Electrophoretic display with accelerated charge balancing circuit

Abstract

An electrophoretic display with an accelerated charge balance circuit comprises a control substrate, a charge balance substrate, a charge balance electrode, a display layer arranged on one side of the control substrate, and the accelerated charge balance circuit. The electrophoretic display comprises a plurality of pixel electrodes, a plurality of capacitor electrodes and a plurality of storage capacitors, wherein the pixel electrodes and the capacitor electrodes are arranged on a control substrate, and one end of each storage capacitor is a capacitor electrode. The accelerated charge balance circuit comprises a charge voltage conversion capacitor which is provided with a first end and a second end. A second electrode of the storage capacitor is electrically connected with the first end of the charge voltage conversion capacitor, and the charge balance electrode is electrically connected with the second end of the charge voltage conversion capacitor.

Description

Technical Field

[0001] The present invention relates to an electrophoretic display, and more particularly to an electrophoretic display having an accelerated charge balance circuit. Background Art

[0002] Electronic paper displays, such as electrophoretic displays (EPDs), have the characteristics of being thin, light, easy to carry, and low in energy consumption, and also have the property of retaining images even after the power is turned off. In addition to being applied to readers, mobile phones, and wearable devices, electronic paper displays can also be used in shelf labels in hypermarkets and instant message billboards at bus stops, taking into account energy conservation and sustainability goals.

[0003] Figure 8A A cross-sectional view of a conventional electrophoretic display 100 is shown. This electrophoretic display 100 is, for example, a black-and-white electrophoretic display 100. The electrophoretic display 100 includes a charge balance substrate 12 (such as a transparent plastic substrate) from top to bottom, a charge balance electrode 14 (such as a transparent conductive electrode layer), an electrophoretic layer (display layer) 20, a control electrode layer PEL, a driving circuit layer 30a, and a control substrate 10 (such as a glass substrate). Figure 8A In the shown architecture, the viewing surface is in the direction close to the charge balance substrate 。12. In addition, as Figure 8A shown, the electrophoretic layer 20 includes a plurality of microcontainers 22 (only one is shown in the figure). The colloidal solution 24 filled in each microcontainer 22 contains a plurality of charged color particles 26 suspended therein (such as charged black particles 26B and charged white particles 26W). The structure of the microcontainer 22 serves as a container for electronic ink (or electrophoretic material). The microcontainer 22 is, for example, made of an organic polymer material and is used to fill the charged color particles 26. In addition, the charged color particles 26 can be a two-color combination (black / white), a three-color combination (black / red / white, black / yellow / white), a four-color combination (black / red / yellow / white, cyan / yellow / magenta / white), etc. Figure 1A In the shown structure, the charged color particles 26 are, for example, a two-color combination and include charged black particles 26B and charged white particles 26W. Furthermore, the microcontainer 22 can be a microcapsule (such as see U.S. Pat. Nos. 7,535,624 and 5,961,804) structure or a microcup (such as see Taiwan Invention TW I230832B) structure.

[0004] The charge balance electrode 14 is generally connected to the ground potential (0V) to provide a common voltage Vcom. The lower control substrate 10 generally uses the TFT Array process of the panel to fabricate the driving circuit layer 30a thereon. Most of the driving switches in the driving circuit layer 30a include thin film transistors fabricated by the amorphous silicon (a-Si) process. The charged color particles 26 carry charges of a predetermined polarity. For example, the charged black particles 26B carry positive charges and the charged white particles 26W carry negative charges. By controlling the voltage polarity and magnitude of each control electrode PE in the driving circuit layer 30a, it is possible to attract the charged black particles 26B and repel the charged white particles 26W corresponding to each pixel (making the pixel appear white on the viewing surface on the opposite side of the control electrode PE) or attract the charged white particles 26W and repel the charged black particles 26B corresponding to each pixel (making the pixel appear black on the viewing surface on the opposite side of the control electrode PE).

[0005] See Figure 8B , for illustration Figure 8A of the operating schematic diagram of the existing black-and-white electrophoretic display 100. As Figure 8B shown, by controlling the voltage polarity and magnitude of each control electrode PE in this control electrode layer PEL through the driving circuit layer 30a, black-and-white pixels can be formed on the viewing surface (near the charge balance substrate 12). If the driving circuit layer 30a controls Figure 8B the control electrode shown as positive voltage, it will attract the negatively charged white particles 26W and push the positively charged black particles away from the electrode contact surface and move them towards the viewing surface, resulting in a relatively larger number of positively charged black particles 26B on the viewing surface to provide a black pixel on the viewing surface. On the contrary, if the driving circuit layer 30a controls Figure 8B the control electrode shown as negative voltage, it will attract the positively charged black particles 26B and push the negatively charged white particles away from the electrode contact surface and move them towards the viewing surface, resulting in a relatively larger number of negatively charged white particles 26W on the viewing surface to provide a white pixel on the viewing surface.

[0006] As Figure 8B shown and in conjunction with reference to Figure 7 , the charge balance electrode 14 (CE) is usually electrically connected to the ground potential (0V, that is, the Vcom potential) and the electrophoretic layer 20 is sandwiched between it and the control electrode layer PEL. The control electrode PE of the control electrode layer PEL and the Vcom potential form a capacitor (electrophoretic capacitor Cp). Since the thickness of the electrophoretic layer is relatively thick, this capacitor is very small. The charges on the control electrode quickly interact with the charged particles and enter the equilibrium state, and the moving distance of the charged particles is very small. In order to increase the energy of each drive, a storage capacitor must be added in the driving circuit layer 30a. One end of the storage capacitor is connected to the control electrode, and the other end forms a parallel storage capacitor Cs with the conductor on the other side of the control electrode facing the electrophoretic layer. InFigure 7 The equivalent circuit of the electrophoresis layer 20 is marked as the electrophoresis capacitor Cp, and further includes the above-mentioned storage capacitor Cs. As Figure 7 shown, the driving circuit layer 30a includes a plurality of thin film transistors 32, and the gate metal of each thin film transistor 32 is electrically connected to the gate line GL (for example, made of the first metal layer M1), the source metal is electrically connected to the data line DL (for example, made of the second metal layer M2), and the drain metal is electrically connected to the corresponding control electrode (also called the pixel electrode) PE. According to the potential applied to the gate metal by the gate line GL, it can be determined whether this thin film transistor 32 is turned on (On) or off (Off); thereby determining whether to transfer the voltage on the data line DL via the source metal to the drain metal, and further to the corresponding control electrode PE and charging the storage capacitor Cs to the same voltage as on the data line. This control electrode PE will also apply the voltage on the corresponding data line to the electrophoresis layer 20. In principle, the driving circuit layer includes a plurality of thin film transistors, a plurality of gate lines and a plurality of data lines. Each of the gate lines is electrically connected to the gates of the plurality of thin film transistors, each of the data lines is electrically connected to the drains or sources of the plurality of thin film transistors, and a plurality of control electrodes, each of the control electrodes is connected to the source or drain of one of the thin film transistors.

[0007] The electrophoresis layer includes an electrophoresis material, and the electrophoresis material includes a plurality of charged color particles. The plurality of charged color particles are disposed in a colloidal solution and can move through the colloidal solution under the influence of an electric field. The plurality of charged color particles include positively charged color particles and / or negatively charged color particles. The charged color particles 26 move under the force of the electric field between the colloidal solutions 24 of the electrophoresis layer 20 with appropriate viscosity, and the moving speed is very slow. The driving circuit layer 30a first quickly stores energy in the storage capacitor Cs, and then the storage capacitor Cs slowly releases the energy to the electrophoresis layer 20 via the control electrode PE as the energy source for the movement of the charged color particles 26. The larger the capacitance value of the storage capacitor Cs, the more energy can be stored, the fewer the number of times of repeated energy storage, and the faster the screen update speed of the electrophoresis display 100. Therefore, in the circuit layout design of the electrophoresis display 100, the area of the storage capacitor Cs will be increased as much as possible to increase the capacitance value. However, in a system with multi-color charged color particles, due to the need to accurately control the moving distance and direction of the charged color particles, the capacitance value of the storage capacitor Cs will be appropriately reduced to reduce the energy supply to increase the accuracy of controlling the moving distance of the charged color particles, but more energy storage times are required, and the update speed of the electrophoresis display 100 will be reduced as a price.

[0008] See Figure 1A and 1C respectively for illustration Figure 8ASimplified schematic diagram and equivalent circuit diagram of some pixel units. There is an electrophoretic capacitance Cp between the charge balance electrode CE and the pixel electrodes (control electrodes) PE1 to PE3, and there is a storage capacitance Cs between the pixel electrodes (control electrodes) PE1 to PE3 and the capacitance electrode CM. Refer to Figure 1B , to illustrate the movement modes of charged color particles (such as positively charged color particles and negatively charged color particles) when no voltage is applied, a positive voltage is applied, and a negative voltage is applied to the control electrodes PE1 to PE3. When no voltage is applied to the control electrodes PE1 to PE3, the charged color particles are roughly in a normal and random distribution, so the equivalent capacitance value of the electrophoretic capacitance Cp is small. When a positive voltage or a negative voltage is applied to the control electrodes PE1 to PE3, the charged color particles are affected by the voltage and move towards the charge balance electrode CE and the control electrodes PE1 to PE3 respectively, so the equivalent capacitance value of the electrophoretic capacitance Cp is large.

[0009] Refer to Figure 2A Parts (A)-(E) of Figure 2A are used to illustrate the three different potential application states, potential application circuits, and potential application waveforms of a pixel unit of an electrophoretic display. Refer to Figure 2A In part (D) of Figure 2A , the gate of the thin-film transistor 32 receives the gate voltage Vg, and the drain applies the control voltage Vst to the control electrode PE to change the electrophoretic capacitance Cp. Figure 2A In part (E) of Figure 2A , in stage A, both the gate voltage Vg and the control voltage Vst are at low potential. As shown in Figure 2A part (A) of Figure 2A , the charged color particles are roughly in a normal and random distribution; in stage B, both the gate voltage Vg and the control voltage Vst are at high potential. As shown in Figure 2A part (B) of [[ID=]16] Figure 2A , the charged color particles are affected by the voltage and start to move towards the charge balance electrode CE and the control electrode PE respectively; in stage C, the gate voltage Vg is at low potential and the control voltage Vst gradually decreases. As shown in Figure 2A Part (C) of , because there is still a positive control voltage Vst, the charged color particles are still affected by the voltage and continue to move towards the charge balance electrode CE and the control electrode PE. In other words, more charged color particles are still affected by the voltage and move to the charge balance electrode CE and the control electrode PE until charge balance is achieved. Refer to Figure 2AIn part (B), when a positive control voltage Vst is first applied to the control electrode PE, since the capacitance of Cs is much larger than that of Cp, the charge on Cp can be ignored first. The charge balance electrode CE is electrically neutral, with positive charges (e.g., 16 positive charges as shown in the figure) on the control electrode PE, and relative negative charges (e.g., 16 negative charges as shown in the figure) on the capacitive electrode CM. As the control voltage Vst is continuously applied, the negatively charged color particles in the electrophoretic layer 20 will be attracted close to the control electrode PE. At the same time, the negative charges on the capacitive electrode CM will flow to the charge balance electrode CE, attracting the positively charged color particles in the electrophoretic layer 20 close to the charge balance electrode CE until charge balance is achieved. For example Figure 2A As shown in part (C), at charge balance, there are approximately equal amounts of charge on the charge balance electrode CE and the capacitive electrode CM, e.g., 8 negative charges as shown in the figure. It should be noted that the charge amounts in the above examples are only for illustrative purposes.

[0010] See Figure 2B Parts (A)-(E) respectively illustrate a pixel unit of an electrophoretic display in three different potential application states, a potential application circuit, and a potential application waveform. As Figure 2B As shown in part (E) of Figure 2B The voltage application of the pixel unit of the electrophoretic display shown is similar to that Figure 2A shown, but a negative voltage is applied to the control voltage Vst, so the movement modes of the positively charged color particles and the negatively charged color particles are opposite to those Figure 2A shown.

[0011] However, in existing electrophoretic displays, since the control voltage applied to the pixel electrode is simply used as the power to move the charged color particles, the movement speed and quantity of the charged color particles are insufficient, affecting the response speed of existing electrophoretic displays. SUMMARY OF THE INVENTION

[0012] The present invention provides an electrophoretic display, by providing an accelerated charge balance circuit, to increase the movement speed and quantity of charged color particles, and improve the response speed of the electrophoretic display.

[0013] To achieve the above object, the present invention provides one, comprising:

[0014] A control substrate, comprising a plurality of thin film transistors, a plurality of pixel electrodes, and a plurality of capacitive electrodes, the plurality of capacitive electrodes being electrically connected together, a plurality of storage capacitors, one end of one of the storage capacitors being one of the capacitive electrodes;

[0015] A charge balance substrate;

[0016] A charge balance electrode;

[0017] A display layer is disposed on one side of the control substrate and includes a plurality of microcontainers. A colloidal solution is filled in one of the microcontainers, and the colloidal solution contains at least one kind of charged color particles;

[0018] An accelerated charge balance circuit includes:

[0019] A charge voltage conversion capacitor has a first end and a second end;

[0020] The capacitive electrode of a storage capacitor of the control substrate is electrically connected to the first end of the charge voltage conversion capacitor, and the charge balance electrode is electrically connected to the second end of the charge voltage conversion capacitor. Brief Description of the Drawings

[0021] Details of one or more embodiments of the subject matter described in this specification are set forth in the following drawings and description. Other features, aspects, and advantages of the subject matter of this specification will become apparent from the description, drawings, and claims, in which:

[0022] Figure 1A It is a simplified schematic diagram of a pixel unit of an existing electrophoretic display. [[ID= nineteen]]

[0023] Figure 1B It is to illustrate the distribution diagram of charged color particles under different applied voltages on the control electrode.

[0024] <, Figure 1C Description Figure 1A Equivalent circuit diagram.

[0025] Figure 2A Parts (A)-(E) of [] illustrate the three different potential application states, potential application circuits, and potential application waveforms of a pixel unit of an existing electrophoretic display, respectively.

[0026] Figure 2B Parts (A)-(E) of [] illustrate the three different potential application states, potential application circuits, and potential application waveforms of a pixel unit of an existing electrophoretic display, respectively.

[0027] Figure 3A Parts (A)-(E) of [] illustrate the three different potential application states, potential application circuits, and potential application waveforms of a pixel unit of the electrophoretic display of the present invention, respectively.

[0028] Figure 3B Parts (A)-(E) of [] illustrate the three different potential application states, potential application circuits, and potential application waveforms of a pixel unit of the electrophoretic display of the present invention, respectively.

[0029] Figure 4A It is a schematic diagram for illustrating an embodiment of an electrophoretic display of the present invention having an accelerated charge balance circuit.

[0030] Figure 4B It is an equivalent circuit diagram of an electrophoretic display with an accelerated charge balance circuit.

[0031] Figure 4C It is a circuit diagram of the accelerated charge balance circuit.

[0032] Figure 5A It shows a schematic diagram of a color electrophoretic display.

[0033] Figure 5B It shows a schematic diagram of another color electrophoretic display.

[0034] Figure 6A It shows a circuit diagram of the connection of the accelerated charge balance circuit and other components according to an embodiment.

[0035] Figure 6B It shows a circuit diagram of the connection of the accelerated charge balance circuit and other components according to another embodiment.

[0036] Figure 7 It shows a circuit diagram of some components of the driving circuit layer.

[0037] Figure 8A It shows a cross-sectional view of an existing electrophoretic display.

[0038] Figure 8B It shows Figure 8A an operating schematic diagram of the existing electrophoretic display. Detailed implementation

[0039] For a detailed description and technical content of the present invention, please refer to the following detailed description and attached drawings as described below. The attached drawings and detailed description are only for illustrative purposes and are not used to limit the present invention.

[0040] See Figure 3A parts (A)-(E) of Figure 4A , 4B, 4C, where Figure 4A is an implementation schematic diagram of an electrophoretic display with an accelerated charge balance circuit according to the present invention, Figure 4B is an equivalent circuit diagram of an electrophoretic display with an accelerated charge balance circuit, and Figure 4C is a circuit diagram of the accelerated charge balance circuit.

[0041] First, see Figure 3A and Figure 4C, the acceleration charge balance circuit 50 of the present invention, for example, includes an operational amplifier circuit 52, a charge-voltage conversion capacitor Cv having a first terminal N1 and a second terminal N2, and a bypass switch SW disposed between the first terminal N1 and the second terminal N2 of the charge-voltage conversion capacitor Cv. The gain of this operational amplifier circuit 52 is, for example, greater than one.

[0042] As Figure 3A shown in part (A) of Figure 3A , and referring also to part (E) of Figure 2A , before the electrophoretic display screen is updated, that is, in stage A, the gate voltage Vg and the control voltage Vst are both at low potential, and the switching voltage Vsw of the bypass switch SW is at high potential (short circuit). At this time, the charged color particles are roughly in a normal and random distribution. After the electrophoretic display screen starts to be updated, that is, in stage B, the gate voltage Vg and the control voltage Vst are both at high potential, and the switching voltage Vsw of the bypass switch SW is at low potential (open circuit), as Figure 2A shown in part (B) of Figure 3A , the charged color particles are respectively affected by the voltage and start to move towards the charge balance electrode CE and the control electrode PE. In stage C, the gate voltage Vg is at low potential and the control voltage Vst gradually decreases, and the switching voltage Vsw of the bypass switch SW remains at low potential (open circuit), as Figure 2A shown in part (C) of Figure 3A . Because there is still a positive control voltage Vst, the charged color particles are still affected by the voltage and continue to move towards the charge balance electrode CE and the control electrode PE. In other words, more charged color particles are still affected by the voltage and move to the charge balance electrode CE and the control electrode PE. As Figure 3A shown in part (C) of Figure 3A , due to the action of the acceleration charge balance circuit 50 of the present invention, more charges move to the charge balance electrode CE, and it more rapidly attracts the charged color particles to move towards the charge balance electrode CE and the control electrode PE, causing more charged color particles to move to the positions required for display and accelerating the screen update speed. The more detailed mechanism of the acceleration charge balance circuit 50 will be described in conjunction with other drawings later. Referring also to Figure 3A part (B) ofFigure 3A As shown in part (C), the capacitive electrode CM has 8 remaining negative charges (8 negative charges flowing out); however, there are more negative charges on the charge balance electrode CE than the number of negative charges flowing out of the capacitive electrode CM, for example, there are 11 negative charges. That is, part of the negative charges on the charge balance electrode CE come from the provision of the accelerated charge balance circuit 50 of the present invention; the speed at which the charged color particles move towards the desired display position can be increased, so as to facilitate accelerating the screen update speed. Here, it should be noted that the charge quantities in the above examples are only for illustrative purposes.

[0043] See Figure 3B Parts (A)-(E), respectively illustrate a pixel unit of an electrophoretic display in three different potential application states, a potential application circuit, and a potential application waveform. As shown in part (E) of 32B, Figure 3B The voltage application of the pixel unit of the electrophoretic display shown is similar to that shown in 3A, but a negative voltage is applied to the control voltage Vst, so the movement modes of the positively charged color particles and the negatively charged color particles are Figure 3A opposite to those shown. Similarly, due to the action of the accelerated charge balance circuit 50 of the present invention, more charges will move to the charge balance electrode CE, and it will more rapidly attract the charged color particles to move towards the charge balance electrode CE and the control electrode PE directions, so that more charged color particles move towards the desired display position, accelerating the screen update speed.

[0044] Figure 5A A schematic diagram showing a color electrophoretic display 100, and the accelerated charge balance circuit 50 of the present invention can be applied to this color electrophoretic display 100. As shown in this figure, this electrophoretic display 100, for example, includes an upper glass substrate 16 from top to bottom, a color filter layer CF, an optical adhesive 13, a charge balance substrate 12 (which can be, for example, a transparent plastic substrate), a charge balance electrode 14 (which can be, for example, a transparent conductive electrode layer), an electrophoretic layer (display layer) 20, a control electrode layer PEL, a driving circuit layer 30a, and a control substrate 10 (which can be, for example, a glass substrate). In Figure 5A the shown structure, the viewing surface is close to the direction of the charge balance substrate 12. In addition, as Figure 5A shown, this display layer 20 includes a plurality of microcontainers 22 (only one is shown in the figure), and the colloidal solution 24 filled in each microcontainer 22 contains a plurality of suspended charged color particles 26 (such as charged black particles 26B and charged white particles 26W). The structure of the microcontainer 22 serves as a container for electronic ink (or electrophoretic material). The microcontainer 22 is, for example, composed of an organic polymer material and is used to fill the charged color particles 26.

[0045] Figure 5BSchematic diagram showing another color electrophoretic display 100 to which the accelerated charge balance circuit 50 of the present invention can be applied. The electrophoretic display 100 of the present invention includes a charge balance substrate 12 from top to bottom (which can be, for example, a transparent plastic substrate), a charge balance electrode 14 (which can be, for example, a transparent conductive electrode layer), a display layer 20, a color filter layer CF, a control electrode layer PEL, a high aperture ratio drive circuit layer 30 (hereinafter referred to as the drive circuit layer 30), and a control substrate 10. Similarly, the display layer 20 includes a plurality of microcontainers 22 (only one is shown in the figure), and a colloidal solution 24 filled in each microcontainer 22 and containing a plurality of charged color particles 26 (such as charged black particles 26B and charged white particles 26W). The microcontainer 22 is, for example, a hollow cavity formed of an organic polymer material and is used to fill the charged color particles 26. According to other embodiments of the present invention (not shown in the figure), the microcontainer 22 can also be filled with a colloidal solution 24 containing a fluid of a color (such as black) and a plurality of charged particles of a single color (such as white particles), and the structure of the microcontainer 22 serves as a container for electronic ink.

[0046] The microcontainer 22 can be in the structure of a microcapsule (for example, see U.S. Patents US 7,535,624 and US5961804) or a microcup (for example, see Taiwan Invention TW I230832B). Furthermore, the microcontainer 22 can also be a microcompartment (for example, see the Taiwan invention application case No. 112135041 of the applicant of the present invention).

[0047] Furthermore, in Figure 5A and 5B In other embodiments of the present invention, the color electrophoretic display 100 of the present invention may not have the color filter layer CF, and / or the colloidal solution 24 of the display layer 20 also includes a plurality of black charged color particles, a plurality of white charged color particles, and a plurality of red charged color particles. The colloidal solution 24 of the display layer 20 also includes a plurality of black charged color particles, a plurality of white charged color particles, a plurality of red charged color particles, and a plurality of yellow charged color particles. The colloidal solution 24 of the display layer 20 also includes a plurality of white charged color particles, a plurality of yellow charged color particles, a plurality of magenta charged color particles, and a plurality of cyan charged color particles. The colloidal solution 24 of the display layer 20 also includes a plurality of white charged color particles, a plurality of red charged color particles, a plurality of yellow charged color particles, and a plurality of blue charged color particles. Each of the above combinations of charged color particles is within the scope of the patent of this case.

[0048] Figure 6A Circuit diagram showing the connection of the accelerated charge balance circuit to other components. As shown in this figure, this accelerated charge balance circuit 50 is electrically connected toFigure 5A and Figure 5B related components of the electrophoretic display 100 shown. More specifically, the accelerating charge balance circuit 50 includes an operational amplifier circuit 52. The input terminal 52A (such as an inverting input terminal) of this operational amplifier circuit 52 is electrically connected to the first terminal N1 of the charge voltage conversion capacitor Cv and the capacitor electrode CM. The output terminal 52B of this operational amplifier circuit 52 is electrically connected to the second terminal N2 of the charge voltage conversion capacitor Cv and the charge balance electrode CE.

[0049] Also refer to Figure 3A part (E) of. Before the electrophoretic display screen is updated, that is, in stage A, the gate voltage Vg and the control voltage Vst are both at low potential, and the switching voltage Vsw of the bypass switch SW is at high potential (short circuit). The output voltage of N2 is at ground potential (GND), which is equivalent to the concept of virtual ground. At this time, the charged color particles in the display layer 20 are roughly in a normal state and randomly distributed. After the electrophoretic display screen starts to be updated, that is, in stage B, the gate voltage Vg and the control voltage Vst are both at high potential, and the switching voltage Vsw of the bypass switch SW is at low potential (open circuit). At this time, a positive voltage is applied to the control electrode PE to attract negatively charged color particles, and a negative voltage is applied to the capacitor electrode CM through the output of the operational amplifier circuit 52 via the charge voltage conversion capacitor Cv, forming a positive charge at the N1 end of the charge voltage conversion capacitor Cv and a negative charge at the CM end (refer to Figure 6A ), and the charges at the N1 end and the CM end have opposite polarities. The input terminal 52A of the operational amplifier circuit 52 is virtually grounded, and the first terminal N1 of the charge voltage conversion capacitor Cv is at a positive potential relative to the second terminal N2. When entering stage C, the N1 end and the CM end will attract each other due to the opposite charge polarities, which can accelerate the removal of the charge at the CM end. When the charges at the N1 end and the CM end combine with each other, the charge at the N2 end will be pushed towards the charge balance electrode CE, so as to accelerate the electron flow towards the charge balance electrode CE to achieve balance. Due to the action of the accelerating charge balance circuit 50 of the present invention, more negatively charged electrons will be quickly driven to move to the charge balance electrode CE, and it will more quickly attract the charged color particles to move towards the charge balance electrode CE and the control electrode PE directions, that is, more charged color particles move to the positions required for display, and the screen update speed is accelerated.

[0050] In Figure 6A the circuit shown, the capacitor electrode CM is connected to virtual ground instead of actual ground, so that static charges can be avoided from accumulating in the actual ground, and the incorrect operation of other circuits due to the fact that the ground potential is not substantially charge-neutral can be avoided. In addition, according to the capacitance formula Q = CV, the voltage across the charge voltage conversion capacitor Cv will increase as the value of the charge voltage conversion capacitor Cv becomes smaller (equivalent to an increase in the gain of the operational amplifier circuit 52), which can accelerate the speed of electrons moving to the charge balance electrode CE.

[0051] Figure 6B Show a circuit diagram of an accelerated charge balance circuit connected to other components according to another embodiment. As shown in this figure, this accelerated charge balance circuit 50 is electrically connected to Figure 5A and Figure 5B the relevant components of the electrophoretic display 100 shown. More specifically, the accelerated charge balance circuit 50 includes an operational amplifier circuit 52. The input terminal 52A of this operational amplifier circuit 52 is electrically connected to the first terminal N1 of the charge voltage conversion capacitor Cv and the capacitor electrode CM. The output terminal 52B of this operational amplifier circuit 52 is electrically connected to the second terminal N2 of the charge voltage conversion capacitor Cv and the charge balance electrode CE.

[0052] Figure 6B The embodiment shown includes two display layers, namely the first display layer 20A and the second display layer 20B. The structure and operation of the first display layer 20A are similar to Figure 6A the display layer 20 shown; and the second display layer 20B can be provided on a substrate different from the control substrate 10 to provide different display contents for this electrophoretic display 100, such as double-sided display. Similarly, before the electrophoretic display screen is updated, that is, in stage A, the gate voltage Vg and the control voltage Vst are both at a low potential, and the switching voltage Vsw of the bypass switch SW is at a high potential (short circuit). At this time, the charged color particles in the first display layer 20A and the second display layer 20B are roughly in a normal and random distribution. After the electrophoretic display screen starts to be updated, that is, in stage B, the gate voltage Vg and the control voltage Vst are both at a high potential, and the switching voltage Vsw of the bypass switch SW is at a low potential (open circuit). At this time, a positive voltage is applied to the control electrode PE for the first display layer 20A to attract negatively charged color particles, and a negative voltage is applied to the capacitor electrode CM of the first display layer 20A. The input terminal 52A of the operational amplifier circuit 52 is at virtual ground, and the first terminal N1 of the charge voltage conversion capacitor Cv is at a positive potential relative to the second terminal N2, which can accelerate the electron flow to the capacitor electrode CM. In addition, for the second display layer 20B, since the current flows from the charge balance electrode CE to the output terminal 52B of the operational amplifier circuit 52, a negative charge is generated on the charge balance electrode CE, making the charge balance electrode CE at a negative potential with respect to the ground. Therefore, the charge balance electrode CE can attract positively charged color particles, and the electrode on the opposite side of the charge balance electrode CE is at a positive potential, so it can attract negatively charged color particles, achieving the effect of charge balance.

[0053] Although not explicitly shown in the figures, the accelerated charge balance circuit 50 is disposed within a control integrated circuit chip, which is disposed on a surface of the control substrate 10; alternatively, the accelerated charge balance circuit 50 is disposed within a control integrated circuit chip, which is disposed on a surface of a flexible circuit board, and one end of the flexible circuit board is pressed against one end of the control substrate 10.

[0054] In addition, in the above embodiments, the charge balance substrate 12 is a transparent substrate, such as a glass substrate or a polymer substrate. The control substrate 10 is a transparent substrate, such as a glass substrate or a polymer substrate. The charge balance electrode CE is a transparent conductive electrode, such as an indium tin oxide electrode (ITO). The plurality of pixel electrodes PE and the plurality of capacitor electrodes CM may also be transparent conductive electrodes, such as an indium tin oxide electrode (ITO). The plurality of thin film transistors 32 are amorphous silicon thin film transistors or organic thin film transistors.

[0055] In summary, by providing an accelerated charge balance circuit having a charge voltage conversion capacitor, the present invention can accelerate the movement speed and quantity of charged color particles and improve the response speed of the electrophoretic display when updating the electrophoretic display screen.

[0056] The components of several embodiments are outlined above, enabling those with ordinary knowledge in the technical field to which the present invention pertains to better understand the concepts of the embodiments of the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains should understand that they can use the embodiments of the present invention as a basis to design or modify other processes and structures to achieve the same purpose and / or obtain the same benefits as those introduced in the embodiments herein. Those with ordinary knowledge in the technical field to which the present invention pertains should also understand that these equivalent structures do not deviate from the spirit and scope of the present invention, and various changes, substitutions, and other options can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be defined by the appended patent application scope.

[0057]

Symbol Description

[0058] Cp: Electrophoretic capacitance

[0059] CE: Charge balance electrode

[0060] Cs: Storage capacitance

[0061] PE1, PE2, PE3, PE: Control electrode

[0062] CM: Capacitor electrode

[0063] Vg: Gate voltage

[0064] Vst: Control voltage

[0065] Vsw: Switching voltage

[0066] SW: Bypass switch

[0067] A, B, C: Phases

[0068] 50: Accelerating charge balance circuit

[0069] 52: Operational amplifier circuit

[0070] N1: First terminal

[0071] N2: Second terminal

[0072] Cv: Charge - voltage conversion capacitor

[0073] 100: Electrophoretic display

[0074] 16: Upper glass substrate

[0075] 12: Charge balance substrate

[0076] CF: Color filter layer

[0077] 13: Optical adhesive

[0078] 14: Charge balance electrode

[0079] 20: Electrophoretic layer

[0080] 22: Micro - container

[0081] 24: Colloidal solution

[0082] 26: Charged color particles

[0083] 26B: Charged black particles

[0084] 26W: Charged white particles

[0085] 30a, 30: Driving circuit layer

[0086] 32: Thin - film transistor

[0087] PEL: Control electrode layer

[0088] 10: Control substrate

[0089] CF1, CF2, CF3: Color filter layer

[0090] Mg: Gate

[0091] M1: First metal layer

[0092] M2: Second metal layer

[0093] 52A: Input terminal

[0094] 52B: Output terminal

[0095] 20A: First display layer

[0096] 20B: Second display layer

[0097] DL: Data line

[0098] GL: Gate line

Claims

1. An electrophoretic display with an accelerated charge balancing circuit, comprising: a control substrate comprising a plurality of thin film transistors, a plurality of pixel electrodes and a plurality of capacitor electrodes, the plurality of capacitor electrodes being electrically connected together, and a plurality of storage capacitors, one end of each storage capacitor being a capacitor electrode; a charge-balancing substrate; a charge balancing electrode disposed on a side surface close to the charge balancing substrate; A display layer is disposed on one side of the control substrate and includes a plurality of microcontainers, one of the microcontainers is filled with a colloidal solution containing at least one type of charged color particles; An accelerated charge balancing circuit includes: A charge-to-voltage conversion capacitor has a first terminal and a second terminal; The capacitor electrode of the storage capacitor of the control substrate is electrically connected to the first end of the charge-voltage conversion capacitor, and the charge balancing electrode is electrically connected to the second end of the charge-voltage conversion capacitor.

2. The electrophoretic display with an accelerated charge balancing circuit according to claim 1, wherein the first end of the charge-voltage conversion capacitor is connected to an input end of the accelerated charge balancing circuit, and the second end of the charge-voltage conversion capacitor is connected to an output end of the accelerated charge balancing circuit. 3 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , further comprising a bypass switch disposed between the first terminal and the second terminal of the charge-to-voltage conversion capacitor. 4 . The electrophoretic display with an accelerated charge balancing circuit according to claim 3 , wherein the bypass switch is short-circuited before the image is updated and is open-circuited after the image is updated. 5 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the microcontainer has a microcapsule structure. 6 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the microcontainer has a microcup structure. 7 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the microcontainer has a microcompartment structure. 8 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein a gain value of the accelerated charge balancing circuit is greater than or equal to one. 9 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the accelerated charge balancing circuit comprises an operational amplifier circuit. 10 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the charge balancing substrate is a transparent substrate.

11. The electrophoretic display with an accelerated charge balancing circuit according to claim 10, wherein the charge balancing electrode is a transparent conductive electrode. 12 . The electrophoretic display with an accelerated charge balancing circuit according to claim 11 , further comprising a color filter layer disposed on one side of the charge balancing electrode. 13 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the control substrate is a transparent substrate. 14 . The electrophoretic display with an accelerated charge balancing circuit according to claim 13 , wherein the plurality of pixel electrodes and the plurality of capacitor electrodes are transparent conductive electrodes. 15 . The electrophoretic display with an accelerated charge balancing circuit according to claim 14 , further comprising a color filter layer disposed on one side of the control substrate. 16 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the plurality of thin film transistors are amorphous silicon thin film transistors or organic thin film transistors. 17 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the accelerated charge balancing circuit is disposed in a control integrated circuit chip, and the control integrated circuit chip is disposed on a surface of the control substrate.

18. The electrophoretic display with an accelerated charge balancing circuit according to claim 1, wherein the accelerated charge balancing circuit is disposed in a control integrated circuit chip, the control integrated circuit chip is disposed on a surface of a flexible printed circuit board, and one end of the flexible printed circuit board is pressed against one end of the control substrate. 19 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the colloidal solution of the display layer comprises a plurality of black charged color particles and a plurality of white charged color particles. 20 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the colloidal solution of the display layer comprises a plurality of black charged color particles, a plurality of white charged color particles, and a plurality of red charged color particles. 21 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the colloidal solution of the display layer comprises a plurality of black charged color particles, a plurality of white charged color particles, a plurality of red charged color particles, and a plurality of yellow charged color particles.

22. The electrophoretic display with an accelerated charge balancing circuit according to claim 1, wherein the colloidal solution of the display layer comprises a plurality of white charged color particles, a plurality of yellow charged color particles, a plurality of magenta charged color particles, and a plurality of cyan charged color particles. 23 . The electrophoretic display with an accelerated charge balancing circuit according to claim 1 , wherein the colloidal solution of the display layer comprises a plurality of white charged color particles, a plurality of yellow charged color particles, a plurality of red charged color particles, and a plurality of blue charged color particles.

Images