ring circuit 40 is connected to a control circuit 30, and the W2 end of the second electrostatic ring circuit 40 is connected to another control circuit.

[0054] In addition, the first electrostatic ring circuit 20 may also be Figure 5 In the circuit shown, the circuit structure of the second electrostatic ring circuit 40 can be any circuit structure, which can also play a role in reducing the influence of leakage current.

[0055] Specifically, refer to Figure 6 The control circuit includes: a switch control circuit 30 (a) and at least one pixel voltage circuit 30 (b). In addition, the control circuit also includes: at least one data signal circuit 30 (c).

[0056] Typically, two pixel voltage circuits GO and GE, and two data signal circuits DO and DE are set; wherein the pixel voltage circuit GO is used to control a part of the pixel circuits 10, the pixel voltage circuit GE is used to control another part of the pixel circuits 10, the data signal circuit DO is used to control a part of the pixel circuits 10, and the data signal circuit DE is used to control another part of the pixel circuits 10.

[0057] Specifically, one of the data signal circuits 30 ( c ) is connected to the common electrode Vcom via the first electrostatic ring circuit 20 .

[0058] In addition, it includes a plurality of data signal circuits 30 (c), the plurality of data signal circuits 30 (c) are connected to each other through the second electrostatic ring circuit 40, the pixel voltage circuit 30 (b) is connected to the data signal circuit 30 (c) through the second electrostatic ring circuit 40, and the switch control circuit 30 (a) is connected to the pixel voltage circuit 30 (b) through the second electrostatic ring circuit 40 at the end away from the common electrode Vcom.

[0059] Among them, the pixel voltage circuits GO and GE are in a low voltage state when the electronic paper display panel is in the display stage, and no leakage current is generated to the common electrode Vcom. Therefore, one of the pixel voltage circuits GO or GE is connected close to the common electrode Vcom, that is, it is directly connected to the common electrode through the first electrostatic ring circuit 20; and the switch control circuit 30 (a) is connected to the end farthest from the common electrode because the leakage current generated is the largest. This series connection method can avoid the influence of the leakage current of high voltage circuits such as SW and GO / GE on the common electrode Vcom, and avoid the occurrence of electronic paper display panel defects.

[0060] In the embodiment of the present invention, other electrostatic ring circuits are used to connect various control circuits in series and then connected to the common electrode, which can also reduce the influence of leakage current on the common electrode Vcom to a certain extent and also falls within the protection scope of the embodiment of the present invention.

[0061] The first thin film transistor T1 , the second thin film transistor T2 , the third thin film transistor T3 and the fourth thin film transistor T4 all have a source-drain homologous structure.

[0062] Specifically, the source-drain homologous structure means that the source and drain are made of the same material, which can release static electricity more quickly and effectively. In addition, the ratio of the width to the length of the channel of the first thin film transistor, the second thin film transistor, the third thin film transistor and the fourth thin film transistor is 11:28.5.

[0063] Reference Figure 7 , when the electronic paper display panel is not connected to the control circuit, but only connected to the electrostatic ring circuit, wherein K1 is the case where only the first electrostatic ring circuit 20 is connected, refer to Figure 5 , different voltages are applied to the W1 end of the first electrostatic loop circuit, and the W2 end of the first electrostatic loop circuit is connected to the common electrode Vcom. It can be seen that no matter how much voltage is applied to the W1 end of the first electrostatic loop circuit, the current of the common electrode is relatively stable, there is no leakage current, or the leakage current is very small and does not affect the common electrode. Figure 3 In the case of the electrostatic ring circuit shown in FIG. 1 , different voltages are applied to the P1 terminal, and the P2 terminal is connected to the common electrode. It can be seen that when the voltage value changes, different degrees of leakage current are generated on the common electrode. When the voltage value is large, the common electrode is affected. It can be seen that the first electrostatic ring circuit 20 provided by the embodiment of the present invention can avoid the influence of the leakage current generated by the control circuit on the common electrode, thereby avoiding the influence on the pixel circuit 10.

[0064] Reference Figure 8, two commonly used electronic paper display panels M1 and M2 are selected, a voltage of 21V is applied to one end of the electrostatic ring circuit of the display panel M1, and the current value of the common electrode of the display panel M1 is detected to be -2.94E-07. The electrostatic ring circuit of the display panel M1 is replaced with the first electrostatic ring circuit in the embodiment of the present invention, so that the W2 end is connected to the common electrode, and a voltage of 21V is also applied to the W1 end, then the current of the common electrode is measured to be -6.90E-09; the same detection operation is performed on the display panel M2, and the current of the common electrode before the electrostatic ring circuit is changed is -2.95E-07, and the current of the common electrode before the change is -4.57E-09; it can be seen that in the electronic paper display panel of the prior art, it is only necessary to replace the electrostatic ring circuit with the first electrostatic ring circuit provided in the embodiment of the present invention to improve the display quality of the electronic paper display panel, and the preparation process of the electronic paper display panel does not need to be changed to a large extent, thereby improving the preparation efficiency of the electronic paper display panel.

[0065] A second aspect of the present invention provides a display device, comprising any one of the electronic paper display panels described above.

[0066] An embodiment of the present invention provides an electronic paper display panel, comprising: a plurality of pixel circuits and a control circuit; the plurality of pixel circuits are all connected to a common electrode; the control circuit is connected to the common electrode via a first electrostatic ring circuit; the first electrostatic ring circuit comprises: a first thin film transistor, a second thin film transistor, a third thin film transistor and a fourth thin film transistor; wherein the gate of the first thin film transistor is connected to the source of the first thin film transistor and the common electrode; the drain of the first thin film transistor is connected to the source of the second thin film transistor; the gate of the second thin film transistor is respectively connected to the drain of the second thin film transistor, the gate of the third thin film transistor and the source of the third thin film transistor; the drain of the third thin film transistor is connected to the source of the fourth thin film transistor; the gate of the fourth thin film transistor is connected to the drain of the fourth thin film transistor and the control circuit. In the embodiment of the present invention, since the gate and drain of the fourth thin film transistor are connected, the voltage difference between the gate and drain of the fourth thin film transistor is zero. Therefore, when a large voltage passes through the control circuit or static electricity is released on the first electrostatic ring circuit, the voltage will be significantly reduced through the first electrostatic ring circuit. In addition, since the gates of the second thin film transistor and the third thin film transistor are suspended, the current cannot pass through the second thin film transistor and the third thin film transistor, which can prevent the leakage current of the control circuit from flowing into the common electrode, thereby affecting the voltage of the common electrode, thereby improving the display quality of the electronic paper display panel and retaining the release of static electricity by the first electrostatic ring circuit.

[0067] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0069] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An electronic paper display panel, characterized in that: It includes: multiple pixel circuits and a control circuit; the multiple pixel circuits are all connected to a common electrode; the control circuit is connected to the common electrode through a first electrostatic ring circuit; the first electrostatic ring circuit includes: a first thin film transistor, a second thin film transistor, a third thin film transistor and a fourth thin film transistor; wherein the gate of the first thin film transistor is connected to the source of the first thin film transistor and the common electrode; the drain of the first thin film transistor is connected to the source of the second thin film transistor; the gate of the second thin film transistor is respectively connected to the drain of the second thin film transistor, the gate of the third thin film transistor and the source of the third thin film transistor; the drain of the third thin film transistor is connected to the source of the fourth thin film transistor; the gate of the fourth thin film transistor is connected to the drain of the fourth thin film transistor and the control circuit.

2. The electronic paper display panel according to claim 1, characterized in that: It comprises a plurality of control circuits; the plurality of control circuits are connected in series via a second electrostatic ring circuit.

3. The electronic paper display panel according to claim 2, characterized in that: The circuit structure of the second electrostatic ring circuit is the same as that of the first electrostatic ring circuit; the gate of the first thin film transistor in the second electrostatic ring circuit is connected to one of the control circuits; the gate of the fourth thin film transistor in the second electrostatic ring circuit is connected to another adjacent control circuit.

4. The electronic paper display panel according to claim 2, characterized in that: The control circuit includes: a switch control circuit and at least one pixel voltage circuit.

5. The electronic paper display panel according to claim 4, characterized in that: The control circuit also includes: at least one data signal circuit.

6. The electronic paper display panel according to claim 5, characterized in that: One of the data signal circuits is connected to the common electrode via the first electrostatic ring circuit.

7. The electronic paper display panel according to claim 6, characterized in that: It includes a plurality of data signal circuits, the plurality of data signal circuits are connected to each other through the second electrostatic ring circuit, the pixel voltage circuit is connected to the data signal circuit through the second electrostatic ring circuit, and the switch control circuit is connected to the pixel voltage circuit through the second electrostatic ring circuit at the end away from the common electrode.

8. The electronic paper display panel according to claim 1, characterized in that: The first thin film transistor, the second thin film transistor, the third thin film transistor and the fourth thin film transistor all have a source-drain homologous structure.

9. The electronic paper display panel according to claim 1, characterized in that: The pixel circuit includes: a fifth thin film transistor, a pixel capacitor, and a storage capacitor; the drain of the fifth thin film transistor is connected to the first electrode of the pixel capacitor and the first electrode of the storage capacitor, and the second electrode of the pixel capacitor is connected to the common electrode; the second electrode of the storage capacitor is connected to the common electrode.

10. A display device, characterized in that: Comprising the electronic paper display panel as described in any one of claims 1-9.

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