JP5471759B2 - Electrophoretic display device, electrophoretic display device driving method, and electronic apparatus - Google Patents

Description

  The present invention relates to an electrophoretic display device, an electrophoretic display device driving method, and an electronic apparatus.

  As a color electrophoretic display (ElectroPhoretic Display), a three-particle electrophoretic display element of white, black, and color has been proposed. For example, in the electrophoretic display elements disclosed in Patent Document 1 and Patent Document 2, positively charged particles (hereinafter, positively charged particles) and negatively charged particles are filled in a filling portion filled with a liquid layer dispersion medium. Three types of particles are contained: (hereinafter, negatively charged particles) and particles that are not positively or negatively charged (hereinafter, uncharged particles). Further, two electrodes are provided for each pixel on the circuit board side of the filling portion, and a common electrode is provided on the side facing the two electrodes across the filling portion. With such a configuration, for example, white or black is displayed by attracting positively charged particles to two electrodes and attracting negatively charged particles to a common electrode. In addition, the positively charged particles are attracted to one of the two electrodes and the negatively charged particles are attracted to the other, so that the uncharged particles can be visually recognized from the common electrode side, thereby performing color display.

JP 2009-9092 A JP 2009-98382 A

  However, Patent Document 1 and Patent Document 2 do not disclose an electrophoretic display device including a display unit in which a plurality of pixels are arranged in a matrix and a driving method thereof. However, a pixel circuit (pixel) in which two sets (1T1C × 2 structure) of pixel switching elements (elements that select scanning lines and switch between data lines and pixels) and capacitors (1T1C) per pixel are provided. In the case of configuring an electrophoretic display device in which three-particle electrophoretic display elements are arranged in a matrix using the memory circuit included in

  When configuring an electrophoretic display device in which three-particle electrophoretic display elements are arranged in a matrix, a requirement to be satisfied is that the two electrodes provided on the circuit board side can be set to different potentials. However, in order to make the two electrodes have different potentials, it is necessary to individually input signals from the data lines corresponding to the respective electrodes in the pixel circuit, so the number of data transfers is two. Further, the charge charged in the capacitor is gradually lost due to the off-leakage current of the selection transistor (pixel switching element), the leakage current of the capacitor itself, the leakage to the electrophoretic display element side, and the like.

  Therefore, in order to obtain a desired contrast, it is necessary to input a signal to the data line several times and to recharge the capacitor, so that there is a problem that current consumption for changing the display becomes large. Also, if the number of data transfers required to obtain a desired contrast is at least two, since there are two capacitors per pixel, the number of data transfers increases to four, and the current consumption required for data transfer is large. There is a problem of becoming.

  The present invention has been made in view of the above problems, and provides an electrophoretic display device in which three-particle electrophoretic display elements are arranged in a matrix, and can reduce current consumption in data transfer and is required for data transfer. An object of the present invention is to provide an electrophoretic display device capable of reducing time.

In order to solve the above problems, an electrophoretic display device of the present invention includes a first pixel electrode and a second pixel electrode, a common electrode facing the first pixel electrode and the second pixel electrode, Electrophoresis having a plurality of pixels each including an electrophoretic element that is sandwiched between the first pixel electrode, the second pixel electrode, and the common electrode and includes positively charged particles, negatively charged particles, and non-current particles. Each of the plurality of pixels includes a scanning line, a data line, a first control line, a second control line, a pixel switching connected to the scanning line, and the data line. A memory circuit connected to the pixel switching element, storing 1-bit data input via the data line and the pixel switching element, and outputting an output signal indicating the 1-bit data; Control lines and said Between the first control line and the first pixel electrode based on an output signal from the memory circuit. And a switch circuit that performs electrical connection and electrical connection between the second control line and the second pixel electrode, and the first pixel electrode via the first control line. And a second drive signal supplied to the second pixel electrode via the second control line, and a signal supply means for supplying the first drive signal to the second pixel electrode. .

  According to this configuration, in the image display operation, the first drive signal and the second drive signal are supplied to the first control line and the second control line via the switch circuit, respectively. Each potential of the pixel electrode and the second pixel electrode can be set to an arbitrary potential according to the color tone of the pixel. For example, since the potential of the first pixel electrode and the second pixel electrode can be the same potential, either the positively charged particle or the negatively charged particle is transferred to the first pixel electrode and the second pixel electrode. It is possible to attract. In addition, since the potentials of the first pixel electrode and the second pixel electrode can be different from each other, the positively charged particles and the negatively charged particles are attracted to the first pixel electrode or the second pixel electrode, respectively. It becomes possible. Thus, an electrophoretic display device in which three-particle electrophoretic display elements are arranged in a matrix can be provided.

  In the electrophoretic display device of the invention, a data line driving circuit for supplying the 1-bit data to the data line, and a scanning line driving circuit for supplying a selection signal for defining an on timing of the pixel switching to the scanning line. And in the data transfer period, the data line driving circuit supplies the 1-bit data to each data line, and the scanning line driving circuit sequentially supplies the selection signal to the scanning lines. The 1-bit data is stored in the memory circuit of each pixel, and in the display period, the first drive signal and the second drive signal are respectively supplied to the first control line and the second drive signal by the signal supply unit. It is preferable to supply to the control line.

  In this manner, the data transfer period for storing data in the memory circuit of each pixel, and the first control line and the second control line respectively connected to the first pixel electrode and the second pixel electrode, respectively, By separately providing a display period in which an image is displayed by supplying a first drive signal and a second drive signal, potential is supplied simultaneously to the first electrode and the second pixel electrode of each pixel in the display period. Therefore, the electric field applied to the electrophoretic element can be controlled with high accuracy, and the quality of color tone display can be improved.

  In the electrophoretic display device of the present invention, in the data transfer period, the data line driving circuit and the scanning line driving circuit may provide the memory circuit of the pixel whose color tone is changed to the first control line and the first control circuit. 1 bit data for electrically connecting the second control line and the second pixel electrode is stored, and the memory circuit of the pixel whose color tone is not changed is stored. First, the inverted data of the 1-bit data is stored, and in the display period, the signal supply means defines the color tone of the pixel whose color tone is changed to the first control line and the second control line. Preferably, the drive signal and the second drive signal are respectively supplied.

  With such a configuration, when an image formed from a plurality of color tones is displayed, the electric field applied to the electrophoretic element is controlled with high accuracy by providing the data transfer period and the display period for each color tone. Therefore, the quality of the color tone display can be improved. In addition, since an electric field applied to an electrophoretic element that constitutes a pixel whose color tone does not change can be controlled, so-called partial driving can be performed, and the quality of color tone display can be improved.

  Further, in the electrophoretic display device of the present invention, when displaying an image formed from a plurality of color tones, the data line driving circuit and the scanning line driving circuit can change the color tone of the pixels in the data transfer period. 1 bit for electrically connecting the first control line and the first pixel electrode to the memory circuit and electrically connecting the second control line and the second pixel electrode Data is stored, and a memory circuit of a pixel whose color tone is not changed performs a first operation of storing inverted data of the 1-bit data. In the display period, the signal supply unit causes the first control line and The first operation and the second operation of performing a second operation of supplying a first drive signal and a second drive signal respectively defining a color tone of a pixel whose color tone is to be changed to a second control line. The combined operation consisting operation is performed for each of the plurality of color tone, it is preferable.

By performing such a combination operation for each of a plurality of color tones, an image formed from a plurality of color tones such as white, black, and color display, for example, three color tones can be displayed.
In addition, when displaying an image formed from three color tones, data transfer can be performed three times, so that an electrophoretic display device capable of reducing current consumption in data transfer can be provided.

In the electrophoretic display device of the present invention, each of the plurality of pixels has a positive power supply line and a negative power supply line, and the memory circuit has a positive power supply terminal connected to the positive power supply line. A one-input two-output latch circuit in which a negative-side power supply terminal is connected to the negative-side power supply line, and the switch circuit connects the first pixel electrode and the first control line. 1 transmission gate, and a second transmission gate for connecting the second pixel electrode and the second control line, wherein the first transmission gate and the second transmission gate are the latches. by the two outputs of the circuit, the respectively the first pixel electrode and the first control line, and the second pixel electrode and the second control line, the city, same period conductive or non-conductive and Said signal supply means, the positive electrode side power supply line, and performs the supply of the power supply potential of the the negative electrode side power supply line, the supply of the common potential to the common electrode, it is preferable.

  As described above, by using the latch circuit as the memory circuit, it is possible to provide an electrophoretic display device capable of reducing current consumption in data transfer and shortening time required for data transfer. Further, according to this configuration, the first transmission gate and the second transmission gate receive the first drive signal and the second drive signal having a potential within the operation range of the latch circuit, respectively, as the first pixel electrode and the second drive gate. It passes through the second pixel electrode. Thus, the potential supplied to the first pixel electrode and the second pixel electrode can be adjusted by arbitrarily controlling the potential of the first drive signal or the second drive signal within the operating range of the latch circuit. It is possible to deal with various color expressions.

In the electrophoretic display device of the present invention, the electrophoretic element includes a filling portion filled with a liquid phase dispersion medium containing three kinds of particles having different colors, and the three kinds of particles are respectively Non-charged particles, positively charged particles, and negatively charged particles are preferable.
Thus, the electrophoretic display device in which the electrophoretic particles in the electrophoretic element are non-charged particles, positively charged particles, and negatively charged particles having different colors, so that the three-particle electrophoretic display elements are arranged in a matrix. Can be provided.

In the electrophoretic display device of the present invention, the electrophoretic element includes a filling portion filled with a liquid phase dispersion medium containing two kinds of particles having different colors, and the two kinds of particles are respectively Positively charged particles and negatively charged particles, and the color of the liquid phase dispersion medium is preferably different from both the positively charged particles and the negatively charged particles.
As described above, the electrophoretic particles in the electrophoretic element are uncharged particles, positively charged particles, and negatively charged particles having different colors, and the color of the liquid phase dispersion medium is different from that of both the positively charged particles and the negatively charged particles. As a result, color display can also be performed in an electrophoretic display device in which two-particle electrophoretic display elements are arranged in a matrix.

In the electrophoretic display device of the invention, the magnitude of the potential supplied between one of the first pixel electrode and the second pixel electrode and the common electrode in the display period. Or, by controlling the time, the distance of the positively charged particles or the negatively charged particles from the common electrode is adjusted, thereby changing the color in the filling portion visually recognized through the common electrode. Is preferred.
As a result, color gradation display can be expressed and display characteristics can be improved.

The driving method of the electrophoretic display device of the present invention includes a first pixel electrode and a second pixel electrode, a common electrode facing the first pixel electrode and the second pixel electrode, and the first pixel electrode. And an electrophoretic element sandwiched between the second pixel electrode and the common electrode and including an electrophoretic element including positively charged particles, negatively charged particles, and non-current particles, and a driving method of an electrophoretic display device having a plurality of pixels A first step of storing 1-bit data in a memory circuit provided in each of the plurality of pixels, a first control line, a second control line, the first pixel electrode, and a second The first control line and the first pixel electrode are electrically connected based on 1-bit data stored in the memory circuit by a switch circuit provided between the pixel electrode and the pixel electrode; and Electrically connecting the second control line and the second pixel electrode; A second step that continues, a first drive signal supplied to the first pixel electrode for the first control line, and a second drive signal supplied to the second pixel electrode for the second control line. And a third step of supplying two drive signals.

  According to this configuration, in the image display operation, the first drive signal and the second drive signal are supplied to the first control line and the second control line via the switch circuit, respectively. Each potential of the pixel electrode and the second pixel electrode can be set to an arbitrary potential according to the color tone of the pixel. For example, since the potential of the first pixel electrode and the second pixel electrode can be the same potential, either the positively charged particle or the negatively charged particle is transferred to the first pixel electrode and the second pixel electrode. It is possible to attract. In addition, since the potentials of the first pixel electrode and the second pixel electrode can be different from each other, the positively charged particles and the negatively charged particles are attracted to the first pixel electrode or the second pixel electrode, respectively. It becomes possible. Accordingly, it is possible to provide a driving method for an electrophoretic display device in which three-particle electrophoretic display elements are arranged in a matrix.

  In the driving method of the electrophoretic display device of the present invention, when displaying an image formed from a plurality of color tones, a combination step including the first step, the second step, and the third step is performed. And performing each of the plurality of color tones, and in the first step, electrically connecting the first control line and the first pixel electrode to a memory circuit of a pixel whose color tone is to be changed; and 1-bit data for electrically connecting a second control line and the second pixel electrode is stored, and inverted data of the 1-bit data is stored in a memory circuit of a pixel whose color tone is not changed. In the third step, a first drive signal and a second drive signal that define the color tone of the pixel whose color tone is to be changed are applied to the first control line and the second control line. It is preferable to supply each .

  By performing such a combination process for each of a plurality of color tones, a driving method of an electrophoretic display device capable of displaying an image formed from a plurality of color tones such as white, black, and color display is provided. be able to. In addition, when an image formed of three color tones is displayed, data transfer can be performed three times. Therefore, a method for driving an electrophoretic display device that can reduce current consumption in data transfer can be provided.

  An electronic apparatus according to the present invention includes the electrophoretic display device described above. Thus, when displaying an image formed from a plurality of color tones, for example, three colors of white, black, and color display, electrophoresis that can reduce the number of data transfer times and suppress power consumption in the data transfer period. An electronic device including the display device can be provided.

1 is a configuration diagram of an electrophoretic display device 100 according to an embodiment of the present invention. FIG. 2 is a circuit configuration diagram of a pixel 40 in the electrophoretic display device 100 shown in FIG. 1. FIG. 3 is a configuration diagram of the electrophoretic element 32 shown in FIG. 2. FIG. 4 is an operation explanatory diagram when black display is performed in the electrophoretic element 32 shown in FIG. 2. 5 is a timing chart used for explaining the operation explanatory diagram shown in FIG. 4. FIG. 3 is an operation explanatory diagram when white display is performed in the electrophoretic element 32 shown in FIG. 2. It is a timing chart used for description of the operation explanatory view shown in FIG. FIG. 4 is an operation explanatory diagram when performing chromatic color display in the electrophoretic element 32 shown in FIG. 2. It is a timing chart used for description of the operation explanatory view shown in FIG. FIG. 6 is an operation explanatory diagram when the display is not changed in the electrophoretic element 32 shown in FIG. 2. It is a timing chart used for description of operation | movement explanatory drawing shown in FIG. FIG. 1 is a flowchart used to explain the operation when performing three-color display in the electrophoretic display device 100. FIG. 4 is an operation explanatory diagram when performing brightness adjustment in the electrophoretic element 32 shown in FIG. 2. It is a figure which shows the wristwatch which is an example of an electronic device. It is a figure which shows the electronic paper which is an example of an electronic device. It is a figure which shows the electronic notebook which is an example of an electronic device.

Hereinafter, an embodiment of an electrophoretic display device, an electrophoretic display device driving method, and an electronic apparatus according to the present invention will be described with reference to the drawings.
[Electrophoretic display device]
FIG. 1 is a configuration block diagram of an electrophoretic display device 100 according to an embodiment of the present invention. As shown in FIG. 1, the electrophoretic display device 100 includes a display unit 5, a scanning line driving circuit 61, a data line driving circuit 62, a common power supply modulation circuit 64 (signal supply means), and a controller 63. I have.

In the display unit 5, a plurality of pixels 40 are formed in a matrix of m pieces along the Y-axis direction and n pieces along the X-axis direction.
The scanning line driving circuit 61 is connected to each pixel 40 through the m scanning lines 66 (Y1, Y2,..., Ym) extending along the X-axis direction in the display unit 5. The scanning line driving circuit 61 sequentially selects the scanning lines 66 from the first row to the m-th row under the control of the controller 63, and the on-timing of the selection transistor 41 (pixel switching element) formed in the pixel 40 described later. Is supplied to each pixel 40 through the selected scanning line 66.
The data line driving circuit 62 is connected to each pixel 40 through n data lines 68 (X1, X2,..., Xn) extending in the display unit 5 along the Y-axis direction. Under the control of the controller 63, the data line driving circuit 62 outputs image signals defining 1-bit image data (1-bit data) corresponding to each of the pixels 40 to the data lines from the first column to the n-th column. 68 to supply to each pixel 40.
In this embodiment, the data line driving circuit 62 supplies a low level (L level) image signal when defining image data “0”, and high when defining image data “1”. Assume that a level (H level) image signal is supplied.

The common power supply modulation circuit 64 includes a first control line 91, a second control line 92, a high potential power supply line 50 (positive power supply line), a low potential power supply line 49 (negative power supply line), and a common electrode wiring 55 ( Each pixel 40 is connected via a common potential power supply line). Under the control of the controller 63, the common power supply modulation circuit 64 generates various signals to be supplied to each of these wirings, and performs electrical connection and disconnection (high impedance) of each of these wirings.
More specifically, in the common power supply modulation circuit 64, a first pixel electrode 351 and a second pixel electrode 352, which will be described later, are connected to the first control line 91 and the second control line 92, respectively. A first drive signal and a second drive signal that define the color tone of the pixel 40 are generated and supplied to the first control line 91 and the second control line 92, respectively. Further, the common power supply modulation circuit 64 generates a power supply potential for a latch circuit 70 formed in the pixel 40 described later and supplies it to the high potential power supply line 50, and electrically connects the ground line and the low potential power supply line 49. Connect or disconnect. Further, the common power supply modulation circuit 64 generates a common potential to be supplied to the common electrode 37 provided in the pixel 40 described later and supplies the common potential to the common electrode wiring 55.

The controller 63 controls the entire operation of the electrophoretic display device 100, and based on image signals and synchronization signals input from an external host control device (not shown), the scanning line driving circuit 61 and the data line driving circuit 62. And the common power supply modulation circuit 64 is controlled.
Next, a detailed configuration of the pixel 40 will be described with reference to FIG.

  FIG. 2 is a circuit configuration diagram of the pixel 40. As shown in FIG. 2, the pixel 40 includes a selection transistor 41 (pixel switching element), a latch circuit 70 (memory circuit), a switch circuit 80, and pixel electrodes (first pixel electrode 351, second pixel). Electrode 352), common electrode 37, and electrophoretic element 32. The pixel 40 has an SRAM (Static Random Access Memory) type configuration in which the latch circuit 70 holds an image signal as a potential.

The selection transistor 41 is a pixel switching element composed of an N-MOS (Negative channel Metal Oxide Semiconductor) transistor. The selection transistor 41 has a gate terminal connected to the scanning line 66, a source terminal connected to the data line 68, and a drain terminal connected to the data input / output terminal N 1 of the latch circuit 70.
The latch circuit 70 includes a transfer inverter 70t and a feedback inverter 70f. Both the transfer inverter 70t and the feedback inverter 70f are C-MOS inverters. The transfer inverter 70t and the feedback inverter 70f have a loop structure in which the other output terminal is connected to each other's input terminal, and each inverter has a high potential connected via a high potential power supply terminal PH. A high potential power supply potential is supplied from the power supply line 50, and a low potential power supply potential is supplied from the low potential power supply line 49 connected via the low potential power supply terminal PL.

  The transfer inverter 70t includes a P-MOS transistor 71 (Positive channel Metal Oxide Semiconductor) and an N-MOS transistor 72 each having a drain terminal connected to the data output terminal N2. The source terminal of the P-MOS transistor 71 is connected to the high potential power supply terminal PH, and the source terminal of the N-MOS transistor 72 is connected to the low potential power supply terminal PL. The gate terminals of the P-MOS transistor 71 and the N-MOS transistor 72 (input terminal of the transfer inverter 70t) are connected to the data input / output terminal N1 (output terminal of the feedback inverter 70f).

  The feedback inverter 70f has a P-MOS transistor 73 and an N-MOS transistor 74 whose drain terminals are connected to the data input / output terminal N1. The gate terminals of the P-MOS transistor 73 and the N-MOS transistor 74 (input terminal of the feedback inverter 70f) are connected to the data output terminal N2 (output terminal of the transfer inverter 70t).

  In the latch circuit 70 having the 1-input / 2-output configuration, when an H-level image signal (pixel data “1”) is stored, the latch circuit 70 outputs an L-level signal from the data output terminal N2, and data input / output An H level signal is output from the terminal N1. On the other hand, when the L level image signal (pixel data “0”) is stored in the latch circuit 70, the latch circuit 70 outputs an H level signal from the data output terminal N 2 and outputs an L level signal from the data input / output terminal N 1. Output a signal.

  The data input / output terminal N 1 and the data output terminal N 2 of the latch circuit 70 are connected to the switch circuit 80. Further, the switch circuit 80 is connected to the first pixel electrode 351 and the second pixel electrode 352, and the first control line 91 and the second control line 92, respectively. The switch circuit 80 includes a first transmission gate TG1 (first switch) and a second transmission gate TG2 (second switch).

  The first transmission gate TG1 includes a P-MOS transistor 81 and an N-MOS transistor 82. The source terminals of the P-MOS transistor 81 and the N-MOS transistor 82 are connected to the first control line 91, and the drain terminals of the P-MOS transistor 81 and the N-MOS transistor 82 are connected to the first pixel electrode 351. Yes. The gate terminal of the P-MOS transistor 81 is connected to the data input / output terminal N 1 of the latch circuit 70, and the gate terminal of the N-MOS transistor 82 is connected to the data output terminal N 2 of the latch circuit 70.

The second transmission gate TG 2 includes a P-MOS transistor 83 and an N-MOS transistor 84. The source terminals of the P-MOS transistor 83 and the N-MOS transistor 84 are connected to the second control line 92, and the drain terminals of the P-MOS transistor 83 and the N-MOS transistor 84 are connected to the second pixel electrode 352. ing.
The gate terminal of the P-MOS transistor 83 is connected to the data input / output terminal N1 of the latch circuit 70, similarly to the P-MOS transistor 81 of the first transmission gate TG1.
Further, the gate terminal of the N-MOS transistor 84 is connected to the data output terminal N2 of the latch circuit 70, similarly to the N-MOS transistor 82 of the first transmission gate TG1.

  As described above, since the connection destinations of the gate terminals of the transistors having the same polarity are the same in the first transmission gate TG1 and the second transmission gate TG2, the pixel electrode and the control line are controlled according to the data input to the latch circuit 70. The connection relationship of is as follows.

  When the L level image signal is stored in the latch circuit 70, the H level signal is output from the data output terminal N2, and the L level signal is output from the data input / output terminal N1, the first transmission gate TG1 is turned on. In this state, the first control line 91 and the first pixel electrode 351 are electrically connected. Also, the second transmission gate TG2 is turned on, and the second control line 92 and the second pixel electrode 352 are electrically connected.

  On the other hand, when the H level image signal is stored in the latch circuit 70, the L level signal is output from the data output terminal N2, and the H level signal is output from the data input / output terminal N1, the first transmission gate TG1. Is turned off, and the first pixel electrode 351 enters a high impedance state (Hi-Z state) in which no potential is supplied. In addition, the second transmission gate TG2 is also turned off, and the second pixel electrode 352 is also in the Hi-Z state.

  In this manner, in the pixel 40, based on the image signal stored in the latch circuit 70, the first transmission gate TG1 and the second transmission gate TG2 simultaneously perform a control operation of conducting or non-conducting. Therefore, whether the pixel electrodes of both the first pixel electrode 351 and the second pixel electrode 352 are both connected to the corresponding control lines, or are both pixel electrodes in the Hi-Z state? , It will be in any one state.

  FIG. 3 is a partial cross-sectional view of the display unit 5 of the electrophoretic display device 100. As shown in FIG. 3, the electrophoretic display device 100 has a configuration in which an electrophoretic element 32 is sandwiched between an element substrate 30 (first substrate) and a counter substrate 31 (second substrate). In the display unit 5, the first pixel electrode 351 and the second pixel electrode 352 are arranged on the electrophoretic element 32 side of the element substrate 30, and the electrophoretic element 32 is arranged via the adhesive layer 33. The first pixel electrode 351 and the second pixel electrode 352 are bonded. The arrangement of the first pixel electrode 351 and the second pixel electrode 352 in a plan view is arbitrary, but as an example, the first pixel electrode 351 and the second pixel electrode 352 are alternately arranged along one direction. Can be arranged.

  The element substrate 30 is a substrate made of glass, plastic, or the like and is not required to be transparent because it is disposed on the side opposite to the image display surface. On the element substrate 30, a circuit layer 34 including the scanning line 66, the data line 68, the selection transistor 41, the latch circuit 70, the switch circuit 80, and the like shown in FIG. 1 and FIG. In addition, a first pixel electrode 351 and a second pixel electrode 352 are formed. The first pixel electrode 351 and the second pixel electrode 352 are formed by stacking nickel plating and gold plating on a Cu foil in this order, Al, ITO (indium tin oxide), or the like.

  On the other hand, the counter substrate 31 is a substrate made of glass, plastic, or the like, and is a transparent substrate because it is disposed on the image display side. A common electrode 37 having a planar shape facing the first pixel electrode 351 and the second pixel electrode 352 is formed on the counter substrate 31 on the electrophoretic element 32 side, and the electrophoretic element 32 is provided on the common electrode 37. It has been. The common electrode 37 is a transparent electrode formed of MgAg, ITO, IZO (indium / zinc oxide), or the like.

  In general, the electrophoretic element 32 is formed in advance on the counter substrate 31 side, and is handled as an electrophoretic sheet including the adhesive layer 33. In the manufacturing process, the electrophoretic sheet is handled in a state where a protective release sheet is attached to the surface of the adhesive layer 33. Then, the electrophoretic sheet from which the release sheet is peeled off is attached to the separately manufactured element substrate 30 (the first pixel electrode 351 and the second pixel electrode 352 and various circuits are formed). Thus, the display unit 5 is formed. For this reason, the adhesive layer 33 exists only on the first pixel electrode 351 and the second pixel electrode 352 side.

The electrophoretic element 32 includes a base body 23 having recesses 27 regularly formed on the upper surface, and a lid 24 provided on the upper surface of the base body 23 so as to close the upper opening of the recesses 27. . Such a base | substrate 23 and the cover part 24 are joined fluid-tightly. The liquid-tight space formed by the inner wall of the concave portion 27 and the lid portion 24 is filled with a liquid phase dispersion medium 25 containing three types of particles A to C (hereinafter simply referred to as “dispersion medium 25”). Has been. Hereinafter, this liquid-tight space is referred to as “filling portion 26”. A common electrode 37 is provided on the upper surface of the lid portion 24 so as to correspond to each concave portion 27. In addition, the above-described pixel electrodes (first pixel electrode 351 and second pixel electrode 352) are provided on the lower surface of the base 23 so as to correspond to the respective recesses 27.
In the electrophoretic display device 100 according to the present embodiment, it is assumed that each filling unit 26 constitutes one pixel 40. Since the plurality of pixels have the same configuration, one pixel 40 will be described below as a representative, and description of other pixels will be omitted.

  The base 23 has insulating properties and impermeability of the dispersion medium 25. The constituent material of the base 23 is not particularly limited. For example, various resin materials such as epoxy resins, acrylic resins, urethane resins, melamine resins, phenol resins, silica, alumina, titania, and the like. These ceramic materials can be used, and one or more of them can be used in combination.

The lid part 24 is substantially colorless and transparent, and has a function as a visual recognition part for visually recognizing the inside of the filling part 26 from the outside of the filling part 26. In addition, as the cover part 24, if the inside of the filling part 26 can be visually recognized from the exterior of the filling part 26, it may not be colorless and transparent, and may be colored. Such a lid portion 24 has insulating properties and impermeability of the dispersion medium 25. The constituent material of the lid 24 is not particularly limited. For example, polyolefin such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, modified polyolefin, polyamide (eg, nylon 6, nylon 66), styrene Various thermoplastic elastomers such as polyvinyl chloride, polyurethane, polyester, fluororubber, chlorinated polyethylene, etc., or copolymers, blends, polymer alloys, etc. mainly composed of these. One or two or more of them can be used in combination.
Further, as described above, the common electrode 37 positioned on the upper portion of the lid portion 24 is a transparent electrode, and the counter substrate 31 positioned further on the common electrode 37 is also a transparent substrate. The inside of the filling part 26 can be visually confirmed.
The separation distance between the upper surface of the lid 24 and the lower surface of the base 23, that is, the separation distance between the common electrode 37 and the pixel electrode is not particularly limited, but is preferably about 10 to 500 μm, and about 20 to 100 μm. More preferably.

Next, the dispersion medium 25 filled in the filling unit 26 will be described.
The dispersion medium 25 is preferably substantially colorless and transparent. As such a dispersion medium 25, a medium having a relatively high insulating property is preferably used. Examples of the dispersion medium 25 include various types of water (distilled water, pure water, ion-exchanged water, etc.), alcohols such as methanol, ethanol, and butanol, cellosolves such as methyl cellosolve, and esters such as methyl acetate and ethyl acetate. , Aromatic hydrocarbons such as ketones such as acetone and methyl ethyl ketone, aliphatic hydrocarbons such as pentane, alicyclic hydrocarbons such as cyclohexane, and benzenes having a long-chain alkyl group such as benzene and toluene Hydrogen, halogenated hydrocarbons such as methylene chloride and chloroform, aromatic heterocycles such as pyridine and pyrazine, nitriles such as acetonitrile and propionitrile, amides such as N, N-dimethylformamide, carboxylate , Mineral oils such as liquid paraffin, vegetable oils such as linoleic acid, linolenic acid and oleic acid, dimethyl Recone oil, methylphenyl silicone oil, silicone oils such as methyl hydrogen silicone oil, fluorine-based liquid, or other various oils such as hydrofluoroether and the like, these can be used alone or as a mixture.

In such a dispersion medium 25, the above-described three kinds of particles A to C are contained. The three types of particles A to C may be contained in the dispersion medium 25, respectively, but are preferably dispersed in the dispersion medium 25. The three types of particles A to C are respectively positively charged positively charged particles A, negatively charged negatively charged particles B, and substantially uncharged uncharged particles C.
The positively charged particle A is a particle having a positive charge. For this reason, among the three electrodes, the particles migrate toward the electrode so as to be adsorbed (attached) to the electrode to which the lowest potential is supplied.
The negatively charged particles B are particles having a negative charge. For this reason, among the three electrodes, the particles migrate toward the electrode so as to be adsorbed by the electrode to which the highest potential is supplied.
Further, the uncharged particles C are particles that do not have an electric charge. For this reason, the uncharged particle C has a potential difference between the three electrodes (that is, the common electrode 37, the first pixel electrode 351, and the second pixel electrode 352, and so on). The particles are dispersed in the dispersion medium 25.

Such positively charged particles A, negatively charged particles B, and uncharged particles C have different colors. The colors of the positively charged particles A, the negatively charged particles B, and the uncharged particles C are not particularly limited, and may be achromatic colors such as black, white, or an intermediate color (gray), red, blue, green, etc. Three colors can be arbitrarily selected from the chromatic colors.
Moreover, the combination of the kind of particle (positively charged particle A, negatively charged particle B, uncharged particle C) and the color of the particle (black, white, blue, red, yellow, etc.) is not particularly limited. For example, positively charged particles A are black particles, negatively charged particles B are white particles, uncharged particles C are yellow particles, positively charged particles A are blue particles, negatively charged particles B are white particles, A combination of particles in which the non-charged particles C are black is exemplified.

As the positively charged particles A and the negatively charged particles B, any particles can be used as long as they have a positive charge and a negative charge, respectively, and are not particularly limited. However, pigment particles, resin particles, ceramic particles, metal At least one of particles, metal oxide particles, or composite particles thereof is preferably used. Further, the constituent material of the non-charged particle C is the same as that of the positively charged particle A and the negatively charged particle B except that a material having no charge is appropriately selected.
Examples of pigments constituting the pigment particles include black pigments such as aniline black, carbon black, and titanium black, white pigments such as titanium dioxide, antimony trioxide, zinc sulfide, and zinc white, and azo series such as monoazo, disazo, and polyazo. Pigments, yellow pigments such as isoindolinone, yellow lead, yellow iron oxide, cadmium yellow and titanium yellow, azo pigments such as monoazo, disazo and polyazo, red pigments such as quinacridone red and chrome vermilion, phthalocyanine blue and indanthrene Blue pigments such as blue, bitumen, ultramarine, and cobalt blue, green pigments such as phthalocyanine green, and the like can be used, and one or more of these can be used in combination.

  Examples of the resin material constituting the resin particles include acrylic resin, urethane resin, urea resin, epoxy resin, rosin resin, polystyrene, polyester, AS resin copolymerized with styrene and acrylonitrile, and the like. These can be used alone or in combination of two or more. The composite particles are, for example, composed of pigment particles whose surfaces are coated with a resin material, resin particles whose surfaces are coated with a pigment, or a mixture of a pigment and a resin material mixed in an appropriate composition ratio. Particles and the like.

The pixel 40 configured as described above selects a potential supply pattern to the common electrode 37, the first pixel electrode 351, and the second pixel electrode 352, and converts the positively charged particles A and the negatively charged particles B to 3 It can be unevenly distributed in the site | part corresponding to the electrode of any one of two electrodes. Thereby, the color in the filling part 26 visually recognized through the common electrode 37 and the cover part 24 can be changed.
Hereinafter, the white, black, and chromatic display operations of the pixel 40 will be described with reference to FIGS. 4, 6, and 8 are circuit diagrams of the pixel 40, and FIGS. 5, 7, and 9 are timing charts corresponding to FIGS. 4, 6, and 8, respectively. In this embodiment, as an example of the combination of the colors of the three particles A to C, the positively charged particles A are black, the negatively charged particles B are white, and the uncharged particles C are chromatic (for example, yellow). . In order to explain the movement of the three particles, FIG. 3, FIG. 7 and FIG. 9 show the device structure of FIG. 3B, which is a simplified illustration of the device shown in FIG.

(Black display)
The black display operation of the pixel 40 will be described with reference to the circuit diagram of FIG. 4 and the timing chart of FIG. In FIG. 5, the power-on period is represented by (1), the image data input period is represented by (2-a), the black display period is represented by (3-a) and (4-a), and the power-off period is represented by (5). Yes. In the present embodiment, a period corresponding to the period (2-a) for storing the image data in the latch circuit 70 is displayed as a data transfer period, and a period corresponding to the black display periods (3-a) and (4-a) is displayed. This is called a period.
In FIG. 5, the potential of the scanning line 66, the potential of the data output terminal N2 of the latch circuit 70, the potential of the first control line 91, the potential of the second control line 92, the potential of the first pixel electrode 351, 2 shows the potential of the second pixel electrode 352 and the potential VCOM of the common electrode 37. Note that the specific potentials (5V, 15V, 0V, etc.) shown in FIG. 5 are merely illustrated for easy understanding of the description, and do not limit the technical scope of the present invention.

  Prior to the power-on period (1) shown in FIG. 5, the first control line 91, the second control line 92, the first pixel electrode 351, the second pixel electrode 352, and the common electrode 37 are all The state is Hi-Z. Note that the scanning line 66 and the power supply line (low potential power line 49, high potential power line 50) connected to the pixel 40 are also in the Hi-Z state.

  In the power-on period (1), the latch circuit 70 is supplied with a potential of about 5 V from the common power supply modulation circuit 64 of FIG. The latch circuit 70 is driven by supplying a potential of 0V. Further, the scanning line driving circuit 61 sets the potential of the scanning line 66 to 0V. Since no image data is yet input to the latch circuit 70, the potential of the data output terminal N2 is assumed to be 0V, and the potential of the data input / output terminal N1 is assumed to be 5V. The potentials of the data output terminals N1 and N2 are either 0V or 5V, and are different from each other. Specifically, when the output terminal N1 is 0V, the output terminal N2 is 5V. Here, the higher potential of the output terminals N1 and N2 is LV.

Next, in the data transfer period (2-a), the scanning line driving circuit 61 sets the potential of the scanning line 66 to (LV + α) and turns on the selection transistor 41. Here, (LV + α) is a potential for facilitating inversion of the latch circuit 70 when the data line driving circuit 62 transfers an H level image signal to the latch circuit via the data line 68. The potential is approximately 7 V, which is higher than the potential of the connected high potential power supply line.
Here, as shown in FIG. 4, the data line driving circuit 62 transfers an L-level image signal (Low) to the latch circuit via the data line 68. Thereby, the latch circuit 70 changes the potential of the data output terminal N2 from 0V to 5V and the potential of the data input / output terminal N1 from 5V to 0V. At this time, the first control line 91, the second control line 92, the first pixel electrode 351, the second pixel electrode 352, and the common electrode 37 are all in the Hi-Z state.

  The latch circuit 70 maintains the potential of the data output terminal N2 and the potential of the data input / output terminal N1 while the potential is supplied to the connected high potential power supply line 50 and low potential power supply line 49. Data transfer when displaying one color (here black) can be done only once. This eliminates the need for multiple data transfers as in the case where the pixel circuit is configured by a combination of the pixel switching element and the capacitor (1T1C). In addition, current consumption associated with data transfer can be reduced.

  At this time, in the latch circuit 70 in which the L level image signal is stored, the data output terminal N2 outputs the 5V H level signal and the data input / output terminal N1 outputs the 0V L level signal. Both the transmission gate TG1 and the second transmission gate TG2 are turned on. However, since the potential of the first control line 91 and the second control line 92 are both in the Hi-Z state, the potential of the first pixel electrode 351 and the second pixel electrode 352 are both Hi−. Z state. That is, the electrophoretic element 32 does not operate during the data transfer period.

When the above data transfer period ends, the display period (3-a) is started next. In the display period (3-a), the common power supply modulation circuit 64 supplies the latch circuit 70 with the high level potential VH through the high potential power supply line 50 and the low level potential VL through the low potential power supply line 49. To do. Here, the high level potential VH is the maximum potential of the potential of the first pixel electrode 351 and the second pixel electrode 352 and the potential supplied to the common electrode 37 when performing display in the pixel 40. For example, FIG. 5 is 15V. Further, the low level potential VL is the minimum potential of the potentials supplied to the first pixel electrode 351 and the second pixel electrode 352 and the common electrode 37 when display is performed in the pixel 40. For example, FIG. Is 0V.
Accordingly, if the high level potential VH is supplied to the first control line 91 or the second control line 92 in the subsequent display period (4-a), the potential of the data output terminal N2 is set to the high level potential VH, the data input. Since the potential of the output terminal N1 is the low level potential VL, the first transmission gate TG1 and the second transmission gate TG2 respectively set the potentials of the first pixel electrode 351 and the second pixel electrode 352 to the high level potential VH. It can be. Further, the potential of the high-potential power supply line 50 is set to a low potential of 5 V in the data transfer period, and is boosted to the high-level potential VH in the data display period, so that the latch circuit 70 holds the data in the period. Standby current can be reduced. In addition, since data transfer can be performed at a low voltage, current consumption can be reduced.

Subsequently, in the display period (4-a), the common power supply modulation circuit 64 supplies a black display potential to the first control line 91, the second control line 92, and the common electrode 37. Specifically, as shown in FIG. 5, the common power supply modulation circuit 64 supplies a high level potential VH to the first control line 91 and the second control line 92 and a low level potential VL to the common electrode 37. .
As a result, the positively charged particles A migrate toward the common electrode 37 so as to be electrically adsorbed by the common electrode 37 supplied with the low level potential VL. Further, the negatively charged particles B migrate toward the two pixel electrodes so as to be electrically adsorbed by the first pixel electrode 351 and the second pixel electrode 352 to which the high level potential VH is supplied.
As a result, as shown in the upper right of FIG. 4, the positively charged particles A are unevenly distributed in the portions corresponding to the common electrode 37, and the negatively charged particles B are portions corresponding to the first pixel electrode 351 and the second pixel electrode 352. Is unevenly distributed. In this state, since the lid portion 24 shown in FIG. 3A is covered with the positively charged particles A, black is visually recognized as the display color. In such a pixel 40, even if the potential supply to the three electrodes is stopped, the positively charged particles A and the negatively charged particles B have characteristics of maintaining the state immediately before the potential supply is stopped. doing. That is, after the black display state is reached, the black display state can be maintained even when the potential supply is stopped in the power-off period (5) shown in FIG. The same applies to a white display state, a chromatic color display state, and the like described later.

(White display)
Next, the operation for displaying white will be described with reference to the circuit diagram of FIG. 6 and the timing chart of FIG. Note that the operations of the latch circuit 70, the first transmission gate TG1, and the second transmission gate TG2 are the same as those in the case of black display, and therefore will be briefly described and different points will be described in detail.
In FIG. 7, the data transfer period (2-a), the display periods (3-a) and (4-a) shown in FIG. 5 are denoted by reference numerals (2-b), (3-b) and (4), respectively. -B), the operation of the pixel 40 in the data transfer period (2-b) and the display period (3-b) is the same as in the case of black display.
That is, in the data transfer period (2-b), the data line driving circuit 62 transfers an L level image signal to the latch circuit 70 through the data line 68. The latch circuit 70 stores an L level image signal, outputs a 5V H level signal from the data output terminal N2, and outputs a 0V L level signal from the data input / output terminal N1. As a result, the latch circuit 70 turns on the first transmission gate TG1 and the second transmission gate TG2. In the display period (3-b), the latch circuit 70 changes the potential of the data output terminal N2 from 5V to 15V and maintains the potential of the data input / output terminal N1 at 0V.

In the display period (4-b), the common power supply modulation circuit 64 supplies a white display potential to the first control line 91, the second control line 92, and the common electrode 37. Specifically, the common power supply modulation circuit 64 supplies a low level potential VL to the first control line 91 and the second control line 92 and a high level potential VH to the common electrode 37, as shown in FIG. .
As a result, the negatively charged particles B migrate toward the common electrode 37 so as to be electrically adsorbed by the common electrode 37 supplied with the high level potential VH. Further, the positively charged particles A migrate toward the two pixel electrodes so as to be electrically adsorbed by the first pixel electrode 351 and the second pixel electrode 352 supplied with the low level potential VL.
As a result, as shown in the upper right of FIG. 6, the negatively charged particles B are unevenly distributed in the part corresponding to the common electrode 37 and the positively charged particles A are parts corresponding to the first pixel electrode 351 and the second pixel electrode 352. Is unevenly distributed. In this state, since the lid portion 24 shown in FIG. 3A is covered with the negatively charged particles B, white is visually recognized as the display color.

(Chromatic display)
Next, the operation for displaying chromatic colors will be described with reference to the circuit diagram of FIG. 8 and the timing chart of FIG. Note that the operations of the latch circuit 70, the first transmission gate TG1, and the second transmission gate TG2 are the same as those in the case of the black display and the white display described above. .
In FIG. 9, the data transfer period (2-a), the display periods (3-a) and (4-a) shown in FIG. 5 are denoted by reference numerals (2-c), (3-c) and (4), respectively. -C), the operation of the pixel 40 in the data transfer period (2-c) and the display period (3-c) is the same as that in the case of black display.
That is, in the data transfer period (2-c), the data line driving circuit 62 transfers an L level image signal to the latch circuit 70 via the data line 68. The latch circuit 70 stores an L level image signal, outputs a 5V H level signal from the data output terminal N2, and outputs a 0V L level signal from the data input / output terminal N1. As a result, the latch circuit 70 turns on the first transmission gate TG1 and the second transmission gate TG2. In the display period (3-c), the latch circuit 70 changes the potential of the data output terminal N2 from 5V to 15V and maintains the potential of the data input / output terminal N1 at 0V.

  In the display period (4-c), the common power supply modulation circuit 64 supplies a chromatic color potential to the first control line 91, the second control line 92, and the common electrode 37. Specifically, as shown in FIG. 9, the common power supply modulation circuit 64 has a high level potential VH for the first control line 91, a low level potential VL for the second control line 92, and 7V (intermediate for the common electrode 37). Potential VM). Note that the intermediate potential VM is an intermediate potential between the low level potential VL and the high level potential VH, as shown in FIG. 8, and here, approximately between the high level potential VH (15 V) and the low level potential VL (0 V). The potential is 7V. That is, an intermediate potential VM is supplied to the common electrode 37 so that no charged particles migrate to the common electrode 37 side. The common power supply modulation circuit 64 may place the common electrode 37 in the Hi-Z state via the common electrode wiring 55. This is because if an electric field is generated between the first pixel electrode 351 and the second pixel electrode 352, one of the positively charged particles A and the negatively charged particles B migrates to one electrode and the other to the other electrode. It is because it can be made.

As a result, the positively charged particles A migrate toward the second pixel electrode 352 so as to be electrically adsorbed by the second pixel electrode 352 supplied with the low level potential VL. Further, the negatively charged particles B migrate toward the first pixel electrode 351 so as to be electrically adsorbed to the first pixel electrode 351 supplied with the high level potential VH.
As a result, as shown in FIG. 8, the positively charged particles A are unevenly distributed in the portion corresponding to the second pixel electrode 352, and the negatively charged particles B are unevenly distributed in the portion corresponding to the first pixel electrode 351. That is, both the positively charged particles A and the negatively charged particles B are unevenly distributed on the lower surface of the filling portion 26 shown in FIG.
On the other hand, as described above, the uncharged particles C are dispersed in the dispersion medium 25 regardless of whether or not a potential difference is generated between the three electrodes. The non-charged particles C that absorb and reflect light, and a chromatic color as a display color is visually recognized through the lid 24.

(Operation when color display is not changed)
The operations of black display, white display, and chromatic color display in the pixel 40 have been described in detail above. The operation when the color display in the pixel 40 is not changed will be described next. This operation is possible because the pixel circuit configuration of the pixel 40 is configured to transfer an L-level image signal from the data line driving circuit 62 only to the pixel whose color display is to be changed.
FIG. 10 is a circuit diagram of the pixel 40, and FIG. 11 is a timing chart corresponding to FIG. In FIG. 11, the operations in the power-on period (1) and the power-off period (5) are the same as the operations in the color display such as the black display described above, so the description is omitted, and the data transfer period (2-d), The operation in the display periods (3-d) and (4-d) will be described in detail.

  In the data transfer period (2-d), the scanning line driving circuit 61 sets the potential of the scanning line 66 to (LV + α) and turns on the selection transistor 41. The data line driving circuit 62 transfers an H level image signal (High) to the latch circuit via the data line 68, as shown in FIG. As a result, an L level signal of 0V is output from the data output terminal N2 of the latch circuit 70 in which an image signal of the H level is stored, and an H level signal of 5V is output from the data input / output terminal N1. Both the transmission gate TG1 and the second transmission gate TG2 are turned off.

In the subsequent display period (3-d), the common power supply modulation circuit 64 supplies the high-level potential VH to the latch circuit via the high-potential power supply line 50, but the latch circuit 70 stores the H-level image signal. Therefore, the potential of the data output terminal N2 is maintained at 0V, and the potential of the data input / output terminal N1 changes from 5V to 15V. That is, the off state is maintained in both the first transmission gate TG1 and the second transmission gate TG2.
Accordingly, in the subsequent display period (4-d), the first pixel electrode 351 and the second pixel electrode 352 are Hi regardless of what potential is supplied to the first control line 91 or the second control line 92. -Z state.

Subsequently, in the display period (4-d), the common power supply modulation circuit 64 applies, for example, a chromatic display potential (see FIG. 9) to the first control line 91, the second control line 92, and the common electrode 37. Supply the same supply potential). However, as described above, the first transmission gate TG1 and the second transmission gate TG2 are off.
Therefore, since no electric field is generated between any two of the first pixel electrode 351, the second pixel electrode 352, and the common electrode 37, the positively charged particles A and the negatively charged particles B It will not migrate even towards, and will maintain the previous state. Here, the previous state is, for example, the state of the particles A to C shown in FIG. That is, the particle state of the pixel 40 having the latch circuit 70 that latches the H-level image signal does not change as shown in the upper right of FIG.
If the previous particle state is the state shown in FIG. 4, that is, if the particle state is in a black display, the black display in the pixel is maintained. Further, if the previous particle state is the state shown in FIG. 6, that is, if the particle state is in the white display, the white display in the pixel is maintained. If the previous particle state is the state shown in FIG. 8, that is, the particle state in the chromatic display, the chromatic display in the pixel is maintained. As described above, when the latch circuit 70 in the pixel 40 stores the H-level image signal, the previous display state is maintained.

(Image display formed from multiple colors)
Next, based on the basic operation of each pixel 40 described above, an operation in the case of displaying an image formed from a plurality of color tones in the electrophoretic display device 100 will be described.
Hereinafter, a case where an image display in which one screen is formed of three colors of white, black, and chromatic is performed will be described with reference to FIG.
FIG. 12 is a flowchart for explaining the display operation. In addition, the symbols 1, 2-a, 3-a,... In the parentheses shown in Steps 1 to 11 shown in FIG. 12 are the same as the symbols used in the description of FIGS. is there.

  First, in step 1, the scanning line drive circuit 61, the data line drive circuit 62, the controller 63, and the common power supply modulation circuit 64 that are circuits for driving the pixels 40 are turned on. The common power supply modulation circuit 64 supplies a potential of 5 V to all the pixels 40 through the high potential power supply line 50 and a potential of 0 V through the low potential power supply line 49 under the control of the controller 63. The latch circuits 70 of all the pixels 40 are driven. Further, the scanning line driving circuit 61 sets the potential of the scanning line 66 connected to all the pixels to 0 V under the control of the controller 63. Note that since no image data is yet input to the latch circuit 70, the potential of the data output terminal N2 in each pixel is assumed to be 0V. The state of the particles is assumed to be in the state of particles shown in the upper right of FIG.

In step 2, the scanning line driving circuit 61 sequentially selects the scanning lines 66 from the first row to the m-th row under the control of the controller 63, and defines the ON timing of the selection transistor 41 formed in each pixel 40. The selection signal to be supplied is supplied to each pixel 40 through the selected scanning line 66. Further, the data line driving circuit 62 transmits an image signal defining 1-bit image data corresponding to each of the pixels 40 via the data lines 68 from the first column to the n-th column under the control of the controller 63. And supplied to each pixel 40.
In this step 1, the data line driving circuit 62 supplies the L level image signal only to the pixel 40 to be changed to black, and the H level is applied to the pixel to be changed to white and the pixel 40 to be changed to chromatic color. Supply image signals.

As a result, the L level image signal is latched in the latch circuit 70 of the pixel 40 to be displayed in black, the potential of the data output terminal N2 of the latch circuit 70 is H level, and the potential of the data input / output terminal N1 is L level. It becomes. That is, the first transmission gate TG1 and the second transmission gate TG2 of the pixel 40 to be displayed in black are turned on, and the first control line 91, the first pixel electrode 351, the second control line 92, and the second transmission line TG2 are turned on. The pixel electrodes 352 are connected to each other.
On the other hand, since the H level image signal is latched in the latch circuit 70 of the pixel 40 for which white display is desired and the pixel 40 for which chromatic color display is desired, the data output terminal N2 of the latch circuit 70 is at the L level and the data input. The potential of the output terminal N1 becomes H level. That is, the first control line 91 and the first pixel electrode 351, and the second control line 92 and the second pixel electrode 352 are not connected in the pixel 40 that wants to perform white display and the pixel 40 that wants to perform chromatic color display. .

  In step 3, the common power supply modulation circuit 64 supplies a potential of 15 V to each pixel 40 latch circuit 70 via the high potential power supply line 50 under the control of the controller 63. At this time, the potential of the data output terminal N2 of the latch circuit 70 of the pixel 40 to be displayed in black is 15V, and the potential of the data input / output terminal N1 is 0V. On the other hand, the potential of the data output terminal N2 of the pixel 40 desired to perform white display and the pixel 40 desired to perform chromatic display remains 0V, and the potential of the data input / output terminal N1 becomes 15V.

In step 4, the common power supply modulation circuit 64 supplies a black display potential to the first control line 91, the second control line 92, and the common electrode 37 under the control of the controller 63. Specifically, as described in the black display period (4-a), the common power supply modulation circuit 64 applies the high level potential VH to the first control line 91 and the second control line 92, and the common electrode 37. Is supplied with a low level potential VL.
As a result, in the pixel 40 where black display is desired, as shown in the upper right of FIG. And unevenly distributed in a portion corresponding to the second pixel electrode 352.
On the other hand, in the pixel 40 for which white display is desired and the pixel 40 for which chromatic color display is desired, no potential is supplied to the first pixel electrode 351 and the second pixel electrode 352, and as shown in the upper right of FIG. The positively charged particles A and the negatively charged particles B do not migrate.

In subsequent step 5, the data line driving circuit 62 supplies an L level image signal only to the pixel 40 desired to be changed to white, and to the pixel 40 changed to black and the pixel 40 desired to be changed to chromatic color in step 4. Supplies an H level image signal. It is assumed that the high potential side potential of the latch circuit 70 is returned to 5 V by the common power supply modulation circuit 64 prior to data transfer.
As a result, in the pixel 40 where white display is desired, the first control line 91 and the first pixel electrode 351 are connected, and the second control line 92 and the second pixel electrode 352 are connected.
On the other hand, in the latch circuit 70 of the pixel 40 that has performed black display and the pixel 40 that is to perform chromatic color display, the first control line 91 and the first pixel electrode 351, the second control line 92, and the second pixel electrode. 352 is not connected.

  In step 6, the common power supply modulation circuit 64 supplies a potential of 15 V to each pixel 40 latch circuit 70 through the high potential power supply line 50 under the control of the controller 63 as in step 6. At this time, the potential of the data output terminal N2 of the latch circuit 70 of the pixel 40 to be displayed in white is 15V, and the potential of the data input / output terminal N1 is 0V. On the other hand, the potential of the data output terminal N2 of the pixel 40 that has performed black display and the pixel 40 that is to perform chromatic display remains 0V, and the potential of the data input / output terminal N1 is 15V.

In subsequent step 7, the common power supply modulation circuit 64 supplies the white display potential to the first control line 91, the second control line 92, and the common electrode 37 under the control of the controller 63. Specifically, as described in the white display period (4-b), the common power supply modulation circuit 64 applies the low level potential VL and the common electrode 37 to the first control line 91 and the second control line 92. Is supplied with a high level potential VH.
As a result, in the pixel 40 where white display is desired, as shown in the upper right of FIG. 6, the negatively charged particles B are unevenly distributed in the portion corresponding to the common electrode 37, and the positively charged particles A are the first pixel electrode 351. And unevenly distributed in a portion corresponding to the second pixel electrode 352.
On the other hand, in the pixel 40 that has performed black display, no potential is supplied to the first pixel electrode 351 and the second pixel electrode 352, and black display is continued as shown in the upper right of FIG. Further, even in the pixel 40 that is desired to perform chromatic color display, no potential is supplied to the first pixel electrode 351 and the second pixel electrode 352, and as shown in the upper right of FIG. B does not migrate.

In step 8, the data line driving circuit 62 supplies the L level image signal only to the pixel 40 to be changed to chromatic color, and the pixel 40 changed to black in step 4 and the pixel changed to white in step 7. 40 is supplied with an H level image signal. It is assumed that the high potential side potential of the latch circuit 70 is returned to 5 V by the common power supply modulation circuit 64 prior to data transfer.
As a result, in the pixel 40 where chromatic color display is desired, the first control line 91 and the first pixel electrode 351 are connected, and the second control line 92 and the second pixel electrode 352 are connected.
On the other hand, in the pixel 40 changed to black and the latch circuit 70 of the pixel 40 changed to white in Step 5, the first control line 91, the first pixel electrode 351, the second control line 92, and the second The pixel electrode 352 is not connected.

  In step 9, the common power supply modulation circuit 64 supplies a potential of 15 V to each pixel 40 latch circuit 70 through the high potential power supply line 50 under the control of the controller 63 as in step 6. At this time, the potential of the data output terminal N2 of the latch circuit 70 of the pixel 40 on which chromatic color display is desired is 15V, and the potential of the data input / output terminal N1 is 0V. On the other hand, the potential of the data output terminal N2 of the pixel 40 changed to black and the data output terminal N2 of the pixel 40 changed to white in step 5 remains 15V.

In subsequent step 10, the common power supply modulation circuit 64 supplies a chromatic color display potential to the first control line 91, the second control line 92, and the common electrode 37 under the control of the controller 63. Specifically, as described in the display period (4-c) of the chromatic color display, the common power supply modulation circuit 64 sets the first control line 91 to the high level potential VH and the second control line 92 to the low level. An intermediate potential VM is supplied to the potential VL and the common electrode 37.
As a result, in the pixel 40 for which chromatic color display is desired, the negatively charged particles B are unevenly distributed in the portion corresponding to the first pixel electrode 351 and the positively charged particles A are the second as shown in the upper right of FIG. It is unevenly distributed in a part corresponding to the pixel electrode 352.
On the other hand, in the pixel 40 changed to black in Step 4, no potential is supplied to the first pixel electrode 351 and the second pixel electrode 352, and black display is continued as shown in the upper right of FIG. Also, in the pixel 40 changed to white in step 76, the potential is not supplied to the first pixel electrode 351 and the second pixel electrode 352, and the white display is continued as shown in the upper right of FIG.

Finally, in step 11, the power of each circuit that was turned on in step 1 is turned off.
As described above, in each display of white, black, and chromatic colors, the L level image signal is transferred only to the pixel to be displayed and the L level image signal is stored in the latch circuit 70 in the data transfer period. In the subsequent display period, a potential indicating display of the color is supplied to the first pixel electrode and the second pixel electrode for each color by the first control signal and the second control signal.
This makes it possible to provide an electrophoretic display device in which three-particle electrophoretic display elements are arranged in a matrix. In addition, since data transfer can be performed three times, which is the number of colors desired to be displayed, it is possible to provide an electrophoretic display device that can reduce current consumption in data transfer and shorten the time required for data transfer.

(Partial drive)
In addition, as described in the display operation in each pixel 40 and the display operation in the electrophoretic display device 100, in the pixel circuit included in the pixel 40, the color tone is changed only in the pixel 40 to which the L-level image signal (image data) is transferred. It has a configuration that switches.
Therefore, it is possible to cope with so-called partial driving in which some of the pixels 40 in all the pixels 40 are partially switched in display.
That is, in the first data transfer (step 2 above), the display is switched and the L-level image signal is transferred only to the pixel 40 where black is desired to be displayed, and the display is switched to black display. At this time, the pixel 40 whose display is not switched and the first pixel electrode 351 and the second pixel electrode 352 of the pixel 40 whose display is to be switched to white or chromatic color in Step 7 and Step 10 are in the Hi-Z state. So the display does not switch. Similarly, in Step 7 and Step 10, an H level image signal is transferred to the pixel 40 whose display is not switched. In this manner, in the three data transfers, the display of the pixels 40 to which the image signal of H level has been transferred is not switched, and partial driving that maintains the previous display can be performed.

(Brightness adjustment)
In the above description, the potential supplied to the first control line 91 and the second control line 92 can be freely set to the same potential as the common electrode 37, for example. Further, the first control line 91 and the second control line 92 can be set to the Hi-Z state. Thereby, the brightness adjustment can be performed in the chromatic color display in the step 10. This brightness adjustment will be described with reference to FIG. As described in step 10 above, in step 10, the common power supply modulation circuit 64 causes the first control line 91 to have a high level potential VH, the second control line 92 to have a low level potential VL, and the common electrode 37 to have an intermediate potential. Supply VM. Thereby, the pixel 40 which displays a chromatic color will be in the state of the particle | grains of the upper right of FIG.
In this state, for example, as shown in FIG. 13, the potential supplied to the first control line 91 is set to the low level potential VL, the second control line 92 is set to the Hi-Z state, and the common electrode 37 is set to the high level potential VH. Supply.

  As a result, an electric field is generated only between the common electrode 37 and the first pixel electrode 351, so that the negatively charged particles B are electrically adsorbed to the common electrode 37, and the first pixel electrode 351. To the common electrode 37. As the negatively charged particles B migrate, the display color gradually changes from chromatic to white. That is, as the negatively charged particle B approaches the common electrode 37, the brightness of the chromatic color increases. As described above, even if the potential supply is stopped by setting the second pixel electrode 352 in the Hi-Z state, the positively charged particles A can be maintained in a state immediately before the potential supply is stopped. Further, the electric field between the common electrode 37 and the first pixel electrode 351 is controlled by controlling the level and supply time of the potential supplied to the first control line 91 and the potential supplied to the common electrode 37. The brightness level of can be adjusted. For example, the potential supply time is controlled, and when the negatively charged particle B reaches the vicinity of the intermediate point between the common electrode 37 and the first pixel electrode 351, the potential supply to the common electrode 37 and the first pixel electrode 351 is performed. If it is stopped, the state of the particles as shown in the upper right of FIG. 13 can be maintained, and the brightness is compared with the intermediate color between chromatic color and white, that is, the chromatic color display (the state of particles in the upper right of FIG. 8). High chromatic colors can be displayed.

Further, when displaying a chromatic color with low brightness, the first control line 91 is set to the Hi-Z state, the potential supplied to the second control line 92 is set to the high level potential VH, and the common electrode 37 is set to the low level potential VL. Supply. As a result, an electric field is generated between the second pixel electrode 352 and the common electrode 37, so that the positively charged particles A are electrically adsorbed by the common electrode 37, so that the second pixel electrode 352 Electrophoresis toward the common electrode 37. As such positively charged particles A migrate, the display color gradually changes from chromatic to black. That is, as the positively charged particles B approach the common electrode 37, the brightness of the chromatic color decreases. For example, as in the case of increasing the brightness, the potential supply time is controlled, and when the positively charged particles A reach the vicinity of the intermediate point between the common electrode 37 and the second pixel electrode 352, the common electrode 37 and the second electrode If the potential supply to the pixel electrode 352 is stopped, a chromatic color and a black color, that is, a chromatic color having a lower brightness than the chromatic color display state (the state of particles in the upper right in FIG. 8) is displayed. be able to.
Thus, the electrophoretic display device 100 of the present embodiment can adjust the brightness with high accuracy.

(Electronics)
Next, a case where the electrophoretic display device 100 of each of the above embodiments is applied to an electronic device will be described.
FIG. 14 is a front view of the wrist watch 1000. The wrist watch 1000 includes a watch case 1002 and a pair of bands 1003 connected to the watch case 1002.
On the front surface of the watch case 1002, a display unit 1005 including the electrophoretic display device 100 of the above embodiment, a second hand 1021, a minute hand 1022, and an hour hand 1023 are provided. On the side surface of the watch case 1002, a crown 1010 and an operation button 1011 are provided as operation elements. The crown 1010 is connected to a winding stem (not shown) provided inside the case, and is integrally provided with the winding stem so that it can be pushed and pulled in multiple stages (for example, two stages) and can be rotated. . The display unit 1005 can display a background image, a character string such as date and time, or a second hand, a minute hand, and an hour hand.

  FIG. 15 is a perspective view illustrating a configuration of the electronic paper 1100. An electronic paper 1100 includes the electrophoretic display device 100 of the above embodiment in a display area 1101. The electronic paper 1100 is flexible and includes a main body 1102 made of a rewritable sheet having the same texture and flexibility as conventional paper.

  FIG. 16 is a perspective view showing the configuration of the electronic notebook 1200. An electronic notebook 1200 is obtained by bundling a plurality of the electronic papers 1100 and sandwiching them between covers 1201. The cover 1201 includes display data input means (not shown) for inputting display data sent from an external device, for example. Thereby, according to the display data, the display content can be changed or updated while the electronic paper is bundled.

  According to the wristwatch 1000, the electronic paper 1100, and the electronic notebook 1200 described above, the electrophoretic display device 100 according to the present invention is employed, so that a high-quality display with a smooth outline is possible and power saving is achieved. In addition, an electronic device having an excellent display portion is obtained. In addition, said electronic device illustrates the electronic device which concerns on this invention, Comprising: The technical scope of this invention is not limited. For example, the electrophoretic display device according to the present invention can be suitably used for a display portion of an electronic device such as a mobile phone or a portable audio device.

Moreover, although embodiment mentioned above demonstrated what formed the filling part with the cover part and the recessed part formed in the base | substrate, it is not limited to this, For example, you may use what is called a microcapsule as a filling part.
Further, the case where three particles of positively charged particles A, negatively charged particles B, and uncharged particles C are used has been described. However, the present invention is not limited to three particles, and the positively charged particles A and By arranging two particles of negatively charged particles B, the present invention can also be effective. By generating an electric field between the first and second pixel electrodes, one of the positively charged particles and the negatively charged particles migrates to one of the first and second pixel electrodes, and the other particle is the first. This is because it migrates to the other of the second pixel electrodes and the color of the chromatic dispersion medium 25 becomes visible through the lid 24.

  DESCRIPTION OF SYMBOLS 100 ... Electrophoretic display device, 23 ... Base | substrate, 24 ... Cover part, 25 ... Dispersion medium, 26 ... Filling part, 27 ... Recessed part, 30 ... Element substrate, 31 ... Opposite substrate, 32 ... Electrophoretic element, 33 ... Adhesive 34, circuit layer, 37 ... common electrode, 40 ... pixel, 41 ... selection transistor, 49 ... low potential power supply line, 50 ... high potential power supply line, 55 ... common electrode wiring, 61 ... scanning line drive circuit, 62 ... Data line drive circuit, 63 ... Controller, 64 ... Common power supply modulation circuit, 66 ... Scan line, 68 ... Data line, 70 ... Latch circuit, 80 ... Switch circuit, 91 ... First control line, 92 ... Second control Line, 351 ... first pixel electrode, 352 ... second pixel electrode, TG1 ... first transmission gate, TG2 ... second transmission gate, 72, 74, 82, 84 ... N-MOS transistors, 71,7 , 81,83 ... P-MOS transistor, 70f, 70t ... inverter, N1 ... data input and output terminals, N2 ... data output terminal, VH ... high-level potential, VL ... low-level potential

Claims (10)

A first pixel electrode and a second pixel electrode; a common electrode opposed to the first pixel electrode and the second pixel electrode; and the first pixel electrode, the second pixel electrode, and the common electrode. An electrophoretic display device having a plurality of pixels provided with an electrophoretic element that is sandwiched and includes positively charged particles, negatively charged particles, and non-current particles ,
Each of the plurality of pixels is
Scanning lines;
Data lines,
A first control line;
A second control line;
A pixel switching element connected to the scan line and the data line;
A memory circuit connected to the pixel switching element, storing 1-bit data input via the data line and the pixel switching element, and outputting an output signal indicating the 1-bit data;
The first control line is provided between the first control line and the second control line and the first pixel electrode and the second pixel electrode, and is based on an output signal from the memory circuit. And a switch circuit for electrical connection between the first pixel electrode and the second control line and the second pixel electrode;
Have
A first drive signal supplied to the first pixel electrode via the first control line, and a second drive signal supplied to the second pixel electrode via the second control line. A signal supply means for supplying
An electrophoretic display device. A data line driving circuit for supplying the 1-bit data to the data line;
A scanning line driving circuit for supplying a selection signal for defining an on timing of the pixel switching to the scanning line;
Comprising
During the data transfer period,
Supplying the 1-bit data to each data line by the data line driving circuit;
By supplying the selection signal to the scanning lines sequentially selected by the scanning line driving circuit, the 1-bit data is stored in the memory circuit of each pixel,
In the display period,
Supplying the first drive signal and the second drive signal to the first control line and the second control line, respectively, by the signal supply means;
The electrophoretic display device according to claim 1. In the data transfer period,
The first control line and the first pixel electrode are electrically connected to a memory circuit of a pixel whose color tone is changed by the data line driving circuit and the scanning line driving circuit, and the second control is performed. 1 bit data for electrically connecting a line and the second pixel electrode is stored, and inverted data of the 1 bit data is stored in a memory circuit of a pixel whose color tone is not changed,
In the display period,
The signal supply means supplies a first drive signal and a second drive signal that define a color tone of a pixel whose color tone is changed to the first control line and the second control line, respectively.
The electrophoretic display device according to claim 2. When displaying an image formed from multiple tones,
In the data transfer period,
The first control line and the first pixel electrode are electrically connected to a memory circuit of a pixel whose color tone is changed by the data line driving circuit and the scanning line driving circuit, and the second control is performed. 1-bit data for electrically connecting a line and the second pixel electrode is stored, and a first operation for storing inverted data of the 1-bit data in a memory circuit of a pixel whose color tone is not changed is performed. ,
In the display period,
Second operation of supplying a first drive signal and a second drive signal for defining a color tone of a pixel whose color tone is changed to the first control line and the second control line by the signal supply unit, respectively. I do,
A combination operation consisting of the first operation and the second operation is performed for each of the plurality of colors.
The electrophoretic display device according to claim 2. Each of the plurality of pixels is
A positive-side power line and a negative-side power line;
The memory circuit is a 1-input 2-output latch circuit in which a positive-side power terminal is connected to the positive-side power line and a negative-side power terminal is connected to the negative-side power line;
The switch circuit includes a first transmission gate that connects the first pixel electrode and the first control line, and a second transmission that connects the second pixel electrode and the second control line. and a gate, said first transmission gate and said second transmission gate, said by the 2 output of the latch circuit, and each of the first pixel electrode and the first control line, and the second The pixel electrode and the second control line are turned on or off for the same period,
The signal supply means performs supply of a power supply potential to the positive power supply line and the negative power supply line, and supply of a common potential to the common electrode.
The electrophoretic display device according to claim 1, wherein the electrophoretic display device is a liquid crystal display device. The electrophoretic element includes a filling portion filled with a liquid phase dispersion medium containing three kinds of particles having different colors.
The three types of particles are uncharged particles, positively charged particles, and negatively charged particles, respectively.
The electrophoretic display device according to claim 5. In the display period,
The positively charged particles or the negatively charged particles are controlled by controlling the magnitude or time of the potential supplied between one of the first pixel electrode and the second pixel electrode and the common electrode. The electrophoretic display device according to claim 6 , wherein a separation distance of the particles from the common electrode is adjusted, thereby changing a color in the filling portion visually recognized through the common electrode. A first pixel electrode and a second pixel electrode; a common electrode opposed to the first pixel electrode and the second pixel electrode; and the first pixel electrode, the second pixel electrode, and the common electrode. An electrophoretic display device having a plurality of pixels, the electrophoretic element being sandwiched and including positively charged particles, negatively charged particles, and non-current-carrying particles ,
A first step of storing 1-bit data in a memory circuit provided in each of the plurality of pixels;
By a switch circuit provided between the first control line and the second control line and the first pixel electrode and the second pixel electrode,
Based on 1-bit data stored in the memory circuit, the first control line and the first pixel electrode are electrically connected, and the second control line and the second pixel electrode are connected to each other. A second step of electrically connecting;
A first drive signal supplied to the first pixel electrode for the first control line and a second drive signal supplied to the second pixel electrode for the second control line are supplied. A third step of
A method for driving an electrophoretic display device, comprising: When displaying an image formed from multiple tones,
Performing a combination step consisting of the first step, the second step and the third step for each of the plurality of colors;
In the first step,
The first control line and the first pixel electrode are electrically connected to a memory circuit of a pixel whose color tone is to be changed, and the second control line and the second pixel electrode are electrically connected to each other. A first operation for storing 1-bit data for connection and storing inverted data of the 1-bit data in a memory circuit of a pixel whose color tone is not changed is performed.
In the third step,
Supplying a first drive signal and a second drive signal for defining a color tone of a pixel whose color tone is changed to the first control line and the second control line, respectively;
9. A method for driving an electrophoretic display device according to claim 8, wherein: An electronic apparatus characterized by including the electrophoretic display device according to any one of claims 1 to 7.

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