Pixel circuit, drive control circuit and method, and electronic paper panel

Abstract

The present invention discloses a pixel circuit, a drive control circuit and method, and an electronic paper panel, belonging to the field of electronic paper technology. The pixel circuit includes: a driving tube, a first switching tube, a second switching tube, a storage capacitor, a clock line, a data line, and a maintenance line; the first end of the driving tube is electrically connected to the first end of the first switching tube and the second switching tube, the second end of the driving tube is electrically connected to the first end of the storage capacitor, the controlled ends of the driving tube, the first switching tube, and the second switching tube are electrically connected to the clock line, the second end of the second switching tube is electrically connected to the data line, and the second end of the first switching tube is electrically connected to the maintenance line; when the images of the current frame and the next frame are the same, the driving tube and the second switching tube are turned off, the first switching tube is turned on, and the maintenance line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube. The present invention can reduce the leakage current of the TFT in the pixel circuit and improve the display effect.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic paper technology, and in particular to pixel circuits, drive control circuits and methods, and electronic paper panels. Background Art

[0002] E-paper is widely used for reading e-books. Compared to traditional books, e-readers are smaller and more portable. A single e-paper reader can store multiple e-books. Compared to existing electronic products (such as mobile phones and tablets), e-paper offers significant power savings and is more in line with current green environmental protection concepts.

[0003] However, since the drive control is achieved through TFT (Thin Film Transistor), and TFT has the characteristic of leakage, that is, when the TFT is in the off state, there is a voltage difference between the TFT source and drain, so there will be leakage current, which affects the display effect, and the longer the leakage time, the greater the impact on the display effect; due to the low refresh rate of electronic paper, the TFT leakage time is long, resulting in a decrease in the potential of the storage capacitor, affecting the display effect. Summary of the Invention

[0004] The main purpose of the embodiments of the present application is to provide a pixel circuit, a drive control circuit and method, and an electronic paper panel, aiming to solve the technical problem of how to reduce the leakage current of TFT in the pixel circuit and improve the display effect.

[0005] To achieve the above object, an embodiment of the present application provides a pixel circuit, the pixel circuit comprising: a driving transistor, a first switching transistor, a second switching transistor, a storage capacitor, a clock line, a data line, and a holding line;

[0006] The first end of the driving transistor is electrically connected to the first ends of the first switching transistor and the second switching transistor, the second end of the driving transistor is electrically connected to the first end of the storage capacitor, the controlled ends of the driving transistor, the first switching transistor, and the second switching transistor are electrically connected to the clock line, the second end of the second switching transistor is electrically connected to the data line, and the second end of the first switching transistor is electrically connected to the hold line;

[0007] When the images of the current frame and the next frame are the same, the driving tube and the second switching tube are turned off, the first switching tube is turned on, and the sustain line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube.

[0008] In one embodiment, the clock line includes: a driving clock line, a first clock line, and a second clock line;

[0009] The driving clock line is electrically connected to the controlled end of the driving tube;

[0010] The first clock line is electrically connected to the controlled end of the first switch tube;

[0011] The second clock line is electrically connected to the controlled end of the second switch tube.

[0012] In one embodiment, when the images of the current frame and the next frame are different, the driving tube and the second switching tube are turned on, the first switching tube is turned off, and the data line transmits the data voltage to the storage capacitor through the second switching tube and the driving tube.

[0013] In addition, to achieve the above-mentioned purpose, an embodiment of the present application also provides a driving control circuit, which includes a driving board and the pixel circuit as described above, and the driving board is used to output a timing control signal to the clock line to change the on and off of the driving tube, the first switching tube and the second switching tube to reduce the leakage current of the driving tube.

[0014] In one embodiment, the driving board is further configured to transmit data to the pixel circuit, so that the pixel circuit outputs the data to an in-plane display.

[0015] In one embodiment, the driving board is further used to stop outputting data of the next frame when the data of the current frame is the same as that of the next frame, so that the driving tube and the second switching tube are turned off, the first switching tube is turned on, and the maintenance line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube.

[0016] In one embodiment, the driving board is also used to normally output the data of the next frame when the data of the current frame is different from that of the next frame, so that the driving tube and the second switching tube are turned on, the first switching tube is turned off, and the data line transmits the data voltage to the storage capacitor through the second switching tube and the driving tube.

[0017] In addition, to achieve the above-mentioned purpose, an embodiment of the present application further provides a drive control method, which is applied to the above-mentioned drive control circuit and includes:

[0018] Obtaining input data, and determining whether the current frame and the next frame are the same based on the input data;

[0019] If so, the driving tube and the second switching tube are controlled to be turned off, and the first switching tube is turned on, so that the sustain line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube.

[0020] In one embodiment, after the step of determining whether the current frame and the next frame are the same based on the input data, the method further includes:

[0021] If not, the driving tube and the second switch tube are controlled to be turned on, and the first switch tube is turned off, so that the data line transmits the data voltage to the storage capacitor through the second switch tube and the driving tube.

[0022] In addition, to achieve the above-mentioned purpose, an embodiment of the present application also provides an array substrate, which includes an effective display area and a non-effective display area, and the non-effective display area surrounds the periphery of the effective display area. The driving control circuit as described above is arranged in the non-effective display area of ​​the array substrate.

[0023] In addition, to achieve the above-mentioned purpose, an embodiment of the present application further provides an electronic paper panel, which includes: a box substrate, an ink layer and the array substrate as described above, wherein the ink layer is arranged between the array substrate and the box substrate.

[0024] The present invention provides a pixel circuit, a drive control circuit and method, and an electronic paper panel. The pixel circuit includes a driver transistor, a first switch transistor, a second switch transistor, a storage capacitor, a clock line, a data line, and a hold line. The first end of the driver transistor is electrically connected to the first end of the first switch transistor and the second switch transistor, the second end of the driver transistor is electrically connected to the first end of the storage capacitor, the controlled ends of the driver transistor, the first switch transistor, and the second switch transistor are electrically connected to the clock line, the second end of the second switch transistor is electrically connected to the data line, and the second end of the first switch transistor is electrically connected to the hold line. When the images of the current frame and the next frame are the same, the driver transistor and the second switch transistor are turned off, the first switch transistor is turned on, and the hold line transmits a data voltage through the first switch transistor to reduce leakage current of the driver transistor. The present invention improves the drive architecture and drive control method of the pixel circuit so that the display images of the current frame and the next frame are the same. That is, when the driver transistor is turned off, the voltages on both sides of the driver transistor can be maintained consistent, thereby achieving the effect of reducing leakage current of the TFT in the pixel circuit, and effectively improving the display effect of the electronic paper using the pixel circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only part of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A schematic structural diagram of a pixel circuit provided in an embodiment of the present application;

[0027] Figure 2 A driving timing diagram of a pixel circuit provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of the structure of a drive control circuit provided in an embodiment of the present application;

[0029] Figure 4 A flowchart of the functions of a drive control circuit provided in an embodiment of the present application;

[0030] Figure 5 A schematic flow chart of a drive control method provided in an embodiment of the present application;

[0031] Figure 6 A schematic structural diagram of an array substrate provided in an embodiment of the present application;

[0032] Figure 7 A schematic structural diagram of an electronic paper panel provided in an embodiment of the present application.

[0033] Explanation of the accompanying symbols: T0, driving tube; T1, first switching tube; T2, second switching tube; Cst, storage capacitor; CK, driving clock line; CK1, first clock line; CK2, second clock line; Source, data line; Hold, holding line; 10, driving board; 20, pixel circuit; 101, effective display area; 102, driving control circuit; 100, array substrate; 200, box substrate; 300, ink layer. DETAILED DESCRIPTION

[0034] In the following description, specific details such as specific system structures and technologies are provided for illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the embodiments of the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the embodiments of the present application.

[0035] It should be noted that although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than that shown in the flowcharts. The terms "first," "second," and the like in the specification, claims, and drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0036] It should also be understood that references to "one embodiment" or "some embodiments" in the description of the embodiments of the present application mean that one or more embodiments of the embodiments of the present application include specific features, structures, or characteristics described in conjunction with the embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0037] E-paper is widely used for reading e-books. Compared to traditional books, e-readers are smaller and more portable. A single e-paper reader can store multiple e-books. Compared to existing electronic products (such as mobile phones and tablets), e-paper offers significant power savings and is more in line with current green environmental protection concepts.

[0038] E-paper displays offer the following advantages: 1) Low power consumption. E-paper consumes minimal power only when changing screens. When displaying text, power is cut off and the original display remains until the next frame of data arrives. 2) No backlight is required. The power supply within the e-paper is solely to the electrodes, controlling the position of the reflective medium. The display is illuminated by ambient light. Conventional e-paper displays offer only two colors: black and white. This close resemblance to a real book has made it widely popular.

[0039] However, since the drive control is achieved through TFT, and TFT has the characteristic of leakage, that is, when the TFT is in the closed state, there will be leakage current due to the voltage difference between the TFT source and drain, which affects the display effect. The longer the leakage time, the greater the impact on the display effect. Since the refresh rate of electronic paper is low, the TFT leakage time is long, resulting in a decrease in the potential of the storage capacitor, affecting the display effect.

[0040] Based on this, the embodiments of the present application provide a pixel circuit, a driving control circuit and method, and an electronic paper panel. By improving the driving architecture and driving control method of the pixel circuit, the display images of the current frame and the next frame are the same, that is, when the driving tube is turned off, the voltages on both sides thereof can be maintained consistent, thereby achieving the effect of reducing the leakage current of the TFT in the pixel circuit, and can effectively improve the display effect of the electronic paper using the pixel circuit.

[0041] The pixel circuit, drive control circuit and method, and electronic paper panel provided in the embodiments of the present application are specifically described through the following embodiments. First, the pixel circuit in the embodiments of the present application is described.

[0042] The present application embodiment provides a pixel circuit, referring to Figure 1 , Figure 1 This is a schematic diagram of the structure of a pixel circuit provided in one embodiment of the present application. In this embodiment, the pixel circuit includes: a driving transistor T0, a first switching transistor T1, a second switching transistor T2, a storage capacitor Cst, a clock line, a data line Source, and a hold line Hold;

[0043] A first end of the driving transistor T0 is electrically connected to the first ends of the first switching transistor T1 and the second switching transistor T2, a second end of the driving transistor T0 is electrically connected to the first end of the storage capacitor Cst, controlled ends of the driving transistor T0, the first switching transistor T1, and the second switching transistor T2 are electrically connected to the clock line, a second end of the second switching transistor T2 is electrically connected to the data line Source, and a second end of the first switching transistor T1 is electrically connected to the hold line Hold;

[0044] When the images of the current frame and the next frame are the same, the driving tube T0 and the second switch tube T2 are turned off, the first switch tube T1 is turned on, and the hold line Hold transmits the data voltage through the first switch tube T1 to reduce the leakage current of the driving tube T0.

[0045] It should be noted that in this embodiment, in the initial state, the pixel circuit must determine its operating state based on the timing control signal and video data sent by the front-end circuit. Generally speaking, when receiving the data corresponding to the first frame, the driver transistor T0 and the second switch transistor T2 will be turned on, the first switch transistor T1 will be turned off, the hold line Hold will not transmit data, and the data line Source will transmit the data voltage to the storage capacitor Cst through the second switch transistor T2 and the driver transistor T0, thereby transmitting the data to the surface for display. If the second frame is the same as the first frame, the data line Source no longer needs to transmit data, which will cause the voltage on both sides of the driver transistor T0 to be inconsistent, thereby generating leakage current. Therefore, to avoid this situation, this embodiment adds a hold line Hold and changes the driving method when the second frame is the same as the first frame. The purpose of maintaining the voltage on both sides of the driver transistor T0 consistent by outputting the data voltage through the hold line Hold is achieved, thereby reducing leakage current and preventing the potential drop of the storage capacitor Cst from affecting the display effect.

[0046] As an example, in this embodiment, the screen switching between the current frame and the next frame will be directly reflected in the voltage change. Therefore, when switching, T0 can be turned off first, and T1 and T2 can be connected as the maintenance line or the data line according to the Data voltage of the pixel. Taking black and white two-color electronic paper as an example, if a white driving voltage is applied to the data line and a black driving voltage is applied to the maintenance line, the pixel is displayed as black. At this time, T2 is turned off and T1 is turned on, and the black driving voltage is applied by the maintenance line to maintain the voltage at both ends of T0 consistent, thereby reducing the leakage current of T0.

[0047] In some feasible embodiments, the clock line includes: a driving clock line CK, a first clock line CK1 and a second clock line CK2;

[0048] The driving clock line CK is electrically connected to the controlled end of the driving transistor T0;

[0049] The first clock line CK1 is electrically connected to the controlled end of the first switch tube T1;

[0050] The second clock line CK2 is electrically connected to the controlled end of the second switch tube T2.

[0051] It can be understood that, in this embodiment, the on and off of the driving transistor T0 , the first switching transistor T1 , and the second switching transistor T2 are respectively controlled by different clock lines.

[0052] In some feasible embodiments, when the images of the current frame and the next frame are different, the driving tube T0 and the second switch tube T2 are turned on, the first switch tube T1 is turned off, and the data line Source transmits the data voltage to the storage capacitor Cst through the second switch tube T2 and the driving tube T0.

[0053] In this embodiment, if the images of the current frame and the next frame are different, there is no need to change the driving method of the pixel circuit. According to the data difference between the frames, the data line Source can transmit the corresponding data through the predetermined route.

[0054] As an example, in combination with the above embodiments, this embodiment shows a driving timing diagram of the current frame and the next frame having the same picture as shown in FIG. Figure 2 As shown by Figure 2 It can be seen that the pictures of frame N are the same as those of frame N+1 and frame N+2. After the data of frame N is written, frame N+1 and frame N+2 remain in the hold state, and the T0 leakage current is reduced by the data line and the hold line.

[0055] An embodiment of the present application provides a pixel circuit, which improves the driving architecture and driving control method of the pixel circuit so that the display images of the current frame and the next frame are the same. That is, when the driving tube is turned off, the voltages on both sides thereof can be maintained consistent, thereby achieving the effect of reducing the leakage current of the TFT in the pixel circuit, and can effectively improve the display effect of the electronic paper using the pixel circuit.

[0056] In addition, the embodiment of the present application also provides a drive control circuit, referring to Figure 3 In this embodiment, the driving control circuit includes a driving board 10 and the pixel circuit 20 as described above. The driving board 10 is used to output a timing control signal to the clock line to change the on and off of the driving tube, the first switching tube and the second switching tube to reduce the leakage current of the driving tube.

[0057] In some feasible embodiments, the driving board 10 is further configured to transmit data to the pixel circuit 20 , so that the pixel circuit 20 outputs the data to an in-plane display.

[0058] In some feasible embodiments, the driving board 10 is further used to determine whether the data of the current frame is the same as the data of the next frame;

[0059] If the data of the current frame is the same as that of the next frame, stop outputting the data of the next frame;

[0060] If the data of the current frame is different from that of the next frame, the data of the next frame is output normally.

[0061] In this embodiment, when the data of the current frame and the next frame are the same, the driving board 10 stops outputting the data of the next frame, so that the driving tube and the second switch tube are turned off, the first switch tube is turned on, and the maintenance line transmits the data voltage through the first switch tube to reduce the leakage current of the driving tube; when the data of the current frame and the next frame are different, the data of the next frame is output normally, so that the driving tube and the second switch tube are turned on, the first switch tube is turned off, and the data line transmits the data voltage to the storage capacitor through the second switch tube and the driving tube.

[0062] As an example, in this embodiment, the function implementation flow chart of the drive control circuit can be referred to Figure 4 ,like Figure 4As shown, the first step is to input data from the front end to the TCON. The second step is to determine whether the data of two adjacent frames are identical. If they are different, normal display is performed, and the TCON transmits the data to the driver, which then transmits it to the panel for display. If the data of the two frames is identical, the TCON does not transmit the data to the driver, and the driver provides the voltage for display. At this time, the driving TFT in the panel is not turned on, that is, the GOA circuit does not output, and the original data voltage is used to maintain the display. During display, the driving voltage value of all pixels in the panel is determined. The same data voltage in a column of pixels is connected to the same data line, the driving TFT is turned off, and the corresponding data voltage is applied to the source, thereby preventing leakage.

[0063] The specific structure of the pixel circuit 20 in this embodiment refers to the above embodiment. Since the driving control circuit provided in this embodiment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0064] In addition, the embodiment of the present application also provides a drive control method, referring to Figure 5 In this embodiment, the drive control method is applied to the drive control circuit as described above, including:

[0065] Step S10, obtaining input data, and determining whether the current frame and the next frame are the same based on the input data;

[0066] In step S20 , if yes, the driving tube and the second switch tube are controlled to be turned off, and the first switch tube is turned on, so that the sustain line transmits the data voltage through the first switch tube to reduce the leakage current of the driving tube.

[0067] In some feasible embodiments, after the above step S10, the method further includes:

[0068] Step S21: If not, control the driving tube and the second switch tube to be turned on, and the first switch tube to be turned off, so that the data line transmits the data voltage to the storage capacitor through the second switch tube and the driving tube.

[0069] The driving control method in this embodiment and the driving control circuit in the above embodiments belong to the same technical concept. The technical details not fully described in this embodiment can be referred to any of the above embodiments. Therefore, this embodiment at least has the same beneficial effects as the above embodiments of the driving control circuit, and will not be described one by one here.

[0070] In addition, the present invention also provides an array substrate, referring to Figure 6In this embodiment, the array substrate includes an effective display area 101 and a non-effective display area. The non-effective display area surrounds the periphery of the effective display area 101, and the above-mentioned driving control circuit 102 is arranged in the non-effective display area of ​​the array substrate.

[0071] The specific structure of the driving control circuit 102 in this embodiment refers to the above embodiment. Since the array substrate provided in this embodiment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0072] In addition, the present invention also provides an electronic paper panel. Figure 7 The electronic paper panel includes an array substrate 100 , a pairing substrate 200 and an ink layer 300 , wherein the ink layer 300 is disposed between the array substrate 100 and the pairing substrate 200 .

[0073] As an example, the electronic paper panel can be applied to a display device, which can be an e-book reader, an electronic tag, a smart watch, a smart phone, a digital newspaper, a textbook and document viewer, a wearable device, a public information display device, a home automation device, a drawing tablet and a notepad, and any other product or component with a display function.

[0074] Those skilled in the art will understand that Figure 7 The structure shown in the figure does not constitute a limitation on the electronic paper panel, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0075] The specific structure of the array substrate 100 in this embodiment refers to the above embodiment. Since the electronic paper panel proposed in this embodiment adopts all the technical solutions of all the above embodiments and belongs to the same technical concept, this embodiment at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0076] It should be noted that the technical solutions of the various embodiments of the present application can be combined with each other, but this must be based on the fact that they can be implemented by technical personnel in this field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0077] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. All equivalent structures or equivalent process changes made based on the application concept of the present application and the contents of the description and drawings of the present application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A pixel circuit, characterized in that: The pixel circuit includes: a driving tube, a first switching tube, a second switching tube, a storage capacitor, a clock line, a data line and a holding line; The first end of the driving transistor is electrically connected to the first ends of the first switching transistor and the second switching transistor, the second end of the driving transistor is electrically connected to the first end of the storage capacitor, the controlled ends of the driving transistor, the first switching transistor, and the second switching transistor are electrically connected to the clock line, the second end of the second switching transistor is electrically connected to the data line, and the second end of the first switching transistor is electrically connected to the hold line; When the images of the current frame and the next frame are the same, the driving tube and the second switching tube are turned off, the first switching tube is turned on, and the sustain line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube.

2. The pixel circuit according to claim 1, wherein: The clock lines include: a driving clock line, a first clock line, and a second clock line; The driving clock line is electrically connected to the controlled end of the driving tube; The first clock line is electrically connected to the controlled end of the first switch tube; The second clock line is electrically connected to the controlled end of the second switch tube.

3. The pixel circuit according to claim 1, wherein: When the images of the current frame and the next frame are different, the driving tube and the second switch tube are turned on, the first switch tube is turned off, and the data line transmits the data voltage to the storage capacitor through the second switch tube and the driving tube.

4. A drive control circuit, characterized in that: The driving control circuit includes a driving board and a pixel circuit as described in any one of claims 1 to 3, and the driving board is used to output a timing control signal to the clock line to change the on and off of the driving tube, the first switching tube and the second switching tube to reduce the leakage current of the driving tube.

5. The drive control circuit according to claim 4, wherein: The driving board is further used to transmit data to the pixel circuit so that the pixel circuit outputs the data to an in-plane display.

6. The drive control circuit according to claim 4, wherein: The driving board is also used to stop outputting the data of the next frame when the data of the current frame is the same as that of the next frame, so that the driving tube and the second switching tube are turned off, the first switching tube is turned on, and the maintenance line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube.

7. The drive control circuit according to claim 4, wherein: The driving board is also used to normally output the data of the next frame when the data of the current frame is different from that of the next frame, so that the driving tube and the second switching tube are turned on, the first switching tube is turned off, and the data line transmits the data voltage to the storage capacitor through the second switching tube and the driving tube.

8. A drive control method, characterized in that: The drive control method is applied to the drive control circuit according to claim 4, comprising: Obtaining input data, and determining whether the current frame and the next frame are the same based on the input data; If so, the driving tube and the second switching tube are controlled to be turned off, and the first switching tube is turned on, so that the sustain line transmits the data voltage through the first switching tube to reduce the leakage current of the driving tube.

9. The driving control method according to claim 8, wherein: After the step of determining whether the current frame and the next frame are the same according to the input data, the method further includes: If not, the driving tube and the second switch tube are controlled to be turned on, and the first switch tube is turned off, so that the data line transmits the data voltage to the storage capacitor through the second switch tube and the driving tube.

10. An electronic paper panel, characterized in that: The electronic paper panel includes: a box substrate, an ink layer and an array substrate, the ink layer is arranged between the array substrate and the box substrate, the array substrate includes an effective display area and a non-effective display area, the non-effective display area surrounds the periphery of the effective display area, and the driving control circuit according to any one of claims 4 to 7 is arranged in the non-effective display area of ​​the array substrate.

Images