Electrophoretic display apparatus

Abstract

This electrophoretic display apparatus comprises: a common electrode; a pixel electrode disposed to correspond to the common electrode; a plurality of color pigments provided between the common electrode and the pixel electrode and dispersed in a solvent; a data driving unit configured to supply a data voltage to the pixel electrode; and a stabilization circuit configured to receive a common voltage supplied to the common electrode, and perform a sinking operation of absorbing a current flowing from the common electrode or a sourcing operation of supplying a current to the common electrode on the basis of a difference between the common voltage and the data voltage.

Description

Electrophoretic display device

[0001] The disclosed invention relates to an electrophoretic display device.

[0002] Electrophoretic Displays (EPDs) are display technologies that utilize the electrophoretic phenomenon to display characters or images by moving charged microparticles using an electric field. When an electric field is applied, the particles move and colors appear, and since the state is maintained even after the electric field is removed, no power is consumed in static images. Thanks to these low-power characteristics, they are widely used in electronic paper (E-paper), such as in e-book readers.

[0003] The display panel of an electrophoretic display device receives data voltage from the pixel electrodes facing the common electrode through thin-film transistors (TFTs). If the potential of the common electrode is not stably formed in response to the data voltage while positive (+) and negative (-) voltage waveforms are supplied to the pixel electrodes, the movement of color pigments dispersed in a solvent between the common electrode and the pixel electrodes becomes distorted, which can lead to color display errors or changes in movement over time, making it difficult to ensure driving reproducibility and stability.

[0004] In addition, if the potential of the common electrode is not stably formed, the applied electric field may be uneven during inversion driving, which may cause afterimages and color distortion as the color pigments are distributed differently from what was intended, making it difficult to ensure lifespan and reliability.

[0005] The present disclosure provides an electrophoretic display device capable of ensuring driving reproducibility, stability, lifespan, and reliability of the electrophoretic display device.

[0006] The technical problems to be solved in this document are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this invention belongs from the description below.

[0007] An electrophoretic display device according to one embodiment of the present disclosure may include: a common electrode; a pixel electrode disposed corresponding to the common electrode; a plurality of color pigments disposed between the common electrode and the pixel electrode and dispersed in a solvent; a data driving unit that supplies a data voltage to the pixel electrode; and a stabilization circuit configured to receive a common voltage supplied to the common electrode and to perform a sinking operation that absorbs a current flowing in from the common electrode or a sourcing operation that supplies a current to the common electrode based on the difference between the common voltage and the data voltage.

[0008] An electrophoretic display device according to another embodiment of the present disclosure may include: a display panel having a plurality of pixels formed therein, wherein a plurality of color pigments dispersed in a solvent are provided between a common electrode and a pixel electrode; a data driving unit that supplies a data voltage to the pixel electrode; a power supply unit that supplies a driving voltage to the data driving unit and supplies a common voltage to the common electrode; a printed circuit board assembly having the power supply unit; and a stabilization circuit configured to receive the common voltage and perform a sinking operation that absorbs a current flowing in from the common electrode or a sourcing operation that supplies a current to the common electrode based on the difference between the common voltage and the data voltage.

[0009] FIG. 1 illustrates an example of the structure of an electrophoretic display device according to one embodiment.

[0010] FIG. 2 is a configuration diagram of an electrophoretic display device according to one embodiment.

[0011] FIG. 3 illustrates a pixel of a display panel of an electrophoretic display device according to one embodiment.

[0012] FIG. 4 is a driving circuit of an electrophoretic display device according to one embodiment.

[0013] FIG. 5 illustrates a voltage waveform output from a data driving unit in an electrophoretic display device according to one embodiment.

[0014] FIG. 6 illustrates the flow of current in an electrophoretic display device according to one embodiment when the data voltage is a positive (+) voltage higher than the common voltage.

[0015] FIG. 7 illustrates the flow of current in an electrophoretic display device according to one embodiment when the data voltage is a negative (-) voltage lower than the common voltage.

[0016] FIG. 8 illustrates the sinking operation of a stabilization circuit in an electrophoretic display device according to one embodiment when the data voltage is a positive (+) voltage higher than the common voltage.

[0017] FIG. 9 illustrates the sourcing operation of a stabilization circuit in an electrophoretic display device according to one embodiment when the data voltage is a negative (-) voltage lower than the common voltage.

[0018] FIG. 10 illustrates the voltage waveform and current waveform of a stabilization circuit in an electrophoretic display device according to one embodiment.

[0019] FIG. 11 illustrates the arrangement of a stabilization circuit in an electrophoretic display device according to one embodiment.

[0020] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and various modifications that may replace the embodiments and drawings of this specification may exist at the time of filing this application.

[0021] Additionally, the same reference numerals or symbols presented in each drawing of this specification represent parts or components that perform substantially the same function.

[0022] Additionally, the singular form of the noun corresponding to the item may include one or multiple items, unless the relevant context clearly indicates otherwise.

[0023] Additionally, in this document, each of the phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B, or C" may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0024] Additionally, the terms "part," "module," and "component" may be implemented in hardware or software. Depending on the embodiments, a plurality of "parts," "modules," and "components" may be implemented as a single component, or a single "part," "module," or "component" may include a plurality of components.

[0025] Furthermore, the terms used in this specification are for describing embodiments and are not intended to limit or / or restrict the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] Additionally, terms including ordinal numbers, such as "first," "second," etc., used herein may be used to describe various components, but said components are not limited by said terms, and said terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any one of a plurality of related described items.

[0027] Where any (e.g., 1st) component is referred to as "coupled" or "connected" to another (e.g., 2nd) component, with or without the terms "functionally" or "communicationly," it means that said any component may be connected to said other component directly (e.g., via a wire), wirelessly, or through a third component.

[0028] When it is said that a component is "connected," "combined," "supported," or "in contact" with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0029] When it is said that a component is located "on" another component, this includes not only cases where one component is in contact with the other, but also cases where another component exists between the two components.

[0030] Meanwhile, terms such as "up / down direction" and "front / back direction" used in the following description are defined based on the drawings, and the shape and position of each component are not limited by these terms. For example, the terms "front" and "rear" below may each be defined based on the X direction shown in the drawings. The terms "up" and "down" below may each be defined based on the Z direction shown in the drawings. The terms "left direction" and "right direction" below may be defined based on the Y direction shown in the drawings. The term "vertical direction" below may each refer to the Z direction shown in the drawings, and the term "horizontal direction" below may each refer to the Y direction shown in the drawings.

[0031] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0032] FIG. 1 illustrates an example of the structure of an electrophoretic display device according to one embodiment, and FIG. 2 is a configuration diagram of an electrophoretic display device according to one embodiment.

[0033] Referring to FIGS. 1 and 2, the electrophoretic display device (1) is a device capable of visually displaying characters or images. In the following examples, the electrophoretic display device (1) is an electronic paper, but is not limited thereto. The form of the display device (10) is not limited as long as it is a device capable of visually displaying images.

[0034] Various components for displaying text or images on a screen may be provided inside the electrophoretic display device (1).

[0035] The electrophoretic display device (1) may include a display panel (10), a panel display driver integrated circuit (PDDI) (20), and a printed circuit board assembly (30).

[0036] The front surface of the display panel (10) forms a screen, and the display panel (10) can form a plurality of pixels. In the display panel (10), the plurality of pixels can each be provided independently. Additionally, characters or images can be displayed on the screen by the plurality of pixels.

[0037] The display panel (10) may include m / n pixels (11).

[0038] A display panel (10) may be formed such that a plurality of data lines (D1 to Dm) and a plurality of gate lines (G1 to Gn) intersect. A TFT may be electrically connected to each pixel (11) in the intersecting area.

[0039] On one side of the display panel (10), a cable (10a) electrically connected to the display panel (10) may be provided.

[0040] The cable (10a) can electrically connect the panel driver (20) and the printed circuit board assembly (30).

[0041] The cable (10a) can electrically connect the panel driver (20) and the display panel (10).

[0042] The cable (10a) may include a flexible flat cable or a film cable that can be bent.

[0043] A panel display driver IC (Panel Display Driver Integrated Circuit, PDDI) (hereinafter panel driver) (20) can be electrically connected to a printed circuit board assembly (30) via a cable (10a).

[0044] The panel driver (20) may be formed integrally with the cable (10a). The panel driver (20) and the cable (10a) may be implemented integrally as a film cable, chip on film (COF), tape carrier package (TCP), etc. However, it is not limited thereto, and the panel driver (20) may be placed on the display panel (10) as a chip on glass (COG).

[0045] The panel driver (20) can transmit electrical signals for each pixel (11) in the correct time and order according to the control of the control unit (31) provided in the printed circuit board assembly (30).

[0046] The printed circuit board assembly (30) may include a control unit (31) and a power supply unit (32).

[0047] The control unit (31) may receive a control signal from the central processing unit (AP or CPU) of the electrophoretic display device (1). The control unit (31) may include a memory, a processor, and a control circuit board on which these are mounted.

[0048] The control unit (31) can generate a driver control signal (gate control signal, data control signal) for controlling the panel driver (20) based on the provided control signal and provide the driver control signal to the panel driver (20).

[0049] The power supply unit (32) can supply power to the display panel (10), the panel driver (20), and the control unit (31).

[0050] When power is supplied to the electrophoretic display device (1), the power supply unit (32) can generate voltages required for driving the display panel (10) using the input power (Vin). The power supply unit (32) can generate driving voltages for the panel driver (20) according to the power control signal provided by the control unit (31). The power supply unit (32) can generate a common voltage provided by the control unit (31).

[0051] The power supply unit (32) can supply a driving voltage to the panel driver (20). For example, the power supply unit (32) can generate a plurality of driving voltages to apply an electric field to a charged color pigment of a pixel (11) of a display panel (10) and supply them to the panel driver (20) to output a waveform for determining the position of the charged color pigment.

[0052] The panel driver (20) may include a gate driver (21) and a data driver (22).

[0053] The gate driver (21) can supply a gate voltage to a plurality of gate lines (G1 to Gn) of the display panel (10) according to a gate control signal provided from the control unit (31). The gate driver (21) can select the TFT of the corresponding line and turn it on or off.

[0054] When the gate driving unit (21) applies a gate voltage to the gate lines (G1 to Gn), the TFT is turned on or turned off by the applied gate voltage, and the pixel (11) of the corresponding line can be driven.

[0055] The data driving unit (22) can supply waveforms to a plurality of data lines (D1 to Dm) of the display panel (10) according to a data control signal provided from the control unit (31).

[0056] The electrophoretic display device (1) can supply a waveform to a specific pixel (11) using a gate driver (21) and a data driver (22). The waveform can be generated in various versions by reflecting the characteristics of the charged color pigment of the pixel (11) and the solvent, the characteristics of the solvent manufacturer's unique manufacturing process, and the operating temperature. For example, control information for implementing a waveform to display white, blue, red, and yellow, etc., on the pixel (11) may be stored in advance.

[0057] The control unit (31) can provide control information for implementing a waveform to the gate driver (21) and the data driver (22). The control unit (31) can perform control to create a waveform implemented as a sequence of positive (+) and negative (-) voltages in a series of reset and write sections to move a charged color pigment to a desired position.

[0058] The data driving unit (22) can generate a waveform using waveform control information from the control unit (31) and a driving voltage supplied from the power supply unit (32), and can supply the generated waveform to a plurality of data lines (D1 to Dm).

[0059] FIG. 3 illustrates a pixel of a display panel of an electrophoretic display device according to one embodiment.

[0060] Referring to FIG. 3, the display panel (10) may include a pixel electrode (12) provided on a lower substrate and a common electrode (13) provided on an upper substrate.

[0061] The pixel electrode (12) and the common electrode (13) can be positioned opposite each other.

[0062] The common electrode (13) provided on the upper substrate can be placed on the side visible to the user as a transparent electrode layer.

[0063] A series of electric fields can be formed in the pixel (11) by the potential difference between the common voltage of the common electrode (13) and the waveform of the pixel electrode (12). This electric field can guide color pigments placed between the common electrode (13) and the pixel electrode (12) to a desired position, thereby enabling the realization of a desired color by utilizing external light reflection.

[0064] Between the common electrode (13) and the pixel electrode (12), color pigments charged with a preset capacitance can be dispersed in a solvent to form an electrophoretic layer.

[0065] The color pigments of the electrophoretic layer can each be charged with positive (+) or negative (-) charges of different polarities and capacities. When a waveform is applied through the data driver (22), the color pigments move to a specific location due to the difference in electric field with the common electrode (13), and a desired color can be realized using external light reflection.

[0066] For example, multiple color pigments may include four color particles (W, B, R, Y).

[0067] The four color particles (W, B, R, Y) may include two pairs of particles with opposite polarities.

[0068] The first pair may include a white particle (W) and a blue particle (B). The white particle (W) may have a high positive (+) charge, and the blue particle (B) may have a high negative (-) charge.

[0069] The second pair may include a red particle (R) and a yellow particle (Y). The red particle (R) may have a low positive (+) charge, and the yellow particle (Y) may have a low negative (-) charge.

[0070] In various embodiments, the white particles (W), blue particles (B), red particles (R), and yellow particles (Y) can be of various shapes.

[0071] The four color particles (W, B, R, Y) can be mixed to adjust the color state. The four colors (W, B, R, Y) can be extended to other colors in addition to white, blue, red, and yellow.

[0072] For example, when a high negative (-) potential is applied to the pixel electrode (12) in comparison to the common voltage of the common electrode (13), a high electric field is generated, causing negatively charged blue particles (B) to move toward the common electrode (13) and highly positively charged white particles (W) to move toward the pixel electrode (12). Since red (R) and yellow particles (Y) have a small capacitance, less force acts on them in the same electric field compared to highly positively charged white particles (W) and highly negatively charged blue particles (B), resulting in a shorter travel distance to the common electrode (13) relative to time. Finally, the movement of blue particles is concentrated toward the common electrode (13) for a specific period, and is displayed as blue to the user through external light reflection. Additionally, when a high positive (+) potential is applied to the pixel electrode (12) in comparison to the common voltage of the common electrode (13), an electric field of opposite polarity is generated, causing the particle distribution to appear reversed from before. Finally, it is displayed to the user as white through external light reflection.

[0073] Additionally, when a low positive (+) potential is applied to the pixel electrode (12) in comparison to the common voltage of the common electrode (13), a low electric field is applied to the blue particles (B) with a high negative (-) charge, thereby restricting their movement toward the pixel electrode (12). The white particles (W) with a high positive (+) charge are also restricted from moving toward the common electrode (13) for the same reason. This is because the low electric field is not strong enough to overcome the strong attractive force between the two particles. On the other hand, the low electric field is sufficient to separate the yellow particles (Y) with a low negative (-) charge and the red particles (R) with a low positive (+) charge, so the red particles (R) with a low positive (+) charge move toward the common electrode (13), and the yellow particles (Y) with a low negative (-) charge move toward the pixel electrode (12). Finally, to the user, it is displayed in red through external light reflection.

[0074] In addition, when a low negative (-) potential is applied to the pixel electrode (12) compared to the common voltage of the common electrode (13), a low electric field of opposite polarity is generated, and the particle distribution appears opposite to the previous one. Finally, it is displayed to the user in yellow through external light reflection.

[0075] FIG. 4 is a driving circuit of an electrophoretic display device according to one embodiment.

[0076] Referring to FIG. 4, the electrophoretic display device (1) may include a stabilization circuit (40).

[0077] The stabilization circuit (40) is electrically connected to the common electrode (13) through the common line (CL).

[0078] The stabilization circuit (40) can stably form the potential of the common electrode (13) for the waveform supplied to the pixel electrode (12).

[0079] The stabilization circuit (40) can stabilize the potential of the common electrode (13) by absorbing the current flowing in from the common electrode (13) or supplying the current to the common electrode (13) according to the difference between the data voltage having a waveform supplied from the data driving unit (22) through the TFT (14) to the pixel electrode (12) and the common voltage supplied to the common electrode (13) in the form of a DC voltage or AC voltage.

[0080] The stabilization circuit (40) can perform a sinking operation that absorbs current flowing in from the common electrode (13) or a sourcing operation that supplies current to the common electrode (13). The stabilization circuit (40) can stabilize the potential of the common electrode (13) by performing the sinking operation or the sourcing operation.

[0081] The stabilization circuit (40) is electrically connected to the common electrode (13).

[0082] The drain electrode of the TFT (14) is electrically connected to the pixel electrode (12).

[0083] The source electrode of the TFT (14) is electrically connected to the data driver (22).

[0084] In various embodiments, the source electrode of the TFT (14) is electrically connected to the pixel electrode (12), and the drain electrode of the TFT (14) can be electrically connected to the data driver (22).

[0085] The gate electrode of the TFT (14) is electrically connected to the gate driver (21).

[0086] The TFT (14) can be turned on or turned off by the gate voltage output from the gate driver (21).

[0087] When the TFT (14) is turned on, the data voltage output from the data driving unit (22) can be supplied to the pixel electrode (12) through the TFT (14).

[0088] A common voltage (Vcom) can be supplied to the common electrode (12).

[0089] Accordingly, an electric field can be formed in the pixel (11) by the potential difference between the data voltage of the pixel electrode (12) and the common voltage of the common electrode (13).

[0090] In the pixel (11), the common electrode (13) and the source electrode of the TFT (14) can be formed as a capacitive load. In various embodiments, the capacitive load can be formed between the common electrode (13) and the pixel electrode (12).

[0091] In order to reproducibly align multiple color pigments of a pixel (11) to a specific position or move them to an initial position, it is necessary to switch high voltages of positive and negative (positive (+) and negative (-)) symmetrical to the common voltage of the common electrode (13) at high speed (e.g., +20V, -20V). In addition, depending on the characteristics or environment of the pixel (11), it is necessary to drive at high speed for a short period of several seconds (e.g., 15 seconds) to several minutes. At this time, it is necessary to stably supply and recover the peak charge / discharge current of several amperes (e.g., 2.5A) of the positive voltage generated during the high voltage switching of each positive voltage.

[0092] It is necessary to supply a positive voltage that is switched at high speed high voltage for initialization and specific alignment of multiple color pigments of a pixel (11), and it is necessary to form a stable potential of a common electrode (13) with respect to the waveform of the positive voltage applied to the pixel electrode (12). That is, by stably supplying and recovering the positive direction peak charge / discharge current (sourcing current / sinking current) generated by the positive high voltage switching, a stable potential of the common electrode (13) can be realized.

[0093] In the past, the potential of the common electrode (13) could not be formed stably due to the unidirectional driving and non-equivalent driving methods of the common electrode driving unit. That is, the common electrode driving unit of the conventional method performed only a sinking operation that absorbs the current flowing in from the common electrode (13) or only a sourcing operation that supplies current to the common electrode (13), or performed a non-equivalent driving in which the sourcing operation and the sinking operation appear unbalanced. As a result, the potential of the common electrode (13) with respect to the data voltage was not formed stably, making it difficult to ensure driving reproducibility, stability, lifespan, and reliability.

[0094] If the potential of the common electrode (13) is not stably formed, the movement of multiple color pigments dispersed in a solvent between the common electrode (13) and the pixel electrode (12) may be distorted, which may result in color display errors or changes in movement over time, making it difficult to ensure driving reproducibility and stability. In addition, since the electric field is non-uniform, afterimages may occur, and color distortion may occur as the color pigments are distributed differently from what was intended, it is difficult to ensure lifespan and reliability.

[0095] The stabilization circuit (40) can form a stable potential of the common electrode (13) by automatically performing a sinking operation that absorbs current flowing in from the common electrode (13) or a sourcing operation that supplies current to the common electrode (13) according to the difference between the data voltage supplied to the pixel electrode (12) and the common voltage supplied to the common electrode (13).

[0096] The stabilization circuit (40) can absorb current flowing in from the common electrode (13) through a sinking operation if the data voltage supplied to the pixel electrode (12) from the data driving unit (22) is a positive (+) voltage higher than the common voltage (Vcom) input to the stabilization circuit (40).

[0097] The stabilization circuit (40) can supply current to the common electrode (13) through a sourcing operation if the data voltage supplied to the pixel electrode (12) from the data driving unit (22) is a negative (-) voltage lower than the common voltage (Vcom) input to the stabilization circuit (40).

[0098] FIG. 5 illustrates a voltage waveform output from a data driving unit in an electrophoretic display device according to one embodiment.

[0099] Referring to FIG. 5, in order to move a desired color pigment among a plurality of color pigments to the common electrode (13), the color pigment located at the common electrode (13) must be moved quickly to a neutral position or an initial position. To do this, a high-voltage positive data voltage must be applied continuously for a long time while inverting between a positive (+) voltage and a negative (-) voltage, which is called the reset section. Afterwards, in order to move a specific charged color pigment to be expressed to the common electrode (13), a data voltage waveform corresponding to a preset amount of charge must be applied to the pixel electrode (12), which is called the writing section.

[0100] The output of the data driving unit (22) is transmitted to the pixel electrode (12) via the TFT (14). When a potential difference is created between the data voltage of the pixel electrode (12) and the common voltage of the common electrode (13), an electric field is formed in the color pigments located between the pixel electrode (12) and the common electrode (13), causing the color pigments to move.

[0101] When a government data voltage is supplied to the pixel electrode (12) during the reset section and / or write section, the electric field applied to the color pigments existing between the pixel electrode (12) and the common electrode (13) can be changed. Accordingly, rapid charging and discharging operations occur in the capacitive load according to the potential difference relationship between the common electrode (13) and the pixel electrode (12), and rapid current changes occur due to the movement of charge.

[0102] The data driving unit (22) can generate a data voltage supplied to the pixel electrode (12) using driving voltages generated by the power supply unit (32). The data voltage can be repeated based on the common voltage within the range of positive (+) voltage (e.g., +19V) and negative (-) voltage (e.g., -19V) to move the charged color pigment to the common electrode (13), and can have multiple voltage levels depending on the charge amount of the charged color pigments. The positive (+) voltage (Vpos) of the data voltage can have multiple voltage levels. The negative (-) voltage (Vneg) of the data voltage can have multiple voltage levels.

[0103] When a specific data voltage waveform (Vpos, Vneg) is supplied to the pixel electrode (12), the electric field in the color pigment between the pixel electrode (12) and the common electrode (13) can be changed.

[0104] When a positive voltage (Vpos) (e.g., +19V) higher than the common voltage (Vcom) (e.g., -1V) is applied to the pixel electrode (12), a charging operation occurs in the capacitive load and a sudden current may flow into the common electrode (13).

[0105] In addition, if a negative voltage (Vneg) (e.g., -19V) lower than the common voltage (Vcom) (e.g., -1V) is applied to the pixel electrode (12), a discharge operation occurs in the capacitive load and a sudden current may flow out from the common electrode (13).

[0106] FIG. 6 illustrates the flow of current in an electrophoretic display device according to one embodiment when the data voltage is a positive (+) voltage higher than the common voltage.

[0107] Referring to FIG. 6, the output of the data driving unit (22) can be supplied to the pixel electrode (12) of each pixel (11) with a plurality of voltages, Vpos1 to Vposn and Vneg1 to Vnegn, based on the common voltage (Vcom).

[0108] When the output of the data driver (22) is a voltage (Vpos) higher than the common voltage (Vcom), for example, when the output of the data driver (22) is a positive (+) voltage (Vpos) higher than the common voltage (Vcom), an electric field is formed in the direction of the common voltage (Vcom), and rapid charging of the capacitive load can occur in the direction of the common voltage (Vcom). At this time, a phenomenon may occur in which a rapid current flows from the capacitive load to the common electrode (13) in the direction of the arrow. The current generated at this time is called sinking current. Due to the rapid change in the electric field of high voltage occurring in the reset section and / or write section, a current flow to the common electrode (13) may occur when charging the capacitive load.

[0109] In order to prevent the common voltage (Vcom) from flowing, it must be possible to sufficiently absorb the sinking current flowing in from the common electrode (13).

[0110] To this end, the stabilization circuit (40) can absorb the sinking current flowing in from the common electrode (13) through a sinking operation when the data voltage supplied from the data driving unit (22) to the pixel electrode (12) is a positive (+) voltage higher than the common voltage (Vcom). Therefore, the inflow characteristics of the current generated during the charging of the capacitive load can be stably secured.

[0111] FIG. 7 illustrates the flow of current in an electrophoretic display device according to one embodiment when the data voltage is a negative (-) voltage lower than the common voltage.

[0112] Referring to FIG. 7, when the output of the data driver (22) is a voltage (Vneg) lower than the common voltage (Vcom), for example, when the output of the data driver (22) is a negative (-) voltage (Vneg) lower than the common voltage (Vcom), an electric field is formed in the direction of the data driver (22), and a rapid discharge of the capacitive load may occur in the direction of the data driver (22). At this time, a phenomenon may occur in which a rapid current flows out from the common electrode (13) in the direction of the arrow. The current generated at this time is called the sourcing current. Due to the rapid change in the electric field of high voltage occurring in the reset section and / or write section, a current flow from the common electrode (13) may repeatedly occur during the discharge of the capacitive load.

[0113] In order to prevent the flow of the common voltage (Vcom), it must be possible to supply the sourcing current flowing out from the common electrode (13).

[0114] To this end, the stabilization circuit (40) can generate a sourcing current to supply to the common electrode (13) through a sourcing operation when the data voltage supplied from the data driving unit (22) to the pixel electrode (12) is a negative (-) voltage lower than the common voltage (Vcom), and can supply the sourcing current to the common electrode (13). Thus, the current outflow characteristics generated during the discharge of the capacitive load can be stably secured.

[0115] Referring again to FIG. 4, the stabilization circuit (40) may include a configuration that improves the driving capability for the common electrode (13) by including an operational amplifier (42) and a current amplifier (43).

[0116] The stabilization circuit (40) may include a voltage input section (41), an operational amplifier (42), and a current amplifier (43).

[0117] The voltage input unit (41) can receive a common voltage (Vcom). The voltage input unit (41) can receive a common voltage (Vcom) from the power supply unit (32).

[0118] The voltage input section (41) can receive AC voltage or DC voltage. For example, DC voltages such as -1V, -2V, and +3V can be received as common voltage.

[0119] The operational amplifier (42) can quickly reflect the voltage change of the common electrode (13). For example, the operational amplifier (42) can quickly reflect the voltage change of the common electrode (13) by receiving feedback on the common voltage of the common electrode (13).

[0120] The positive (+) voltage (VDDp) and negative (-) voltage (VDDn) applied to the operational amplifier (42) may include a voltage range greater than the variable range of the common voltage.

[0121] The operational amplifier (42) may include an OP-AMP. A common voltage (Vcom) input to the voltage input section (41) is supplied to the non-inverting input terminal (+) of the operational amplifier (42), and the voltage of the output node of the current amplifier (43) may be fed back and supplied to the inverting input terminal (-).

[0122] The output terminal of the operational amplifier (42) can be connected to the input node of the current amplifier (43).

[0123] The operational amplifier (42) can supply the sinking current or sourcing current required to drive the current amplifier (43).

[0124] The current amplifier (43) may include a first switching element (Q1), a second switching element (Q2) connected to the first switching element (Q1), and a resistor (R1) connected to the first switching element (Q1) and the second switching element (Q2).

[0125] For example, the first switching element (Q1) may be an NPN switching element and an NPN transistor, and the second switching element (Q2) may be a PNP switching element and a PNP transistor.

[0126] The first switching element (Q1) has its collector connected to a positive (+) voltage (VDDp) and its emitter connected to an output node.

[0127] The second switching element (Q2) has its collector connected to a negative (-) voltage (VDDn) and its emitter connected to an output node.

[0128] One side of the resistor (R1) can be commonly connected to the output terminal of the operational amplifier (42), the base of the first switching element (Q1), and the second switching element (Q2). The other side of the resistor (R1) can be commonly connected to the emitters of the first switching element (Q1) and the second switching element (Q2).

[0129] The current amplifier (43) may include a push-pull amplifier.

[0130] When a voltage higher than the common voltage (Vcom) is applied to the pixel electrode (12), a peak current may flow from the pixel electrode (12) to the common electrode (13) for the charging operation of the capacitive load. For example, when a positive (+) voltage higher than the common voltage (Vcom) is applied to the pixel electrode (12), a peak current may flow into the common electrode (13). At this time, in order to prevent the flow of the common voltage (Vcom), the peak inflow current (sinking current) must be accepted.

[0131] To this end, the current amplifier (43) can turn off the upper side first switching element (Q1) and turn on the lower side second switching element (Q2) by the current flowing from the common electrode (13) to the operational amplifier (42). Thus, the current amplifier (43) can sufficiently absorb the peak current flowing from the common electrode (13).

[0132] When a voltage lower than the common voltage (Vcom) is applied to the pixel electrode (12), a peak current may flow out to the common electrode (13) for the discharge operation of the capacitive load. For example, when a negative (-) voltage lower than the common voltage (Vcom) is applied to the pixel electrode (12), a peak current may flow out from the common electrode (13). At this time, in order to prevent the flow of the common voltage (Vcom), it must be possible to supply a sufficient amount of peak outflow current (sourcing current).

[0133] To this end, the current amplifier (43) can turn on the upper side first switching element (Q1) and turn off the lower side second switching element (Q2) by the current output from the operational amplifier (42) to the common electrode (13). Thus, the current amplifier (43) can amplify the current and supply an epitome of current to the common electrode (13).

[0134] A voltage difference can be formed across the ends of the resistor (R1) by the current flowing in and out between the operational amplifier (42) and the common electrode (13).

[0135] When a voltage difference is formed across the ends of the resistor (R1), the base current of the first switching element (Q1) and the second switching element (Q2) is generated or released by this voltage difference, thereby allowing the first switching element (Q1) and the second switching element (Q2) to be selectively turned on or off.

[0136] The resistance value of resistor (R1) can be adjusted according to the charge / discharge current of the capacitive load. If the resistance value of resistor (R1) is set to a value that is too high, it can obstruct the output current flow of the operational amplifier (42), causing fluctuations in the common voltage (Vcom). Additionally, since this can be fed back to the operational amplifier (42) and lead to characteristic degradation, the resistance value of resistor (R1) must be appropriately adjusted for each device.

[0137] FIG. 8 illustrates the sinking operation of a stabilization circuit in an electrophoretic display device according to one embodiment when the data voltage is a positive (+) voltage higher than the common voltage.

[0138] Referring to FIG. 8, it is assumed that the common voltage (Vcom) of the stabilization circuit (40) is -1V and the data voltage is +19V.

[0139] When a common voltage (Vcom) of -1V is applied to the stabilization circuit (40) and a data voltage of +19V is applied to the pixel electrode (12), an electric field is formed in the direction of the common voltage (Vcom) between the pixel electrode (12) and the common electrode (13), and a charging operation may occur in the capacitive load of the pixel (11). At this time, a peak current may rapidly flow into the common electrode (13). At this time, the stabilization circuit (40) must accept the peak inflow current in order to prevent the flow of the common voltage (Vcom).

[0140] A voltage difference is formed across the ends of the resistor (R1) by the current flowing in from the common electrode (13), and due to this voltage difference, the upper side first switching element (Q1) of the current amplifier (43) is turned off and the lower side second switching element (Q2) is turned on. Accordingly, the peak inflow current (sinking current) flowing from the pixel electrode (12) to the common electrode (13) can be absorbed in the direction of the arrow. At this time, some of the sinking current can flow through the resistor (R1) into the interior of the operational amplifier (42).

[0141] In this way, when the common voltage (Vcom) is -1V and the data voltage is +19V, a voltage difference across the resistor (R1) is generated by the current flowing in from the common electrode (13), and the upper side first switching element (Q1) is turned off and the lower side second switching element (Q2) is turned on by the voltage difference across the resistor (R1), thereby allowing the peak current flowing in from the common electrode (13) to be absorbed.

[0142] Accordingly, when the data voltage is higher than the common voltage (Vcom), the stabilization circuit (40) can prevent the common voltage (Vcom) from flowing by absorbing the sinking current flowing from the common electrode (13) through a sinking operation, thereby forming a stable potential of the common electrode (13) with respect to the data voltage. As a result, the driving reproducibility, stability, lifespan, and reliability of the electrophoretic display device can be secured.

[0143] FIG. 9 illustrates the sourcing operation of a stabilization circuit in an electrophoretic display device according to one embodiment when the data voltage is a negative (-) voltage lower than the common voltage.

[0144] Referring to FIG. 9, it is assumed that the common voltage (Vcom) of the stabilization circuit (40) is -1V and the data voltage is -19V.

[0145] When a common voltage (Vcom) of -1V is applied to the stabilization circuit (40) and a data voltage of -19V is applied to the pixel electrode (12), an electric field is formed in the direction of the common voltage (Vcom) between the pixel electrode (12) and the common electrode (13), and a discharge operation may occur in the capacitive load of the pixel (11). At this time, a peak current may rapidly flow out from the common electrode (13). At this time, the stabilization circuit (40) must sufficiently supply the peak outflow current to the common electrode (13) in order to prevent the flow of the common voltage (Vcom).

[0146] A voltage difference is formed across the ends of the resistor (R1) by the current flowing from the operational amplifier (42) to the common electrode (13), and due to this voltage difference, the upper side first switching element (Q1) of the current amplifier (43) is turned on and the lower side second switching element (Q2) is turned off. Accordingly, the stabilization circuit (40) can generate a peak outflow current (sourcing current) flowing from the common electrode (13) and supply it in the direction of the arrow.

[0147] In this way, when the common voltage (Vcom) is -1V and the data voltage is -19V, a voltage difference across the resistor (R1) is generated by the current flowing from the operational amplifier (42) to the common electrode (13), and by the voltage difference across the resistor (R1), the upper side first switching element (Q1) is turned on and the lower side second switching element (Q2) is turned off, thereby generating a peak current supplied to the common electrode (13) and supplying it to the common electrode (3).

[0148] Accordingly, when the data voltage is lower than the common voltage (Vcom), the stabilization circuit (40) can prevent the common voltage from flowing by generating and supplying a sourcing current to the common electrode (13) through a sourcing operation, thereby forming a stable potential of the common electrode (13) with respect to the data voltage. As a result, the driving reproducibility, stability, lifespan, and reliability of the electrophoretic display device can be secured.

[0149] FIG. 10 illustrates the voltage waveform and current waveform of a stabilization circuit in an electrophoretic display device according to one embodiment. FIG. 10 illustrates, for example, the case where a power supply that performs a sinking operation with a VCOM voltage source of -1V is used.

[0150] Referring to FIG. 10(a), the waveform of the common voltage (Vcom) and the current waveform are shown in a conventional method without a stabilization circuit (40). FIG. 10(a) shows that when a sourcing current from the common electrode (13) is required, the sourcing current cannot be supplied, and the voltage of the common electrode (13) is drawn out as a data voltage and flows.

[0151] In the past, the potential of the common electrode (13) for the data voltage could not be stably formed due to the unidirectional driving or non-equivalent driving of the common electrode driving unit.

[0152] In other words, due to unidirectional driving, the existing method can perform only sinking or only sourcing operations. Furthermore, in the existing method, unbalanced sinking and sourcing operations occur due to non-equilibrium driving.

[0153] As a result, the sinking current and sourcing current in the waveform of the current (Icom) are not only insufficient but also cannot be supplied in a balanced manner, causing the waveform of the common voltage (Vcom) to become unstable. For example, the common voltage (Vcom) may fluctuate unstably from -1V to -3V. Consequently, the potential of the common electrode (13) for the data voltage is not formed stably, making it difficult to ensure driving reproducibility, stability, lifespan, and reliability.

[0154] Referring to FIG. 10 (b), the waveform of a common voltage (Vcom) and a current waveform in a stabilization circuit (40) of an electrophoretic display device (1) according to one embodiment are disclosed.

[0155] The stabilization circuit (40) can stably form the potential of the common electrode (13) for the data voltage while positive (+) and negative (-) voltage waveforms are supplied to the pixel electrode (12).

[0156] That is, if the data voltage is a positive (+) voltage higher than the common voltage (Vcom), the stabilization circuit (40) can sufficiently absorb the peak current flowing in from the common electrode (13) through a sinking operation so that a fast charging operation is performed from the capacitive load. Additionally, if the data voltage is a negative (-) voltage lower than the common voltage (Vcom), the stabilization circuit (40) can generate and supply a peak current to the common electrode (13) through a sourcing operation so that a fast discharging operation is performed from the capacitive load.

[0157] As a result, the sinking current and sourcing current can be supplied sufficiently and in a balanced manner in the waveform of the current (Icom), so that the waveform of the common voltage (Vcom) can be maintained in a stable state. That is, by absorbing the sinking current or generating and supplying the sourcing current according to the difference between the common voltage and the data voltage, the waveform of the common voltage (Vcom) does not have fluctuations such as the Vcom waveform of FIG. 10, and thus can be maintained in a stable state. As a result, the potential of the common electrode (13) with respect to the data voltage is formed stably as in FIG. 10 (b), thereby ensuring driving reproducibility, stability, lifespan, and reliability.

[0158] Meanwhile, in the electrophoretic display device (1) according to one embodiment, the driving voltage of the common electrode (13) does not need to be a fixed DC voltage and can also be implemented as an AC voltage according to the pixel driving characteristics. Even if an AC voltage is applied to the common electrode (13), both sinking and sourcing operations are possible based on the relative difference with the data voltage regardless of the polarity of the voltage, just as when using a DC voltage.

[0159] FIG. 11 illustrates the arrangement of a stabilization circuit in an electrophoretic display device according to one embodiment.

[0160] Referring to FIG. 11, the stabilization circuit (40) can be embedded within the panel driver (20). For example, the stabilization circuit (40) can be embedded within the data driver (22). By embedding the stabilization circuit (40) within the data driver (22), the placement efficiency of the stabilization circuit (40) is improved, and effective implementation is possible.

[0161] Additionally, the stabilization circuit (40) can be designed and placed inside the display panel (10) using a thin-film transistor. High stability can be secured by designing and placing the stabilization circuit (40) at a location adjacent to the common electrode (13) of the display panel (10).

[0162] In various embodiments, the stabilization circuit (40) can be placed in the printed circuit board assembly (30).

[0163] In the case where the distribution characteristics of the common electrode (13) in the display panel (10) are non-uniform or the common electrode (13) is divided into multiple parts due to an increase in the charge / discharge current, a stabilization circuit (40) can be placed to handle each divided area. In the entire display panel, the outer area or a part of the common electrode characteristics can also be divided and a stabilization circuit (40) can be placed.

[0164] According to the present disclosure, a stable common electrode potential for the data voltage can be formed, thereby ensuring driving reproducibility, stability, lifespan, and reliability of the electrophoretic display device.

[0165] An electrophoretic display device (1) according to one embodiment of the present disclosure may include: a common electrode (13); a pixel electrode (12) arranged to correspond to the common electrode (13); a plurality of color pigments arranged between the common electrode (13) and the pixel electrode (12) and dispersed in a solvent; a data driving unit (22) that supplies a data voltage to the pixel electrode (12); and a stabilization circuit configured to receive a common voltage supplied to the common electrode and to perform a sinking operation that absorbs a current flowing in from the common electrode or a sourcing operation that supplies a current to the common electrode based on the difference between the common voltage and the data voltage.

[0166] The above stabilization circuit (40) can perform the sinking operation in response to the data voltage being higher than the common voltage.

[0167] The above stabilization circuit (40) can absorb the sinking current flowing from the pixel electrode (12) to the common electrode (13) through the sinking operation.

[0168] The above stabilization circuit (40) can perform the sourcing operation in response to the data voltage being lower than the common voltage.

[0169] The above stabilization circuit (40) can generate a current supplied to the common electrode (13) in the stabilization circuit (40) through the sourcing operation and supply the current to the common electrode (13).

[0170] The above stabilization circuit (40) includes: a voltage input unit (41) that receives the common voltage; an operational amplifier (42) that receives the common voltage from the voltage input unit (41); and a current amplifier (43) connected to the operational amplifier (42). The operational amplifier (42) may have the common voltage supplied to a non-inverting input terminal, the voltage of the output node of the current amplifier (43) fed back to the inverting input terminal, and the output terminal connected to the input node of the current amplifier (43).

[0171] The current amplifier (43) comprises: a first switching element (Q1); a second switching element (Q2) connected to the first switching element (Q1); and a resistor (R1) connected to the first switching element (Q1) and the second switching element (Q2); wherein the first switching element (Q1) includes an NPN switching element and the second switching element (Q2) includes a PNP switching element, and one side of the resistor (R1) is commonly connected to the output terminal of the operational amplifier (42), the base of the first switching element (Q1) and the second switching element (Q2), and the other side can be commonly connected to the emitter of the first switching element (Q1) and the second switching element (Q2).

[0172] The above current amplifier (43) can be configured such that the first switching element (Q1) is turned off and the second switching element (Q2) is turned on in response to the voltage difference formed across the resistor (R1) by the current flowing from the common electrode (13) to the operational amplifier (42).

[0173] The above current amplifier (43) can be configured such that the first switching element (Q1) is turned on and the second switching element (Q2) is turned off in response to the voltage difference formed across the resistor (R1) by the current supplied to the common electrode (13) from the operational amplifier (42), thereby supplying current to the common electrode (13).

[0174] The above current amplifier (43) may include a push-pull amplifier.

[0175] The above common voltage may be a DC voltage or an AC voltage.

[0176] The above stabilization circuit (40) can automatically perform the sinking operation or the sourcing operation by means of the current flowing in from the common electrode or the current supplied to the common electrode in response to the common voltage being an AC voltage and the difference between the AC voltage and the data voltage.

[0177] The above stabilization circuit (40) can be embedded in the data driving unit (22).

[0178] An electrophoretic display device (1) according to another embodiment of the present disclosure may include: a display panel (10) having a plurality of pixels (11) formed therein, wherein a plurality of color pigments dispersed in a solvent are provided between a common electrode (13) and a pixel electrode (12); a data driving unit (22) that supplies a data voltage to the pixel electrode (12); a power supply unit (32) that supplies a driving voltage to the data driving unit (22) and supplies a common voltage to the common electrode (13); a printed circuit board assembly (30) having the power supply unit (32); and a stabilization circuit (40) configured to receive the common voltage and perform a sinking operation that absorbs a current flowing in from the common electrode (13) or a sourcing operation that supplies a current to the common electrode (13) based on the difference between the common voltage and the data voltage.

[0179] The above stabilization circuit (40) may be placed on the display panel (10) or the printed circuit board assembly (30).

[0180] The above stabilization circuit (40) can absorb the sinking current flowing from the pixel electrode (13) to the common electrode (12) through the sinking operation in response to the data voltage being higher than the common voltage.

[0181] The above stabilization circuit (40) can generate a current supplied to the common electrode (13) in the stabilization circuit (40) through the sourcing operation in response to the data voltage being lower than the common voltage, and supply the current to the common electrode (12).

[0182] The above stabilization circuit (40) comprises: a voltage input unit (41) receiving the common voltage; an operational amplifier (42) receiving the common voltage from the voltage input unit (41); and a current amplifier (43) connected to the operational amplifier (42); wherein the current amplifier (43) comprises: a first switching element (Q1); a second switching element (Q2) connected to the first switching element (Q1); and a resistor (R1) connected to the first switching element (Q1) and the second switching element (Q2); The first switching element (Q1) includes an NPN switching element, and the second switching element (Q2) includes a PNP switching element. One side of the resistor (R1) is commonly connected to the output terminal of the operational amplifier (42), the base of the first switching element (Q1), and the second switching element (Q2), and the other side can be commonly connected to the emitter of the first switching element (Q1) and the second switching element (Q2).

[0183] The above current amplifier (43) can have the first switching element (Q1) turned off and the second switching element (Q2) turned on in response to the voltage difference formed across the resistor (R1) by the current flowing from the common electrode (13) to the operational amplifier (42), so as to absorb the current flowing from the common electrode.

[0184] The above current amplifier (43) can be configured such that the first switching element (Q1) is turned on and the second switching element (Q2) is turned off in response to the voltage difference formed across the resistor (R1) by the current supplied to the common electrode (13) from the operational amplifier (42), thereby supplying current to the common electrode.

[0185] Meanwhile, the disclosed embodiments may be implemented in the form of a storage medium that stores instructions executable by a computer. The instructions may be stored in the form of program code, and when executed by a processor, they may generate a program module to perform the operation of the disclosed embodiments.

[0186] Computer-readable recording media include all types of recording media that store instructions that can be decoded by a computer. Examples include ROM (read-only memory), RAM (random access memory), magnetic tape, magnetic disk, flash memory, optical data storage devices, etc.

[0187] Additionally, computer-readable recording media may be provided in the form of non-transitory storage media. Here, 'non-transitory storage media' simply means that it is a tangible device and does not contain a signal (e.g., electromagnetic waves), and this term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily. For example, 'non-transitory storage media' may include a buffer in which data is stored temporarily.

[0188] According to one embodiment, the method according to the various embodiments disclosed herein may be provided by being included in a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or distributed online (e.g., download or upload) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., downloadable app) may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0189] As described above, the disclosed embodiments have been explained with reference to the attached drawings. Those skilled in the art will understand that the present invention may be practiced in forms different from the disclosed embodiments without changing the technical spirit or essential features of the invention. The disclosed embodiments are illustrative and should not be interpreted restrictively.

Claims

1. Common electrode; A pixel electrode positioned to correspond to the above common electrode; A plurality of color pigments disposed between the common electrode and the pixel electrode and dispersed in a solvent; A data driving unit that supplies a data voltage to the pixel electrode; and An electrophoretic display device comprising: a stabilization circuit configured to receive a common voltage supplied to the common electrode and to perform a sinking operation that absorbs a current flowing in from the common electrode based on the difference between the common voltage and the data voltage, or a sourcing operation that supplies a current to the common electrode.

2. In Paragraph 1, The above stabilization circuit is, An electrophoretic display device that performs the sinking operation in response to the data voltage being higher than the common voltage.

3. In Paragraph 2, The above stabilization circuit is, An electrophoretic display device that absorbs a sinking current flowing from the pixel electrode to the common electrode through the above sinking operation.

4. In Paragraph 1, The above stabilization circuit is, An electrophoretic display device that performs the sourcing operation in response to the above data voltage being lower than the above common voltage.

5. In Paragraph 4, The above stabilization circuit is, An electrophoretic display device that, through the above sourcing operation, generates a current supplied to the common electrode in the stabilization circuit and supplies the current to the common electrode.

6. In Paragraph 1, The above stabilization circuit is, A voltage input unit that receives the above common voltage; An operational amplifier that receives the common voltage from the above voltage input section; and A current amplifier connected to the above operational amplifier; comprising, The above operational amplifier is, An electrophoretic display device in which the above common voltage is supplied to a non-inverting input terminal, the voltage of the output node of the current amplifier is fed back to the inverting input terminal, and the output terminal is connected to the input node of the current amplifier.

7. In Paragraph 6, The above current amplifier is, First switching element (Q1); A second switching element (Q2) connected to the first switching element (Q1); and A resistor (R1) connected to the first switching element (Q1) and the second switching element (Q2); comprising, The first switching element (Q1) includes an NPN switching element, and The second switching element (Q2) includes a PNP switching element, and An electrophoretic display device in which one side of the resistor (R1) is commonly connected to the output terminal of the operational amplifier, the base of the first switching element (Q1) and the second switching element (Q2), and the other side is commonly connected to the emitter of the first switching element (Q1) and the second switching element (Q2).

8. In Paragraph 7, The above current amplifier is, An electrophoretic display device in which the first switching element (Q1) is turned off and the second switching element (Q2) is turned on in response to the voltage difference formed across the ends of the resistor (R1) by the current flowing from the common electrode to the operational amplifier.

9. In Paragraph 7, The above current amplifier is, An electrophoretic display device in which the first switching element (Q1) is turned on and the second switching element (Q2) is turned off in response to the voltage difference formed across the ends of the resistor (R1) by the current supplied to the common electrode from the operational amplifier.

10. In Paragraph 6, The above current amplifier is, Electrophoretic display device including a push-pull amplifier.

11. In Paragraph 1, The above common voltage is an electrophoretic display device in which the common voltage is a DC voltage or an AC voltage.

12. In Paragraph 11, The above stabilization circuit is, An electrophoretic display device that automatically performs the sinking operation or the sourcing operation by means of a current flowing in from the common electrode or a current supplied to the common electrode in response to the common voltage being an AC voltage, according to the difference between the AC voltage and the data voltage.

13. In Paragraph 1, The above stabilization circuit is, Electrophoretic display device embedded in the above data driving unit.

14. A display panel having a plurality of pixels formed therein, wherein a plurality of color pigments dispersed in a solvent are provided between a common electrode and a pixel electrode; A data driving unit that supplies a data voltage to the pixel electrode; A power supply unit that supplies a driving voltage to the above data driving unit and supplies a common voltage to the above common electrode; A printed circuit board assembly having the above-mentioned power supply; and An electrophoretic display device comprising: a stabilization circuit configured to receive the common voltage and perform a sinking operation that absorbs current flowing in from the common electrode or a sourcing operation that supplies current to the common electrode based on the difference between the common voltage and the data voltage.

15. In Paragraph 14, The above stabilization circuit is, An electrophoretic display device disposed on the display panel or the printed circuit board assembly.

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