Electrophoretic display device

Abstract

This electrophoretic display device comprises: a common electrode to which a common voltage is provided; a pixel electrode disposed corresponding 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 that supplies a data voltage to the pixel electrode; and a current supply circuit configured to perform, on the basis of a difference between a data voltage of the current frame and a data voltage of the previous frame, a sourcing operation for supplying a current to the data driving unit or a sinking operation for absorbing a current introduced from the data driving unit.

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 a data voltage from the pixel electrode facing the common electrode through the pixel's thin-film transistor (TFT). A capacitive load is formed between the pixel's common electrode and the source electrode of the TFT.

[0004] In order to align multiple charged color pigments dispersed in a solvent between the common electrode and the pixel electrode to a desired position, positive and negative data voltages are supplied to the pixel electrodes by rapidly switching high voltages of positive (+) and negative (-) polarity.

[0005] During high-voltage switching of the government, rapid charging and discharging operations occur in the capacitive load, and current changes are generated by the movement of color pigments.

[0006] To maintain a stable potential applied to color pigments, the peak charge / discharge currents in the positive and negative directions generated during the charging and discharging of a capacitive load must be stably supplied and recovered. If the supply of charge / discharge current is not smooth, the waveform of the data voltage becomes distorted. When the waveform of the data voltage is distorted, the potential of the color pigments becomes unstable, causing the alignment of the color pigments to deviate from the desired position. Consequently, it is difficult to ensure driving reproducibility, stability, lifespan, and reliability.

[0007] The present disclosure provides an electrophoretic display device capable of ensuring driving reproducibility, stability, lifespan, and reliability of the electrophoretic display device.

[0008] The technical problems to be solved in this document are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which this invention belongs from the description below.

[0009] An electrophoretic display device according to one embodiment of the present disclosure may include: a common electrode to which a common voltage is supplied; 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 current supply circuit configured to perform a sourcing operation that supplies current to the data driving unit based on the difference between the data voltage of a current frame and the data voltage of a previous frame, or a sinking operation that absorbs current flowing in from the data driving unit.

[0010] FIG. 1 is a configuration diagram of an electrophoretic display device according to one embodiment.

[0011] FIG. 2 illustrates a pixel of a display panel of an electrophoretic display device according to one embodiment.

[0012] FIG. 3 is a configuration diagram of a power supply unit of an electrophoretic display device according to one embodiment.

[0013] FIG. 4 is a configuration diagram of a current supply circuit of an electrophoretic display device according to one embodiment.

[0014] FIG. 5 illustrates the waveform of a data voltage supplied from a data driving unit to a pixel electrode in an electrophoretic display device according to one embodiment.

[0015] FIG. 6 illustrates the voltage level and charge / discharge sequence of a data voltage waveform supplied to a pixel electrode from a data driving unit of an electrophoretic display device according to one embodiment.

[0016] FIG. 7 illustrates the current flow according to the sourcing operation of the current supply circuit during charging of a capacitive load in an electrophoretic display device according to one embodiment.

[0017] FIG. 8 illustrates the current flow according to the sinking operation of the stabilization circuit during charging of a capacitive load in an electrophoretic display device according to one embodiment.

[0018] FIG. 9 illustrates the current flow according to the sinking operation of the current supply circuit during the discharge of a capacitive load in an electrophoretic display device according to one embodiment.

[0019] FIG. 10 illustrates the current flow according to the sourcing operation of the stabilization circuit during the discharge of a capacitive load 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 is a configuration diagram of an electrophoretic display device according to one embodiment.

[0033] Referring to FIG. 1, 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 display device (10) is not limited in form as long as it is a device capable of visually displaying images.

[0034] The electrophoretic display device (1) may include a display panel (10), a panel display driver integrated circuit (PDDI) (20), a control unit (30), and a power supply unit (40).

[0035] The display panel (10) may include m / n pixels (11).

[0036] 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.

[0037] The panel driver (20) can transmit electrical signals to each pixel (11) in the correct time and order according to the control of the control unit (30).

[0038] The control unit (30) may receive a control signal from the central processing unit (AP or CPU) of the electrophoretic display device (1). The control unit (30) may include a memory, a processor, and a control circuit board on which these are mounted.

[0039] The control unit (30) 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).

[0040] The power supply unit (40) can supply power to the display panel (10), the panel driver (20), and the control unit (30).

[0041] When power is supplied to the electrophoretic display device (1), the power supply unit (40) can generate voltages required for driving the display panel (10) using the input power (Vin). The power supply unit (40) can generate driving voltages according to the power control signal provided by the control unit (30).

[0042] The power supply unit (40) can supply a driving voltage to the panel driver (20). For example, the power supply unit (40) 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.

[0043] The panel driver (20) may include a gate driver (21) and a data driver (22).

[0044] 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 (30). The gate driver (21) can select the TFT of the corresponding line and turn it on or off.

[0045] 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.

[0046] 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 (30).

[0047] 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.

[0048] The control unit (30) can provide control information for implementing a waveform to the gate driver (21) and the data driver (22). The control unit (30) 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.

[0049] The data driving unit (22) can generate a waveform using waveform control information from the control unit (30) and a driving voltage supplied from the power supply unit (40), and can supply the generated waveform to a plurality of data lines (D1 to Dm).

[0050] FIG. 2 illustrates a pixel of a display panel of an electrophoretic display device according to one embodiment.

[0051] Referring to FIG. 2, the display panel (10) may include a pixel electrode (12) provided on a lower substrate and a common electrode (13) on an upper substrate.

[0052] The pixel electrode (12) and the common electrode (13) can be positioned opposite each other.

[0053] The common electrode (13) provided on the upper substrate can be placed on the side visible to the user as a transparent electrode layer.

[0054] 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.

[0055] 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.

[0056] 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 position due to the difference in electric field with the common electrode (13), and can realize a desired color using external light reflection.

[0057] For example, multiple color pigments may include four color particles (W, B, R, Y).

[0058] The four color particles (W, B, R, Y) may include two pairs of particles with opposite polarities.

[0059] 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.

[0060] 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.

[0061] In various embodiments, the white particles (W), blue particles (B), red particles (R), and yellow particles (Y) can be of various shapes.

[0062] 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.

[0063] For example, when a high negative (-) potential is applied to the pixel electrode (12) compared to the common voltage of the common electrode (13), a high electric field is generated, causing negative (-) charged blue particles (B) to move toward the common electrode (13) and high positive (+) charged white particles (W) to move toward the pixel electrode (12). Since red (R) and yellow particles (Y) have a small capacitance, less force is applied in the same electric field compared to high positive (+) charged white particles (W) and high negative (-) charged blue particles (B), so the distance traveled to the common electrode (13) is shorter relative to the time. Finally, the movement of blue particles (B) toward the common electrode (13) is concentrated for a specific period of time, and is displayed to the user as blue through external light reflection.

[0064] In addition, when a high positive (+) potential is applied to the pixel electrode (12) compared to the common voltage of the common electrode (13), an electric field of opposite polarity is generated, and the particle distribution appears opposite to the previous one. Finally, it is displayed to the user as white through external light reflection.

[0065] 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.

[0066] In addition, when a low negative (-) potential is applied compared to the common voltage of the common electrode (13), a low electric field of opposite polarity is generated, and the particle distribution appears reversed from before. Finally, it is displayed to the user as yellow through external light reflection.

[0067] FIG. 3 is a configuration diagram of a power supply unit of an electrophoretic display device according to one embodiment.

[0068] Referring to FIG. 3, the power supply unit (40) can generate a driving voltage required to drive the display panel (10) using the input power (Vin).

[0069] The power supply unit (40) can supply a driving voltage to the data driving unit (22).

[0070] The data driving unit (22) can generate a data voltage having a waveform using the driving voltage supplied from the power supply unit (40) and supply it to the pixel electrode (12) of the pixel (11). The data voltage supplied to the pixel electrode (12) may include a waveform in which high voltages of positive (+) polarity and negative (-) polarity alternate. The positive (+) voltage and negative (-) voltage of the data voltage may each have multiple voltage levels. Accordingly, the voltage level of the driving voltage supplied from the power supply unit (40) to the data driving unit (22) may also have multiple voltage levels.

[0071] The power supply unit (40) can generate a multi-voltage level driving voltage using the input power (Vin) and supply the multi-voltage level driving voltage to the data driving unit (22).

[0072] The power supply unit (40) may include a current supply circuit (50). In various embodiments, the current supply circuit (50) may be embedded in the panel driver (20). For example, the current supply circuit (50) may be embedded in the data driver (22). The current supply circuit (50) may be referred to as a voltage supply circuit (50). The current supply circuit (50) may optionally output a driving voltage of multiple voltage levels to the data driver (22).

[0073] The current supply circuit (50) may include a first current supply circuit (50_1) to an nth current supply circuit (50_n). The first current supply circuit (50_1) may output a driving voltage of a first voltage level to the data driving unit (22). The second current supply circuit (50_2) may output a driving voltage of a second voltage level to the data driving unit (22). The nth current supply circuit (50_n) may output a driving voltage of an nth voltage level to the data driving unit (22).

[0074] For example, the multi-voltage level driving voltage may include six voltage levels: Vh_high, Vh_medium, Vh_low, Vl_low, Vl_medium, and Vl_high. Vh_high, Vh_medium, and Vh_low may be positive (+) voltages. In this case, the voltage values ​​may be higher in the order of Vh_high, Vh_medium, and Vh_low (Vh_high > Vh_medium > Vh_low). Additionally, Vl_low, Vl_medium, and Vl_high may be negative (-) voltages. In this case, the voltage values ​​may be higher in the order of Vl_low, Vl_medium, and Vl_high (Vl_low > Vl_medium > Vl_high).

[0075] FIG. 4 is a configuration diagram of a current supply circuit of an electrophoretic display device according to one embodiment.

[0076] Referring to FIG. 4, the current supply circuit (50) can be electrically connected to the data driving unit (22).

[0077] The current supply circuit (50) can output a driving voltage of multiple voltage levels to the data driving unit (22).

[0078] For example, the current supply circuit (50) can output one of six voltage levels, Vh_high, Vh_medium, Vh_low, Vl_low, Vl_medium, and Vl_high, to the data driving unit (22).

[0079] The data driving unit (22) can be electrically connected to the source electrode of the TFT (14) through a data line.

[0080] The drain electrode of the TFT (14) can be electrically connected to the pixel electrode (12).

[0081] In various embodiments, the source electrode of the TFT (14) may be electrically connected to the pixel electrode (12), and the drain electrode of the TFT (14) may be electrically connected to the data driver (22).

[0082] The gate electrode of the TFT (14) can be electrically connected to the gate driver (21).

[0083] The TFT (14) can be turned on or turned off by the gate voltage output from the gate driver (21).

[0084] 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).

[0085] A common voltage (Vcom) can be supplied to the common electrode (12). The common voltage can be a DC voltage or an AC voltage.

[0086] 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).

[0087] 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).

[0088] 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 (e.g., +20V, -20V) of positive (+) and negative (-) symmetrical to the common voltage of the common electrode (13) at high speed (e.g., 85Hz). Additionally, 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, the pulsed charge / discharge current (sourcing current / sinking current) of several amperes (e.g., 2.5A) generated during the high voltage switching of each positive electrode must be stably supplied and recovered in order to stably maintain the potential applied to the color pigments. If the supply of charge / discharge current is not smooth, distortion of the waveform of the data voltage occurs, and the potential applied to the color pigments is misaligned, so that the alignment of the color pigments may be misaligned from the desired position. As a result, it is difficult to ensure drive reproducibility, lifespan, and reliability.

[0089] The current supply circuit (50) can supply current to the data driving unit (22) or absorb current flowing in from the data driving unit (22). The current supply circuit (50) can supply current to a capacitive load through the data driving unit (22) and absorb current flowing from the capacitive load to the data driving unit (22).

[0090] The current supply circuit (50) can perform a sourcing operation to supply charging current to the capacitive load when charging the capacitive load, or a sinking operation to absorb discharge current from the capacitive load when discharging the capacitive load.

[0091] The current supply circuit (50) generates current to be supplied from the current supply circuit (50) to the data driving unit (22) through a sourcing operation when charging a capacitive load, and can supply the generated current to the capacitive load through the data driving unit (22).

[0092] The current supply circuit (50) can absorb the current flowing from the capacitive load through the data driving unit (22) to the current supply circuit (50) through a sinking operation when the capacitive load is discharged.

[0093] The current supply circuit (50) performs a sourcing operation when charging the capacitive load and automatically performs a sinking operation when discharging the capacitive load, thereby stably supplying and recovering the positive and negative peak charge / discharge currents generated during the charging and discharging of the capacitive load, so that the potential applied to the color pigments can be stably maintained. Therefore, the waveform of the data voltage is not distorted, so the color pigments can be moved to the desired position. As a result, driving reproducibility, stability, lifespan, and reliability can be secured.

[0094] FIG. 5 illustrates the waveform of a data voltage supplied from a data driving unit to a pixel electrode in an electrophoretic display device according to one embodiment.

[0095] 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 pigments located at the common electrode (13) must be rapidly moved 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 waveform of a data voltage corresponding to a preset amount of charge must be applied to the pixel electrode (12), which is called the writing section.

[0096] 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.

[0097] When a data voltage of the government 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 a change in current occurs due to the movement of charge.

[0098] 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.

[0099] FIG. 6 illustrates a data voltage of multiple voltage levels and a charge / discharge sequence supplied to a pixel electrode from a data driving unit of an electrophoretic display device according to one embodiment.

[0100] Referring to Fig. 6, the data voltage may have a waveform that rises in steps and falls in steps.

[0101] For example, the voltage levels of the data voltage waveform may include six voltage levels: Vh_high, Vh_medium, Vh_low, Vl_low, Vl_medium, and Vl_high. Vh_high, Vh_medium, and Vh_low may be positive (+) voltages. In this case, the voltage values ​​may be higher in the order of Vh_high, Vh_medium, and Vh_low (Vh_high > Vh_medium > Vh_low). Additionally, Vl_low, Vl_medium, and Vl_high may be negative (-) voltages. In this case, the voltage values ​​may be higher in the order of Vl_low, Vl_medium, and Vl_high (Vl_low > Vl_medium > Vl_high).

[0102] As illustrated in FIG. 6(a), the waveform of the data voltage may include a rising pattern in which the voltage value rises from Vh_low to Vh_medium and a rising pattern in which the voltage value rises from Vh_medium to Vh_high even within a positive (+) voltage (Vpos). The waveform of the data voltage may also include a rising pattern in which the voltage value rises from Vl_high to Vl_medium and a rising pattern in which the voltage value rises from Vl_medium to Vl_low even within a negative (-) voltage (Vneg).

[0103] As illustrated in FIG. 6(b), the waveform of the data voltage may include a falling pattern in which the voltage value falls from Vh_high to Vh_medium and a falling pattern in which the voltage value falls from Vh_medium to Vh_low even within a positive (+) voltage (Vpos). The waveform of the data voltage may also include a falling pattern in which the voltage value falls from Vl_low to Vl_medium and a falling pattern in which the voltage value falls from Vl_medium to Vl_high even within a negative (-) voltage (Vneg).

[0104] Additionally, the waveform of the data voltage may include various rising patterns, such as a rising pattern in which the voltage value rises from Vh_low to Vh_high, a rising pattern in which it rises from Vl_high to Vl_low, and a rising pattern in which it rises from Vl_high to Vh_high. The waveform of the data voltage may also include various falling patterns, such as a falling pattern in which it falls from Vh_high to Vh_low, a falling pattern in which it falls from Vl_low to Vl_high, and a rising pattern in which it falls from Vh_high to Vl_high.

[0105] The capacitive load can repeat charging and discharging operations as the data voltage supplied to the pixel electrode (12) varies from frame to frame.

[0106] Referring again to FIG. 4, the current supply circuit (50) may include a register (REG) (51), a digital-to-analog converter (DAC) (52), an operational amplifier (53), and a current amplifier (54).

[0107] Digital data regarding the driving voltage supplied to the data driving unit (22) can be stored in the register (51).

[0108] A digital-to-analog converter (DAC) (52) can receive digital data stored in a register (51) and convert it into an analog voltage.

[0109] The positive (+) voltage (VDDp) and negative (-) voltage (VDDn) of the operational amplifier (53) may include a voltage range greater than the variable range of the voltage input from the digital-to-analog converter (52).

[0110] The operational amplifier (53) may include an OP-AMP. A driving voltage input from a digital-to-analog converter (52) is supplied to the non-inverting input terminal (+) of the operational amplifier (42), and the voltage of the output node of the current amplifier (54) may be fed back and supplied to the inverting input terminal (-).

[0111] The output terminal of the operational amplifier (53) can be connected to the input node of the current amplifier (54).

[0112] The operational amplifier (53) can supply the sinking current or sourcing current required to drive the current amplifier (54).

[0113] The operational amplifier (53) can output current by comparing the feedback voltage of the non-inverting input terminal (+) and the inverting input terminal (-).

[0114] The current amplifier (54) 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).

[0115] 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.

[0116] The first switching element (Q1) has its collector connected to a positive (+) voltage (VDDp) and its emitter connected to an output node.

[0117] The second switching element (Q2) has its collector connected to a negative (-) voltage (VDDn) and its emitter connected to an output node.

[0118] One side of the resistor (R1) can be commonly connected to the output terminal of the operational amplifier (53), 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).

[0119] The current amplifier (54) may include a push-pull amplifier.

[0120] The current amplifier (54) 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 (53) to the current amplifier (54). Accordingly, the current amplifier (54) can amplify the current output from the operational amplifier (53) and supply it to the data supply unit (22).

[0121] Additionally, the current amplifier (54) can turn off the upper side first switching element (Q1) and turn on the lower side second switching element (Q2) by the incoming current flowing from the data driving unit (22) to the operational amplifier (53). Accordingly, the current amplifier (43) can sufficiently absorb the current flowing in from the data driving unit (22).

[0122] A voltage difference can be formed across the resistor (R1) by the current passing through the resistor (R1) of the current amplifier (54). When a voltage difference is formed across 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. The resistance value of the resistor (R1) can be adjusted according to the charge / discharge current of the capacitive load.

[0123] The current supply circuit (50) having the above configuration can stably supply and recover the positive peak charge / discharge current generated during the charge / discharge of a capacitive load by automatically supplying current to the data driver (22) through a sourcing operation or absorbing the current flowing in from the data driver (22) through a sinking operation, thereby maintaining the potential applied to the color pigments stably. Therefore, the waveform of the data voltage is not distorted, allowing the color pigments to be moved to a desired position. As a result, driving reproducibility, stability, lifespan, and reliability can be secured.

[0124] The electrophoretic display device (1) may further include a stabilization circuit (60).

[0125] The stabilization circuit (60) is electrically connected to the common electrode (13) through the common line (CL).

[0126] The stabilization circuit (60) can stably form the potential of the common electrode (13) for the data voltage supplied to the pixel electrode (12).

[0127] The stabilization circuit (60) can stabilize the potential of the common electrode (13) by absorbing the current flowing in from the common electrode (13) or supplying current to the common electrode (13) during the charging and discharging of the capacitive load of the pixel (11), thereby preventing the common voltage (Vcom) from flowing to the pixel electrode (12).

[0128] The stabilization circuit (60) can perform a sinking operation that absorbs current flowing in from the capacitive load when charging the capacitive load, or a sourcing operation that supplies current to the capacitive load when discharging the capacitive load.

[0129] The stabilization circuit (60) can absorb current flowing into the common electrode (13) through a sinking operation when charging the capacitive load.

[0130] The stabilization circuit (60) can supply current to the common electrode (13) through a sourcing operation during the discharge of the capacitive load.

[0131] The stabilization circuit (60) can stabilize the potential of the common electrode (13) by performing a sinking operation when charging the capacitive load and automatically performing a sourcing operation when discharging the capacitive load, thereby ensuring driving reproducibility, stability, lifespan, and reliability.

[0132] FIG. 7 illustrates the current flow according to the sourcing operation of the current supply circuit during charging of a capacitive load in an electrophoretic display device according to one embodiment.

[0133] Referring to Fig. 7, it is common for the charging and discharging current of a capacitive load to flow based on the common voltage and the data voltage, but in driving the capacitive load, it can be determined whether the current frame must perform a charging operation or a discharging operation based on the charging and discharging state of the previous frame.

[0134] If the capacitive load was negatively charged to Vl_high (e.g., -19V) in the previous frame, a charging current is required to transfer the capacitive load to a negatively charged state of Vl_low (e.g., -5V), which is higher than Vl_high, in the current frame. In other words, if the voltage level of the data voltage in the current frame is higher than the voltage level of the data voltage in the previous frame, the capacitive load requires charging, so sufficient charging current must be supplied to the capacitive load.

[0135] To this end, the current supply circuit (50) can supply Vl_low, which has a voltage level higher than Vl_high, to the data driving unit (22). Although Vl_low is a negative (-) voltage, charging of the capacitive load is required based on the common voltage. Therefore, the current supply circuit for Vl_low needs to perform an operation for charging the capacitive load.

[0136] The current supply circuit (50) can supply charging current in the direction of the arrow through a sourcing operation to increase the charge amount of the capacitive load by the voltage rise (ΔV) between Vl_low and Vl_high.

[0137] Additionally, a charging current is required to transfer the capacitive load from a state of (+) charging to Vh_low (e.g., +5V) in the previous frame to a (+) charging state of Vh_medium (e.g., +10V), which is higher than Vh_low, in the current frame.

[0138] To this end, the current supply circuit (50) can supply Vh_medium, which has a voltage level higher than Vh_low, to the data driving unit (22). Since Vh_medium is a positive (+) voltage, charging to the capacitive load is required based on the common voltage. Therefore, the current supply circuit for Vh_medium needs to perform an operation for charging the capacitive load.

[0139] The current supply circuit (50) can supply charging current in the direction of the arrow through a sourcing operation to increase the charge amount of the capacitive load by the voltage rise (ΔV) between Vh_medium and Vh_low.

[0140] In this way, the current supply circuit (50) can supply charging current to the capacitive load by supplying current to the data driving unit (22) through a sourcing operation when charging the capacitive load.

[0141] FIG. 8 illustrates the current flow according to the sinking operation of the stabilization circuit during charging of a capacitive load in an electrophoretic display device according to one embodiment.

[0142] Referring to FIG. 8, the stabilization circuit (60) may include a voltage input section (61), an operational amplifier (62), and a current amplifier (63).

[0143] The voltage input unit (61) can receive a common voltage (Vcom). The voltage input unit (61) can receive a common voltage (Vcom) from the power supply unit (40).

[0144] The voltage input section (61) can receive AC voltage or DC voltage. For example, DC voltages such as -1V, -2V, and +3V can be received as common voltage.

[0145] The operational amplifier (62) can quickly reflect the voltage change of the common electrode (13). For example, the operational amplifier (62) can quickly reflect the voltage change of the common electrode (13) by receiving feedback on the common voltage of the common electrode (13).

[0146] The positive (+) voltage (VDDp) and negative (-) voltage (VDDn) applied to the operational amplifier (62) may include a voltage range greater than the variable range of the common voltage.

[0147] The operational amplifier (62) may include an OP-AMP. A common voltage (Vcom) input to the voltage input section (61) is supplied to the non-inverting input terminal (+) of the operational amplifier (62), and the voltage of the output node of the current amplifier (63) may be fed back and supplied to the inverting input terminal (-).

[0148] The output terminal of the operational amplifier (62) can be connected to the input node of the current amplifier (63).

[0149] The operational amplifier (62) can supply the sinking current or sourcing current required to drive the current amplifier (63).

[0150] The current amplifier (63) may include a third switching element (Q3), a fourth switching element (Q4) connected to the third switching element (Q3), and a resistor (R2) connected to the third switching element (Q3) and the fourth switching element (Q4).

[0151] For example, the third switching element (Q3) may be an NPN switching element, such as an NPN transistor, and the fourth switching element (Q4) may be a PNP switching element, such as a PNP transistor.

[0152] The third switching element (Q3) has its collector connected to a positive (+) voltage (VDDp) and its emitter connected to an output node.

[0153] The fourth switching element (Q4) has its collector connected to a negative (-) voltage (VDDn) and its emitter connected to an output node.

[0154] One side of the resistor (R2) can be commonly connected to the output terminal of the operational amplifier (62), the base of the third switching element (Q3), and the base of the fourth switching element (Q4). The other side of the resistor (R2) can be commonly connected to the emitters of the third switching element (Q3) and the fourth switching element (Q4).

[0155] The current amplifier (63) may include a push-pull amplifier.

[0156] The current amplifier (63) can turn on the upper third switching element (Q3) and turn off the lower fourth switching element (Q4) by the current output from the operational amplifier (62) to the current amplifier (63). Accordingly, the current amplifier (63) can amplify the current output from the operational amplifier (62) and supply it to the common electrode (13).

[0157] Additionally, the current amplifier (63) can turn off the upper side third switching element (Q3) and turn on the lower side fourth switching element (Q4) by the current flowing from the common electrode (13) to the operational amplifier (62). Thus, the current amplifier (63) can absorb the current flowing from the common electrode (13).

[0158] A voltage difference can be formed across the resistor (R2) by the current passing through the resistor (R2) of the current amplifier (63). When a voltage difference is formed across the resistor (R2), the base current of the third switching element (Q3) and the fourth switching element (Q4) is generated or released by this voltage difference, thereby allowing the third switching element (Q3) and the fourth switching element (Q4) to be selectively turned on or off. The resistance value of the resistor (R2) can be adjusted according to the charge / discharge current of the capacitive load.

[0159] The stabilization circuit (60) having the above configuration can stabilize the potential of the common electrode (13) by supplying current to the common electrode (13) through a sourcing operation or by absorbing current flowing in from the common electrode (13) through a sinking operation, thereby preventing the common voltage from flowing to the pixel electrode (12).

[0160] The stabilization circuit (60) can perform a sinking operation when charging the capacitive load and a sourcing operation when discharging the capacitive load. The stabilization circuit (60) can absorb current flowing in from the common electrode (13) through the sinking operation when charging the capacitive load. The stabilization circuit (60) can supply current to the common electrode (13) through the sourcing operation when discharging the capacitive load.

[0161] The stabilization circuit (60) can stabilize the potential of the common electrode (13) by performing a sinking operation when charging the capacitive load and automatically performing a sourcing operation when discharging the capacitive load, thereby ensuring driving reproducibility, stability, lifespan, and reliability.

[0162] Below, we assume that the common voltage is -1V and the data voltage rises from +5V to +19V.

[0163] When a common voltage of -1V is applied to the common electrode (13) and the data voltage applied to the pixel electrode (12) rises from +5V to +19V, charging is required for the capacitive load.

[0164] The stabilization circuit (60) must be able to receive current flowing in from the common electrode (13) in order to prevent flow of the common voltage.

[0165] A voltage difference is formed across the ends of the resistor (R2) by the current flowing in from the common electrode (13), and due to this voltage difference, the upper side third switching element (Q3) of the current amplifier (63) is turned off and the lower side fourth switching element (Q4) is turned on. Accordingly, the current flowing from the pixel electrode (12) to the common electrode (13) can be absorbed in the direction of the arrow.

[0166] In this way, if the data voltage of the current frame is higher than the data voltage of the previous frame, the current supply circuit (50) can output current through a sourcing operation and supply it to the capacitive load via the data driving unit (22). At the same time, the stabilization circuit (60) can absorb the current flowing in from the common electrode (13) through a sinking operation. Therefore, the capacitive load can be charged while maintaining a stable potential during charging of the capacitive load.

[0167] FIG. 9 illustrates the current flow according to the sinking operation of the current supply circuit during the discharge of a capacitive load in an electrophoretic display device according to one embodiment.

[0168] Referring to FIG. 9, in the previous frame, the capacitive load was positively charged to Vh_high (e.g., +19V), and in the current frame, a discharge current is required to transfer the capacitive load to a positively charged state of Vh_low (e.g., +5V), which is lower than Vh_high. That is, when the voltage level of the data voltage in the current frame is lower than the voltage level of the data voltage in the previous frame, the discharge current from the capacitive load must be absorbed because the discharge of the capacitive load is required.

[0169] To this end, the current supply circuit (50) can supply Vh_low, which has a voltage level lower than Vh_high, to the data driving unit (22). Although Vh_low is a positive (+) voltage, discharge of the capacitive load is required relative to the common voltage. Therefore, the current supply circuit for Vh_low needs to perform an operation for the discharge of the capacitive load.

[0170] The current supply circuit (50) can absorb the discharge current flowing in the direction of the arrow through a sinking operation to reduce the charge amount of the capacitive load by the voltage drop (ΔV) between Vh_high and Vh_low.

[0171] Additionally, a discharge current is required to transfer the capacitive load from a negatively charged state of Vl_low (e.g., -5V) in the previous frame to a negatively charged state of Vl_medium (e.g., -10V) in the current frame, which is lower than Vl_low.

[0172] To this end, the current supply circuit (50) can supply Vl_medium, which has a voltage level lower than Vl_low, to the data driving unit (22). Since Vl_medium is a negative (-) voltage, discharge of the capacitive load is required relative to the common voltage. Therefore, the current supply circuit for Vl_medium needs to perform an operation for discharging the capacitive load.

[0173] The current supply circuit (50) can absorb discharge current in the direction of the arrow through a sinking operation to increase the charge amount of the capacitive load by the voltage rise (ΔV) between Vl_low and Vl_medium.

[0174] In this way, the current supply circuit (50) can absorb the discharge current of the capacitive load by absorbing the current flowing in from the data driving unit (22) through a sinking operation during the discharge of the capacitive load.

[0175] FIG. 10 illustrates the current flow according to the sourcing operation of the stabilization circuit during the discharge of a capacitive load in an electrophoretic display device according to one embodiment.

[0176] Referring to Fig. 10, assume a case where the common voltage is -1V and the data voltage drops from +19V to +5V.

[0177] When a common voltage of -1V is applied to the common electrode (13) and the data voltage applied to the pixel electrode (12) drops from +19V to +5V, a discharge is required in the capacitive load.

[0178] The stabilization circuit (60) must be able to supply current to the common electrode (13) so that no flow of the common voltage occurs.

[0179] A voltage difference is formed across the ends of the resistor (R2) by the current output from the operational amplifier (62) to the current amplifier (63), and due to this voltage difference, the upper side third switching element (Q3) of the current amplifier (63) is turned on and the lower side fourth switching element (Q4) is turned off. Thus, current can be supplied to the common electrode (13) in the direction of the arrow.

[0180] In this way, if the data voltage of the current frame is lower than the data voltage of the previous frame, the current supply circuit (50) can absorb the current flowing in from the data driving unit (22) through a sinking operation. At the same time, the stabilization circuit (60) can supply current to the common electrode (13) through a sourcing operation. Thus, the capacitive load can be discharged while maintaining a stable potential during the discharge of the capacitive load.

[0181] According to the present disclosure, when charging a capacitive load, the current supply circuit (50) performs a sourcing operation and the stabilization circuit (60) performs a sinking operation, and when discharging a capacitive load, the current supply circuit (50) performs a sinking operation and the stabilization circuit (60) performs a sourcing operation, thereby ensuring the driving reproducibility, stability, lifespan, and reliability of the electrophoretic display device.

[0182] An electrophoretic display device (1) according to one embodiment of the present disclosure may include: a common electrode (13) to which a common voltage is supplied; 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 current supply circuit (50) configured to perform a sourcing operation that supplies current to the data driving unit (22) based on the difference between the data voltage of the current frame and the data voltage of the previous frame, or a sinking operation that absorbs current flowing in from the data driving unit (22).

[0183] The current supply circuit (50) can perform the sourcing operation in response to the data voltage of the current frame being higher than the data voltage of the previous frame.

[0184] The current supply circuit (50) can generate a current to be supplied to the data driving unit (22) from the current supply circuit (50) through the sourcing operation and supply the current to the data driving unit (22).

[0185] The current supply circuit (50) can perform the sinking operation in response to the data voltage of the current frame being lower than the data voltage of the previous frame.

[0186] The above current supply circuit (50) can absorb current flowing in from the data driving unit (22) through the sinking operation.

[0187] The above current supply circuit (50) includes an operational amplifier (53) into which the driving voltage of the data driving unit (22) is input; and a current amplifier (54) connected to the operational amplifier. The operational amplifier (53) has the driving voltage supplied to a non-inverting input terminal, the voltage of the output node of the current amplifier (54) fed back to the inverting input terminal, and the output terminal can be connected to the input node of the current amplifier (54).

[0188] The current amplifier (54) 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 (53), 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).

[0189] The current amplifier (54) can have the first switching element (Q1) turned on and the second switching element (Q2) turned off in response to the voltage difference formed across the resistor (R1) by the current output from the operational amplifier to the data driving unit, so as to supply current to the data driving unit.

[0190] The above current amplifier (54) 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 (R3) by the current flowing from the data driving unit to the operational amplifier.

[0191] The above current supply circuit (50) can be embedded in the data driving unit (22).

[0192] It may further include a stabilization circuit (60) configured to perform a sourcing operation that supplies current to the common electrode (13) or a sinking operation that absorbs current flowing in from the common electrode (13) based on the difference between the data voltage of the current frame and the data voltage of the previous frame.

[0193] The above stabilization circuit (60) can perform the sinking operation in response to the data voltage of the current frame being higher than the data voltage of the previous frame.

[0194] The above stabilization circuit (60) can perform the sourcing operation in response to the data voltage of the current frame being lower than the data voltage of the previous frame.

[0195] The above stabilization circuit (60) includes: a voltage input unit (61) that receives the common voltage; an operational amplifier (62) that receives the common voltage from the voltage input unit; and a current amplifier (63) connected to the operational amplifier. The operational amplifier (62) may have the common voltage supplied to a non-inverting input terminal, the voltage of the output node of the current amplifier (63) fed back to the inverting input terminal, and the output terminal connected to the input node of the current amplifier (63).

[0196] The current amplifier (63) comprises a third switching element (Q3); a fourth switching element (Q4) connected to the third switching element (Q3); and a resistor (R2) connected to the third switching element (Q3) and the fourth switching element (Q4). The third switching element (Q3) includes an NPN switching element, and the fourth switching element (Q4) includes a PNP switching element. One side of the resistor (R2) is commonly connected to the output terminal of the operational amplifier (63), the base of the third switching element (Q3), and the fourth switching element (Q4), and the other side can be commonly connected to the emitter of the third switching element (Q3) and the fourth switching element (Q4).

[0197] In response to the voltage difference formed across the ends of the resistor (R2) by the current flowing from the common electrode (13) to the operational amplifier, the third switching element (Q3) can be turned off and the fourth switching element (Q4) can be turned on so as to absorb the current flowing from the common electrode (13).

[0198] In the above current amplifier (63), the third switching element (Q3) can be turned on and the fourth switching element (Q4) can be turned off in response to the voltage difference formed across the ends of the resistor (R2) by the current supplied to the common electrode (13) from the operational amplifier to supply current to the common electrode (13).

[0199] An electrophoretic display device (1) according to another embodiment of the present disclosure comprises: 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); and a power supply unit (40) that generates a driving voltage of the data driving unit (22). The power supply unit includes a stabilization circuit (60) connected to the common electrode (13); the power supply unit includes a current supply circuit (50) configured to supply the driving voltage to the data driving unit (22) and to perform a sourcing operation of supplying current to the data driving unit (22) based on the difference between the data voltage of the current frame and the data voltage of the previous frame, or a sinking operation of absorbing current flowing in from the data driving unit (22); and the stabilization circuit (60) can perform a sourcing operation of supplying current to the common electrode (13) based on the difference between the data voltage of the current frame and the data voltage of the previous frame, or a sinking operation of absorbing current flowing in from the common electrode (13).

[0200] The current supply circuit (50) can perform the sourcing operation in response to the data voltage of the current frame being higher than the data voltage of the previous frame, and perform the sinking operation in response to the data voltage of the current frame being lower than the data voltage of the previous frame.

[0201] The above stabilization circuit (60) can perform the sinking operation in response to the data voltage of the current frame being higher than the data voltage of the previous frame, and perform the sourcing operation in response to the data voltage of the current frame being lower than the data voltage of the previous frame.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] 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.

[0206] 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. A common electrode to which a common voltage is supplied; 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 current supply circuit configured to perform a sourcing operation of supplying current to a data driver or a sinking operation of absorbing current flowing in from the data driver based on the difference between the data voltage of the current frame and the data voltage of the previous frame.

2. In Paragraph 1, The above current supply circuit is, An electrophoretic display device that performs the sourcing operation in response to the data voltage of the current frame being higher than the data voltage of the previous frame.

3. In Paragraph 2, The above current supply circuit is, An electrophoretic display device that generates a current supplied to a data driver in the current supply circuit through the above sourcing operation and supplies the current to the data driver.

4. In Paragraph 1, The above current supply circuit is, An electrophoretic display device that performs the sinking operation in response to the data voltage of the current frame being lower than the data voltage of the previous frame.

5. In Paragraph 4, The above current supply circuit is, An electrophoretic display device that absorbs current flowing in from the data driving unit through the above sinking operation.

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

9. 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 data driving unit to the operational amplifier.

10. In Paragraph 1, The above current supply circuit is an electrophoretic display device embedded in the above data driving unit.

11. In Paragraph 1, An electrophoretic display device further comprising: a stabilization circuit configured to perform a sourcing operation of supplying current to the common electrode or a sinking operation of absorbing current flowing in from the common electrode based on the difference between the data voltage of the current frame and the data voltage of the previous frame.

12. In Paragraph 11, The above stabilization circuit is, An electrophoretic display device that performs the sinking operation in response to the data voltage of the current frame being higher than the data voltage of the previous frame.

13. In Paragraph 11, The above stabilization circuit is, An electrophoretic display device that performs the sourcing operation in response to the data voltage of the current frame being lower than the data voltage of the previous frame.

14. In Paragraph 11, 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.

15. In Paragraph 14, The above current amplifier is, Third switching element (Q3); A fourth switching element (Q4) connected to the third switching element (Q3); and A resistor (R2) connected to the third switching element (Q3) and the fourth switching element (Q4); comprising, The above third switching element (Q3) includes an NPN switching element, and The above-mentioned fourth switching element (Q4) includes a PNP switching element, and An electrophoretic display device in which one side of the resistor (R2) is commonly connected to the output terminal of the operational amplifier, the base of the third switching element (Q3) and the fourth switching element (Q4), and the other side is commonly connected to the emitter of the third switching element (Q3) and the fourth switching element (Q4).

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