WO2016190136A1

WO2016190136A1 - Display device

Info

Publication number: WO2016190136A1
Application number: PCT/JP2016/064327
Authority: WO
Inventors: 湯本　昭
Original assignee: ソニー株式会社
Priority date: 2015-05-26
Filing date: 2016-05-13
Publication date: 2016-12-01
Also published as: JP2016218412A

Abstract

This display device is provided with: a display element (30) having a display state that changes depending on changes in the applied voltage; a drive substrate (10) in which a thin film transistor (15) having a first gate electrode (12), a semiconductor layer (151), an electrode pair consisting of a source electrode (152A) and a drain electrode (152B) is present on each of multiple lower electrodes (17) which apply a voltage to the display element (30); and a display substrate (20) which is arranged opposite of the drive substrate (10) with the display element (30) arranged therebetween and which has an upper electrode (22), wherein the drive substrate (10) comprises a first gate electrode (12) and an insulated, elastic member (13) disposed between said first gate electrode (12) and the semiconductor layer (151).

Description

Display device

The present disclosure relates to a display device including a display element whose display state is controlled by a voltage such as an electrophoretic display (EPD).

Recently, a display device using a twisting ball method, an electrophoresis method, a magnetophoresis method or the like has been developed as a reflective image display medium capable of handwritten input. In such a device, a position input with a pen is detected by a sensor, and calculation processing is performed by the system based on the position information, and a locus of pen input is displayed on a display. In a display device having such an information processing flow, it takes time to detect position information (sensing) and arithmetic operation between pen input and display, and therefore, from the pen input to the display of the trajectory to the human eye. There is a delay.

For the purpose of improving this delay, for example, Patent Document 1 discloses an image forming apparatus in which a pressure-sensitive conductive layer is provided on the display surface side. In this image forming apparatus, an electric field is partially generated by applying pressure to the pressure-sensitive conductive layer with a pen or the like, and handwriting input and display thereof are possible without using a sensor. Further, for example, in Patent Document 2, an AC signal supply circuit and a signal receiving circuit are provided for one indicator detection sensor, and an indicator detection for detecting a position pressed by the indicator based on a change in capacitance. An apparatus is disclosed.

Japanese Patent Laid-Open No. 2002-14380 Japanese Patent Laid-Open No. 2015-57742

In the image forming apparatus of Patent Document 1, although the delay is improved, the pressure-sensitive conductive layer is relatively expensive, and the display body is also relatively expensive. There was a problem in terms of cost effectiveness in commercialization. In addition, in this image forming apparatus, since the pressure-sensitive conductive layer is disposed between the display substrate and the display element, the pressure-sensitive conductive layer is required to be transparent and have excellent optical characteristics. However, in reality, there is no pressure-sensitive conductive layer having sufficient transparency and excellent optical characteristics, and it has been difficult to realize an image forming apparatus capable of handwriting input having such a configuration. Further, the pointer detection apparatus of Patent Document 2 also has a problem in terms of cost effectiveness.

Therefore, it is desirable to provide a display device that is cost-effective and capable of handwritten input with little delay.

A first display device according to an embodiment of the present disclosure includes a first gate electrode, a display element that changes a display state according to a change in applied voltage, and a plurality of lower electrodes that apply a voltage to the display element. A drive substrate provided with a thin film transistor having a semiconductor layer, a pair of source and drain electrodes, a display substrate and a display substrate having an upper electrode, and a drive substrate, An elastic member having an insulating property is provided between the first gate electrode and the semiconductor layer.

A second display device according to an embodiment of the present disclosure includes a plurality of gate lines and a plurality of signal lines, a display element whose display state changes according to a change in applied voltage, and a plurality of voltages that apply a voltage to the display element. A driving substrate having a lower electrode, a first gate electrode, a second gate electrode, a semiconductor layer, a pair of source and drain electrodes provided on each of the plurality of lower electrodes and a supporting member, and a voltage applied to the display element A driving substrate provided with a thin film transistor having a first gate electrode and a second gate electrode, a semiconductor layer, a pair of source electrodes and a drain electrode, and a display element between each of the plurality of lower electrodes to be applied. In addition, the thin film transistor includes a support member and a display element. In addition, a semiconductor layer, a pair of source and drain electrodes, and a second gate electrode are provided in this order from the support member side, and a first gate electrode is provided on the surface of the support member opposite to the display element, The first gate electrode has an insulating elastic member between the support member and the second gate electrode is electrically connected to the gate line.

A third display device according to an embodiment of the present disclosure includes a plurality of gate lines and a plurality of signal lines, a display element that changes a display state in accordance with a change in applied voltage, and a plurality of voltages that apply a voltage to the display element. A first thin film transistor and a second gate electrode, a second semiconductor layer, a first gate electrode, a first gate electrode provided on each of the plurality of lower electrodes, a first semiconductor layer, a pair of first source electrode and drain electrode A driving substrate having a pair of second source electrode and drain electrode sharing a drain electrode of the thin film transistor, a driving substrate having a support member, and a display substrate having a display element disposed between the driving substrate and an upper electrode In the first thin film transistor, the first gate electrode is provided on the surface of the support member opposite to the display element, and the support member and the display element. A first semiconductor layer, a pair of first source electrode and drain electrode are provided in this order, and an insulating elastic member is disposed between the first gate electrode and the semiconductor layer, In the second thin film transistor, a second gate electrode, a second semiconductor layer, a pair of second source electrode and drain electrode are provided in this order from the support member side between the support member and the display element, and the second gate electrode The drain electrode is electrically connected to the signal line to the gate line.

In the first to third display devices according to an embodiment of the present disclosure, a thin film transistor having a first gate electrode, a semiconductor layer, a pair of source electrodes and a drain electrode is provided on each of a plurality of lower electrodes provided on the drive substrate side. By providing an elastic member having insulation between the first gate electrode and the semiconductor layer, switching of the display state of the pressed position, that is, handwriting input is possible without using an expensive member. Become. In addition, display can be switched from input (pressing) to display without using an input information detection system or arithmetic processing system.

According to the first to third display devices of an embodiment of the present disclosure, each of the plurality of lower electrodes provided on the drive substrate side includes the first gate electrode, the semiconductor layer, the pair of source electrodes, and the drain electrode. In addition to providing the thin film transistor, an elastic member having an insulating property is provided between the first gate electrode and the semiconductor layer. Thereby, the display state of the pressed position can be switched without using a costly member. Furthermore, display can be switched from input (pressing) to display without detecting information such as the input position and performing arithmetic processing. Therefore, it is possible to provide a display device that is cost-effective and capable of handwritten input with little delay. Note that the effects described here are not necessarily limited, and may be any effects described in the present disclosure.

3 is a cross-sectional view illustrating a configuration of a display device according to a first embodiment of the present disclosure. FIG. It is a plane schematic diagram of the electrophoretic element used for the display apparatus shown in FIG. It is a schematic diagram explaining operation | movement of the display apparatus shown in FIG. It is sectional drawing showing the structure of the display apparatus which concerns on 2nd Embodiment of this indication. It is a top view showing the whole structure of the display apparatus shown in FIG. FIG. 6 is a circuit diagram illustrating an example of a pixel drive circuit of the display device illustrated in FIG. 5. It is sectional drawing showing the structure of the display apparatus which concerns on 3rd Embodiment of this indication. FIG. 8 is a circuit diagram illustrating an example of a pixel drive circuit of the display device illustrated in FIG. 7. FIG. 8 is a circuit diagram illustrating another example of the pixel drive circuit of the display device illustrated in FIG. 7. FIG. 10 is a cross-sectional view illustrating a configuration of a display device according to a modified example of the present disclosure. It is a perspective view showing the external appearance of the tablet personal computer using the display apparatus of this indication.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The order of explanation is as follows.
1. First Embodiment (Example in which an elastic member is provided between a first gate electrode (common electrode) of a TFT electrically connected to each pixel electrode and a semiconductor layer)
1-1. Configuration of display device 1-2. Manufacturing method of display device 1-3. Preferred operation method of display device 1-4. Action / Effect Second Embodiment (Example in which a second gate electrode is provided on a semiconductor layer of a TFT electrically connected to each pixel electrode (top gate type))
3. Third Embodiment (Example in which a second gate electrode is provided below a semiconductor layer of a TFT electrically connected to each pixel electrode (bottom gate type))
4). Modification 5 Application example (electronic equipment)

<1. First Embodiment>
FIG. 1 illustrates a cross-sectional configuration of a display device (display device 1) according to a first embodiment of the present disclosure. The display device 1 is a display device capable of handwritten input, and is suitable for various electronic devices such as an electronic paper display, for example. This display device 1 includes, for example, an electrophoretic element 30 having a memory property as a display element between a drive substrate 10 and a display substrate 20 which are arranged to face each other via a spacer (not shown). is there. In the present embodiment, the display device 1 is electrically connected to the pixel electrode 17 and the pixel electrode 17 that are formed separately on the drive substrate 10 side, for example, for each pixel, and is common between the pixels. A thin film transistor 15 (TFT) having an electrode (common electrode 12) as a gate electrode is provided, and an elastic member 13 is provided between the common electrode 12 and the semiconductor layer 151.

(1-1. Configuration of display device)
In the drive substrate 10, for example, the TFT 15 and the pixel electrode 17 are stacked in this order on one surface (display surface S 1 side) of the support member 14, and the elastic member 13 is interposed on the other surface (back surface S 2 side) of the support member 14. The common electrode 12 and the support substrate 11 are stacked in this order.

The support substrate 11 is formed of, for example, one or more of inorganic materials, metal materials, plastic materials, and the like. The inorganic material is, for example, silicon (Si), silicon oxide (SiO _x ), silicon nitride (SiN _x ), aluminum oxide (AlO _x ), or the like. Examples of the silicon oxide include glass or spin-on-glass (SOG). Etc. are included. Examples of the metal material include aluminum (Al), nickel (Ni), and stainless steel. Examples of the plastic material include polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethyl ether ketone (PEEK), cycloolefin polymer (COP), polyimide (PI), and polyether sulfone (PES). Etc.

The support substrate 11 may be light transmissive or non-light transmissive. Further, the support substrate 11 may be a rigid substrate such as a wafer, or may be a flexible thin layer glass or film. However, since a flexible (foldable) electronic paper display can be realized, it is desirable to be made of a flexible material.

The common electrode 12 is a gate electrode of the TFT 15 and is formed on one surface of the support substrate 11, for example, the entire displayable region. The common electrode 12 is, for example, any one of conductive materials such as Al, Mo, ITO, Ni, Ti, Cr, Zn, C (carbon), gold (Au), silver (Ag), and copper (Cu). Or two or more types are included. The common electrode 12 may be divided and formed in a matrix by adding a configuration for supplying power to each electrode.

The elastic member 13 is provided on the common electrode 12 and has an insulating property and a property (elasticity) that returns to the original shape after unloading although it is deformed by pressing. Moreover, it is preferable that the elastic member 13 has a high dielectric constant, and specifically, it is preferable that it is comprised with the elastomer. Examples of elastomers include, for example, nitrile rubber, hydrogenated nitrile rubber, fluorine rubber, acrylic rubber, silicone rubber, urethane rubber, ethylene prohydrene rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, natural rubber, isoprene rubber , Styrene butadiene rubber, butadiene rubber, polysulfide rubber, norbornene rubber, and various thermoplastic elastomers. These may be mixed or post-treatment such as foaming or filler kneading. Among these, it is particularly preferable to use a polyurethane resin classified as a thermoplastic elastomer.

The support member 14 may be light transmissive or non-light transmissive similarly to the support substrate 11. Although details will be described later, the support member 14 is preferably a flexible thin-layer glass or film that can apply the pressure from the display surface S1 to the elastic member 13.

TFT 15 is for switching the display state of the pressed position. The TFT 15 includes a semiconductor layer 151 and a pair of source electrode 152A and drain electrode 152B provided on the elastic member 13 (more precisely, on the support member 14) using the common electrode 12 as a gate electrode. . The semiconductor layer 151 may be an inorganic TFT using an inorganic semiconductor layer or an organic TFT using an organic semiconductor layer. In the TFT 15, the first potential is applied to the source electrode 152 A, and the drain electrode 152 B is electrically connected to the pixel electrode 17. When the display surface S1 is pressed with a pen or the like, the thickness of the elastic member 13 in this portion is reduced, the common electrode 12 acts as a gate electrode, and the TFT 15 in the vicinity of the pressed position becomes conductive. As a result, a negative potential is supplied to the pixel electrode 17 and the display state of the pressed position is switched.

The insulating layer 16 is made of, for example, an insulating resin material such as polyimide.

The pixel electrode 17 is formed on the insulating layer 16 so as to be divided into a plurality of matrixes, for example. The pixel electrode 17 includes, for example, one or more of conductive materials such as Al, Mo, ITO, Ni, Ti, Cr, Zn, C, Au, Ag, and Cu. The pixel electrode 17 is connected to the TFT 15 (specifically, the drain electrode 152B) through a contact hole 16A provided in the insulating layer 16.

The display substrate 20 is provided with a counter electrode 22 on one surface of the support member 21.

The support member 21 has flexibility and is made of, for example, PET, TAC, PEN, PC, acrylic, glass, or the like. In addition, a material similar to that of the support member 14 may be used except that it is light transmissive. This is because an image is displayed on the upper surface side of the display substrate 20, and thus the support member 21 needs to be light transmissive. The thickness of the support member 21 is, for example, 10 μm to 250 μm.

The counter electrode 22 includes, for example, one or more of translucent conductive materials (transparent conductive materials). Examples of such a conductive material include indium oxide-tin oxide (ITO), antimony oxide-tin oxide (ATO), fluorine-doped tin oxide (FTO), and aluminum-doped zinc oxide (AZO). The thickness of the counter electrode 22 is, for example, 0.001 μm to 1 μm. The counter electrode 22 is formed, for example, on one surface of the support member 21, for example, the entire displayable region, as with the common electrode 12, but a configuration for supplying power to each electrode is added. Thus, similarly to the pixel electrode 12, for example, the pixel electrode 12 may be divided into a plurality of parts in a matrix.

When displaying an image on the display substrate 20 side, since the electrophoretic element 30 is viewed through the counter electrode 22, the light transmittance of the counter electrode 22 is preferably as high as possible, for example, 80% or more. It is. The electric resistance of the counter electrode 22 is preferably as low as possible, for example, 100Ω / □ (square) or less.

For example, an electrophoretic element 30 that is voltage-controlled is provided as a display element between the drive substrate 10 and the display substrate 20. The electrophoretic element 30 generates contrast using an electrophoretic phenomenon, and the electrophoretic particles 32 move between a pair of electrodes (the pixel electrode 17 and the counter electrode 22) according to a voltage. The display is switched. For example, the electrophoretic element 30 is responsible for black display and white display by the electrophoretic particles 32 colored in black and the porous layer 33 colored in white, and in the electrophoretic element (specifically, disposed oppositely). This is a so-called microcup type electrophoretic element in which columns (spacers) having a high elastic modulus are provided between the electrodes).

Hereinafter, the configuration of the electrophoretic element 30 of the present embodiment will be described. As shown in FIG. 2, the electrophoretic element 30 includes, for example, a porous layer 33 together with the electrophoretic particles 32 in the insulating liquid 31. The porous layer 33 is a three-dimensional structure formed by the fibrous structure 331 including the non-migrating particles 332, and for the migrating particles 32 to pass through the portion where the fibrous structure 331 does not exist. A plurality of gaps (pores 333) are provided. Note that FIG. 2 schematically shows the configuration of the electrophoretic element 30 and may differ from the actual size and shape.

The insulating liquid 31 is, for example, one type or two or more types of non-aqueous solvents such as an organic solvent, and specifically includes paraffin or isoparaffin. It is preferable that the viscosity and refractive index of the insulating liquid 31 be as low as possible. This is because the mobility (response speed) of the migrating particles 32 is improved, and the energy (power consumption) required to move the migrating particles 32 is lowered accordingly. In addition, since the difference between the refractive index of the insulating liquid 31 and the refractive index of the porous layer 33 is increased, the light reflectance of the porous layer 33 is increased. Note that a weak conductive liquid may be used instead of the insulating liquid 31.

The insulating liquid 31 may contain various materials as necessary. This material is, for example, a colorant, a charge control agent, a dispersion stabilizer, a viscosity modifier, a surfactant or a resin.

The electrophoretic particles 32 are one or more charged particles that are electrically movable, and are dispersed in the insulating liquid 31. The migrating particles 32 can move between the pixel electrode 17 and the counter electrode 22 in the insulating liquid 31. The migrating particles 32 also have arbitrary optical reflection characteristics (light reflectivity). The light reflectance of the migrating particles 32 is not particularly limited, but is preferably set so that at least the migrating particles 32 can shield the porous layer 33. This is because contrast is generated by utilizing the difference between the light reflectance of the migrating particles 32 and the light reflectance of the porous layer 33.

The migrating particles 32 are, for example, one kind or two or more kinds of particles (powder) such as an organic pigment, an inorganic pigment, a dye, a carbon material, a metal material, a metal oxide, glass, or a polymer material (resin). . The migrating particles 32 may be pulverized particles or capsule particles of resin solids containing the above-described particles.

Organic pigments include, for example, azo pigments, metal complex azo pigments, polycondensed azo pigments, flavanthrone pigments, benzimidazolone pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, perylene pigments, perinones. Pigments, anthrapyridine pigments, pyranthrone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments or indanthrene pigments. Inorganic pigments include, for example, zinc white, antimony white, carbon black, iron black, titanium boride, bengara, mapico yellow, red lead, cadmium yellow, zinc sulfide, lithopone, barium sulfide, cadmium selenide, calcium carbonate, barium sulfate, Lead chromate, lead sulfate, barium carbonate, lead white or alumina white. Examples of the dye include nigrosine dyes, azo dyes, phthalocyanine dyes, quinophthalone dyes, anthraquinone dyes, and methine dyes. The carbon material is, for example, carbon black. The metal material is, for example, gold, silver or copper. Examples of metal oxides include titanium oxide, zinc oxide, zirconium oxide, barium titanate, potassium titanate, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, and copper-chromium-manganese oxide. Or copper-iron-chromium oxide. The polymer material is, for example, a polymer compound in which a functional group having a light absorption region in the visible light region is introduced. As long as the polymer compound has a light absorption region in the visible light region, the type of the compound is not particularly limited.

The specific forming material of the migrating particles 32 is selected according to the role of the migrating particles 32 in order to cause contrast, for example. For example, the material in which white display is performed by the migrating particles 32 is, for example, a metal oxide such as titanium oxide, zinc oxide, zirconium oxide, barium titanate or potassium titanate, and among these, titanium oxide is preferable. This is because it is excellent in electrochemical stability and dispersibility and has high reflectance. On the other hand, the material in the case where black display is performed by the migrating particles 32 is, for example, a carbon material or a metal oxide. The carbon material is, for example, carbon black, and the metal oxide is, for example, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, copper-chromium-manganese oxide, or copper-iron. -Chromium oxide and the like. Among these, a carbon material is preferable. This is because excellent chemical stability, mobility and light absorption are obtained.

The content (concentration) of the migrating particles 32 in the insulating liquid 31 is not particularly limited, and is, for example, 0.1 wt% to 10 wt%. This is because shielding (concealment) and mobility of the migrating particles 32 are ensured. In this case, if it is less than 0.1% by weight, the migrating particles 32 may not easily shield the porous layer 33. On the other hand, when the amount is more than 10% by weight, the dispersibility of the migrating particles 32 is lowered, so that the migrating particles 32 are difficult to migrate and may be aggregated in some cases.

The average particle diameter of the migrating particles 32 is preferably in the range of 0.1 μm to 10 μm, for example.

In addition, it is preferable that the migrating particles 32 are easily dispersed and charged in the insulating liquid 31 over a long period of time and are not easily adsorbed by the porous layer 33. For this reason, in order to disperse the electrophoretic particles 32 by electrostatic repulsion, a dispersant (or a charge adjusting agent) may be used, or the electrophoretic particles 32 may be subjected to a surface treatment, or both may be used in combination.

The dispersing agent is, for example, Solsperse series manufactured by Lubrizol, BYK® series or Anti-Terra® series manufactured by BYK-Chemie, or Span series manufactured by ICI® Americas®.

The surface treatment is, for example, rosin treatment, surfactant treatment, pigment derivative treatment, coupling agent treatment, graft polymerization treatment or microencapsulation treatment. Among these, graft polymerization treatment, microencapsulation treatment, or a combination thereof is preferable. This is because long-term dispersion stability and the like can be obtained.

The surface treatment material is, for example, a material (adsorbing material) having a functional group and a polymerizable functional group that can be adsorbed on the surface of the migrating particle 32. The type of functional group that can be adsorbed is determined according to the material for forming the migrating particles 32. For example, carbon materials such as carbon black are aniline derivatives such as 4-vinylaniline, and metal oxides are organosilane derivatives such as 3- (trimethoxysilyl) propyl methacrylate. . Examples of the polymerizable functional group include a vinyl group, an acrylic group, and a methacryl group.

Further, the material for surface treatment is, for example, a material (graftable material) that can be grafted on the surface of the migrating particles 32 into which a polymerizable functional group is introduced. The graft material preferably has a polymerizable functional group and a dispersing functional group that can be dispersed in the insulating liquid 31 and can maintain dispersibility due to steric hindrance. The kind of polymerizable functional group is the same as that described for the adsorptive material. The dispersing functional group is, for example, a branched alkyl group when the insulating liquid 31 is paraffin. In order to polymerize and graft the graft material, for example, a polymerization initiator such as azobisisobutyronitrile (AIBN) may be used.

For reference, the details of the method for dispersing the migrating particles 32 in the insulating liquid 31 as described above are described in “Dispersion Technology of Ultrafine Particles and Its Evaluation—Surface Treatment / Fine Grinding and Air / Liquid / Polymer”. It is published in books such as “Dispersion Stabilization ~ (Science & Technology)”.

The porous layer 33 is, for example, a three-dimensional structure (irregular network structure such as a nonwoven fabric) formed by a fibrous structure 331 as shown in FIG. The porous layer 33 has a plurality of gaps (pores 333) through which the migrating particles 32 pass in places where the fibrous structure 331 does not exist. In FIG. 1, the illustration of the porous layer 33 is simplified.

The fibrous structure 331 includes one or more non-migrating particles 332, and the non-migrating particles 332 are held by the fibrous structure 331. In the porous layer 33 which is a three-dimensional structure, one fibrous structure 331 may be entangled at random, or a plurality of fibrous structures 331 may be gathered and overlap at random. However, both may be mixed. When there are a plurality of fibrous structures 331, each fibrous structure 331 preferably holds one or more non-migrating particles 332. FIG. 2 shows a case where the porous layer 33 is formed by a plurality of fibrous structures 331.

The reason why the porous layer 33 is a three-dimensional structure is that the irregular three-dimensional structure easily causes external light to be irregularly reflected (multiple scattering), so that the light reflectance of the porous layer 33 increases and the high light This is because the porous layer 33 can be thin in order to obtain the reflectance. As a result, the contrast increases and the energy required to move the migrating particles 32 decreases. In addition, since the average pore diameter of the pores 333 is increased and the number thereof is increased, the migrating particles 32 can easily pass through the pores 333. As a result, the time required to move the migrating particles 32 is shortened, and the energy required to move the migrating particles 32 is also reduced.

The reason why the non-migrating particles 332 are included in the fibrous structure 331 is that the light reflectance of the porous layer 33 is higher because external light is more easily diffusely reflected. Thereby, contrast becomes higher.

The shape (appearance) of the fibrous structure 331 is not particularly limited as long as the fibrous structure 331 has a sufficiently long length with respect to the fiber diameter as described above. Specifically, it may be linear, may be curled, or may be bent in the middle. Moreover, you may branch to 1 or 2 or more directions on the way, not only extending in one direction. The formation method of the fibrous structure 331 is not particularly limited. For example, a phase separation method, a phase inversion method, an electrostatic (electric field) spinning method, a melt spinning method, a wet spinning method, a dry spinning method, a gel spinning method, A sol-gel method or a spray coating method is preferred. This is because a fibrous material having a sufficiently large length with respect to the fiber diameter can be easily and stably formed.

The average fiber diameter of the fibrous structure 331 is not particularly limited, but is preferably as small as possible. This is because light easily diffuses and the average pore diameter of the pores 333 increases. For this reason, it is preferable that the average fiber diameter of the fibrous structure 331 is 10 micrometers or less. In addition, although the minimum of an average fiber diameter is not specifically limited, For example, it is 0.1 micrometer and may be less than that. This average fiber diameter is measured, for example, by microscopic observation using a scanning electron microscope (SEM) or the like. Note that the average length of the fibrous structure 331 may be arbitrary.

The average pore diameter of the pores 333 is not particularly limited, but is preferably as large as possible. This is because the migrating particles 32 easily pass through the pores 333. Therefore, the average pore diameter of the pores 333 is preferably 0.1 μm to 10 μm.

The thickness of the porous layer 33 is not particularly limited, but is, for example, 5 μm to 100 μm. This is because the shielding property of the porous layer 33 is enhanced and the migrating particles 32 easily pass through the pores 333.

As a material constituting the fibrous structure 331, for example, one or two or more of polymer materials or inorganic materials are included, and other materials may be included. Examples of the polymer material include nylon, polylactic acid, polyamide, polyimide, polyethylene terephthalate, polyacrylonitrile, polyethylene oxide, polyvinyl carbazole, polyvinyl chloride, polyurethane, polystyrene, polyvinyl alcohol, polysulfone, polyvinyl pyrrolidone, polyvinylidene fluoride, polyhexa Fluoropropylene, cellulose acetate, collagen, gelatin, chitosan or copolymers thereof. The inorganic material is, for example, titanium oxide. Among these, a polymer material is preferable as a material for forming the fibrous structure 331. This is because the reactivity (photoreactivity, etc.) is low (chemically stable), so that an unintended decomposition reaction of the fibrous structure 331 is suppressed. Note that in the case where the fibrous structure 331 is formed of a highly reactive material, the surface of the fibrous structure 331 is preferably covered with an arbitrary protective layer.

In particular, the fibrous structure 331 is preferably a nanofiber. Since the three-dimensional structure is complicated and external light is likely to be diffusely reflected, the light reflectance of the porous layer 33 is further increased, and the volume ratio of the pores 333 to the unit volume of the porous layer 33 is increased. This is because the migrating particles 32 can easily pass through the pores 333. Thereby, the contrast becomes higher and the energy required to move the migrating particles 32 becomes lower. Nanofiber is a fibrous substance having a fiber diameter of 0.001 μm to 0.1 μm and a length that is 100 times or more of the fiber diameter. The fibrous structure 331 that is a nanofiber is preferably formed by an electrospinning method using a polymer material. This is because the fibrous structure 331 having a small fiber diameter can be easily and stably formed.

This fibrous structure 331 preferably has an optical reflection characteristic different from that of the migrating particles 32. Specifically, the light reflectance of the fibrous structure 331 is not particularly limited, but is preferably set so that at least the porous layer 33 can shield the migrating particles 32 as a whole. As described above, this is because contrast is generated by utilizing the difference between the light reflectance of the migrating particles 32 and the light reflectance of the porous layer 33.

Non-electrophoretic particles 332 are particles that are fixed to the fibrous structure 331 and do not migrate electrically. As long as the non-migrating particles 332 are held by the fibrous structure 331, the non-migrating particles 332 may be partially exposed from the fibrous structure 331 or embedded therein.

The specific forming material of the non-migrating particles 332 is selected according to the role played by the non-migrating particles 332 in order to generate contrast, for example. Specifically, a metal oxide is preferable and titanium oxide is more preferable. This is because it is excellent in electrochemical stability and fixability, and high reflectance can be obtained. As long as a contrast can be generated, the material for forming the non-migrating particles 332 may be the same material as the material for forming the migrating particles 32 or may be a different material.

Although not shown here, the spacer is for keeping the drive substrate 10 and the display substrate 20 between, and for example, preventing the bias of the migrating particles 32 in the plane of the display device 1. The spacer is made of, for example, an insulating material such as a polymer material, a seal material mixed with fine particles, and the like. The shape of the spacer is not particularly limited, but is preferably a shape that does not hinder the movement of the migrating particles 32 between the pixel electrode 17 and the counter electrode 22 and can uniformly distribute it, for example, a lattice shape. . Further, in view of the manufacturing process described later, for example, it is preferable that the shape is an inversely tapered shape from the drive substrate 10 side to the display substrate 20 side. The thickness of the spacer is not particularly limited, but in particular, it is preferably as thin as possible in order to reduce power consumption, for example, 10 μm to 100 μm. The spacer may be formed at an appropriate position in the display layer.

(1-2. Manufacturing method of display device)
The display device 1 of the present embodiment can be formed by, for example, the following method. The counter electrode 22 is provided on one surface of the support member 21 by using an existing method such as various film forming methods, and the display substrate 20 is formed. Next, a spacer is formed on the counter electrode 22. The spacer can be formed by, for example, the following imprint method. First, a solution containing a spacer constituent material (for example, a photosensitive resin material) is applied onto the counter electrode 22. Next, a mold having a recess on the coated surface is pressed and exposed to light, and then the mold is removed. Thereby, a columnar spacer is formed. At this time, the spacer preferably has a so-called reverse taper in which the width gradually decreases from the display substrate 20 side to the drive substrate 10 side. Thereby, a type | mold can be easily removed from a spacer.

Subsequently, a fibrous structure 331 is disposed between adjacent spacers. First, for example, polyacrylonitrile as a fibrous structure 331 is dispersed or dissolved in N, N′-dimethylformamide, and, for example, titanium oxide is added as non-electrophoretic particles 332 and sufficiently stirred to obtain a polymer solution (spinning). Solution). Subsequently, the spinning solution is used to spin on another substrate by, for example, an electrostatic spinning method. The fibrous structure 331 is formed by a phase separation method, a phase inversion method, a melt spinning method, a wet spinning method, a dry spinning method, a gel spinning method, a sol-gel method, a spray coating method, or the like instead of the electrostatic spinning method. May be.

As a method for forming the fibrous structure 331, a method of forming a fibrous structure by perforating a polymer film using laser processing has been proposed (see Japanese Patent Application Laid-Open No. 2005-107146). ), Only large pores having a pore diameter of about 50 μm can be formed by this method, and the migrating particles may not be completely shielded by the fibrous structure.

Next, the fibrous structure 331 is divided into appropriate sizes and placed between the spacers (cells). Specifically, by pressing the fibrous structure 331 from above (the direction opposite to the support member 21), the fibrous structure 331 is scraped off by the spacer. The cut fibrous structure 331 is accommodated between the spacers. In this way, the porous layer 33 in which the non-electrophoretic particles 332 are held on the fibrous structure 331 is formed.

Subsequently, the drive substrate 10 is prepared. First, after forming the TFT 15 and the insulating layer 16 on the support member 14, a contact hole 16 A is provided in the insulating layer 16. Next, after forming a metal film on the insulating layer 16, the pixel electrode 17 is formed by patterning. Subsequently, the support member 14 is bonded to the elastic member 13 of the support substrate 11 in which the common electrode 12 and the elastic member 13 are stacked in this order, and the drive substrate 10 is formed.

Next, after applying the insulating liquid 31 in which the migrating particles 32 are dispersed to the display substrate 20 on which the porous layer 33 is disposed, this is applied to the sealing layer via a sealing agent (not shown), for example. The peeling member (not shown) provided with (not shown) is made to oppose. Finally, after the peeling member is peeled off, the driving substrate 10 in which the common electrode 12, the elastic member, the TFT 15 and the pixel electrode 17 are provided on the support substrate 11 via an adhesive layer (not shown) on the seal layer. To fix. The display device 1 is completed through the above steps.

(1-3. Preferred Operating Method of Display Device)
In the display device 1 of the present embodiment, the counter electrode 22 is normally connected to, for example, the ground (GND), and a first potential (here, a negative potential) is applied to the source electrode 152A, for example. . A positive or negative potential is applied to the common electrode 12 depending on the dopant added to the semiconductor material constituting the semiconductor layer 151. In a state in which no pressure is applied (not pressed) to the display surface S1, the common electrode 12 and the semiconductor layer 151 are electrically insulated from each other by the elastic member 13, and thus are applied to the source electrode 151A. The negative potential is not applied to the pixel electrode 17. For this reason, the migrating particles 32 responsible for the display do not move and are arranged, for example, on the pixel electrode 17 side. The migrating particles 32 are black particles that are negatively charged.

As shown in FIG. 3, when the display device 1 is pressed (pressed) at an arbitrary position with the input pen 50, the thickness of the elastic member 13 in the pressed portion is reduced, and the common electrode 12 and the semiconductor layer The distance to 151 decreases and the common electrode 12 acts as a gate electrode. That is, charges are induced in the semiconductor layer 151, and the TFT 15 near the pen tip of the input pen 50 becomes conductive. As a result, a negative potential is supplied to the pixel electrode 17, and the negatively charged migrating particles 32 receive a product force and move toward the counter electrode 22, thereby drawing a black line on the display surface S 1.

Note that the input pen 50 does not have to be a pen dedicated to the display device 1 of the present embodiment, and the shape and structure thereof are not particularly limited as long as the display surface S1 can be pressurized.

(1-4. Action and effect)
In a reflective image display device that allows general handwriting input, from input to display, such as detection by the input position sensor and calculation processing of the detected position information from handwriting input to display on the display Since there is a process of sensing position information and calculation processing, the human eye feels a delay from input to display.

As an image display device for improving this delay, as described above, an image forming apparatus provided with a pressure-sensitive conductive layer on the display surface side has been considered. In this image forming apparatus, an electric field is partially generated by applying pressure to the pressure-sensitive conductive layer with a pen or the like, and a locus input by handwriting is displayed without using a sensor. For this reason, the delay from input to display is eliminated. However, since the pressure-sensitive conductive layer is relatively expensive and the display body is also relatively expensive, there is a problem in terms of cost-effectiveness for commercialization of a device to which a handwriting input function is added. It was.

Further, in order to realize such an image forming apparatus, it is required that the pressure-sensitive conductive layer is transparent and has excellent optical characteristics. Therefore, it has been difficult to realize an image forming apparatus capable of handwriting input having such a configuration. Further, even if it is developed, there is a problem in that luminance and resolution are lowered because an image is visually recognized through the pressure-sensitive conductive layer. Furthermore, since there is a pressure-sensitive conductive layer above the display element, there is a problem that parallax occurs due to the separation of the thickness of the pressure-sensitive conductive layer from the distance between the input surface and the image display surface (display element).

In addition, for example, an indicator detection device is disclosed in which an AC signal supply circuit and a signal reception circuit are provided for one indicator detection sensor, and a position pressed by the indicator is detected based on a change in capacitance. However, this indicator detection device also has a problem in terms of cost effectiveness.

On the other hand, in the display device 1 of the present embodiment, the TFT 15 is provided in each of the plurality of pixel electrodes 17 provided on the drive substrate 10 side, and the gate electrode constituting the TFT 15 is used as the common electrode 12 in common. An elastic member 13 having insulating properties is provided between the electrode 12 and the semiconductor layer 151. Thereby, when an arbitrary position is pressed (pressed) with the input pen 50 or the like, the thickness of the elastic member 13 in the pressed portion is reduced, the common electrode 12 acts as a gate electrode, and the semiconductor layer 151 is charged. As a result, the TFT 15 near the pen tip of the input pen 50 becomes conductive and the display state is switched. That is, handwritten input can be performed without using expensive members and without using an input information detection system or arithmetic processing system from input (pressing) to display.

As described above, in the present embodiment, among the drive substrate 10 and the display substrate 20 that are disposed so as to face each other with the electrophoretic element 30 therebetween, the pixel electrode 17 that is divided and formed on the drive substrate 10 and the pixel The TFT 15 electrically connected to the electrode 17 is provided, and the insulating elastic member 13 is provided between the gate electrode (common electrode 12) of the TFT 15 and the semiconductor layer 151. Thus, by pressing (pressing) an arbitrary position with the input pen 50 or the like, the TFT 15 in the pressed portion is turned on and applied to the source electrode 152A on the pixel electrode 17 in the pressing portion. A potential is supplied. At this time, if the potential supplied to the pixel electrode and the charge of the migrating particles 32 are the same, the movement, that is, the display state is switched by the product force. Therefore, it is possible to switch the display without using expensive members and without performing input information detection and calculation processing from input (pressing) to display, which is cost-effective and delay-free. It is possible to provide a display device capable of inputting a small amount of handwriting.

Further, since the distance between the input surface and the image display surface (display element) is only the thickness of the support member 21 and the counter electrode 22, display at a position close to the input surface is possible. That is, it is possible to provide the display device 1 with less parallax.

Hereinafter, the second and third embodiments and modifications will be described. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

<2. Second Embodiment>
FIG. 4 illustrates a cross-sectional configuration of a display device (display device 2) according to the second embodiment of the present disclosure. The display device 2 is a display device capable of handwritten input, and is suitable for various electronic devices such as an electronic paper display. As in the first embodiment, the display device 2 is a display element, for example, electrophoresis between a drive substrate 10 and a display substrate 20 that are arranged to face each other via a spacer (not shown). An element 30 is provided. In the present embodiment, the display device 2 includes, for example, a pixel electrode 17 formed separately for each pixel and a TFT 25 electrically connected to the pixel electrode 17 on the drive substrate 10 side. As a gate electrode constituting the TFT 25, the common electrode 12 is provided below the semiconductor layer 251 (on the support substrate 11 side) via the elastic member 13, and the gate electrode 253 (on the display element 30 side) is also provided above the semiconductor layer 251. The second embodiment differs from the first embodiment in that a second gate electrode) is provided. In the TFT 25, the common electrode 12 and the gate electrode 253 share the semiconductor layer 251 and the pair of source electrode 252A and drain electrode 252B, respectively, so that the common electrode 12 similar to that in the first embodiment is used as the gate electrode. And the active matrix driving TFT using the gate electrode 253 as the gate electrode.

FIG. 5 shows the configuration of the display device 2. The display device 2 includes a signal line driving circuit 120 and a gate line driving circuit 130 which are active matrix driving drivers around the display area. A pixel driving circuit 140 is provided in the display area. FIG. 6 illustrates an example of the pixel driving circuit 140. The pixel driving circuit 140 is an active pixel driving circuit provided with one transistor (Tr1) and one capacitor (holding capacity; Cs) used in a general liquid crystal display or an electrophoresis apparatus. The transistor Tr1 may have, for example, an inverted stagger structure (so-called bottom gate type) or a stagger structure (top gate type), and is not particularly limited. In this embodiment mode, the so-called top gate type TFT 25 in which the gate electrode 253 is provided over the semiconductor layer 251 illustrated in FIG. 5 corresponds to the transistor Tr1.

In the pixel driving circuit 140, a plurality of signal lines 120A are arranged in the column direction, and a plurality of gate lines 130A are arranged in the row direction. An intersection between each signal line 120A and each gate line 130A corresponds to one pixel. Each signal line 120A is connected to the signal line drive circuit 120, and each gate line 130A is connected to the gate line drive circuit 130. Each signal line 120A is connected to a gate electrode 253 provided in the corresponding pixel, and each signal line 120A is connected to a source electrode 252A. The drain electrode 252B is electrically connected to the pixel electrode 17. One of the capacitors Cs is connected to the Cs line 150 A, and the other is connected to the counter electrode 22.

In the display device 2, the gate lines 130A are sequentially selected one by one, the TFTs 25 on the selected gate lines 130A are turned on, and the voltage applied to the signal line 120A at the moment of conduction is stored in the capacitor Cs in the pixel. . Thereafter, even when the gate line 130A is not selected, the voltage is held in the capacitor Cs, and thus the display element (electrophoretic element 30) is continuously driven. Note that the capacitor Cs may be omitted when the TFT 25 itself or the display element functions as a storage capacitor.

The gate electrode 253 has a function as a potential shield from the pixel electrode 17 in addition to a function as a gate electrode of a video display TFT.

As described above, in the display device 2 of the present embodiment, the common electrode 12 and the gate electrode 253 sharing the semiconductor layer 251 and the pair of source electrode 252A and drain electrode 252B are provided above the semiconductor layer 251. It is possible to provide a display device capable of active matrix driving together with handwriting input.

Note that the display device 2 of the present embodiment can move the migrating particles 32 that have moved to the counter electrode 22 side by handwriting input to the pixel electrode 17 side by using an active matrix driving TFT. That is, the black line drawn on the display surface S1 of the display device 2 can be erased (white display). As a result, the display device 2 can be used repeatedly, for example, as an ordinary electronic book terminal or an electronic notebook capable of handwriting input.

<3. Third Embodiment>
FIG. 7 illustrates a cross-sectional configuration of a display device (display device 3) according to the third embodiment of the present disclosure. The display device 3 is a display device capable of handwritten input, and is suitable for various electronic devices such as an electronic paper display. As in the first embodiment, the display device 3 is, for example, an electrophoresis device as a display element between a drive substrate 10 and a display substrate 20 that are arranged to face each other via a spacer (not shown). An element 30 is provided. In the display device 3 of the present embodiment, the TFT 35 connected to the pixel electrode 17 is configured separately as a handwriting input TFT 35A and an active matrix driving TFT 35B. Different from form.

In the active matrix driving TFT 35B in this embodiment, the gate electrode 351 is provided on the support member 14, and the gate electrode 351, the gate insulating layer 352, the semiconductor layer 353B, the pair of the source electrode 354C, and the drain electrode 354B are arranged in this order. This is a so-called bottom gate type TFT provided. The TFT 35A for handwriting input has the same configuration as the TFT 15 in the first embodiment. The

TFTs

35A and 35B share a drain electrode 354B, and the drain electrode 354B is electrically connected to the pixel electrode 17.

Similar to the second embodiment, the display device 3 includes a signal line driving circuit 120 and a gate line driving circuit 130 that are drivers for driving an active matrix around the display area. Is provided with a pixel driving circuit 140. FIG. 8 illustrates an example of the pixel drive circuit 140 of the display device 3. Similar to the display device 2, the pixel drive circuit 140 of the display device 3 is an active pixel drive circuit provided with one transistor (Tr1) and one capacitor (holding capacity; Cs). In the present embodiment, this is provided with a transistor Tr2 for handwriting input. The drain electrode of the transistor Tr2 is connected to the pixel electrode 17 together with the transistor Tr1 as described above, and the source electrode is connected to the signal line 120A. It is connected to the. When a black line is drawn by handwriting input, the signal line 120A is drawn by applying a potential corresponding to black display (for example, a negative potential when the migrating particles 32 are negatively charged). It becomes possible.

Similar to the second embodiment, when the bottom gate type TFT for driving the active matrix is formed integrally with the TFT for handwriting input, unlike the second embodiment, the TFT for handwriting input functions. It becomes difficult to realize a handwriting function by pressing. This is because the gate electrode as the active matrix driving TFT provided on the support member 14 shields the electric field from the common electrode 12 which is the gate electrode of the handwriting input TFT.

Therefore, as described above, in the display device 3 of the present embodiment, the bottom gate type TFT 35B for active matrix driving that shares the drain electrode 354B of the TFT 35A for handwriting input is provided. This makes it possible to use amorphous silicon, which is excellent in cost, as the semiconductor layer 353B of the bottom gate type TFT 35B for active matrix driving. Therefore, in addition to the effects in the first and second embodiments, it is possible to provide a display device that is more cost-effective.

In the pixel driving circuit shown in FIG. 8, the example in which the source electrode of the transistor Tr2 for handwriting input is connected to the signal line 120A is shown, but the present invention is not limited to this. For example, as shown in FIG. 9, a dedicated line 160A for applying a first potential to the source electrode of the transistor Tr2 for handwriting input may be provided and connected thereto. As a result, although the number of wirings is increased, the control of the signal line 120A is simplified.

<4. Modification>
FIG. 10 illustrates a cross-sectional configuration of a display device (display device 4) according to a modified example of the present disclosure. The display device 4 is a display device capable of handwritten input, and is suitable for various electronic devices such as an electronic paper display, for example. As in the first embodiment, the display device 4 includes, for example, electrophoresis as a display element between the drive substrate 10 and the display substrate 20 that are arranged to face each other via a spacer (not shown). An element 30 is provided. The display device 4 of this modification is a combination of the display device 2 of the second embodiment and the display device 3 of the third embodiment, and is electrically connected to each pixel electrode 17. The TFT 45 includes a bottom gate type active matrix driving TFT 45B and a handwriting input TFT 45A in which the common electrode 12 is a gate electrode and the gate electrode 455 is provided on the semiconductor layer 453A.

The TFT 45 in this modification is composed of a TFT 45A for handwriting input and a TFT 45B for active matrix driving. The TFT 45A includes a common electrode 12 provided with an elastic member 13 below the support member 14 (on the back surface S2 side) as a gate electrode, and a semiconductor layer 453A provided on the support member 14 via a gate insulating film 452. And a pair of source electrode 454A, drain electrode 454B, and gate electrode 455 provided with insulating layer 16 on semiconductor layer 453A. The TFT 45B includes a gate electrode 451 provided on the support member 14, a semiconductor layer 453B provided on the gate electrode 451 through a gate insulating film 452, and a pair of source electrode 454C and drain electrode 454B. Yes. The drain electrode 454B is shared by the TFT 45A and the TFT 45B, and is electrically connected to the pixel electrode 17.

The gate electrode 455 of the TFT 45A in this modification is for reducing the influence of the potential applied to the pixel electrode 17 on the semiconductor layer 453A of the TFT 45A. Further, the threshold value of the TFT 45A can be adjusted by applying an appropriate voltage to the gate electrode 455. Specifically, for example, in the case where the semiconductor layer 453A is made of amorphous silicon, the threshold value is increased by applying a negative potential to the gate electrode 455, and the pressure required for drawing is relatively increased. Further, by applying a positive potential to the gate electrode 455, the threshold value is lowered, and the pressure required for drawing is relatively lowered. In this way, it is possible to arbitrarily adjust the pressure required for drawing when inputting by handwriting.

As described above, in this modification, the threshold value of the TFT 45A can be adjusted by providing the gate electrode 455 on the semiconductor layer 453A of the TFT 45A for handwriting input and applying an appropriate voltage thereto. Accordingly, it is possible to arbitrarily adjust the pressure required for drawing when inputting by handwriting, and it is possible to reflect the pressure (writing pressure) of the pressing in an analog manner in the drawing by handwriting input.

It should be noted that the pressing required for drawing when inputting by hand can also be adjusted by adjusting the voltage applied to the common electrode 12. Further, the pressing required for drawing can be adjusted by adjusting the off-side voltage of the gate electrode 253 of the TFT 25 in the second embodiment.

<5. Application example>
Next, application examples of the display devices 1 to 4 of the first to third embodiments and the modified examples will be described. However, the configuration of the electronic device described below is merely an example, and the configuration can be changed as appropriate.

FIG. 11 shows the appearance of a tablet personal computer. The tablet personal computer has, for example, a display unit 610 and a housing 620, and the display unit 610 is configured by the display device 1 (or any one of the display devices 2 to 4).

Further, the display devices 1 to 4 of the first to third embodiments and the modifications may be applied to an electronic bulletin board or the like.

The first to third embodiments and modifications have been described above, but the present disclosure is not limited to the aspects described in the above embodiments and the like, and various modifications are possible. For example, in the above-described embodiment and the like, a microcup type electrophoretic element is used as the electrophoretic element 30, but for example, a so-called multi-capsule in which white and black colored electrophoretic particles are enclosed is provided. A microcapsule electrophoretic element may be used. Moreover, the display element used for this indication is not limited to an electrophoretic element, if it has memory property.

In the first embodiment, the configuration including the insulating liquid 31, the migrating particles 32, and the porous layer 33 is illustrated as the electrophoretic element 30, but the configuration of the electrophoretic element 30 (display layer) is as follows. However, the present invention is not limited to the one using the porous layer 33 as long as the contrast can be formed by light reflection for each pixel using the electrophoresis phenomenon. For example, a capsule type or a type without a fibrous structure (colored liquid itself) may be used.

In addition, the effect described in this specification is an illustration to the last, and is not limited, Moreover, there may exist another effect.

In addition, this indication can also take the following structures.
(1)
A thin film transistor having a first gate electrode, a semiconductor layer, a pair of source electrodes and a drain electrode on each of a display element whose display state changes in accordance with a change in applied voltage and a plurality of lower electrodes for applying a voltage to the display element And a display substrate having an upper electrode disposed between the display element and the display element, the drive substrate including the first gate electrode, the semiconductor layer, and the semiconductor layer. A display device having an insulating elastic member between the two.
(2)
The display device according to (1), wherein the first gate electrode is a common electrode for the plurality of lower electrodes.
(3)
The thin film transistor has the semiconductor layer and the pair of source / drain electrodes on a surface of the support member on the display element side, and the elastic member on the surface of the support member opposite to the display element. The display device according to (1) or (2), including the first gate electrode.
(4)
The display device according to any one of (1) to (3), wherein one of the pair of source and drain electrodes and the lower electrode are electrically connected.
(5)
The display device according to (4), wherein the upper electrode is connected to a ground, and a first potential is applied to the other of the pair of source electrode and drain electrode.
(6)
The display device according to any one of (3) to (5), wherein the thin film transistor includes a second gate electrode on the display element side of the support member.
(7)
The display device according to (6), wherein the second gate electrode is provided between the semiconductor layer and the lower electrode.
(8)
The display device according to (6), wherein the second gate electrode is provided between the semiconductor layer and the support member.
(9)
The display device according to any one of (1) to (8), wherein the display element has a memory property.
(10)
The display according to any one of (1) to (9), wherein the display element is an electrophoretic element including electrophoretic particles and a porous layer formed of a fibrous structure in an insulating liquid. apparatus.
(11)
The display device according to (10), wherein the fibrous structure includes non-electrophoretic particles having light reflectivity different from the electrophoretic particles.
(12)
A plurality of gate lines and a plurality of signal lines, a display element whose display state changes according to a change in applied voltage, a plurality of lower electrodes for applying voltage to the display element, and a plurality of lower electrodes A first gate electrode, a second gate electrode, a semiconductor layer, a thin film transistor comprising a pair of source and drain electrodes, a drive substrate having a support member, and a plurality of lower electrodes for applying a voltage to the display element; A driving substrate provided with a thin film transistor having a first gate electrode and a second gate electrode, a semiconductor layer, a pair of source electrodes and a drain electrode between members, and a display element disposed between the driving substrate and the driving substrate. A display substrate having an upper electrode, and in the thin film transistor, the support portion is provided between the support member and the display element. The semiconductor layer, the pair of source and drain electrodes, and the second gate electrode are provided in this order from the side, and the first gate electrode is provided on the surface of the support member opposite to the display element. The first gate electrode includes an elastic member having insulation between the first gate electrode and the support member, and the second gate electrode is electrically connected to the gate line.
(13)
A plurality of gate lines and a plurality of signal lines, a display element whose display state changes according to a change in applied voltage, a plurality of lower electrodes for applying voltage to the display element, and a plurality of lower electrodes A first gate electrode, a first semiconductor layer, a first thin film transistor comprising a pair of first source electrode and drain electrode, a second gate electrode, a second semiconductor layer, and a pair of first transistors sharing the drain electrode of the first thin film transistor. A first driving transistor having a second thin film transistor composed of two source electrodes and a drain electrode and a driving substrate having a support member; a display substrate having the display element disposed between the driving substrate and an upper electrode; Then, the first gate electrode is provided on the surface of the support member opposite to the display element, and the support member and the display element In addition, the first semiconductor layer, the pair of the first source electrode and the drain electrode are provided in this order, and an insulating elastic member is disposed between the first gate electrode and the first semiconductor layer. In the second thin film transistor, the second gate electrode, the second semiconductor layer, the pair of the second source electrode and the drain electrode are arranged in this order from the support member side between the support member and the display element. A display device provided, wherein the second gate electrode is electrically connected to the gate line, and the drain electrode is electrically connected to the signal line.

This application claims priority on the basis of Japanese Patent Application No. 2015-106812 filed on May 26, 2015 at the Japan Patent Office. The entire contents of this application are hereby incorporated by reference. Incorporated into.

Those skilled in the art will envision various modifications, combinations, subcombinations, and changes, depending on design requirements and other factors, which are within the scope of the appended claims and their equivalents. It is understood that

Claims

A display element whose display state changes according to a change in applied voltage;
A driving substrate in which a thin film transistor having a first gate electrode, a semiconductor layer, a pair of source and drain electrodes is provided on each of the plurality of lower electrodes for applying a voltage to the display element;
The display element is disposed opposite to the drive substrate between the display elements, and includes a display substrate having an upper electrode,
The drive substrate includes an elastic member having insulation between the first gate electrode and the semiconductor layer.
The display device according to claim 1, wherein the first gate electrode is a common electrode for the plurality of lower electrodes.
The thin film transistor has the semiconductor layer and the pair of source / drain electrodes on a surface of the support member on the display element side, and the elastic member on the surface of the support member opposite to the display element. The display device according to claim 1, comprising the first gate electrode.
The display device according to claim 1, wherein one of the pair of source and drain electrodes and the lower electrode are electrically connected.
The display device according to claim 4, wherein the upper electrode is connected to a ground, and the other of the pair of source electrode and drain electrode is applied with a first potential.
4. The display device according to claim 3, wherein the thin film transistor has a second gate electrode on the display element side of the support member.
The display device according to claim 6, wherein the second gate electrode is provided between the semiconductor layer and the lower electrode.
The display device according to claim 6, wherein the second gate electrode is provided between the semiconductor layer and the support member.
The image display device according to claim 1, wherein the display element has a memory property.
The display device according to claim 1, wherein the display element is an electrophoretic element including an electrophoretic particle and a porous layer formed of a fibrous structure in an insulating liquid.
The display device according to claim 10, wherein the fibrous structure includes non-migrating particles having light reflectivity different from the migrating particles.
Multiple gate lines and multiple signal lines;
A display element whose display state changes according to a change in applied voltage;
A plurality of lower electrodes for applying a voltage to the display element, a first gate electrode, a second gate electrode, a semiconductor layer provided on each of the plurality of lower electrodes, a thin film transistor comprising a pair of source and drain electrodes, and a support member A drive board having
A driving substrate provided with a thin film transistor having a first gate electrode and a second gate electrode, a semiconductor layer, a pair of a source electrode and a drain electrode, with a supporting member interposed between each of the plurality of lower electrodes for applying a voltage to the display element When,
The display element is disposed opposite to the drive substrate between the display elements, and includes a display substrate having an upper electrode,
In the thin film transistor, the semiconductor layer, the pair of source and drain electrodes, and the second gate electrode are provided in this order from the support member side between the support member and the display element. The first gate electrode is provided on a surface opposite to the display element;
The first gate electrode has an insulating elastic member between the support member and
The display device, wherein the second gate electrode is electrically connected to the gate line.
Multiple gate lines and multiple signal lines;
A display element whose display state changes according to a change in applied voltage;
A plurality of lower electrodes for applying a voltage to the display element; a first gate electrode provided on each of the plurality of lower electrodes; a first semiconductor layer; a first thin film transistor comprising a pair of first source and drain electrodes; A driving substrate having a two-gate electrode, a second semiconductor layer, a second thin film transistor comprising a pair of second source electrode and drain electrode sharing the drain electrode of the first thin film transistor, and a support member;
The display element is disposed opposite to the drive substrate between the display elements, and includes a display substrate having an upper electrode,
In the first thin film transistor, a first gate electrode is provided on a surface of the support member opposite to the display element, and the first semiconductor layer and the pair of first sources are provided between the support member and the display element. An electrode and a drain electrode are provided in this order, and an elastic member having insulating properties is disposed between the first gate electrode and the first semiconductor layer,
In the second thin film transistor, a second gate electrode, a second semiconductor layer, a pair of the second source electrode and the drain electrode are provided in this order from the support member side between the support member and the display element. The display device, wherein the second gate electrode is electrically connected to the gate line, and the drain electrode is electrically connected to the signal line.