JP5369934B2 - Optical writing type display device, driving method thereof, and electronic apparatus - Google Patents

Description

  The present invention relates to an optical writing display device, a driving method thereof, and an electronic apparatus.

  2. Description of the Related Art Conventionally, an optical writing type display device using a modulation medium having a memory property (cholesteric liquid crystal or electrophoretic dispersion liquid) is known. For example, in Patent Document 1 below, as an optical writing display device, a connection electrode is provided between a variable resistance layer whose resistance value is changed by light irradiation and a display medium layer for performing image display via a partial pressure control layer. It is disclosed to form a multilayer electrode structure in which a drive electrode and a release electrode are laminated.

JP 2007-171260 A

  According to the optical writable display device described in Patent Document 1, it is possible to erase (reset) the entire image displayed in the display area without irradiating light. On the other hand, however, the structure is complicated because a multi-layered electrode is formed for each pixel.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an optical writing display device that can easily perform a reset operation with a relatively simple structure and a driving method thereof. One of them.

The optical writing type display device of the present invention includes a display unit in which a plurality of pixels are arranged, and the display unit includes a pixel electrode formed for each pixel, and a transistor connected to the pixel electrode, A common electrode opposed to the plurality of pixel electrodes, an electro-optic material layer having a memory property disposed between the plurality of pixel electrodes and the common electrode, and a gate of the transistor and connected directly to each other Alternatively, a plurality of scanning lines connected through an electric circuit and a plurality of data lines connected to the source of the transistor and connected to each other directly or through an electric circuit are formed, and the display A control unit that controls a unit, and the control unit inputs a first gate potential for turning on the transistor to the scanning line belonging to the display unit, and the data line A first operation for inputting a first data potential; a second operation for inputting a potential for turning off the transistor to the scanning line; and a second operation for inputting a second data potential to the data line belonging to the display portion. The second data potential is lower than the potential of the common electrode when the first data potential is higher than the potential of the common electrode, and the first data potential is Is lower than the potential of the common electrode, the potential is higher than the potential of the common electrode, and the control unit erases the display image of the display unit by the first operation, and the second operation The display portion is held in a writable state, and in the second operation, the pixel can be written by selectively leaking the transistor by light irradiation .

  According to this configuration, since a transistor is used as the pixel switching element, a simple structure can be achieved. Then, by inputting a scanning signal for turning on the transistors to the mutually connected scanning lines, and inputting an image signal for setting the electro-optic material layer to a predetermined display state to the mutually connected data lines, The entire display unit can be easily and quickly shifted to the same display state. Therefore, according to the present invention, it is possible to provide an optical writing display device that can easily perform a reset operation with a relatively simple structure.

It is also preferable to have a plurality of the display portions.
With such a configuration, images can be displayed in various forms. For example, it is possible to realize an optical writable display device capable of displaying a desired image using at least one display unit and performing handwriting input using at least one display unit.

A plurality of pixels belonging to the first display unit are arranged in the first region, and the first region is arranged in the first region. It is also preferable that a plurality of the pixels belonging to the second display unit different from the display unit are arranged.
With such a configuration, an area where handwriting input or the like is possible is formed in the other part (second display part) while using a part of the display part (first display part) as an image display area. can do.

The first display unit and the second display unit, wherein the pixel belonging to the first display unit and the pixel belonging to the second display unit are the scanning line or the data line It is also preferable that they are arranged alternately along the extending direction.
With such a configuration, a display unit in which pixels belonging to the first display unit and pixels belonging to the second display unit are mixed is used. Therefore, for example, a desired image is formed by the pixels belonging to the first display unit. And an overwriting function by handwriting input or the like can be realized by pixels belonging to the second display portion.

A control unit configured to control the display unit, wherein the control unit inputs a first gate potential for turning on the transistor to the scanning line belonging to the display unit, and the first data is input to the data line; A first operation for inputting a potential and a second operation for inputting a second data potential to the data line belonging to the display portion are executed, and the second data potential is the first data When the potential is higher than the potential of the common electrode, the potential is lower than the potential of the common electrode. When the first data potential is lower than the potential of the common electrode, the potential is higher than the potential of the common electrode. A configuration is also preferable.
Specifically, the display image on the display unit is erased by the first operation, and the display unit is held in a writable state by the second operation. According to this configuration, the reset operation of the display unit can be easily performed by the first operation. In the second operation, the polarity of the potential difference with respect to the common electrode is opposite to that in the first operation. It is possible to make the display portion writable only by inputting the second data potential.
In the optical writing display device having the above structure, the first gate potential for turning on the transistor is input to the scanning line and the first data line is input to the data line during the period when the image of the display portion is erased. When the first data potential is higher than the potential of the common electrode with respect to the data line during a period in which the data potential is input and the display portion is held in a writable state, the common electrode When the first data potential is lower than the potential of the common electrode, the second data potential that is higher than the potential of the common electrode is input.

The control unit may perform a third operation of inputting a third potential that is substantially the same potential as the common electrode to the data line belonging to the display unit after the first or second operation. preferable. Specifically, the display unit is held in a rewrite prohibited state by the third operation.
According to this configuration, after an image is displayed on the display unit in the second operation, it is possible to prevent unintended writing due to incident external light or the like, and it is possible to stably maintain the display state of the image. .
The optical writing display device having the above configuration is specified as a third potential that is substantially the same potential as the common electrode being input to the data line during a period in which the display portion is held in a rewrite prohibition state. .

The driving method of the optical writing type display device of the present invention includes a display unit in which a plurality of pixels are arranged, and the display unit is connected to the pixel electrode formed for each pixel and the pixel electrode. A transistor, a common electrode facing the plurality of pixel electrodes, an electro-optic material layer having a memory property disposed between the plurality of pixel electrodes and the common electrode, and a gate of the transistor A method of driving an optical writing display device comprising: a plurality of scanning lines directly connected to each other; and a plurality of data lines connected to the sources of the transistors and directly connected to each other. An image erasing step of inputting a first gate potential for turning on the transistor to the scanning line belonging to the display unit and inputting a first data potential to the data line Inputs the potential of said transistor in an off state to the scan lines, the the data line belonging to the display unit, the potential of the first of said common electrode when the data potential is higher than the potential of the common electrode a lower potential, have a, an image writing step of inputting a second data potential is higher than the potential of the common electrode when said first data potential is lower than the potential of the common electrode In the image writing step, the pixel is writable by selectively leaking the transistor by light irradiation .
According to this driving method, the reset operation of the display unit can be easily executed in the image erasing step. In the image writing step, the image can be written on the display unit by a simple operation of inputting a second data potential, which is opposite in polarity to the common electrode potential, from the first data potential to the data line. It can be in a state.

It is preferable that an image holding step of inputting a third potential that is substantially the same potential as the common electrode to the data line belonging to the display portion.
According to this driving method, after an image is displayed on the display unit, it is possible to prevent unintended writing due to incident external light or the like, and it is possible to stably maintain the display state of the image.

The first display unit and the second display unit, and in the image writing step, the second data potential is input to the data line belonging to the second display unit, It is also preferable to input a third data potential that is substantially the same potential as the common electrode to the data line belonging to the first display portion.
According to this driving method, when the first and second display units are provided, the second display unit can be in a writable state while the first display unit can be in a write-inhibited state. . Thereby, the area | region which hold | maintains the displayed image and the area | region which enables handwritten input etc. can be formed.

An electronic apparatus according to the present invention includes the above-described optical writing display device.
According to this configuration, it is possible to provide an electronic apparatus including a display unit including an optical writing type display device that is excellent in functionality and manufacturability.

1 is a circuit configuration diagram of an electrophoretic display device according to a first embodiment. FIG. The top view of an electrophoretic display device, sectional drawing, sectional drawing of a microcapsule. The top view and sectional drawing of the element substrate in 1 pixel. Operation | movement explanatory drawing of an electrophoretic element. The flowchart which shows the drive method which concerns on 1st Embodiment. The timing chart which shows the drive method which concerns on 1st Embodiment. FIG. 3 is a diagram illustrating two pixels that are targets for explanation of the driving method according to the first embodiment. FIG. 3 is a diagram illustrating two pixels that are targets for explanation in the driving method according to the first embodiment. Explanatory drawing of the image writing apparatus in the drive method which concerns on 1st Embodiment. The top view and operation explanatory drawing of the electrophoretic display apparatus which concern on a 1st modification. The circuit block diagram of the electrophoretic display device which concerns on 2nd Embodiment. The top view and operation | movement explanatory drawing of the electrophoretic display device of 2nd Embodiment. The flowchart which shows the drive method which concerns on 2nd Embodiment. The circuit block diagram of the electrophoretic display device which concerns on 3rd Embodiment. The top view and operation | movement explanatory drawing of the electrophoretic display device of 3rd Embodiment. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device.

The optical writing display device of the present invention will be described below with reference to the drawings.
The scope of the present invention is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

(First embodiment)
FIG. 1 is a circuit configuration diagram of an electrophoretic display device which is a first embodiment of the optical writing type display device of the present invention.
The electrophoretic display device 100 includes a display unit 5 in which a plurality of pixels 40 are arranged in a matrix. In the display unit 5, m scanning lines 66 (Y1, Y2, ..., Yi, ..., Ym) and n data lines 68 (X1, X2, ..., Xj, ..., Xn) cross each other. The pixels 40 are provided corresponding to the intersections between the scanning lines 66 and the data lines 68.

Around the display unit 5, connection wiring 66 a that connects ends of the plurality of scanning lines 66 extending from the display unit 5 and ends of the plurality of data lines 68 extended from the display unit 5 are connected. The connection wiring 68a for connecting the two and the connection terminals 6, 7, and 8 are formed.
The connection terminal 6 is connected to the connection wiring 66a, and is connected to all the scanning lines 66 of the display unit 5 through the connection wiring 66a. The connection terminal 8 is connected to the connection wiring 68a and is connected to all the data lines 68 of the display unit 5 through the connection wiring 68a. The connection terminal 7 is connected to a common electrode 37 formed as an electrode common to the plurality of pixels 40.

Each pixel 40 of the display unit 5 is provided with a selection transistor 41, a pixel electrode 35, an electrophoretic element 32 (electro-optical material layer), and a common electrode 37.
The selection transistor 41 is a pixel switching element made of, for example, NMOS (Negative Metal Oxide Semiconductor) -TFT (Thin Film 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 pixel electrode 35.

Next, FIG. 2A is a plan view of the electrophoretic display device 100, and FIG. 2B is a partial cross-sectional view of the electrophoretic display device 100 in the display unit 5.
As shown in FIG. 2A, the display unit 5 is formed in a region where the element substrate 30 and the counter substrate 31 overlap in plan view, and in a region on the element substrate 30 protruding outside the counter substrate 31, A connection wiring 66 a connected to the scanning line 66 extending from the display unit 5 and a connection wiring 68 a connected to the data line 68 are formed. The connection wirings 66 a and 68 a are respectively connected to connection terminals 6 and 8 formed at one corner of the element substrate 30. The connection terminal 7 formed between the connection terminals 6 and 8 is connected via the connection wiring 67 formed on the element substrate 30 and the inter-substrate connection portion 9 that electrically connects the element substrate 30 and the counter substrate 31. The common electrode 37 is connected.

As shown in FIG. 2B, the electrophoretic display device 100 is an electric device in which a plurality of microcapsules 20 are arranged between an element substrate (first substrate) 30 and a counter substrate (second substrate) 31. The electrophoretic element 32 is sandwiched.
In the display unit 5, a circuit layer 34 in which a scanning line 66, a data line 68, a selection transistor 41 and the like are formed is provided on the electrophoretic element 32 side of the element substrate 30, and a plurality of pixels are provided on the circuit layer 34. The electrodes 35 are 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. The pixel electrode 35 has a voltage applied to an electrophoretic element 32 formed by laminating nickel plating and gold plating on a Cu (copper) foil in this order, Al (aluminum), ITO (indium tin oxide), or the like. Is an electrode to which is applied.

Here, FIG. 3A is a plan view of the element substrate 30 in one pixel 40, and FIG. 3B is a cross-sectional view at a position along the line AA ′ in FIG.
As shown in FIG. 3A, the select transistor 41 connects the semiconductor layer 41a having a substantially rectangular shape in plan view, the source electrode 41c extending from the data line 68, and the semiconductor layer 41a and the pixel electrode 35. A drain electrode 41d and a gate electrode 41e extending from the scanning line 66 are included.

  3B, the gate electrode 41e (scanning line 66) made of Al or Al alloy is formed on the element substrate 30, and the gate electrode 41e is covered with silicon oxide or silicon. A gate insulating film 41b made of nitride is formed. A semiconductor layer 41a made of amorphous silicon or polysilicon is formed in a region facing the gate electrode 41e via the gate insulating film 41b. A source electrode 41c and a drain electrode 41d made of Al or an Al alloy are formed so as to partially run over the semiconductor layer 41a. An interlayer insulating film 34a made of silicon oxide or silicon nitride is formed to cover the source electrode 41c (data line 68), the drain electrode 41d, the semiconductor layer 41a, and the gate insulating film 41b. A pixel electrode 35 is formed on the interlayer insulating film 34a. The pixel electrode 35 and the drain electrode 41d are connected through a contact hole 34b that passes through the interlayer insulating film 34a and reaches the drain electrode 41d.

Returning to FIG. 2B, a planar common electrode 37 facing the pixel electrodes 35 is formed on the counter substrate 31 on the electrophoretic element 32 side, and the electrophoretic element 32 is formed on the common electrode 37. Is provided.
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. The common electrode 37 is an electrode for applying a voltage to the electrophoretic element 32 together with the pixel electrode 35, and is formed of MgAg (magnesium silver), ITO (indium tin oxide), IZO (indium zinc oxide) or the like. It is a transparent electrode.
The electrophoretic element 32 and the pixel electrode 35 are bonded via the adhesive layer 33, so that the element substrate 30 and the counter substrate 31 are bonded.

  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. And the display part 5 is formed by sticking the said electrophoretic sheet which peeled the release sheet with respect to the element board | substrate 30 (The pixel electrode 35, various circuits, etc.) which were manufactured separately. For this reason, the adhesive layer 33 exists only on the pixel electrode 35 side.

  FIG. 2C is a schematic cross-sectional view of the microcapsule 20. The microcapsule 20 has a particle size of, for example, about 50 μm and encloses therein a dispersion medium 21, a plurality of white particles (electrophoretic particles) 27, and a plurality of black particles (electrophoretic particles) 26. It is a spherical body. As shown in FIG. 2B, the microcapsule 20 is sandwiched between the common electrode 37 and the pixel electrode 35, and one or a plurality of microcapsules 20 are arranged in one pixel 40. One microcapsule 20 may be arranged over a plurality of pixels 40.

The outer shell portion (wall film) of the microcapsule 20 is formed using a translucent polymer resin such as an acrylic resin such as polymethyl methacrylate or polyethyl methacrylate, a urea resin, or gum arabic.
The dispersion medium 21 is a liquid that disperses the white particles 27 and the black particles 26 in the microcapsules 20. Examples of the dispersion medium 21 include water, alcohol solvents (methanol, ethanol, isopropanol, butanol, octanol, methyl cellosolve, etc.), esters (ethyl acetate, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). ), Aliphatic hydrocarbons (pentane, hexane, octane, etc.), alicyclic hydrocarbons (cyclohexane, methylcyclohexane, etc.), aromatic hydrocarbons (benzene, toluene, benzenes having a long-chain alkyl group ( Xylene, hexylbenzene, hebutylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, tetradecylbenzene)), halogenated hydrocarbons (methylene chloride, chloroform, tetrachloride) Element, and 1,2-dichloroethane), can be exemplified a carboxylate, it may be other oils. These substances can be used alone or as a mixture, and a surfactant or the like may be further blended.

The white particles 27 are particles (polymer or colloid) made of a white pigment such as titanium dioxide, zinc white, and antimony trioxide, and are used, for example, by being negatively charged. The black particles 26 are particles (polymer or colloid) made of a black pigment such as aniline black or carbon black, and are used by being charged positively, for example.
These pigments include electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, compound charge control agents, titanium-based coupling agents, aluminum-based coupling agents, silanes as necessary. A dispersant such as a system coupling agent, a lubricant, a stabilizer, and the like can be added.
Further, instead of the black particles 26 and the white particles 27, for example, pigments such as red, green, and blue may be used. According to such a configuration, red, green, blue, or the like can be displayed on the display unit 5.

FIG. 4 is an operation explanatory diagram of the electrophoretic element. 4A shows a case where the pixel 40 displays white, and FIG. 4B shows a case where the pixel 40 displays black.
In the case of white display shown in FIG. 4A, the common electrode 37 is held at a relatively high potential and the pixel electrode 35 is held at a relatively low potential. As a result, the negatively charged white particles 27 are attracted to the common electrode 37, while the positively charged black particles 26 are attracted to the pixel electrode 35. As a result, when this pixel is viewed from the common electrode 37 side which is the display surface side, white (W) is recognized.
In the case of black display shown in FIG. 4B, the common electrode 37 is held at a relatively low potential, and the pixel electrode 35 is held at a relatively high potential. As a result, the positively charged black particles 26 are attracted to the common electrode 37, while the negatively charged white particles 27 are attracted to the pixel electrode 35. As a result, when this pixel is viewed from the common electrode 37 side, black (B) is recognized.
FIG. 4 is an operation explanatory diagram when black particles are positively charged and white particles are negatively charged. However, if necessary, black particles may be negatively charged and white particles may be positively charged. Good. In this case, when a potential is supplied in the same manner as described above, a display in which white display and black display are reversed can be obtained.

[Driving method]
Next, a driving method of the electrophoretic display device of this embodiment will be described with reference to FIGS.
FIG. 5 is a flowchart showing a series of operations when an image is displayed on the electrophoretic display device 100. FIG. 6 is a timing chart corresponding to FIG. 7 and 8 are explanatory diagrams showing potential states of two pixels in each step of the driving method of the present embodiment. FIG. 9 is a diagram showing an image writing apparatus used for carrying out the driving method of the present embodiment.

FIG. 5 shows a flow when the pixel 40A shown in FIGS. 7 and 8 is displayed in black and 40B is displayed in white. In FIG. 6, the potential Vg of the scanning line 66 input via the connection terminal 6, the potential Vs of the data line 68 input via the connection terminal 8, and the common electrode input via the connection terminal 7. 37, the potential Va of the pixel electrode 35A belonging to the pixel 40A, and the potential Vb of the pixel electrode 35B belonging to the pixel 40B are shown.
7 and 8, the subscripts “A” and “B” in each symbol are used to clearly distinguish the two pixels 40 (40A and 40B) that are the objects of the description and the constituent elements belonging to them. There is no other intention.

  An image writing device 200 shown in FIG. 9 includes a light source device 210, a controller 220 (control unit), and an image mask 230. The controller 220 is provided with a plurality of connection terminals 221 respectively connected to the connection terminals 6 to 8 provided in the electrophoretic display device 100, and is configured to be able to supply a predetermined potential to the connection terminals 6 to 8. ing. In addition, the controller 220 drives and controls the light source device 210, irradiates the image mask 230 with the light LT emitted from the light source device 210, and uses the light LT that has passed through the opening 230 a of the image mask 230. The display unit 5 is irradiated.

  The image mask 230 may be one in which an opening 230a corresponding to an image is formed on a light-shielding substrate, and is an apparatus capable of electrically controlling transmission / blocking of light, such as a liquid crystal device. Also good. Furthermore, the pattern of the light LT formed by the image mask 230 may be reduced or enlarged to irradiate the electrophoretic display device 100.

As shown in FIG. 5, the driving method of the present embodiment includes an image erasing step S101 (first operation), an image writing step S102 (second operation), and an image holding step S103.
First, in the display unit 5 before the image erasing step S101, as shown in FIG. 7A, the pixel 40A is displayed in black and the pixel 40B is displayed in white. Since the connection terminals 6 to 8 are not connected to connection terminals of external devices, the pixel electrodes 35A and 35B and the common electrode 37 are all in a high impedance state (Hi-Z) in which they are electrically disconnected.

  Next, when executing the image erasing step S101 and the image writing step S102, the electrophoretic display device 100 is set in the image writing device 200 as shown in FIG. Specifically, the display unit 5 of the electrophoretic display device 100 and the image mask 230 are arranged to face each other, and the connection terminals 221 corresponding to the image writing device 200 are connected to the connection terminals 6 to 8 of the element substrate 30. Are connected to each other.

Then, when proceeding to the image erasing step S101, a high level (for example, 12V) that turns on the selection transistor 41 to the scanning line 66 (potential Vg) from the controller 220 of the image writing device 200 via the connection terminals 6-8. And the low level potential VL (for example, −10 V; first data potential) is input to the data line 68 (potential Vs). In addition, the ground potential GND (0 V) is input to the common electrode 37 (potential Vcom).
In the image erasing step S101, the light source device 210 is in an off state, and the light LT is not irradiated to the electrophoretic display device 100.

  Then, as shown in FIG. 7B, the selection transistors 41A and 41B are turned on by the high-level scanning signal input to the scanning line 66, and the low-level potential VL of the data line 68 is applied to the pixel electrodes 35A and 35B. Entered. Then, the electrophoretic element 32 is driven by the potential difference between the pixel electrodes 35A and 35B having the low level potential VL and the common electrode 37 having the ground potential GND, and both the pixels 40A and 40B are displayed in white (FIG. 4 ( a)). In the electrophoretic display device 100 of the present embodiment, all the scanning lines 66 of the display unit 5 are connected to each other via the connection wiring 66a, and all the data lines 68 are connected to each other via the connection wiring 68a. Thus, by the above operation, all the pixels 40 of the display unit 5 are displayed in white, and the entire surface of the display unit 5 is erased.

  In the image erasing step S101, it is only necessary to shift all the pixels 40 of the display unit 5 to a single gradation, and a specific driving method can be changed within a range in which such an object can be achieved. For example, although the potential Vcom of the common electrode 37 is the ground potential GND (0 V) in the above, it may be a high level potential VH (for example, 10 V).

Next, in the image writing step S102, a low level (for example, −12 V) potential is input from the controller 220 to the scanning line 66 (potential Vg) via the connection terminals 6 to 8, and the data line 68 (potential). A high level potential VH (for example, 10 V; second data potential) is input to Vs), and a ground potential GND (0 V) is input to the common electrode 37 (potential Vcom).
In the state shown in FIG. 7C, the scanning line 66 is at the low level, and the selection transistors 41A and 41B are in the off state. Since the potential relationship between the pixel electrodes 35A and 35B in the high impedance state and the common electrode 37 is the same as that in the image erasing step S101, the display state of the display unit 5 does not change.

If the electrophoretic display device 100 is held in the voltage application state, the light source device 210 is turned on by the controller 220, and the light LT emitted from the light source device 210 is transmitted through the image mask 230 to the electrophoretic display device. 100 is irradiated. In the example shown in FIG. 8A, the pixel 40A is irradiated with the light LT emitted from the image writing device 200, while the pixel 40B is not irradiated with the light LT. Then, a leak current is generated only in the selection transistor 41A of the pixel 40A irradiated with light, and a current flows from the data line 68 held at the high level potential VH to the pixel electrode 35A.
As a result, the potential of the pixel electrode 35A rises as shown in FIG. 6, and a potential difference is generated between the pixel electrode 35A and the common electrode 37 held at the ground potential GND. The electrophoretic element 32 is driven by the potential difference, and the pixel 40A shifts to black display (see FIG. 4B).
In this way, only the pixels 40 irradiated with the light LT among the pixels 40 of the display unit 5 are selectively shifted to black display, and a predetermined image is written on the display unit 5.

In the present embodiment, the potential Vcom of the common electrode 37 is held at the ground potential GND in the image writing step S102, but may be held at a low level potential VL (for example, −10 V). Even in this case, when the potential Va of the pixel electrode 35A belonging to the pixel 40A irradiated with light becomes higher than the potential Vcom of the common electrode 37, the pixel 40A changes to black display.
Further, the second data potential is selected so as to have a polarity opposite to that of the first data potential with respect to the potential Vcom of the common electrode 37. Alternatively, the second data potential is lower than the potential Vcom when the first data potential is higher than the potential Vcom of the common electrode 37, and is higher than the potential Vcom when the first data potential is lower than the potential Vcom. Set to potential.

Next, when proceeding to the image holding step S103, as shown in FIG. 8B and FIG. 6, the data line 68 (potential Vs) and the common electrode 37 (potential Vcom) are connected from the controller 220 via the connection terminals 6-8. ) Is inputted with the ground potential GND.
Thus, by making the data line 68 and the common electrode 37 have the same potential, it is possible to prevent erroneous writing when the pixel 40 of the display unit 5 is irradiated with light. That is, even if light is emitted to the pixel 40 and light leakage occurs in the selection transistor 41 in the image holding step S103, the potential of the pixel electrode 35 belonging to the pixel 40 irradiated with light becomes the ground potential GND. No potential difference occurs between the common electrode 37 held at the potential GND and the display state of the electrophoretic element 32 does not change.
After the image holding step S103, the electrophoretic display device 100 is detached from the image writing device 200, and the connection terminals 6 to 8 are disconnected from the connection terminal 221. As a result, the scanning line 66, the data line 68, and the common electrode 37 are set in a high impedance state, and the image displayed on the display unit 5 is held.

  In the image holding step S103, the data line 68 and the common electrode 37 do not necessarily have the same potential. Specifically, the potentials Vs and Vcom may be set so that the potential difference between the potential Vs of the data line 68 and the potential Vcom of the common electrode 37 is equal to or lower than the threshold voltage of the electrophoretic element 32. Here, there is a case where there is no clear threshold voltage, but it may be set to a voltage that does not substantially affect the optical characteristics. In such a range, even if the pixel 40 is irradiated with light and the potential Vs of the data line 68 is input to the pixel electrode 35, the potential difference between the pixel electrode 35 and the common electrode 37 is the same as that of the electrophoretic element 32. The display voltage of the pixel 40 does not change because the voltage is lower than the threshold voltage.

  As described above in detail, the electrophoretic display device 100 of the present embodiment can use the same electrode structure as that of the active matrix liquid crystal device, so that the structure can be simplified and the productivity can be improved. It is excellent and advantageous in terms of cost. Further, the entire display unit 5 can be shifted to a single gradation only by inputting a predetermined potential via the connection wirings 66a and 68a, and the reset operation can be executed easily and quickly.

[First Modification]
In the electrophoretic display device 100 of the above-described embodiment, the image writing is performed using the image writing device 200 including the image mask 230. However, handwriting input using an optical pen is performed on the electrophoretic display device 100. Can also be done.

FIG. 10A is a plan view of an electrophoretic display device 100A having a configuration suitable for handwriting input, and FIG. 10B is a schematic diagram illustrating a handwriting input operation.
The electrophoretic display device 100A shown in FIG. 10A is common to the electrophoretic display device 100 according to the first embodiment in its basic configuration, while the controller 63 is connected to the connection terminals 6 to 8 on the element substrate 30. The difference is that the (control unit) is implemented.

  In the electrophoretic display device 100A, the controller 63 executes each of the image erasing step S101, the image writing step S102, and the image holding step S103 shown in FIG. That is, the controller 63 inputs a predetermined potential to the scanning line 66 (connection wiring 66a), the common electrode 37, and the data line 68 (connection wiring 68a) via the connection terminals 6 to 8 in each of steps S101 to S103. The display unit 5 is controlled.

More specifically, the controller 63 starts an image display operation on the display unit 5 in response to a signal input from a host device (not shown). When the image display operation is started, first, an image erasing step S101 is executed, the entire surface of the display unit 5 is displayed in white, and the previously displayed image is erased.
Thereafter, when the image writing step S102 is entered, the controller 63 inputs the high level potential VH to the data line 68 and also inputs the ground potential GND to the common electrode 37, so that the display unit 5 can be written with the light pen 250. To a different state. Then, when the display unit 5 held in a writable state is scanned by the light pen 250 that emits the light LT from the tip, only the pixels 40 irradiated with the light selectively shift to black display, An image corresponding to the locus of the light pen 250 is displayed on the display unit 5.

  Thereafter, after a lapse of a predetermined time from the start of the image writing step S102, or the signal input from the host device, the process proceeds to the image holding step S103. Then, the controller 63 holds the data line 68 and the common electrode 37 at substantially the same potential, and thereby unintentional writing may be performed due to incidence of external light on the display unit 5 or erroneous input of the light pen 250. Is prevented.

  In the first modified example, the potential input to the common electrode 37 in the image erasing step S101 may be the high level potential VH. Further, the low level potential VL may be inputted to the common electrode 37 in the image writing step S102. In the image holding step S103, the data line 68 and the common electrode 37 may have different potentials within a range where the potential difference between them is equal to or less than the threshold voltage of the electrophoretic element 32.

Further, in the electrophoretic display device 100A, a mechanism for determining whether the light pen 250 is in contact with or close to the electrophoretic display device 100A may be provided. For example, a touch panel may be provided on the outer surface side of the counter substrate 31, or a piezoelectric sensor or an optical sensor may be provided on the counter substrate 31 or the element substrate 30.
By providing such a mechanism, when the light pen 250 is not in contact with or approaching the electrophoretic display device 100A, the ground potential GND (0 V) is input to the data line 68, and the light pen 250 has contacted or approached. Only when the data line 68 can be driven to input the high-level potential VH. With such a driving method, writing can be performed with the optical pen 250 when necessary, and malfunction (unintentional writing) due to incidence of external light or the like can be prevented.

  Further, the electrophoretic display device 100A has a configuration suitable for handwritten input by the optical pen 250, but image writing by the image writing device 200 shown in FIG. 9 is also possible. In this case, the electrophoretic display device 100 </ b> A in which the display unit 5 can write an image by the controller 63 is set in the image writing device 200, and the display unit 5 is irradiated with light LT via the image mask 230. The image corresponding to the image mask 230 can be written in the electrophoretic display device 100A.

  Furthermore, although the electrophoretic display device 100A has been described as a configuration suitable for handwriting input using the optical pen 250, handwriting input using the optical pen is also performed in the electrophoretic display device 100 according to the first embodiment. Is possible. In this case, an external controller is connected to the connection terminals 6 to 8 of the electrophoretic display device 100, and the predetermined potential in the image writing step S102 is input from the external controller.

[Second Modification]
In the above-described embodiment, the image is erased by displaying the entire display unit 5 in white in the image erasing step S101, and the image is displayed by displaying some pixels 40 of the display unit 5 in black in the image writing step S102. However, a white image component may be displayed on a black background. A driving method in this case will be described below.

First, in the image erasing step S101, a high-level (for example, 12 V) potential that turns on the selection transistor 41 on the scanning line 66 (potential Vg) from the controller 220 of the image writing device 200 via the connection terminals 6-8. And a high level potential VH (for example, 10 V) is input to the data line 68 (potential Vs). In addition, the ground potential GND (0 V) is input to the common electrode 37 (potential Vcom).
As a result, the pixel electrode 35 has a relatively high potential and the common electrode 37 has a relatively low potential, and the entire display unit 5 is displayed in black (see FIG. 4B). Note that a low level potential VL (for example, −10 V) may be input to the common electrode 37.

Next, in the image writing step S102, a low level (for example, −12 V) potential is input from the controller 220 to the scanning line 66 (potential Vg) via the connection terminals 6 to 8, and the data line 68 (potential Vs). The low level potential VL (for example, −10 V) is input to the common electrode 37 (potential Vcom), and the ground potential GND (0 V) is input to the common electrode 37 (potential Vcom).
When the light LT is irradiated to the pixel 40 held in the above-described potential state, a leakage current is generated in the selection transistor 41 irradiated with the light, and the potential of the pixel electrode 35 is decreased. As a result, when the pixel electrode 35 has a relatively low potential and the common electrode 37 has a relatively high potential, the pixel 40 shifts to white display. As a result, the display unit 5 is in a state where a white image component (a region irradiated with light) is displayed on a black background.
In the image writing step S102, the high level potential VH may be input to the common electrode 37.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 11 is a circuit configuration diagram of the electrophoretic display device according to the second embodiment, and FIG. 12 is an operation explanatory diagram of the electrophoretic display device according to the second embodiment.
In each drawing referred to below, the same reference numerals are given to the same components as those in the first embodiment and the modifications thereof, and detailed description thereof will be omitted.

As shown in FIG. 11, the electrophoretic display device 300 of this embodiment includes a first display unit 5A and a second display unit 5B.
In the first display portion 5A, m1 scanning lines 66 and n1 data lines 68 are formed, and pixels 40 are provided corresponding to the intersections of the scanning lines 66 and the data lines 68. ing. Accordingly, the pixels 40 are arranged in a matrix of m1 rows × n1 columns. All the scanning lines 66 formed in the first display portion 5A are connected to the connection terminal 6 through the connection wiring 66a, and all the data lines 68 are connected to the connection terminal 8 through the connection wiring 68a. A common electrode 37 is connected to the connection terminal 7 provided in the vicinity of the connection terminals 6 and 8.

  On the other hand, m2 scanning lines 366 and n2 data lines 368 are formed in the second display portion 5B, and the pixels 340 correspond to the intersections of the scanning lines 366 and the data lines 368. Is provided. Accordingly, the pixels 340 are arranged in a matrix of m2 rows × n2 columns. All the scanning lines 366 formed in the second display portion 5B are connected to the connection terminal 306 through the connection wiring 366a, and all the data lines 368 are connected to the connection terminal 308 through the connection wiring 368a. The pixel 340 has the same configuration as that of the pixel 40 of the first display section 5A, and includes a selection transistor 41, a pixel electrode 35, an electrophoretic element 32, and a common electrode 37.

In the electrophoretic display device 300 of this embodiment, the number m1 of the scanning lines 66 and the number n1 of the data lines 68, the number m2 of the scanning lines 366, and the number n2 of the data lines 368 can be set to arbitrary natural numbers. . That is, the first display unit 5A and the second display unit 5B can be configured by an arbitrary number of pixels 40 and 340, respectively.
Further, the definition of the pixels 40 and 340 may be different between the first display unit 5A and the second display unit 5B. For example, the first display unit 5A has fineness (for example, about 300 to 600 ppi) suitable for displaying characters and images, and the second display unit 5B has fineness (for example, about 50 to 100 ppi) suitable for handwriting input. Also good.
Furthermore, the outer shape of the first display unit 5A and the second display unit 5B is not limited to a rectangular shape, but may be an arbitrary planar shape such as a triangular shape, a pentagonal or higher polygonal shape, a circular shape, or an elliptical shape. Can do.

FIG. 12A is a plan view illustrating a schematic configuration of the electrophoretic display device 300.
The electrophoretic display device 300 includes an element substrate 330 and a counter substrate 31, and the first display unit 5A and the second display unit 5B are disposed in a region where the element substrate 330 and the counter substrate 31 overlap in plan view. Is formed. A controller 363 (control unit) is mounted on a region of the element substrate 330 that protrudes from the counter substrate 31. The controller 363 is connected to the connection terminals 6 to 8 and the connection terminals 306 and 308 shown in FIG.

  The element substrate 330 has the same configuration as the element substrate 30 except that the element substrate 330 includes a first display unit 5A and a second display unit 5B corresponding to the display unit 5 of the element substrate 30 according to the first embodiment. The controller 363 is configured to be able to supply a predetermined potential to the connection terminals 6 to 8 and the connection terminals 306 and 308.

[Driving method]
Next, a driving method of the electrophoretic display device 300 of this embodiment will be described.
FIG. 13 is a flowchart illustrating an example of a driving method of the electrophoretic display device of the present embodiment.
As shown in FIG. 13, the driving method according to the present embodiment includes a first image erasing step S201, a first image writing step S202, a first image holding step S203, and a second image erasing step S204. And a second image writing step S205 and a second image holding step S206.

In the first image erasing step S201 to the first image holding step S203, for example, character information TXT as shown in FIG. 12A is written to the first display unit 5A.
First, in the first image holding step S201, a high-level potential that turns on the selection transistor 41 is input from the controller 363 to all the scanning lines 66 of the first display unit 5A via the connection terminal 6. The low level potential VL (for example, −10 V) for displaying the electrophoretic element 32 in white is input to all the data lines 68 via the connection terminals 8. In addition, the ground potential GND (0 V) is input to the common electrode 37 via the connection terminal 7. Thereby, the entire surface of the first display portion 5A is displayed in white and is in an erased state.

  Next, in the first image writing step S202, the electrophoretic display device 300 is set in the image writing device 200 shown in FIG. At this time, the image mask 230 on which the pattern corresponding to the character information TXT shown in FIG. 12 is formed and the first display portion 5A of the electrophoretic display device 300 are aligned and arranged. However, since the electrophoretic display device 300 includes the controller 363, the connection terminal 221 of the image writing device 200 is not connected to the electrophoretic display device 300.

  Thereafter, a low level potential for turning off the selection transistor 41 is input to the scanning line 66 from the controller 363 via the connection terminals 6 to 8, and a high level potential VH (for example, 10 V) is input to the data line 68. The ground potential GND (0 V) is input to the common electrode 37 (potential Vcom). As a result, the first display section 5A is in a state in which an image can be written.

  When the first display unit 5A is held in the voltage application state, the light source device 210 of the image writing device 200 is operated, and the light LT is transmitted to the first display unit 5A via the image mask 230. Irradiate. Thereby, a leakage current is generated in the selection transistor 41 in the pixel 40 irradiated with the light LT, and the potential of the pixel electrode 35 is increased. As a result, the pixels 40 irradiated with light are selectively shifted to black display, and an image corresponding to the image mask 230 is displayed on the first display unit 5A.

  Thereafter, when the process proceeds to the first image holding step S203, the ground potential GND is input from the controller 363 to the data line 68 and the common electrode 37 via the connection terminals 6-8. Thereby, the change in the display state of the first display unit 5A thereafter is prevented, and the display image is held.

If the character information TXT is displayed on the first display unit 5A as described above, the mode shifts to the handwriting input mode using the optical pen. In the handwriting input mode, the second image erasing step S204 to the second image holding step S206 are repeatedly executed once or a plurality of times.
In the handwriting input mode (steps S204 to S206), the first display unit 5A holds the potential state of the image holding step S203 described above, and the display image of the first display unit 5A does not change.

  In the second image erasing step S204, a high-level potential that turns on the selection transistor 41 is input from the controller 363 via the connection terminal 306 to all the scanning lines 366 of the second display portion 5B. A low level potential VL (for example, −10 V) for displaying the electrophoretic element 32 in white is input to all the data lines 368 via the terminal 308. In addition, the ground potential GND (0 V) is input to the common electrode 37 via the connection terminal 7. As a result, the entire surface of the second display portion 5B is displayed in white and is in an erased state.

Next, in the second image writing step S205, as shown in FIG. 12B, handwritten input with the optical pen 250 is performed on the second display unit 5B of the electrophoretic display device 300.
In the second image writing step S205, a low-level potential that turns off the selection transistor 41 is input to the scanning line 366 from the controller 363 via the connection terminals 306 and 308, and the high-level potential VH is input to the data line 368. (For example, 10V) is input. In addition, the ground potential GND (0 V) is input to the common electrode 37 (potential Vcom) via the connection terminal 7. As a result, the second display section 5B is in a state in which an image can be written.

  Then, when the optical pen 250 is brought close to the second display unit 5B held in the voltage application state as shown in FIG. 12B, the pixel 340 irradiated with the light LT of the optical pen 250. As a result, a leakage current is generated in the selection transistor 41 and the potential of the pixel electrode 35 is increased. As a result, the pixel 340 irradiated with light is selectively shifted to black display, and a black mark is written on the second display portion 5B.

  Thereafter, when the process proceeds to the second image holding step S206, the ground potential GND is input from the controller 363 to the data line 368 via the connection terminal 308, and the ground potential GND is input to the common electrode 37 via the connection terminal 7. . Thereby, also in the 2nd display part 5B, the change of a display state is prevented and the written black mark is hold | maintained.

  As described above in detail, according to the electrophoretic display device 300 of the second embodiment, the first display unit 5A and the second display unit 5B can be operated independently of each other. That is, only the second display unit 5B can be in a state where image writing is possible while fixing the display state of the first display unit 5A. Thereby, for example, horizontally written character information is displayed on the first display unit 5A, and then a check symbol or the like is added to the beginning of the line (second display unit 5B) with the optical pen 250 or the like. It can be used suitably.

  In the electrophoretic display device 300 of the present embodiment, a mechanism for determining whether the optical pen 250 is in contact with or close to the electrophoretic display device 300 may be provided. Thereby, writing can be performed with the optical pen 250 when necessary, and malfunction (unintentional writing) due to incidence of external light or the like can be prevented.

  The second display unit 5B may be provided not only at the beginning (left side in the figure) of the character information TXT displayed on the first display unit 5A but also at the end of the line (right side in the figure). Furthermore, you may provide in the one side part (upper side part) of the column direction (direction orthogonal to a row direction) of the character information TXT in the 1st display part 5A, and the other side part (lower side part).

In the above embodiment, the case has been described in which the character information TXT is displayed only on the first display unit 5A and the display state is fixed at the time of handwriting input. However, the character information and image are also displayed on the second display unit 5B. Of course, you can make it happen.
When both the first display unit 5A and the second display unit 5B are used for image display, the first display is performed in the first image erasing step S201 to the first image holding step S203 shown in FIG. By simultaneously driving the unit 5A and the second display unit 5B, an image can be easily written.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS.
FIG. 14 is a circuit configuration diagram of the electrophoretic display device according to the third embodiment, and FIG. 15 is an operation explanatory diagram of the electrophoretic display device according to the third embodiment.
In each drawing referred to below, the same reference numerals are given to the same components as those in the first embodiment, the modified example, and the second embodiment, and the detailed description thereof will be omitted.

As shown in FIG. 14, the electrophoretic display device 400 of this embodiment includes a display unit 50 in which a plurality of pixels 40 and a plurality of pixels 340 are arranged.
In the display unit 50, a plurality of scanning lines 66 and a plurality of data lines 68 are formed, and pixels 40 are provided corresponding to the intersections of the scanning lines 66 and the data lines 68. All the scanning lines 66 are connected to the connection terminal 6 through the connection wiring 66a, and all the data lines 68 are connected to the connection terminal 8 through the connection wiring 68a.
In addition, a plurality of scanning lines 366 and a plurality of data lines 368 are formed, and a pixel 340 is formed corresponding to an intersection of the scanning line 366 and the data line 368. All the scanning lines 366 are connected to the connection terminal 306 via the connection wiring 366a, and all the data lines 368 are connected to the connection terminal 308 via the connection wiring 368a.
Each of the pixels 40 and 340 includes a selection transistor 41, a pixel electrode 35, an electrophoretic element 32, and a common electrode 37.

  In the case of the present embodiment, in the display unit 50, the pixels 40 and 340 are mutually connected in the row direction (extending direction of the scanning lines 66 and 366) and the column direction (extending direction of the data lines 68 and 368). They are arranged alternately so as to be adjacent to each other. That is, the electrophoretic display device 400 of the present embodiment has a configuration in which the pixels 40 of the first display unit 5A according to the second embodiment and the pixels 340 of the second display unit 5B are mixedly arranged in a checkered pattern. I have.

FIG. 15A is a plan view showing a schematic configuration of the electrophoretic display device 400.
The electrophoretic display device 400 includes an element substrate 430 and a counter substrate 31, and the display unit 50 is formed in a region where the element substrate 430 and the counter substrate 31 overlap in plan view. A controller 363 (control unit) is mounted in a region of the element substrate 430 that protrudes beyond the counter substrate 31. The controller 363 is connected to the connection terminals 6 to 8 and the connection terminals 306 and 308 shown in FIG.
The element substrate 430 has the same configuration as the element substrate 330 according to the second embodiment except for the arrangement of the pixels 40 and the pixels 340. The controller 363 is configured to be able to supply a predetermined potential to the connection terminals 6 to 8 and the connection terminals 306 and 308, and controls a plurality of pixels 40 belonging to the display unit 50 by potential input via the connection terminals 6 and 8. In addition, the plurality of pixels 340 can be controlled by potential input through the connection terminals 306 and 308.

[Driving method]
Next, a driving method of the electrophoretic display device 400 of the present embodiment will be described.
The flowchart shown in FIG. 13 can be applied to the driving method of the electrophoretic display device 400 of the present embodiment. That is, the first image erasing step S201, the first image writing step S202, the first image holding step S203, the second image erasing step S204, the second image writing step S205, A driving method including the second image holding step S206 can be applied.

In the first image erasing step S201 to the first image holding step S203 in the present embodiment, a desired image is written in the array of the pixels 40 of the display unit 50.
Specifically, in the first image holding step S201, a high-level potential that turns on the selection transistor 41 is input from the controller 363 to all the scanning lines 66 of the display unit 50 via the connection terminal 6. A low level potential VL (for example, −10 V) for displaying the electrophoretic element 32 in white is input to all the data lines 68 via the connection terminals 8. In addition, the ground potential GND (0 V) is input to the common electrode 37 via the connection terminal 7. As a result, all the pixels 40 of the display unit 50 are displayed in white and are in an erased state.

  Next, in the first image writing step S202, the electrophoretic display device 400 is set in the image writing device 200 shown in FIG. At this time, the image mask 230 on which a pattern corresponding to the image to be displayed on the display unit 50 is formed and the display unit 50 of the electrophoretic display device 300 are aligned and arranged. However, since the electrophoretic display device 400 includes the controller 363, the connection terminal 221 of the image writing device 200 is not connected to the electrophoretic display device 400.

  Thereafter, a low level potential for turning off the selection transistor 41 is input to the scanning line 66 from the controller 363 via the connection terminals 6 to 8, and a high level potential VH (for example, 10 V) is input to the data line 68. The ground potential GND (0 V) is input to the common electrode 37 (potential Vcom). Thereby, the pixel 40 of the display unit 50 is in a state in which an image can be written.

  If the pixel 40 is maintained in the voltage application state, the light source device 210 of the image writing device 200 is operated to irradiate the display unit 50 with the light LT via the image mask 230. Thereby, a leakage current is generated in the selection transistor 41 in the pixel 40 irradiated with the light LT, and the potential of the pixel electrode 35 is increased. As a result, the pixels 40 irradiated with light are selectively shifted to black display, and an image corresponding to the image mask 230 is displayed on the display unit 50.

  Thereafter, when the process proceeds to the first image holding step S203, the ground potential GND is input from the controller 363 to the data line 68 and the common electrode 37 via the connection terminals 6-8. Thereby, the change of the display state of the pixel 40 after that is prevented, and the display image is held.

If the image comprised by the pixel 40 is displayed by the above, it will transfer to the handwriting input mode by an optical pen. In the handwriting input mode, the second image erasing step S204 to the second image holding step S206 are repeatedly executed once or a plurality of times.
In the handwriting input mode (steps S204 to S206), the pixel 40 holds the potential state of the image holding step S203 described above, and the already displayed image does not change.

  In the second image erasing step S204, a high-level potential that turns on the selection transistor 41 is input from the controller 363 to all the scanning lines 366 of the display unit 50 via the connection terminal 306. Thus, a low level potential VL (for example, −10 V) for displaying the electrophoretic element 32 in white is input to all the data lines 368. In addition, the ground potential GND (0 V) is input to the common electrode 37 via the connection terminal 7. As a result, all the pixels 340 of the display unit 50 are displayed in white and are in an erased state.

Next, in the second image writing step S205, as shown in FIG. 15B, handwritten input by the optical pen 250 is performed in the area composed of the pixels 340 in the display unit 50 of the electrophoretic display device 400. .
In the second image writing step S205, a low-level potential that turns off the selection transistor 41 is input to the scanning line 366 from the controller 363 via the connection terminals 306 and 308, and the high-level potential VH is input to the data line 368. (For example, 10V) is input. In addition, the ground potential GND (0 V) is input to the common electrode 37 (potential Vcom) via the connection terminal 7. Thereby, the pixel 340 is in a state in which an image can be written.

  When the pixel 340 is scanned with the light pen 250 as shown in FIG. 15B on the display unit 50 in which the voltage application state is maintained, the selection transistor is used in the pixel 340 irradiated with the light LT of the light pen 250. A leak current is generated at 41, and the potential of the pixel electrode 35 rises. As a result, the pixel 340 irradiated with light is selectively shifted to black display, and the image can be overwritten as shown in the figure.

  Thereafter, when the process proceeds to the second image holding step S206, the ground potential GND is input from the controller 363 to the data line 368 via the connection terminal 308, and the ground potential GND is input to the common electrode 37 via the connection terminal 7. . As a result, the display state of the image composed of the pixels 340 is also prevented from being changed, and the entered image is retained.

  As described above in detail, according to the electrophoretic display device 400 of the third embodiment, the pixels 40 and the pixels 340 are mixedly arranged in a checkered pattern. Can be displayed and handwritten input using the pixels 340 can be performed. Thereby, for example, character information or the like is displayed by the pixel 40, and it can be suitably used for an application in which a check symbol, a line segment, or the like is added with the optical pen 250 or the like.

  In the electrophoretic display device 400 of this embodiment, a mechanism for determining whether the optical pen 250 is in contact with or close to the electrophoretic display device 400 may be provided. Thereby, writing can be performed with the optical pen 250 when necessary, and malfunction (unintentional writing) due to incidence of external light or the like can be prevented.

  In the above embodiment, an image is displayed using only the pixel 40, and an image by handwriting input is displayed by the pixel 340. However, character information and an image may be displayed by both the pixel 40 and the pixel 340. Good. In this case, an image can be easily written by simultaneously driving the pixel 40 and the pixel 340 in the first image erasing step S201 to the first image holding step S203 shown in FIG. In this case, the process may move to the second image writing step S205 without executing the second image erasing step S204. In this way, in the second image writing step S205, among the pixels 340, the pixels 340 that are not used for image display in the first image erasing step S201 to the first image holding step S203 (that is, black Handwritten input can be performed on the pixel 340) that is not displayed. That is, the image written by handwriting in the second image writing step S205 is overwritten on the image written in the pixel 40 and the pixel 340 through the first image erasing step S201 to the first image holding step S203. Can do.

  Further, in the electrophoretic display device 400 of the present embodiment, the display unit 50 can be configured by an arbitrary number of pixels 40 and 340, respectively. Further, in the present embodiment, the pixels 40 and the pixels 340 are arranged in a one-to-one correspondence, but the number ratio may be different. For example, a configuration in which a number of pixels 340 about ½ to 1/10 of the number of pixels 40 is mixed in an area where a large number of pixels 40 are arranged. Further, the dimensions of the pixel 40 and the pixel 340 may be different. For example, the pixel 40 is formed to have a dimension suitable for displaying characters and images (for example, about 300 to 600 ppi), and the pixel 340 has a dimension suitable for handwriting input (for example, about 50 to 100 ppi). It may be formed.

The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention.
For example, in each of the above embodiments, the light LT is irradiated from the outer surface side of the counter substrate 31, but the light LT may be irradiated from the outer surface side of the element substrate 30 or the element substrate 330. In some cases, the light LT may be irradiated from both the outer surface side of the counter substrate 31 and the outer surface side of the element substrate 30 (330).

The configuration of the selection transistor 41 is not particularly limited, and may be a transistor using an organic semiconductor layer in addition to a configuration using amorphous silicon or polysilicon.
A TFT using amorphous silicon or polysilicon has good sensitivity to the light LT and requires less energy for optical writing. In addition, it is easy to enlarge the screen.
On the other hand, a transistor using an organic semiconductor layer can be formed at a low temperature and can be formed on a transparent member that is more flexible than glass.

Furthermore, the configuration of the pixels 40 and 340 is not particularly limited, and various configurations can be employed. For example, the pixels 40 and 340 may be provided with a storage capacitor connected in parallel to the electrophoretic element 32.
Furthermore, in each of the above embodiments, the case where the scanning lines 66, the data lines 68, the scanning lines 366, and the data lines 368 are connected to each other via the connection wirings 66a, 68a, 366a, and 368a has been described. For example, the scanning lines 66 may be connected to each other via another electric circuit. In other words, a configuration having a scanning line driving circuit that is connected to the scanning line 66 and has a function of collectively selecting all the scanning lines 66, or connected to the data line 68 and all the data lines are connected. A configuration having a data line driving circuit having a function of collectively selecting 68 is also possible.

  In each of the above embodiments, the electrophoretic display device including the electrophoretic element 32 as the electro-optical material layer has been described as an example. However, the electro-optical material layer is not limited to the electrophoretic element and has a memory property. If so, a known electro-optic material layer can be applied. For example, an electro-optical material layer composed of cholesteric liquid crystal, PDLC, electrochromic material, twisting ball, toner, or the like can be used.

(Electronics)
Next, a case where the electrophoretic display devices 100, 100A, 300, and 400 of the above embodiments are applied to an electronic device will be described.
FIG. 16 is a perspective view illustrating a configuration of the electronic paper 1100. The electronic paper 1100 includes the electrophoretic display device 100 (100A, 300, 400) of the above-described 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. 17 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 electronic paper 1100 and the electronic notebook 1200 described above, since the electrophoretic display device according to the present invention is employed, the optical writing type display unit configured to be easily reset by a simple structure is provided. Electronic equipment.
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 (optical writing display device) according to the present invention can also be suitably used for a display portion of an electronic device such as a mobile phone or a portable audio device.

  100, 100A, 300, 400 Electrophoretic display device (optical writing type display device), 5, 50 display unit, 5A first display unit, 5B second display unit, 6, 7, 8, 306, 308 connection terminal , 9 Inter-substrate connection part, 30, 330, 430 Element substrate, 31 Counter substrate, 32 Electrophoretic element (electro-optic material layer), 33 Adhesive layer, 35 Pixel electrode, 37 Common electrode, 40, 40A, 40B, 340 Pixel, 41, 41A, 41B Select transistor, 63, 363 Controller (control unit), 66, 366 Scan line, 68, 368 Data line, 66a, 68a, 366a, 368a, 67 Connection wiring, LT light

Claims (10)

A display unit in which a plurality of pixels are arranged;
In the display section,
A pixel electrode formed for each pixel, and a transistor connected to the pixel electrode;
A common electrode facing the plurality of pixel electrodes;
An electro-optic material layer having memory properties disposed between the plurality of pixel electrodes and the common electrode;
A plurality of scanning lines connected to the gates of the transistors and connected to each other directly or via an electric circuit;
A plurality of data lines connected to the source of the transistor and connected to each other directly or via an electric circuit are formed ;
A control unit for controlling the display unit;
The control unit inputs a first gate potential that turns on the transistor to the scan line belonging to the display unit, and inputs a first data potential to the data line;
Performing a second operation of inputting a potential for turning off the transistor to the scan line and inputting a second data potential to the data line belonging to the display section;
The second data potential is lower than the potential of the common electrode when the first data potential is higher than the potential of the common electrode, and the first data potential is lower than the potential of the common electrode. In this case, the potential is higher than the potential of the common electrode,
The control unit causes the display image of the display unit to be erased by the first operation, holds the display unit in a writable state by the second operation,
In the second operation, the pixel is writable by selectively leaking the transistor by light irradiation .   The optical writing display device according to claim 1, comprising a plurality of the display units. A first region and a second region partitioned in a plane;
The plurality of pixels belonging to the first display unit are arranged in the first region, while the plurality of pixels belonging to the second display unit different from the first display unit are arranged in the second region. 3. The optical writing display device according to claim 2, wherein pixels are arranged. The first display unit and the second display unit,
The pixels belonging to the first display portion and the pixels belonging to the second display portion are alternately arranged along the extending direction of the scanning line or the data line. The optical writing display device according to claim 2. After the first or second operation, the control unit performs a third operation of inputting a third potential which is substantially the same potential as the common electrode to the data line belonging to the display unit. The optical writing display device according to claim 1 , wherein the optical writing display device is a display device. The optical writing display device according to claim 5 , wherein the control unit holds the display unit in a rewrite-inhibited state by the third operation. A display unit in which a plurality of pixels are arranged is provided, and the display unit includes a pixel electrode formed for each pixel, a transistor connected to the pixel electrode, and a common electrode facing the plurality of pixel electrodes And a plurality of electro-optical material layers having memory properties arranged between the plurality of pixel electrodes and the common electrode, and a plurality of layers connected to the gate of the transistor and directly or via an electric circuit A scanning line and a plurality of data lines connected to the source of the transistor and connected to each other directly or through an electric circuit, and a method for driving an optical writing display device, comprising:
An image erasing step of inputting a first gate potential to turn on the transistor to the scanning line belonging to the display unit and inputting a first data potential to the data line;
A potential for turning off the transistor is input to the scanning line, and when the first data potential is higher than the potential of the common electrode, the potential of the common electrode is higher than the potential of the common electrode. a low potential, have a, an image writing step of inputting a second data potential is higher than the potential of the common electrode when said first data potential is lower than the potential of the common electrode,
In the image writing step, the pixel is writable by selectively leaking the transistor by light irradiation . 8. The method of driving an optical writing display device according to claim 7 , further comprising an image holding step of inputting a third potential that is substantially the same potential as the common electrode to the data line belonging to the display section. The first display unit and the second display unit;
In the image writing step,
While inputting the second data potential to the data line belonging to the second display unit,
Wherein the data line belonging to the first display unit, the optical writing type display device according to claim 7 or 8, characterized in that entering the third data potential which is the common electrode and substantially the same potential Driving method. An electronic apparatus comprising the optical writing type display device according to any one of claims 1 to 6.

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