Electronic paper display panel, driving method thereof and electronic paper display device

Abstract

The invention provides an electronic paper display panel, a driving method thereof and an electronic paper display device.The electronic paper display panel comprises a plurality of pixel units arranged in an array mode, each pixel unit comprises a pixel driving circuit and a display unit, and each display unit comprises a first electrode, an electronic ink layer and a second electrode. The pixel driving circuit comprises a first thin film transistor, a second thin film transistor, a switching output circuit and a storage capacitor, in a non-driving period, the second thin film transistor receives a low-level signal to trigger turn-off, the switching output circuit switches to output a negative voltage signal to the first thin film transistor, the first thin film transistor is in a thorough turn-off state, and the storage capacitor is connected with the second thin film transistor. The first thin film transistor is in an off state, off-state leakage current is reduced, the second thin film transistor is in an off state, the leakage current between the storage capacitor and the data line is further reduced, the problems of picture residual images, contrast reduction and the like caused by the leakage current of the electronic paper display panel are solved, and the display effect of the electronic paper display panel is improved.

Description

Technical Field

[0001] This invention belongs to the field of electronic paper technology, and particularly relates to an electronic paper display panel and its driving method, and an electronic paper display device. Background Technology

[0002] Electronic paper (E-paper) is a novel display technology designed to simulate the look and reading experience of traditional paper. Its core technology involves applying a driving voltage within the panel to move electronic ink (E-ink) to display different grayscale levels or colors, and maintaining the original display image when the driving voltage is removed. Key features of electronic paper include low power consumption, clear readability in sunlight, flexible display, and portability.

[0003] The electronic paper display panel includes an array of pixel units. Each pixel unit includes a pixel driving circuit and a display unit. The pixel driving circuit includes at least a thin-film transistor and a storage capacitor. When the display unit is displaying, the thin-film transistor is turned on and transmits data signals to the storage capacitor, and applies a driving voltage to the display unit. The electronic ink in the display unit moves and displays. When the thin-film transistor is turned off, the output driving voltage is cut off, and the display unit maintains the original display image.

[0004] Electronic paper needs to maintain a static image for a long time due to its ultra-low power consumption characteristics. However, when the thin-film transistor is turned off, the potential of the storage capacitor continues to decay due to the off-state leakage current, which causes the electronic ink to shift, resulting in problems such as image ghosting and decreased contrast. Summary of the Invention

[0005] The purpose of this invention is to provide an electronic paper display panel that solves the problem of abnormal image caused by off-state leakage current in the thin-film transistors of the pixel driving circuit in traditional electronic paper display panels.

[0006] A first aspect of the present invention provides an electronic paper display panel, comprising a plurality of pixel units arranged in an array, each pixel unit comprising a pixel driving circuit and a display unit connected to each other;

[0007] The display unit includes a first electrode, an electronic ink layer, and a second electrode stacked together. The pixel driving circuit operates sequentially during driving and non-driving periods. Each pixel driving circuit is connected to a data line and a first scan line. The pixel driving circuit includes: The storage capacitor includes a first electrode plate and a second electrode plate disposed opposite to each other. The first electrode plate is connected to a first electrode corresponding to the display unit, and the second electrode plate is connected to a common electrode terminal. A first thin-film transistor, the second end of the first thin-film transistor being connected to the first electrode plate, the first thin-film transistor being used to trigger conduction when receiving a high-level signal and to trigger turn-off when receiving a negative voltage signal; A switching output circuit is connected to the control terminal of the first thin-film transistor. The switching output circuit is used to switch the output of the high-level signal during the driving period and to switch the output of the negative voltage signal during the non-driving period. The second thin-film transistor is connected to the data line, the first scan line, and a first terminal of the first thin-film transistor. The second thin-film transistor is used to be turned on during the driving period based on a high-level signal of the first scan line and to transmit the data signal of the data line to the first thin-film transistor, and to be turned off during the non-driving period based on a low-level signal of the first scan line.

[0008] Optionally, the pixel driving circuit operates sequentially during the pre-start-up period, the driving period, and the non-driving period; The switching output circuit is also used to switch the output of the high-level signal during the pre-start period; The second thin-film transistor is also configured to trigger a shutdown based on a low-level signal from the first scan line during the pre-start-up period.

[0009] Optionally, the pixel driving circuit is also connected to the second scan line, the third scan line, the first signal line, and the second signal line; The switching output circuit includes: A third thin-film transistor, wherein the control terminal of the third thin-film transistor is connected to the second scan line, the first terminal of the third thin-film transistor is connected to the first signal line, and the second terminal of the third thin-film transistor is connected to the control terminal of the first thin-film transistor, the third thin-film transistor is used to trigger conduction according to the high-level signal of the second scan line during the non-driving period and transmit the negative voltage signal on the first signal line to the first thin-film transistor; A fourth thin-film transistor, wherein the control terminal of the fourth thin-film transistor is connected to the third scan line, the first terminal of the fourth thin-film transistor is connected to the second signal line, and the second terminal of the fourth thin-film transistor is connected to the control terminal of the first thin-film transistor, the fourth thin-film transistor being used to be triggered to conduct according to the high-level signal of the third scan line during the pre-start period and the driving period, and to transmit the high-level signal of the second signal line to the first thin-film transistor.

[0010] Optionally, the pixel driving circuit further includes: A filtering circuit is connected between the output terminal of the switching output circuit and the control terminal of the first thin-film transistor. The filtering circuit is used to filter the output signal of the switching output circuit.

[0011] Optionally, the filtering circuit includes an operational amplifier, the non-inverting input of which is connected to the input of the switching output circuit, and the inverting input, output, and control terminal of the first thin-film transistor.

[0012] Optionally, the electronic paper display panel further includes an array substrate, wherein the first signal line, the second signal line, and the data line of each pixel driving circuit are arranged side by side on the array substrate along a first direction; The first scan line, the second scan line, and the third scan line of each pixel driving circuit are arranged side by side on the array substrate along a second direction, and the first direction and the second direction intersect.

[0013] A second aspect of the present invention provides a driving method for an electronic paper display panel, applied to the electronic paper display panel as described above, wherein the driving method for the electronic paper display panel operates sequentially during a driving period and a non-driving period; The driving method for the electronic paper display panel includes: During the driving period, the first control signal is output to control the switching output circuit to output a high-level signal, as well as to output a data signal to the data line and output a high-level signal to the first scan line; During the non-driving period, the second control signal is output to control the switching output circuit to output a negative voltage signal, and to cut off the output data signal to the data line and output a low-level signal to the first scan line.

[0014] Optionally, the driving method of the electronic paper display panel operates sequentially in a pre-start period, the driving period, and the non-driving period; The driving method for the electronic paper display panel further includes: During the pre-start-up period, the first control signal is output to control the switching output circuit to output the high-level signal and output a low-level signal to the first scan line.

[0015] Optionally, the switching output circuit includes a third thin-film transistor and a fourth thin-film transistor; The driving method for the electronic paper display panel includes: During the pre-start-up period, low-level signals, low-level signals, and high-level signals are output to the first scan line, the second scan line, and the third scan line, respectively, and negative voltage signals and high-level signals are output to the first signal line and the second signal line, respectively. During the driving period, a high-level signal, a low-level signal, and a high-level signal are respectively output to the first scan line, the second scan line, and the third scan line, and a negative voltage signal, a high-level signal, and a data signal are respectively output to the first signal line, the second signal line, and the data line; During the non-driving period, a low-level signal, a high-level signal, and a low-level signal are output to the first scan line, the second scan line, and the third scan line, respectively, and a negative voltage signal and a low-level signal are output to the first signal line and the second signal line, respectively.

[0016] A third aspect of the present invention provides an electronic paper display device, including a driving circuit and an electronic paper display panel as described above. The driving circuit is connected to corresponding data lines, scan lines and signal lines of the electronic paper display panel, and the driving circuit is used to implement the driving method of the electronic paper display panel as described above.

[0017] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: The above-mentioned electronic paper display panel includes multiple pixel units arranged in an array. Each pixel unit includes a pixel driving circuit and a display unit. The display unit includes a first electrode, an electronic ink layer, and a second electrode. The pixel driving circuit includes a first thin-film transistor, a second thin-film transistor, a switching output circuit, and a storage capacitor. During non-driving periods, the second thin-film transistor receives a low-level signal and is triggered to turn off. The switching output circuit switches to output a negative voltage signal to the first thin-film transistor, which is in a completely off state, reducing the off-state leakage current. Furthermore, the second thin-film transistor is in an off state, further reducing the leakage current between the storage capacitor and the data line. This improves the problems of image retention and contrast reduction caused by leakage current in the electronic paper display panel, thereby improving the display effect of the electronic paper display panel. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a first structure of an electronic paper display panel provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of a pixel unit provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of a first type of pixel driving circuit provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the first type of signal waveform of the pixel driving circuit provided in Embodiments 1 and 2 of the present invention; Figure 5 This is a schematic diagram of a second type of signal waveform of the pixel driving circuit provided in Embodiments 1 and 2 of the present invention; Figure 6 This is a second circuit diagram of the pixel driving circuit provided in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of a third type of signal waveform for the pixel driving circuit provided in Embodiments 1 and 2 of the present invention; Figure 8 This is a schematic diagram of a third type of pixel driving circuit provided in Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of the fourth type of pixel driving circuit provided in Embodiment 1 of the present invention; Figure 10 This is a schematic diagram of a second structure of the electronic paper display panel provided in Embodiment 1 of the present invention; Figure 11 This is a schematic diagram of the first process of the driving method for the electronic paper display panel provided in Embodiment 2 of the present invention; Figure 12 This is a schematic diagram of a second process for driving an electronic paper display panel according to Embodiment 2 of the present invention; Figure 13 This is a schematic diagram of a third process for driving an electronic paper display panel according to Embodiment 2 of the present invention. Figure 14 This is a schematic diagram of the electronic paper display device provided in Embodiment 3 of the present invention.

[0019] The figures in the diagram are labeled as follows: 100. Electronic paper display panel; 200. Driving circuit; 1. Array substrate; 2. Pixel unit; 21. Pixel driving circuit; 22. Display unit; 221. First electrode; 222. Electronic ink layer; 223. Second electrode; 211. Switching output circuit; 212. Filtering circuit; T1, First thin-film transistor; T2, Second thin-film transistor; T3, Third thin-film transistor; T4, Fourth thin-film transistor; U1, Operational amplifier; Cst, Storage capacitor; SL1, First scan line; SL2, Second scan line; SL3, Third scan line; DL1, Data line; S1, First signal line; S2, Second signal line; Vcom, common electrode voltage; X1, first direction; Y1, second direction; t1, driving period; t2, non-driving period; t3, pre-start period. Detailed Implementation

[0020] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Example 1 like Figure 1 As shown, a first aspect of the present invention provides an electronic paper display panel 100, which includes a plurality of pixel units 2 arranged in an array. Each pixel unit 2 includes a pixel driving circuit 21 and a display unit 22 connected to each other. The electronic paper display panel 100 may be composed of an array substrate 1, a counter substrate and an electronic ink layer 222, wherein the electronic ink layer 222 is disposed between the array substrate 1 and the counter substrate.

[0023] like Figure 2 As shown, the display unit 22 includes a first electrode 221, an electronic ink layer 222, and a second electrode 223 stacked together. The pixel driving circuit 21 and the first electrode 221 are disposed on the array substrate 1, and the second electrode 223 is disposed on the opposing substrate. A common electrode voltage Vcom is applied to the second electrode 223. The pixel driving circuit 21 operates sequentially during driving period t1 and non-driving period t2. During driving period t1, the pixel driving circuit 21 receives corresponding control signals and data signals and applies a driving voltage to the first electrode 221 of the display unit 22. The driving voltage and the common electrode voltage Vcom on the second electrode 223 form a driving voltage, which drives the electronic ink of the electronic ink layer 222 to move to the position of the first electrode 221, thereby displaying the corresponding grayscale or color.

[0024] During the non-driving period t2, the pixel driving circuit 21 maintains the driving voltage of the first electrode 221 and keeps the electronic ink at the current position of the first electrode 221 to achieve static image display.

[0025] In order to improve the leakage current of the pixel driving circuit 21 and to address the problem that the voltage of the first electrode 221 becomes unstable due to the drop in driving voltage, which in turn causes the electronic ink to shift and cause abnormal images, in this embodiment, each pixel driving circuit 21 is connected to the data line DL1 and the first scan line SL1. The pixel units 2 arranged in the array perform line-by-line scanning according to the line scanning signal input to the corresponding first scan line SL1 and display the corresponding image information according to the input data signal.

[0026] like Figure 3 As shown, in this embodiment, the pixel driving circuit 21 includes: The storage capacitor Cst includes a first plate and a second plate arranged opposite to each other. The first plate is connected to the first electrode 221 of the corresponding display unit 22, and the second plate is connected to the common electrode. The first thin-film transistor T1 has its second terminal connected to the first plate. The first thin-film transistor T1 is used to trigger conduction when receiving a high-level signal and to trigger turn-off when receiving a negative voltage signal. The switching output circuit 211 is connected to the control terminal of the first thin film transistor T1. The switching output circuit 211 is used to switch the output high-level signal during the driving period t1 and switch the output negative voltage signal during the non-driving period t2. The second thin-film transistor T2 is connected to the data line DL1, the first scan line SL1 and the first terminal of the first thin-film transistor T1 respectively. The second thin-film transistor T2 is used to be turned on by triggering the high-level signal of the first scan line SL1 during the driving period t1 and to transmit the data signal of the data line DL1 to the first thin-film transistor T1, and to be turned off by triggering the low-level signal of the first scan line SL1 during the non-driving period t2.

[0027] In this embodiment, reference Figure 4 As shown, the pixel driving circuit 21 operates in each frame during driving period t1 and non-driving period t2. During driving period t1 of the current frame, when scanning line by line to the line where the current pixel unit 2 is located, the switching output circuit 211 outputs a high-level signal to the first thin-film transistor T1 according to the received control signal or control logic. The row scanning signal input by the first scan line SL1 is the row enable signal, that is, a high-level signal is input to the second thin-film transistor T2. The first thin-film transistor T1 and the second thin-film transistor T2 are turned on. The data signal input by the data line DL1 is transmitted to the first plate of the storage capacitor Cst and the first electrode 221 of the display unit 22 through the second thin-film transistor T2 and the first thin-film transistor T1. The storage capacitor Cst is charged and the voltage of the first plate and the first electrode 221 reaches the driving voltage during driving period t1. The driving voltage of the first electrode 221 and the common electrode voltage Vcom on the second electrode 223 form the driving voltage, and drive the electronic ink of the electronic ink layer 222 to move to the position of the first electrode 221, thereby displaying the corresponding gray level or color.

[0028] During the non-driving period t2 of the current frame, i.e., when scanning line by line to the next line or not yet scanning the current line, the first scan line SL1 switches the input line off signal, i.e., switches the output low-level signal to the second thin-film transistor T2. During the non-driving period t2, the data signal input is cut off, and the second thin-film transistor T2 is turned off. Simultaneously, the switching output circuit 211 switches the output negative voltage signal to the first thin-film transistor T1. The negative voltage signal is negative, and the first thin-film transistor T1 is completely turned off. The internal leakage current path of the first thin-film transistor T1 is cut off, reducing the leakage current between the first thin-film transistor T1 and the storage capacitor Cst. The second thin-film transistor T2 is also turned off. In this state, the leakage current path between the storage capacitor Cst and the data line DL1 is cut off, reducing the leakage current between the storage capacitor Cst and the data line DL1. The terminal voltage of the first plate and the first electrode 221 of the storage capacitor Cst is maintained at the driving voltage, and the electronic ink inside the display unit 22 is maintained at the current position of the first electrode 221, realizing static image display. Furthermore, due to the improvement of leakage current, the electric field inside the display unit 22 will not change significantly. Correspondingly, the display image of the display unit 22 remains static, and there will be no problems of image retention or contrast reduction due to the decrease in electric field voltage, thus improving the display effect of the display unit 22 and the electronic paper display panel 100.

[0029] Furthermore, in order to reduce the signal crosstalk problem when two switches are turned on at the same time, in an optional embodiment, the pixel driving circuit 21 operates sequentially in the pre-start period t3, the driving period t1, and the non-driving period t2; The switching output circuit 211 is also used to switch the output high-level signal during the pre-start-up period t3; The second thin-film transistor T2 is also used to trigger shutdown during the pre-start-up period t3 based on the low-level signal of the first scan line SL1.

[0030] In this embodiment, as Figure 5 As shown, in each frame, there is also a pre-start-up period t3 between the driving period t1. During the pre-start-up period t3, the first scan line SL1 outputs a low-level signal to the second thin-film transistor T2, and the second thin-film transistor T2 is in the off state. At the same time, the switching output circuit 211 switches to output a high-level signal to the first thin-film transistor T1, and the first thin-film transistor T1 is triggered to turn on. At this time, the storage capacitor Cst is not charged, and there is no driving voltage input to the first plate and the first electrode 221. Correspondingly, the electronic ink inside the display unit 22 remains in a static state. By controlling the second thin-film transistor T2 to turn on first, signal crosstalk can be prevented when the two thin-film transistors switch on at the same time during the driving period t1, and the spike voltage of the first plate and the second electrode 223 can be avoided, which would lead to the display unit 22 displaying abnormally.

[0031] The first scan line SL1 and data line DL1 are connected to the driving circuit 200 outside the electronic paper display panel 100 or to the driving circuit 200 bonded to the electronic paper display panel 100, and the driving circuit 200 provides the corresponding row scan signal and data signal. The switching output circuit 211 can be connected to the driving circuit 200 or to other control units, and switches the output of high-level signal and negative voltage signal respectively during the pre-start period t3, the driving period t1, and the non-driving period t2.

[0032] The switching output circuit 211 can be composed of corresponding switches. In an optional embodiment, such as... Figure 6 As shown, the pixel driving circuit 21 is also connected to the second scan line SL2, the third scan line SL3, the first signal line S1, and the second signal line S2.

[0033] The switching output circuit 211 includes: The third thin-film transistor T3 has its control terminal connected to the second scan line SL2, its first terminal connected to the first signal line S1, and its second terminal connected to the control terminal of the first thin-film transistor T1. The third thin-film transistor T3 is used to be triggered to conduct during the non-driving period t2 according to the high-level signal of the second scan line SL2 and to transmit the negative voltage signal on the first signal line S1 to the first thin-film transistor T1. The fourth thin-film transistor T4 has its control terminal connected to the third scan line SL3, its first terminal connected to the second signal line S2, and its second terminal connected to the control terminal of the first thin-film transistor T1. The fourth thin-film transistor T4 is used to be triggered to conduct during the pre-start-up period t3 and the drive period t1 according to the high-level signal of the third scan line SL3 and to transmit the high-level signal of the second signal line S2 to the first thin-film transistor T1.

[0034] In this embodiment, as Figure 7As shown, during the pre-start-up period t3, the first scan line SL1 receives a low-level signal, the data line DL1 is cut off from inputting a data signal, the second scan line SL2 receives a low-level signal, the first signal line S1 receives a negative voltage signal, the third scan line SL3 receives a high-level signal, and the second signal line S2 receives a high-level signal. Correspondingly, the third thin-film transistor T3 is triggered to turn off, and the fourth thin-film transistor T4 is triggered to turn on. The high-level signal input to the second signal line S2 is transmitted to the first thin-film transistor T1 through the fourth thin-film transistor T4, and the first thin-film transistor T1 turns on. At the same time, the second thin-film transistor T2 receives a low-level signal and is triggered to turn off. At this time, the storage capacitor Cst is not charged, and there is no driving voltage input to the first plate and the first electrode 221. Correspondingly, the electronic ink inside the display unit 22 remains stationary. By controlling the second thin-film transistor T2 to turn on first, signal crosstalk can be prevented when the two thin-film transistors switch on simultaneously during the driving period t1, thus avoiding voltage spikes on the first plate and the second electrode 223, which could lead to abnormal display of the display unit 22.

[0035] During the driving period t1, the first scan line SL1 receives a high-level signal, the data line DL1 receives a data signal, the second scan line SL2 receives a low-level signal, the first signal line S1 receives a negative voltage signal, the third scan line SL3 receives a high-level signal, the second signal line S2 receives a high-level signal, the third thin-film transistor T3 is turned off, and the fourth thin-film transistor T4 is triggered to turn on. The high-level signal input from the second signal line S2 is transmitted to the first thin-film transistor T1 through the fourth thin-film transistor T4, and the first thin-film transistor T1 turns on. At the same time, the second thin-film transistor T2 receives a high-level signal and is triggered to turn on. The data signal input from the data line DL1 is transmitted to the first plate of the storage capacitor Cst and the first electrode 221 of the display unit 22 through the second thin-film transistor T2 and the first thin-film transistor T1. The storage capacitor Cst is charged, and the voltage between the first plate and the first electrode 221 reaches the driving voltage during the driving period t1. The driving voltage of the first electrode 221 and the common electrode voltage Vcom on the second electrode 223 form the driving voltage, which drives the electronic ink of the electronic ink layer 222 to move to the position of the first electrode 221, thereby displaying the corresponding grayscale or color.

[0036] During the non-driving period t2, the first scan line SL1 receives a low-level signal, the data line DL1 is cut off from inputting a data signal, the second scan line SL2 receives a high-level signal, the first signal line S1 receives a negative voltage signal, the third scan line SL3 receives a low-level signal, the second signal line S2 receives a low-level signal, the third thin-film transistor T3 is triggered to turn on, and the fourth thin-film transistor T4 is triggered to turn off. The negative voltage signal is transmitted to the first thin-film transistor T1 through the third thin-film transistor T3, turning off the first thin-film transistor T1. The internal leakage current path of the first thin-film transistor T1 is cut off, reducing the leakage current between the first thin-film transistor T1 and the storage capacitor Cst. Meanwhile, the second thin-film transistor T2 is triggered. The shutdown process cuts off the leakage current path between the storage capacitor Cst and the data line DL1, reducing the leakage current between them. The voltage at the first plate and the first electrode 221 of the storage capacitor Cst is maintained at the driving voltage, and the electronic ink inside the display unit 22 is kept at the current position of the first electrode 221, achieving static image display. Furthermore, due to the improvement in leakage current, the electric field inside the display unit 22 does not change significantly. Correspondingly, the display image of the display unit 22 remains static, and there is no problem of image retention or contrast reduction caused by the drop in electric field voltage, thus improving the display effect of the display unit 22 and the electronic paper display panel 100.

[0037] Furthermore, in order to reduce noise interference during signal switching, in an optional embodiment, such as Figure 8 As shown, the pixel driving circuit 21 also includes: The filter circuit 212 is connected between the output terminal of the switching output circuit 211 and the control terminal of the first thin-film transistor T1. The filter circuit 212 is used to filter the output signal of the switching output circuit 211 to eliminate noise generated when the switching output circuit 211 switches the output. During the pre-start period t3 and the driving period t1, the filter circuit 212 filters the high-level signal output by the fourth thin-film transistor T4, and during the non-driving period t2, it filters the negative voltage signal output by the third thin-film transistor T3. The filter circuit 212 transmits the corresponding high-level signal and negative voltage signal to the first thin-film transistor T1 and controls the first thin-film transistor T1 to switch on and off accordingly.

[0038] The filter circuit 212 can adopt corresponding capacitors, filters, and other structures. In an optional embodiment, such as... Figure 9 As shown, the filter circuit 212 includes an operational amplifier. The non-inverting input terminal of the operational amplifier is connected to the input terminal of the switching output circuit 211. The inverting input terminal and the output terminal of the operational amplifier are connected to the control terminal of the first thin-film transistor T1. The operational amplifier forms a voltage follower, which can realize the proportional output of high-level signals and negative voltage signals. At the same time, it can realize signal isolation and avoid signal attenuation and interference.

[0039] In order to optimize the wiring of the electronic paper display panel 100 and avoid the electronic paper display panel 100 becoming too large in one direction due to too many lines, in an optional embodiment, such as Figure 10 As shown, the electronic paper display panel 100 also includes an array substrate 1, and the first signal line S1, the second signal line S2 and the data line DL1 of each pixel driving circuit 21 are arranged side by side on the array substrate 1 along the first direction X1. Each pixel driving circuit 21 has a first scan line SL1, a second scan line SL2, and a third scan line SL3 arranged side by side on the array substrate 1 along the second direction Y1, and the first direction X1 and the second direction Y1 intersect.

[0040] In this embodiment, multiple pixel driving circuits 21 of multiple pixel units 2 in the same row are connected to the same first scan line SL1, second scan line SL2 and third scan line SL3; multiple pixel units 2 in the same column are connected to the same data line DL1, first signal line S1 and second signal line S2; and pixel driving circuits 21 of pixel units 2 in different rows are connected to different first scan lines SL1, second scan lines SL2 and third scan lines SL3; and pixel driving circuits 21 of pixel units 2 in different columns are connected to different data lines DL1, first signal line S1 and second signal line S2. The driving circuit 200 controls the pixel units 2 arranged in the array to drive row by row by applying corresponding data signals, high and low level signals and negative voltage signals, and displays the corresponding image information. The first scan line SL1, second scan line SL2 and third scan line SL3 are arranged sequentially along the second direction Y1, and the first signal line S1, second signal line S2 and data line DL1 are arranged sequentially along the first direction X1, which can ensure that the size of the electronic paper display panel 100 is comparable along the first direction X1 and the second direction Y1.

[0041] Meanwhile, since the first signal line S1 maintains an input negative voltage signal, multiple first signal lines S1 can be connected together in the non-display area of ​​the electronic paper display panel 100, thereby reducing the number of signal ports in the non-display area.

[0042] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: The above-mentioned electronic paper display panel 100 includes a plurality of pixel units 2 arranged in an array. The pixel unit 2 includes a pixel driving circuit 21 and a display unit 22. The display unit 22 includes a first electrode 221, an electronic ink layer 222 and a second electrode 223. The pixel driving circuit 21 includes a first thin film transistor T1, a second thin film transistor T2, a switching output circuit 211 and a storage capacitor Cst. During the non-driving period t2, the second thin film transistor T2 receives a low-level signal and is triggered to turn off. The switching output circuit 211 switches the output of a negative voltage signal to the first thin film transistor T1. The first thin film transistor T1 is in a completely off state, reducing the off-state leakage current. Furthermore, the second thin film transistor T2 is in a off state, further reducing the leakage current between the storage capacitor Cst and the data line DL1. This improves the problems of image retention and contrast reduction caused by leakage current in the electronic paper display panel 100, and improves the display effect of the electronic paper display panel 100.

[0043] Example 2 A second aspect of the present invention provides a driving method for an electronic paper display panel 100, which is applied to the electronic paper display panel 100 as described above. The driving method for the electronic paper display panel 100 operates sequentially during driving period t1 and non-driving period t2. like Figure 11 As shown, the driving method for the electronic paper display panel 100 includes: S10. During the driving period t1, the first control signal is output to control the switching output circuit 211 to output a high-level signal, as well as to output a data signal to the data line DL1 and output a high-level signal to the first scan line SL1. S20. During the non-driving period t2, the second control signal is output to control the switching output circuit 211 to output a negative voltage signal, and to cut off the output data signal to the data line DL1 and output a low-level signal to the first scan line SL1.

[0044] In this embodiment, reference Figure 4As shown, the driving method of the electronic paper display panel 100 operates in each frame during driving period t1 and non-driving period t2. During driving period t1 of the current frame, when scanning line by line to the line where the current pixel unit 2 is located, a first control signal is output to control the switching output circuit 211 to output a high-level signal to the first thin-film transistor T1 and to output a high-level signal to the first scan line SL1, i.e., to input a high-level signal to the second thin-film transistor T2. The first thin-film transistor T1 and the second thin-film transistor T2 are turned on, and at the same time, a data signal is output to the data line DL1. The data signal input to the data line DL1 is transmitted through the second thin-film transistor T2 and the first thin-film transistor T1 to the first plate of the storage capacitor Cst and the first electrode 221 of the display unit 22. The storage capacitor Cst is charged and the voltage of the first plate and the first electrode 221 reaches the driving voltage during driving period t1. The driving voltage of the first electrode 221 and the common electrode voltage Vcom on the second electrode 223 form a driving voltage, which drives the electronic ink of the electronic ink layer 222 to move to the position of the first electrode 221, thereby displaying the corresponding grayscale or color.

[0045] During the non-driving period t2 of the current frame, the output low-level signal is switched to the first scan line SL1, which means the output low-level signal is switched to the second thin-film transistor T2. During the non-driving period t2, the output data signal is cut off, and the second thin-film transistor T2 is turned off. At the same time, the second control signal is output to control the switching output circuit 211 to switch the output negative voltage signal to the first thin-film transistor T1. The first thin-film transistor T1 is in a completely off state, and the leakage current path inside the first thin-film transistor T1 is cut off, reducing the leakage current between the first thin-film transistor T1 and the storage capacitor Cst. The second thin-film transistor T2 is in a turned-off state, cutting off the leakage current path between the storage capacitor Cst and the data line DL1, reducing the leakage current between the storage capacitor Cst and the data line DL1. The terminal voltage of the first plate and the first electrode 221 of the storage capacitor Cst is maintained at the driving voltage, and the electronic ink inside the display unit 22 is maintained at the current position of the first electrode 221, realizing static image display. Due to the improvement of leakage current, the display effect of the display unit 22 and the electronic paper display panel 100 is improved.

[0046] Furthermore, in order to reduce the problem of signal crosstalk when two switches are turned on at the same time, in an optional embodiment, the driving method of the electronic paper display panel 100 operates sequentially in the pre-start period t3, the driving period t1, and the non-driving period t2. like Figure 12 As shown, the driving method for the electronic paper display panel 100 further includes: S30. During the pre-start-up period t3, the first control signal is output to control the switching output circuit 211 to output a high-level signal and a low-level signal to the first scan line SL1.

[0047] In this embodiment, as Figure 5 As shown, in each frame, there is also a pre-start-up period t3 between the driving period t1. During the pre-start-up period t3, a low-level signal is output to the first scan line SL1, that is, a low-level signal is output to the second thin-film transistor T2. The second thin-film transistor T2 is in the off state. At the same time, the first control signal is output to control the switching output circuit 211 to switch the output high-level signal to the first thin-film transistor T1. The first thin-film transistor T1 is triggered to conduct. At this time, the storage capacitor Cst is not charged, and there is no driving voltage input to the first plate and the first electrode 221. Correspondingly, the electronic ink inside the display unit 22 remains in a static state. By controlling the second thin-film transistor T2 to conduct first, signal crosstalk can be prevented when the two thin-film transistors switch to conduct at the same time during the driving period t1, avoiding the problem of voltage spikes on the first plate and the second electrode 223, which could lead to abnormal display of the display unit 22.

[0048] The first control signal and the second control signal can be specifically set according to the corresponding structure of the switching output circuit 211. In an optional embodiment, such as... Figure 6 As shown, the switching output circuit 211 includes a third thin-film transistor T3 and a fourth thin-film transistor T4.

[0049] like Figure 13 As shown, the driving method for the electronic paper display panel 100 includes: S40. During the pre-start period t3, output low-level signal, low-level signal and high-level signal to the first scan line SL1, the second scan line SL2 and the third scan line SL3 respectively, and output negative voltage signal and high-level signal to the first signal line S1 and the second signal line S2 respectively.

[0050] At this time, the first control signal includes a low-level signal output to the second scan line SL2, a high-level signal output to the third scan line SL3, a negative voltage signal output to the first signal line S1, and a high-level signal output to the second signal line S2.

[0051] Correspondingly, the third thin-film transistor T3 is triggered to turn off, and the fourth thin-film transistor T4 is triggered to turn on. The high-level signal input from the second signal line S2 is transmitted to the first thin-film transistor T1 through the fourth thin-film transistor T4, and the first thin-film transistor T1 turns on. At the same time, the second thin-film transistor T2 receives a low-level signal and is triggered to turn off. At this time, the storage capacitor Cst is not charged, and there is no driving voltage input to the first plate and the first electrode 221. Correspondingly, the electronic ink inside the display unit 22 remains stationary. By controlling the second thin-film transistor T2 to turn on first, signal crosstalk can be prevented when the two thin-film transistors switch on simultaneously during the driving period t1, thus avoiding voltage spikes on the first plate and the second electrode 223, which could lead to abnormal display of the display unit 22.

[0052] S50. During the driving period t1, high-level signal, low-level signal, and high-level signal are output to the first scan line SL1, the second scan line SL2, and the third scan line SL3, respectively. In addition, negative voltage signal, high-level signal, and data signal are output to the first signal line S1, the second signal line S2, and the data line DL1, respectively.

[0053] At this time, the third thin-film transistor T3 is turned off, and the fourth thin-film transistor T4 is triggered to turn on. The high-level signal input from the second signal line S2 is transmitted to the first thin-film transistor T1 through the fourth thin-film transistor T4, and the first thin-film transistor T1 turns on. At the same time, the second thin-film transistor T2 receives the high-level signal and is triggered to turn on. The data signal input from the data line DL1 is transmitted to the first plate of the storage capacitor Cst and the first electrode 221 of the display unit 22 through the second thin-film transistor T2 and the first thin-film transistor T1. The storage capacitor Cst is charged, and the voltage of the first plate and the first electrode 221 reaches the driving voltage during the driving period t1. The driving voltage of the first electrode 221 and the common electrode voltage Vcom on the second electrode 223 form the driving voltage, which drives the electronic ink of the electronic ink layer 222 to move to the position of the first electrode 221, thereby displaying the corresponding grayscale or color.

[0054] S60. During the non-driving period t2, output low-level signals, high-level signals, and low-level signals to the first scan line SL1, the second scan line SL2, and the third scan line SL3, respectively, and output negative voltage signals and low-level signals to the first signal line S1 and the second signal line S2, respectively.

[0055] At this time, the second control signal includes a high-level signal output to the second scan line SL2, a low-level signal output to the third scan line SL3, a negative voltage signal output to the first signal line S1, and a low-level signal output to the second signal line S2.

[0056] The third thin-film transistor T3 is triggered to turn on, and the fourth thin-film transistor T4 is triggered to turn off. The negative voltage signal is transmitted to the first thin-film transistor T1 through the third thin-film transistor T3, and the first thin-film transistor T1 is turned off. The leakage current path inside the first thin-film transistor T1 is cut off, reducing the leakage current between the first thin-film transistor T1 and the storage capacitor Cst. At the same time, the second thin-film transistor T2 is triggered to turn off, cutting off the leakage current path between the storage capacitor Cst and the data line DL1, reducing the leakage current between the storage capacitor Cst and the data line DL1. The terminal voltage of the first plate and the first electrode 221 of the storage capacitor Cst is maintained at the driving voltage, and the electronic ink inside the display unit 22 is maintained at the current position of the first electrode 221, realizing static image display. Due to the improvement of leakage current, the electric field inside the display unit 22 will not change significantly. Correspondingly, the display image of the display unit 22 remains static, and there will be no problem of image retention or contrast reduction due to the drop in electric field voltage, thus improving the display effect of the display unit 22 and the electronic paper display panel 100.

[0057] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0058] Example 3 A third aspect of the present invention provides an electronic paper display device, such as... Figure 14 As shown, the electronic paper display device includes a driving circuit 200 and an electronic paper display panel 100. The specific structure of the electronic paper display panel 100 is as described in the above embodiments. Since this electronic paper display device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. The driving circuit 200 is connected to the corresponding data line DL1, scan line, and signal line of the electronic paper display panel 100, and the driving circuit 200 is used to implement the driving method of the electronic paper display panel 100 described above.

[0059] The driving circuit 200 may include a corresponding source driving circuit, a gate driving circuit, and a signal source circuit. The source driving circuit is connected to the data line DL1 and provides a data signal. The gate driving circuit is connected to multiple scan lines and provides corresponding high and low level signals. The signal source circuit can be connected to the first signal line S1 and the second signal line S2 and provides corresponding negative voltage signals and high and low level signals. The driving circuit 200 also includes a timing controller. The timing controller has a built-in memory for storing the driving method of the electronic paper display panel 100. The timing controller controls the source driving circuit, the gate driving circuit, and the signal source circuit to output corresponding high and low level signals and negative voltage signals to the electronic paper display panel 100 according to the driving method of the electronic paper display panel 100, so that the electronic paper display panel 100 displays corresponding image information and reduces the leakage current of the electronic paper display panel 100.

[0060] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An electronic paper display panel, characterized in that, It includes multiple pixel units arranged in an array, each of which includes a pixel driving circuit and a display unit connected to each other; The display unit includes a first electrode, an electronic ink layer, and a second electrode stacked together. The pixel driving circuit operates sequentially during driving and non-driving periods. Each pixel driving circuit is connected to a data line and a first scan line. The pixel driving circuit includes: The storage capacitor includes a first electrode plate and a second electrode plate disposed opposite to each other. The first electrode plate is connected to a first electrode corresponding to the display unit, and the second electrode plate is connected to a common electrode terminal. A first thin-film transistor, the second end of the first thin-film transistor being connected to the first electrode plate, the first thin-film transistor being used to trigger conduction when receiving a high-level signal and to trigger turn-off when receiving a negative voltage signal; A switching output circuit is connected to the control terminal of the first thin-film transistor. The switching output circuit is used to switch the output of the high-level signal during the driving period and to switch the output of the negative voltage signal during the non-driving period. The second thin-film transistor is connected to the data line, the first scan line, and a first terminal of the first thin-film transistor. The second thin-film transistor is used to be turned on during the driving period based on a high-level signal of the first scan line and to transmit the data signal of the data line to the first thin-film transistor, and to be turned off during the non-driving period based on a low-level signal of the first scan line.

2. The electronic paper display panel as described in claim 1, characterized in that, The pixel driving circuit operates sequentially during the pre-start-up period, the driving period, and the non-driving period; The switching output circuit is also used to switch the output of the high-level signal during the pre-start period; The second thin-film transistor is also configured to trigger a shutdown based on a low-level signal from the first scan line during the pre-start-up period.

3. The electronic paper display panel as described in claim 2, characterized in that, The pixel driving circuit is also connected to the second scan line, the third scan line, the first signal line, and the second signal line; The switching output circuit includes: A third thin-film transistor, wherein the control terminal of the third thin-film transistor is connected to the second scan line, the first terminal of the third thin-film transistor is connected to the first signal line, and the second terminal of the third thin-film transistor is connected to the control terminal of the first thin-film transistor, the third thin-film transistor is used to trigger conduction according to the high-level signal of the second scan line during the non-driving period and transmit the negative voltage signal on the first signal line to the first thin-film transistor; A fourth thin-film transistor, wherein the control terminal of the fourth thin-film transistor is connected to the third scan line, the first terminal of the fourth thin-film transistor is connected to the second signal line, and the second terminal of the fourth thin-film transistor is connected to the control terminal of the first thin-film transistor, the fourth thin-film transistor being used to be triggered to conduct according to the high-level signal of the third scan line during the pre-start period and the driving period, and to transmit the high-level signal of the second signal line to the first thin-film transistor.

4. The electronic paper display panel as described in claim 3, characterized in that, The pixel driving circuit also includes: A filtering circuit is connected between the output terminal of the switching output circuit and the control terminal of the first thin-film transistor. The filtering circuit is used to filter the output signal of the switching output circuit.

5. The electronic paper display panel as described in claim 4, characterized in that, The filtering circuit includes an operational amplifier, the non-inverting input of which is connected to the input of the switching output circuit, and the inverting input, output, and control terminals of the first thin-film transistor.

6. The electronic paper display panel as described in claim 3, characterized in that, The electronic paper display panel further includes an array substrate, wherein the first signal line, the second signal line, and the data line of each pixel driving circuit are arranged side by side on the array substrate along a first direction; The first scan line, the second scan line, and the third scan line of each pixel driving circuit are arranged side by side on the array substrate along a second direction, and the first direction and the second direction intersect.

7. A driving method for an electronic paper display panel, applied to the electronic paper display panel as described in any one of claims 1 to 6, characterized in that, The driving method of the electronic paper display panel operates sequentially during the driving period and the non-driving period; The driving method for the electronic paper display panel includes: During the driving period, the first control signal is output to control the switching output circuit to output a high-level signal, as well as to output a data signal to the data line and output a high-level signal to the first scan line; During the non-driving period, the second control signal is output to control the switching output circuit to output a negative voltage signal, and to cut off the output data signal to the data line and output a low-level signal to the first scan line.

8. The driving method for an electronic paper display panel as described in claim 7, characterized in that, The driving method for the electronic paper display panel operates sequentially during the pre-start-up period, the driving period, and the non-driving period; The driving method for the electronic paper display panel further includes: During the pre-start-up period, the first control signal is output to control the switching output circuit to output the high-level signal and output a low-level signal to the first scan line.

9. The driving method for an electronic paper display panel as described in claim 7, characterized in that, The switching output circuit includes a third thin-film transistor and a fourth thin-film transistor; The driving method for the electronic paper display panel includes: During the pre-start-up period, low-level signals, low-level signals, and high-level signals are output to the first scan line, the second scan line, and the third scan line, respectively, and negative voltage signals and high-level signals are output to the first signal line and the second signal line, respectively. During the driving period, a high-level signal, a low-level signal, and a high-level signal are respectively output to the first scan line, the second scan line, and the third scan line, and a negative voltage signal, a high-level signal, and a data signal are respectively output to the first signal line, the second signal line, and the data line; During the non-driving period, a low-level signal, a high-level signal, and a low-level signal are output to the first scan line, the second scan line, and the third scan line, respectively, and a negative voltage signal and a low-level signal are output to the first signal line and the second signal line, respectively.

10. An electronic paper display device, characterized in that, The device includes a driving circuit and an electronic paper display panel as described in any one of claims 1 to 6. The driving circuit is connected to the corresponding data lines, scan lines, and signal lines of the electronic paper display panel. The driving circuit is used to implement the driving method of the electronic paper display panel as described in any one of claims 7 to 9.

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