Patent ID: 12262616

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. The present invention may be carried out in various embodiments, and should not be construed as being limited to any of the following embodiments. In the drawings, components may be shown schematically regarding the width, thickness, shape and the like, instead of being shown in accordance with the actual sizes, for the sake of clear illustration. The drawings are merely examples and do not limit the present invention in any way. Regarding the present invention, in the case where a specific component shown in a drawing and a specific component shown in another drawing are the same as, or correspond to, each other, the components bear the same reference sign (or the same signs followed by letters “a”, “b” or the like), and detailed descriptions thereof may be omitted. The terms “first”, “second” and the like used for components are merely provided for the sake of convenience, more specifically, for distinguishing the components from each other, and do not have any other significance unless otherwise specified.

In the specification, an expression that a component is “on”, “above”, or “below” another component encompasses a case where such a component is in direct contact with another component and also a case where such a component is not in direct contact with another component, namely, a case where still another component is provided between such a component and another component, unless otherwise specified.

First Embodiment

In this embodiment, a touch panel display having a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen will be described.

1-1. Structured of the Display Device

FIG.1shows a structure of a touch panel display100in an embodiment according to the present invention. The touch panel display100includes a transparent resin substrate124, and a display portion102, a driving circuit portion104, a terminal portion106and a touch sensor108provided on a first surface of the transparent resin substrate124. The display portion102includes a plurality of pixels110. The plurality of pixels110are arrayed in a first direction (e.g., a Y direction shown inFIG.1) and a second direction crossing the first direction (e.g., an X direction shown inFIG.1). The plurality of pixels110may be arrayed in any of various patterns, for example, a stripe pattern, a delta pattern, a Bayer arrangement, a PenTile matrix, a diamond PenTile matrix or the like.

The touch sensor108includes a first sensor electrode114and a second sensor electrode116. The first sensor electrode114has a pattern extending in the first direction. The second sensor electrode116has a pattern extending in the second direction crossing the first direction. The first sensor electrode114and the second sensor electrode116may each have any pattern, for example, a flat plate-like (strip-like) pattern. A plurality of the first sensor electrodes114and a plurality of the second sensor electrodes116are provided. The plurality of first sensor electrodes114are arrayed in the second direction, and the plurality of second sensor electrodes116are arrayed in the first direction. The first sensor electrodes114and the second sensor electrodes116are located to cross each other with an insulating layer being provided between the first sensor electrodes114and the second sensor electrodes116.

The terminal portion106includes a plurality of terminal electrodes118located along one side of the transparent resin substrate124. The plurality of terminal electrodes118are electrically connected with a flexible printed circuit board122and act as terminals to which a signal is input from an external circuit.

The driving circuit portion104includes a first driving circuit112a, a second driving circuit112b, and a third driving circuit112c. The first driving circuit112a, the second driving circuit112band the third driving circuit112cmay be located in any manner. For example, the first driving circuit112aand the third driving circuit112cmay each include a thin film transistor (TFT) and may be formed on the transparent resin substrate124, whereas the second driving circuit112bmay include a semiconductor integrated circuit (LSI) and may be mounted on the flexible printed circuit board122in the form of a bare chip. The semiconductor integrated circuit mounted on the flexible printed circuit board122may be referred to also as a “driver IC”. The second driving circuit112bmay include a video signal processing circuit113outputting a video signal to the plurality of pixels110and a sensor signal processing circuit115processing a signal from the touch sensor108in an integrated manner. In this manner, the cost for mounting the second driving circuit112bis decreased.

The display portion102and the touch sensor108may be located so as to partially or entirely overlap each other. The display portion102displays an image or a video, and the touch sensor108has a function of sensing a touch or an approach of a finger of a human or the like. The touch sensor108senses an operation made on a graphic user interface (GUI) such as an icon, a key or the like displayed on the display portion102.

The touch sensor108has a function of sensing a touch or an approach of a finger of a human or the like by use of a change in an electrostatic capacitance. The first sensor electrodes114each act as a receiver electrode (Rx electrode), and sequentially output detection signals (Vdet). The second sensor electrodes116each act as a transmitter electrode (Tx electrode), and are sequentially supplied with common driving signals (Vcom) from the third driving circuit112c.

The touch panel display100performs an input/output function by the display portion102displaying an image and the touch sensor108detecting a touch on a screen. The display portion102is driven by a scanning signal output from the first driving circuit112aand a video signal output from the second driving circuit112b. The touch sensor108is driven by a detection signal input to any of the first sensor electrodes114via the corresponding terminal electrode118and a common driving signal supplied to any of the second sensor electrodes116from the third driving circuit112c. A graphic user interface (GUI) such as an icon or the like is displayed on the display portion102and a touch on the screen is sensed by the touch sensor108, so that it is distinguishable whether or not an operation is made on the GUI.

FIG.2is a perspective view showing a structure of the touch panel display100. The touch panel display100includes the transparent resin substrate124in which the first sensor electrodes114and the second sensor electrodes116are embedded. The touch sensor108includes the first sensor electrodes114and the second sensor electrodes116. The display portion102including the array of the pixels110, the driving circuit portion104, the terminal portion106including an array of the terminal electrodes118and the like are provided on the transparent resin substrate124. The shield electrode126is provided between the first sensor electrodes114/the second sensor electrodes116and the display portion102. A sealing layer128may be provided on the display portion102. The sealing layer128is provided to protect the display portion102and the driving circuit portion104. The first sensor electrodes114and the second sensor electrodes116embedded in the transparent resin substrate124are each electrically connected with the corresponding terminal electrode118via a contact hole formed in the transparent resin substrate124.

The pixels110each include a light emitting element. As the light emitting element, for example, an organic electroluminescence element (hereinafter, also referred to as an “organic EL element”) is used. The touch panel display100has a so-called bottom emission structure, by which light emitted from the pixels110is output via the transparent resin substrate124. Therefore, the transparent resin substrate124is light-transmissive. The first sensor electrodes114, the second sensor electrodes116and the shield electrode126are located as overlapping the pixels110, and therefore are also light-transmissive. For example, the first sensor electrodes114, the second sensor electrodes116and the shield electrode126are each formed of a transparent conductive film. As shown inFIG.2, the touch panel display100has a structure by which an image displayed on the display portion102is visually recognizable through the transparent resin substrate124. Namely, the touch panel display100has a structure by which an image displayed on the display portion102is visually recognizable via the touch sensor108.

The sealing layer128may have any structure. For example, the sealing layer128is formed of an inorganic insulating film such as a silicon oxide film, a silicon nitride film or the like. Alternatively, the sealing layer128may be formed of a resin material such as a polyimide resin, an acrylic resin, an epoxy resin or the like. The sealing layer128is provided to prevent the light emitting elements provided in the pixels110from being deteriorated.

1-2. Equivalent Circuit of the Pixel

FIG.3shows an example of equivalent circuit of one pixel110a. The pixel110aincludes an organic EL element134, a selection transistor136, a driving transistor138, and a capacitance element140. The selection transistor136and the driving transistor138each have a dual-gate structure in which a semiconductor layer (referred to also as an “active layer”) is held between two gate electrodes. The driving transistor138includes a first gate electrode154and a second gate electrode166, and the selection transistor136includes a first gate electrode156and a second gate electrode168.

The selection transistor136and the driving transistor138are each an insulating gate-type field effect transistor, in which a source and a drain thereof act as signal input/output terminals and gates thereof each act as control terminals controlling the transistor to be on or off. In the equivalent circuit shown inFIG.3, the selection transistor136and the driving transistor138are each an n-channel type transistor.

The control terminals of the selection transistor136(i.e., the first gate electrode156and the second gate electrode168) are electrically connected with a gate signal line142a. One of the input/output terminals (first terminal: source or drain) of the selection transistor136is electrically connected with a data signal line144, and the other of the input/output terminals (second terminal: drain or source) of the selection transistor136is electrically connected with the control terminals of the driving transistor138(the first gate electrode154and the second gate electrode166). One of the input/output terminals (first terminal: source) of the driving transistor138is electrically connected with a common line146(146a,146b,146c), and the other of the input/output terminals (second terminal: drain) of the driving transistor138is electrically connected with one of terminals (first terminal) of the organic EL element134. The capacitance element140has one of terminals thereof (first terminal) electrically connected with the control terminals of the driving transistor138(the first gate electrode154and the second gate electrode166), and has the other of the terminals thereof (second terminal) electrically connected with the common line146(146a,146b,146c). The other of the terminals (second terminal) of the organic EL element134is electrically connected with a power supply line148.

The first common line146a, the second common line146band the third common line146care supplied with a certain potential (e.g., ground potential). The power supply line148is supplied with a power supply potential VDD, which is higher than the potential of the common line146. One of the terminals (first terminal) of the organic EL element134is a cathode electrode (also referred to as a “cathode” or a “negative electrode”), and the other of the terminals (second terminal) of the organic EL element134is an anode electrode (also referred to as an “anode” or a “positive electrode”). When a voltage higher than, or equal to, a threshold voltage is applied to the control terminals of the driving transistor138, an electric current flows in the organic EL element134connected between the power supply line148and the common line146. The intensity of light emitted by the organic EL element134is controlled by a drain current in the driving transistor138.

1-3. Structure of the Pixel

FIG.4shows an example of planar structure of the pixel110acorresponding to the equivalent circuit shown inFIG.3.FIG.5Ashows a cross-sectional structure of the pixel110ataken along line A1-A2shown inFIG.4.FIG.5Bshows a cross-sectional structure of the pixel110ataken along line B1-B2shown inFIG.4.FIG.5Bshows a cross-sectional structure of the selection transistor136and the capacitance element140.FIG.5Ashows a cross-sectional structure of the driving transistor138and the organic EL element134. In the following description,FIG.4,FIG.5AandFIG.5Bwill be referred to, as necessary. In the plan view of the pixel110ashown inFIG.4, the first sensor electrode114, the second sensor electrode116and the organic EL element134are omitted.

As shown inFIG.4, the pixel110aincludes the driving transistor138, the selection transistor136and the capacitance element140. In the pixel110a, the gate signal line142a, the data signal line144and the common line146connected with these components are located.

As shown inFIG.5AandFIG.5B, the first sensor electrode114and the second sensor electrode116are embedded in the transparent resin substrate124. The first sensor electrode114and the second sensor electrode116form the touch sensor108. The driving transistor138, the selection transistor136, the capacitance element140and the organic EL element134are provided on the transparent resin substrate124. The shield electrode126is located between the first sensor electrode114/the second sensor electrode116, and the driving transistor138/the selection transistor136/the capacitance element140/the organic EL element134.

The second sensor electrode116have an opening119in a region overlapping the first gate electrode154. The second sensor electrode116as the transmitter electrode (Tx electrode) is supplied with a common driving signal (Vcom). Only a third transparent resin layer150cis provided between the second sensor electrode116and the first gate electrode154, and thus the second sensor electrode116and the first gate electrode154are located relatively close to each other. In this case, when a driving signal is applied to the second sensor electrode116while the first gate electrode154is in a floating state, an electric field is generated by the driving signal and may act on the first gate electrode154to destabilize the operation of the driving transistor138. As a result, the driving transistor138may malfunction. It is preferred that a fourth transparent resin layer150dis made thick in order to put the first gate electrode154far from the second sensor electrode116. For example, the fourth transparent resin layer150dmay have a thickness of 10 μm or greater, preferably 15 μm or greater. It is further preferred that the second sensor electrode116has the opening119. The opening119formed in the second sensor electrode116prevents the common driving signal (Vcom) from influencing the first gate electrode154.

In the meantime, in a region where the selection transistor136is located, it is preferred that the second sensor electrode116covers the first gate electrode156. The first gate electrode156is supplied with a scanning signal from the gate signal line142a. The scanning signal applied to the first gate electrode156is at least a two-level signal voltage having a voltage that turns on the selection transistor136and a voltage that turns off the selection transistor136. The second sensor electrode116is located as overlapping the first gate electrode156, and as a result, shields the electric field generated by the signal voltage. With such a structure, the signal voltage applied to the first gate electrode156is prevented from acting on the first sensor electrode114. This stabilizes the operation of the touch sensor108and prevents the touch sensor from malfunctioning.

1-3-1. Transparent Resin Substrate

The transparent resin substrate124has a structure in which a plurality of transparent resin layers150are stacked. The first sensor electrode114and the second sensor electrode116are held between the plurality of transparent resin layers150. For example, as shown inFIG.5AandFIG.5B, the first sensor electrode114is provided between a first transparent resin layer150aand a second transparent resin layer150b. The second sensor electrode116is provided between the second transparent resin layer150band the third transparent resin layer150c. In this manner, the transparent resin substrate124includes the plurality of transparent resin layers150, so that the first sensor electrode114and the second sensor electrode116are embedded in the transparent resin substrate124.

The transparent resin substrate124further includes the shield electrode126provided on a top surface of the third transparent resin layer150c. The shield electrode126is provided to spread in substantially the entirety of the pixel110ain a planar direction. In this embodiment, the shield electrode126has a first opening152ain a region overlapping the driving transistor138and a second opening152bin a region overlapping the selection transistor136. The shield electrode126is supplied with a certain potential. For example, the shield electrode126is supplied with the ground potential. The first opening152aand the second opening152bprovided in the shield electrode126prevent the potential of the shield electrode126from acting directly on the gates of the transistors.

The shield electrode126is light-transmissive. The shield electrode126is formed of, for example, a transparent conductive film. The transparent conductive film may be formed of a conductive metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO2) or the like; a transparent conductive film of, for example, a metal nitride or a metal oxide nitride such as titanium nitride (TiNx), titanium oxynitride (TiON) or the like; or a conductive organic material such as polyaniline, graphene or the like. Alternatively, the shield electrode126may be formed of a metal material such as aluminum, titanium, copper or the like and may have an opening in positional correspondence with the pixel110asuch that light is transmitted through the opening.

A fourth transparent resin layer150dis provided on the shield electrode126. The fourth transparent resin layer150dforms an insulating surface of the transparent resin substrate124. It is preferred that the fourth transparent resin layer150dhas a flat surface because components such as transistors and the like that are included in the pixel110aare provided on the fourth transparent resin layer150d.

The transparent resin substrate124is formed of a resin material and thus is flexible. Usable as the resin material are, for example, a transparent polyimide resin, a transparent polyethylenenaphthalate resin, a transparent para-polyamide resin, or the like. In the case where a transparent polyimide resin or a transparent polyethylenenaphthalate resin is used, a gas barrier film formed of silicon nitride or the like may further be provided because these resins are inferior to glass in gas barrier property. By contrast, a transparent para-polyamide resin is high in transparency, heat resistance and gas barrier property, and thus is preferably usable for the transparent resin layers150. The first transparent resin layer150a, the second transparent resin layer150b, the third transparent resin layer150cand the fourth transparent resin layer150dmay be formed of the same resin material as each other, at least a part of the layers may be formed of a different resin material, or all the layers may be formed of different resin materials from each other. Since the plurality of transparent resin layers are included in the transparent resin substrate124, the electrodes of the touch sensor108may be provided in the transparent resin substrate124.

It is preferred that the transparent resin substrate124has a heat resistance against a temperature of 150° C. to 400° C. In the case where, for example, the highest process temperature (heating temperature) at which the pixel110ais formed is 250° C. or lower, a para-polyamide resin is usable as the resin material. Use of the para-polyamide resin improves the gas barrier property of the transparent resin substrate124. In the case where, for example, the highest process temperature (heating temperature) at which the pixel110ais formed is more than 250° C., it is preferred to use a transparent polyimide resin from the point of view of heat resistance.

Cellulose nanofiber (CNF) may be mixed with a transparent polyimide resin or a transparent para-polyamide resin. Mixture of the cellulose nanofiber (CNF) with the transparent polyimide resin or the transparent para-polyamide resin provides advantages of improving the rigidity and suppressing the contraction to improve the size stability. In order to provide such advantages, the cellulose nanofiber (CNF) may be contained in any of the first transparent resin layer150a, the second transparent resin layer150b, the third transparent resin layer150cand the fourth transparent resin layer150d. It is preferred that the mixing ratio of the cellulose nanofiber (CNF) is 1% by weight to 10% by weight.

It is preferred that the first transparent resin layer150a, the second transparent resin layer150b, the third transparent resin layer150cand the fourth transparent resin layer150deach have a thickness of 3 μm to 10 μm in order to realize a function of a structure that maintains the shape of the transparent resin substrate124and a function of a flattening film that embeds the first sensor electrode114and the second sensor electrode116.

As described above, the touch panel display100in this embodiment includes the touch sensor108embedded in the transparent resin substrate124, and thus is decreased in thickness and weight.

FIG.6is a plan view showing the positional arrangement of the first sensor electrodes114and the second sensor electrodes116included in the touch sensor108. The first sensor electrodes114are of a flat plate-like (strip-like) conductive pattern extending in the Y direction. The second sensor electrodes116are of a flat plate-like (strip-like) conductive pattern extending in the X direction. The plurality of first sensor electrodes114are arrayed in the X direction, and the plurality of second sensor electrodes116are arrayed in the Y direction. The plurality of first sensor electrodes114and the plurality of second sensor electrodes116are located as crossing each other with the second transparent resin layer150bbeing located between the plurality of first sensor electrodes114and the plurality of second sensor electrodes116. The first sensor electrodes114and the second sensor electrodes116are located at a plane through which the light emitted from the pixels110ais output, and therefore are each formed of a transparent conductive film. The first sensor electrodes114and the second sensor electrodes116are provided with the second transparent resin layer150bbeing located between the first sensor electrodes114and the second sensor electrodes116. The second transparent resin layer150bacts as a dielectric film, so that an electrostatic capacitance is formed between the first sensor electrodes114and the second sensor electrodes116.

The first sensor electrodes114are each supplied with a detection signal (Vdet) and used as a receiver electrode (Rx electrode). The second sensor electrodes116are each supplied with a common driving signal (Vcom) and used as a transmitter electrode (Tx electrode). In the transparent resin substrate124, the first sensor electrodes114and the second sensor electrodes116form the touch sensor108. The touch sensor108has the electrostatic capacitance thereof changed when a finger of a human or the like touches or approaches the touch sensor108. The touch sensor108using such a characteristic is formed in the transparent resin substrate124.

The first sensor electrodes114and the second sensor electrodes116are located in a part of, or in the entirety of, the display portion102. The first sensor electrodes114and the second sensor electrodes116are light-transmissive. The first sensor electrodes114and the second sensor electrodes116are each formed of, for example, a transparent conductive film. The transparent conductive film may be formed of a conductive metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO2) or the like; a transparent conductive film of, for example, a metal nitride or a metal oxide nitride such as titanium nitride (TiNx), titanium oxynitride (TiON) or the like; or a conductive organic material such as polyaniline, graphene or the like. Alternatively, the first sensor electrodes114and the second sensor electrodes116may be formed of a metal material such as aluminum, titanium, copper or the like and each have an opening in positional correspondence with the pixel110asuch that light is transmitted through the opening.

The plurality of first sensor electrodes114and the plurality of second sensor electrodes116may be provided in any number. The first sensor electrodes114and the second sensor electrodes116merely need to distinguish, for example, a range in which a finger of a human touches the first sensor electrodes114and the second sensor electrodes116. Therefore, the first sensor electrodes114and the second sensor electrodes116are provided in a number significantly smaller than the number of the pixels110a. In the case where, for example, the display portion102has an area size (screen size) of 5 inches, the diagonal line of the display portion102has a length of 125 mm. In this case, for example, 1080×1920 pixels110amay be provided. The number of the first sensor electrodes114may be 12 (pitch: 5 mm; electrode width: 1.0 mm to 1.5 mm) or 25 (pitch: 2.5 mm: electrode width: 0.5 mm to 0.7 mm). The number of the second sensor electrodes116may be 22 (pitch: 5 mm; electrode width: 4.9 mm) or 45 (pitch: 2.5 mm; electrode width: 2.4 mm).

1-3-2. Structure of the Circuit Elements

As shown inFIG.5AandFIG.5B, the driving transistor138, the selection transistor136, the capacitance element140and the organic EL element134are provided on the transparent resin substrate124. In this embodiment, the driving transistor138and the selection transistor136each have a dual-gate structure, and the organic EL element134has a so-called inverse stack structure, in which organic electroluminescence layers are stacked from the cathode electrode side.

1-3-2-1. Driving Transistor

The driving transistor138has a structure in which the first gate electrode154, a first insulating layer158, a first oxide semiconductor layer162a, a second insulating layer154, and the second gate electrode166are stacked. The first gate electrode154is located to overlap the first oxide semiconductor layer162awith the first insulating layer158being located between the first gate electrode154and the first oxide semiconductor layer162a. The second gate electrode116is located to overlap the first oxide semiconductor layer162awith the second insulating layer164being located between the second gate electrode166and the first oxide semiconductor layer162a. The first gate electrode154, the second gate electrode166and the first oxide semiconductor layer162ahave a common overlapping region. The driving transistor138includes a channel region where the first oxide semiconductor layer162aoverlaps the first gate electrode154and the second gate electrode166. The first gate electrode154is located in the opening152a, and is embedded by the fourth transparent resin layer150d. The second gate electrode166is located on the second insulating layer164(on the side opposite to the transparent resin substrate124).

A first transparent conductive layer160aand a second transparent conductive layer160bare located between the first insulating layer158and the first oxide semiconductor layer162a. As seen in a plan view, the first transparent conductive layer160aand the second transparent conductive layer160bare located to hold the first gate electrode154and the second gate electrode166from both of two sides in a horizontal direction. The first transparent conductive layer160aand the second transparent conductive layer160bmay be located such that tip portions thereof overlap the first gate electrode154and the second gate electrode166. The first transparent conductive layer160aand the second transparent conductive layer160bare located to contact the first oxide semiconductor layer162a. The driving transistor138includes a drain region where the first transparent conductive layer160ais in contact with the first oxide semiconductor layer162a, and includes a source region where the second transparent conductive layer160bis in contact with the first oxide semiconductor layer162a.

The first oxide semiconductor layer162ais formed of a metal oxide material. The metal oxide material may be a four-component oxide material, a three-component oxide material, a two-component oxide material or a one-component oxide material. Such metal oxide materials may be in an amorphous state, a crystalline state, or a mixed state of the amorphous state and the crystalline state.

Examples of the four-component oxide material include an In2O3—Ga2O3—SnO2—ZnO-based oxide material. Examples of the three-component oxide material include an In2O3—Ga2O3—SnO2-based oxide material, an In2O3—Ga2O3—ZnO-based oxide material, an In2O3—SnO2—ZnO-based oxide material, an In2O3—Al2O3—ZnO-based oxide material, a Ga2O3—SnO2—ZnO-based oxide material, a Ga2O3—Al2O3—ZnO-based oxide material, an SnO2—Al2O3—ZnO-based oxide material. Examples of the two-component oxide material include an In2O3—ZnO-based oxide material, an SnO2—ZnO-based oxide material, an Al2O3—ZnO-based oxide material, an MgO—ZnO-based oxide material, an SnO2—MgO-based oxide material, and an In2O3—MgO-based oxide material. Examples of the one-component oxide material include an In2O3-based oxide material, an SnO2-based oxide material, and a ZnO-based oxide material. The above-described oxide semiconductors may each contain silicon (Si), nickel (Ni), tungsten (W), hafnium (Hf) or titanium (Ti). For example, the In—Ga—Zn—O-based oxide material identified above is an oxide material containing at least In, Ga and Zn with no specific limitation on the composition ratio. In other words, the oxide semiconductor layer162may be a thin film represented by chemical formula InMO3(ZnO)m(m>0). In the chemical formula, M is one or a plurality of metal elements selected from Ga, Al, Mg, Ti, Ta, W, Hf and Si. The four-component oxide material, the three-component oxide material, the two-component oxide material, and the one-component oxide material described above are not limited to containing an oxide having a stoichiometric composition, and may be an oxide material having a composition shifted from the stoichiometric composition. Such a metal oxide semiconductor material has a bandgap of 3.0 eV or larger and is visible light-transmissive.

The first transparent conductive layer160aand a second transparent conductive layer160bare formed of a conductive metal oxide material, a conductive metal nitride material or a conductive metal oxide nitride material. Examples of the metal oxide material include indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO2), niobium-containing titanium oxide (TiNbOx), and the like. Such a metal oxide material may form a good ohmic contact with the oxide semiconductor layer162. A transparent and conductive metal nitride or a transparent and conductive metal oxide nitride such as titanium nitride (TiNx), titanium oxynitride (TiON) or the like is also usable.

As shown inFIG.5A, the driving transistor138is electrically connected with the second common line146b. The first oxide semiconductor layer162aand the second transparent conductive layer160bextend to a region where the third common line146cis located, and are electrically connected with the third common line146c. The first oxide semiconductor layer162ais above, and contacts, the third common line146c, whereas the second transparent conductive layer160bis below, and contacts, the third common line146c. The second common line146bis provided in contact with the shield electrode126, and is supplied with the same potential as that of the shield electrode126. The third common line146cis electrically connected with the second common line146bvia a contact hole153aprovided in the first insulating layer158and the fourth transparent resin layer150d. As shown inFIG.4, in a planar layout, the third common line146cis electrically connected with the second common line146bextending in the first direction (the Y direction shown inFIG.4). The first common line146a, the second common line146band the third common line146care formed of a metal material such as titanium, aluminum, molybdenum, copper or the like.

The first insulating layer158has a structure in which a first silicon nitride film174aand a first silicon oxide film176aare stacked from the side of the first gate electrode154. The second insulating layer164has a structure in which, for example, a second silicon oxide film176band a second silicon nitride film174bare stacked from the side of the first oxide semiconductor layer162a. The first oxide semiconductor layer162ais provided in contact with the first silicon oxide film176aand the second silicon oxide film176b. The first oxide semiconductor layer162ais provided in contact with these silicon oxide films, and thus is expected to suppress generation of oxygen deficiency. It is preferred that the first silicon oxide film176aand the second silicon oxide film176bprovided in contact with a channel region of the first oxide semiconductor layer162ahave no oxygen deficiency and contain an excessive amount of oxygen. The first silicon oxide film176aand the second silicon oxide film176b, when containing an excessive amount of oxygen, may each be an oxygen supply source for the first oxide semiconductor layer162a. The “silicon oxide film containing an excessive amount of oxygen” encompasses a film containing a larger amount of oxygen than the stoichiometric composition. The silicon oxide film containing an excessive amount of oxygen may contain an excessive amount of oxygen in a lattice. The first insulating layer158and the second insulating layer164may contain a silicon oxide nitride film or an aluminum oxide film instead of the silicon oxide film.

The first gate electrode154and the second gate electrode166are formed of a metal material such as aluminum (Al), molybdenum (Mo), tungsten (W), zirconium (Zr), copper (Cu) or the like. Example of aluminum alloy include an aluminum-neodymium alloy (Al—Nd), an aluminum-neodymium-nickel alloy (Al—Nd—Ni), an aluminum-carbon-nickel alloy (Al—C—Ni), a copper-nickel alloy (Cu—Ni), and the like. For example, the first gate electrode154and the second gate electrode166may each be formed of a film of aluminum or a molybdenum-tungsten (MoW) alloy or the like. The first gate electrode154may include a first gate electrode layer154aformed of the same transparent conductive film as that of the shield electrode126and a first gate electrode layer154bformed of any of the above-described metal films.

The driving transistor138is covered with a flattening layer172. The flattening layer172is formed of, for example, an organic resin material such as an acrylic resin, a polyimide resin, an epoxy resin, a polyamide resin or the like. The flattening layer172has a surface thereof flattened when being coated with a composition containing a precursor of an organic resin material during the manufacturing of the touch panel display100, by the leveling action of the coating film. Alternatively, the flattening film172may be formed of an inorganic insulating film such as a silicon oxide film, a silicon nitride film or the like.

The driving transistor138in this embodiment has a dual-gate structure in which the first oxide semiconductor layer162ais held between the two gate electrodes (the first gate electrode154and the second gate electrode166). It is preferred that the first gate electrode154and the second gate electrode166are electrically connected with each other and are of the same potential. With such an arrangement, the driving transistor138has a current driving capability thereof improved, and thus provides a sufficient level of current to drive the organic EL element134. For example, even if the operation point of the organic element134is fluctuated, the driving transistor138may perform constant current driving in accordance with the fluctuation in the operation point.

1-3-2-2. Selection Transistor

The selection transistor136has a structure in which the first gate electrode156, the first insulating layer158, a second oxide semiconductor layer162b, the second insulating layer164, and the second gate electrode168are stacked. The selection transistor136includes a channel region where the second oxide semiconductor layer162boverlaps the first gate electrode156and the second gate electrode168. The first gate electrode156is located in the opening152bof the shield electrode126. The first gate electrode156may have a structure in which, in the second opening152b, a first gate electrode layer156aformed of the same transparent conductive film as that of the shield electrode126and a first gate electrode layer156bformed of a metal film are stacked on each other. A third transparent conductive layer160cand a fourth transparent conductive layer160dare provided between the first insulating layer158and the second oxide semiconductor layer162b. The third transparent conductive layer160cand the fourth transparent conductive layer160dare provided in contact with the second oxide semiconductor layer162b, and thus act as a source region and a drain region respectively. As seen in a plan view, the third transparent conductive layer160cand the fourth transparent conductive layer160dare provided to hold the first gate electrode156and the second gate electrode168from both of two sides in the horizontal direction.

The third transparent conductive layer160cis electrically connected with the data signal line144. The data signal line144is in direct contact with a top surface of the third transparent conductive layer160c. The second oxide semiconductor layer162bis provided to extend to a region where the data signal line144is provided and to cover the data signal line144. The data signal line144is in direct contact with the third transparent conductive layer160c, and thus has a larger contact area size, and a lower contact resistance, than in the case where the data signal line144is connected with the third transparent conductive layer160cvia a contact hole. The data signal line144has the top surface and a side surface be covered with the second oxide semiconductor layer162b, and thus is not exposed to an oxidizing atmosphere or a reducing atmosphere during the manufacturing of the touch panel display100. Therefore, the data signal line144is capable of suppressing the surface thereof from having a high resistance.

The fourth transparent conductive layer160dis electrically connected with a drain electrode169. The second oxide semiconductor layer162bis provided on a top surface of the fourth transparent conductive layer160dto cover the drain electrode169. The drain electrode169is electrically connected with the second gate electrode166of the driving transistor138. The selection transistor136has a dual-gate structure in which the second oxide semiconductor layer162bis held between the first gate electrode156and the second gate electrode168. This improves the switching characteristics of, and decreases the off-current of, the selection transistor136.

1-3-2-3. Capacitance Element

As shown inFIG.5B, the capacitance element140has a structure in which a first capacitance electrode170a, the first insulating layer158and a second capacitance electrode170bare stacked. The first capacitance element170ais formed in a region where the fourth transparent conductive layer160dand the second oxide semiconductor layer162bare extended to be outer to the drain electrode169. The first capacitance element170ahas a structure in which the fourth transparent conductive layer160dand the second oxide semiconductor layer160bare stacked on each other. The first capacitance element170ais electrically connected with the drain of the selection transistor136. The second first capacitance element170bis formed in the same layer as that of the second gate electrode168, and is electrically connected with the first common line146avia a contact hole153bprovided in the first insulating layer158and the fourth transparent resin layer150d.

1-3-2-4. Organic EL Element

As shown inFIG.5A, the organic EL element134has a structure in which a first electrode180corresponding to a cathode electrode, an electron transfer layer182, an electron injection layer184, a light emitting layer186, a hole transfer layer188, a hole injection layer190, and a second electrode192corresponding to an anode electrode are stacked from the side of the transparent resin substrate124.

In a region where the organic EL element134is provided, the flattening layer172and the second insulating layer164has an opening178. The first electrode180as the cathode electrode of the organic EL element134is located as overlapping the opening178. The opening178exposes a top surface of the electron transfer layer182located on the first electrode180. The electron injection layer184, the light emitting layer186, the hole transfer layer188, the hole injection layer190and the second electrode192as the anode electrode are stacked on the electron transfer layer182in positional correspondence with the opening178. A region where these stacked layers and the first electrode180overlap each other is a light emitting region of the organic EL element134. Hereinafter, each of the layers included in the organic EL element134will be described in detail.

1-3-2-4-1. Cathode Electrode

The first electrode180acting as the cathode electrode is formed of a transparent conductive film. Specifically, the first transparent conductive layer160is extended to the region of the organic EL element134to form the first electrode180. The first transparent conductive layer160aand the first electrode180are formed of one continuous conductive film, so that the driving transistor138and the organic EL element134are electrically connected with each other. The organic EL element134and the driving transistor138are directly connected with each other, not via a contact hole. Such an arrangement simplifies the structure of the pixel110a.

The first electrode180acting as the cathode electrode is formed of the same conductive film as that of the first transparent conductive layer160a. The first transparent conductive layer160ais formed of a conductive metal oxide material, a conductive metal nitride material or a conductive metal oxide nitride material. A conductive film formed of such a material has a bandgap of 2.8 eV or larger, preferably 3.0 eV or larger, and thus transmits substantially all the light of a visible range. Therefore, the first electrode180is usable as an electrode of the organic EL element134on the light output side.

On the first electrode180, the first oxide semiconductor layer162amay be provided as extending from the driving transistor138. The first oxide semiconductor layer162ahas a bandgap of 3.0 eV or larger and thus is visible light-transmissive. As described below, the electron transfer layer182is formed of a metal oxide. Therefore, the first oxide semiconductor layer162a, which is formed of the same material or the same type of material as that of the electron transfer layer182, is provided between the first electrode180acting as the cathode electrode and the electron transfer layer182, so that formation of an electron injection barrier is prevented. In other words, the first oxide semiconductor layer162aextending from the channel region of the driving transistor138is usable as a part of the electron transfer layer182, which is in contact with the first electrode180.

1-3-2-4-2. Electron Transfer Layer

The electron transfer layer182is formed of a metal oxide material. The metal oxide material may be substantially the same four-component oxide material, three-component oxide material, two-component oxide material or one-component oxide material as that of the oxide semiconductor layer162. Such metal oxide materials may be in an amorphous state, a crystalline state, or a mixed state of the amorphous state and the crystalline state.

For example, the electron transfer layer182may be formed to contain one or a plurality of substances selected from an indium oxide, a zinc oxide, a gallium (Ga) oxide, a tin (Sn) oxide, a magnesium (Mg) oxide, a silicon (Si) oxide, a hafnium (Hf) oxide, a tantalum (Ta) oxide and a niobium (Nb) oxide. These metal oxide materials have a bandgap of 3.0 eV or larger and is visible light-transmissive. It is preferred that the electron transfer layer182has a thickness of 50 nm to 100 nm. The electron transfer layer182may be as thick as possible, so that the effect of preventing the short-circuiting between the first electrode180and the second electrode192is improved. The electron transfer layer182is formed by sputtering, vacuum vapor deposition, coating or the like.

It is preferred that the electron transfer layer182has a carrier concentration that is 1/10 or less, preferably 1/100 or less, of that of the first oxide semiconductor layer162a. In other words, it is preferred that the first oxide semiconductor layer162ahas a carrier concentration, in a region in contact with the electron transfer layer182, that is 10 times or greater, preferably 100 times or greater, the carrier concentration of the electron transfer layer182. Specifically, it is preferred that the carrier concentration of the electron transfer layer182is 1013/cm3to 1017/cm3, whereas the carrier concentration of the first oxide semiconductor layer162ais 1015/cm3to 1019/cm3, and that the difference in the carrier concentration between the layers is one digit or greater, preferably two digits or greater. The first oxide semiconductor layer162ahas a carrier concentration of 1015/cm3to 1019/cm3, so that the resistance loss is decreased in the electrical connection between the driving transistor138and the organic EL element134and thus the driving voltage is suppressed from increasing. If the carrier concentration of the electron transfer layer182is 1020/cm3or greater, the excited state in the light emitting layer186is deactivated and thus the light emission efficiency is decreased. By contrast, if the carrier concentration of the electron transfer layer182is 1013/cm3or less, the number of the carriers supplied to the light emitting light186is decreased and thus a sufficient level of luminance is not provided. As described above, the first oxide semiconductor layer162aextending from the driving transistor138is provided in contact with the light transfer layer182and the carrier concentrations of the layers are made different from each other, so that the driving voltage is prevented from increasing and the light emission efficiency of the organic EL element134is increased.

The carrier concentration of the electron transfer layer182may be controlled by controlling the concentration of the oxygen deficiency in an oxide semiconductor film. The oxygen deficiency in the oxide semiconductor film acts as a donor. When the density of the oxygen deficiency in the oxide semiconductor film is increased, the carrier concentration is increased, whereas when the density of the oxygen deficiency in the oxide semiconductor film is decreased, the carrier concentration is decreased. The oxygen deficiency in the oxide semiconductor film may be increased by, for example, causing hydrogen to act thereon, and may be decreased by supplying oxygen.

1-3-2-4-3. Electron Injection Layer

In the organic EL element134, the electron injection layer184is used to lower the energy barrier and thus to promote the injection of electrons into the electron transfer layer182from the cathode electrode. It is preferred that the electron injection layer184is provided to make it easier for the electrons to be injected from the electron transfer layer182formed of an oxide semiconductor into the light emitting layer186. Therefore, in the organic EL element134, the electron injection layer184is provided between the electron transfer layer182and the light emitting layer186.

It is desired that the electron injection layer184is formed of a material having a small work function in order to inject electrons into the light emitting layer186. The electron injection layer184is formed to contain a calcium (Ca) oxide and an aluminum (Al) oxide. It is preferred that, for example, C12A7 (12CaO·7Al2O3) electride for the electron injection layer184. C12A7 electride has semiconductor characteristics and is controllable to have any resistance between a high resistance and a low resistance. C12A7 electride also has a work function of 2.4 eV to 3.2 eV, which is substantially equal to that of an alkaline metal material. Therefore, C12A7 electride is preferably usable for the electron injection layer184.

The electron injection layer184formed of C12A7 electride is formed by sputtering with polycrystalline C12A7 electride being used as a target. Since C12A7 electride has semiconductor characteristic, it is preferred that the electron injection layer184has a thickness of 1 nm to 100 nm. If the thickness of the electron injection layer184is less than this range, an interface having a small energy barrier cannot be formed between the electron injection layer184and the light emitting layer186. If the thickness of the electron injection layer184is greater than this range, the resistance is too high and thus the driving voltage is increased. It is preferred that C12A7 electride has a Ca:Al molar ratio of 13:13 to 11:16. Since the electron injection layer184is formed by sputtering, it is preferred that C12A7 electride is amorphous. C12A7 electride may be crystalline.

C12A7 electride is stable in the air, and thus has an advantage of being easier to handle than an alkaline metal compound conventionally used for an electron injection layer, for example, lithium fluoride (LiF), lithium oxide (Li2O), sodium chloride (NaCl), potassium chloride (KCl) or the like. With such an advantage, it is made unnecessary to perform operations in dry air or in an inert gas during the formation of the organic EL element134, which alleviates the manufacturing conditions.

C12A7 electride has a high ionization potential, and thus is usable for a hole blocking layer when being provided on the side opposite to the hole transfer layer188with the light emitting layer186being held between the hole blocking layer and the hole transfer layer188. Namely, the electron injection layer184formed of C12A7 electride is provided between the electron transfer layer182and the light emitting layer186, so that holes injected into the light emitting layer186are suppressed from moving to reach the first electrode180acting as the cathode electrode. As a result, the light emission efficiency is improved.

1-3-2-4-4. Light Emitting Layer

The light emitting layer186may be formed of any of various materials. Examples of the material usable for the light emitting layer186include a fluorescent compound that emits fluorescence and a phosphorescent compound that emits phosphorescence. For example, a light emitting layer corresponding to red and a light emitting layer corresponding to green may each be formed of a phosphorescent compound, whereas a light emitting layer corresponding to blue may be formed of a fluorescent compound. In the case of being formed of a white light emitting layer, the light emitting layer186may have a structure in which a blue light emitting layer and a yellow light emitting layer are stacked on each other. The light emitting layer186may be formed by vapor deposition, transfer, spin-coating, spray-coating, gravure printing or the like. The light emitting layer186may have an optionally selected thickness, for example, a thickness in the range of 10 nm to 100 nm.

1-3-2-4-5. Hole Transfer Layer

The hole transfer layer188is formed of a material having a hole transfer property. The hole transfer layer188may be formed of, for example, an arylamine-based compound. an amine compound containing a carbazole group, an amine compound containing a fluorene derivative, or the like. The hole transfer layer188is formed by vacuum vapor deposition, coating or the like. The hole transfer layer188may be formed by such a method to have a thickness of 10 nm to 500 nm. The hole transfer layer188may be omitted.

1-3-2-4-6. Hole Injection Layer

The hole injection layer190contains a substance having a high level of property of injecting holes into an organic layer. Examples of substance having such a high level of property of injecting holes include a metal oxide such as a molybdenum oxide, a vanadium oxide, a ruthenium oxide, a tungsten oxide, a manganese oxide, or the like. Alternatively, phthalocyanine (H2PC), copper (II) phthalocyanine (CuPC), hexaazatriphenylenehexacarbonnitrile (HAT-(CN)6) or the like may be used. The hole injection layer190of such a material is formed by vacuum vapor deposition, coating or the like. The hole injection layer190is formed by such a method to have a thickness of 1 nm to 100 nm.

1-3-2-4-7. Anode Electrode

The second electrode192acting as the anode electrode is formed of a metal material, an alloy or a conductive compound having a large work function (specifically. 4.0 eV or larger). The second electrode192is formed of, for example, indium tin oxide (ITO), indium zinc oxide (IZO), indium oxide containing tungsten oxide and zinc oxide (IWZO), or the like. The second electrode192acting as the anode electrode formed of such a conductive metal oxide material is formed by vacuum vapor deposition or sputtering. Since the organic EL element134is of a bottom emission-type, it is preferred that the second electrode192acting as the anode electrode is light-reflective or has a light-reflecting surface. Since a film of a conductive metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO) or the like is light-transmissive, a metal film of aluminum (Al), silver (Ag) or the like may be stacked on a surface of the second electrode192that is opposite to the hole injection layer190. Although being omitted inFIG.4,FIG.5AandFIG.5B, a passivation layer blocking the transmission of oxygen (O2) or moisture (H2O) may be provided on the second electrode192.

As described above, the pixel110ain this embodiment has a structure in which the driving transistor138having an n-channel conductivity and the organic EL element134are electrically connected with each other. The organic EL element134are of a bottom emission-type, and emitted light toward the shield electrode126. The electron transfer layer182and the electron injection layer184, which are lower layers of the organic EL element134, are formed of an inorganic insulating material. Therefore, the organic EL element134suppresses the characteristics thereof from being deteriorated and stabilizes the characteristics thereof.

1-4. Structure of the Touch Sensor

As described above with reference toFIG.6, the first sensor electrodes114and the second sensor electrodes116are located to cross each other so as to form a matrix.FIG.7shows a structure of the touch sensor108and the driving circuit112located as overlapping the display portion102.

FIG.7shows the touch sensor108including the first sensor electrodes114and the second sensor electrodes116, and the first driving circuit112a, the second driving circuit112band the third driving circuit112clocated outer to the touch sensor108. The first driving circuit112ahas a function of sequentially selecting scanning signal lines located in the display portion102and outputting the scanning signals. The third driving circuit112cis a scanning circuit for the touch sensor108, and has a function of sequentially selecting the second sensor electrodes116and outputting the common driving signals (Vcom). The first driving circuit112aand the third driving circuit112ceach include a sequential logic circuit such as a shift register or the like.

By contrast, the second driving circuit112bincludes circuit blocks having different functions form each other. The circuit blocks include a touch sensor sensing circuit block117a, a touch sensor scanning circuit block117b, a scanning signal line driving circuit block117c, and a video signal line driving circuit block117d. It is preferred that the second driving circuit112bincluding these circuit blocks117is realized by one semiconductor chip (integrated circuit).FIG.7shows a form in which the second driving circuit112bincluding the plurality of circuit blocks is realized by one bare chip and is mounted on the flexible printed circuit board122by COF (Chip on Film). One semiconductor chip is provided to have such a plurality of functions in this manner, so that the cost for mounting is decreased.

In the second driving circuit112b, the touch sensor sensing circuit block117ais connected with the first sensor electrodes114. The touch sensor sensing circuit block117ahas a function of sequentially outputting sensing signals (Vdet) to the first sensor electrodes114. The touch sensor scanning circuit block117bhas a function of outputting a timing signal and the common driving signal (Vcom) to the third driving circuit112c. The scanning signal line driving circuit block117chas a function of outputting a timing signal, synchronized to a video signal, to the first driving circuit112a. The video signal line driving circuit block117dis connected with video signal lines located in the display portion102, and has a function of outputting a video signal to the video signal lines.

FIG.8shows a form in which the first driving circuit112aand the third driving circuit112care located on both of two sides of the display portion102. In this circuit layout, the scanning signal lines (not shown) located in the display portion102are supplied with the same scanning signal from both of the two sides, and the second sensor electrodes116are supplied with the same common driving signal (Vcom) from both of the two sides. With such a circuit layout, even in the case of having a large load capacitance, the scanning signal lines and the second sensor electrodes116may be driven at high speed. In the second driving circuit112b, the touch sensor sensing circuit block117a, the touch sensor scanning circuit block117b, the scanning signal line driving circuit block117cand the video signal line driving circuit block117dare integrated into one semiconductor chip (integrated circuit). Such an arrangement decreases the number of steps of mounting the semiconductor chip (integrated circuit) on the flexible printed circuit board122as compared with the case where the circuit blocks are realized by individual semiconductor chips (integrated circuits).

In the case where a semiconductor chip (integrated circuit) that controls the touch sensor108and a semiconductor chip (integrated circuit) that drives the display portion102are realized by individual semiconductor chips, these two semiconductor chips need to be mounted. In this case, the same mounting steps are repeated twice, which decreases the productivity. By contrast, in this embodiment, only one mounting step is needed. This improves the manufacturing yield and decreases the manufacturing cost.

In the example shown inFIG.7, the second driving circuit112bis realized by one semiconductor chip. The present invention is not limited to this, and the circuit blocks may be realized by individual semiconductor chips.

FIG.9schematically shows a cross-sectional structure of the touch panel display100. The touch panel display100includes the transparent resin substrate124including the first sensor electrodes114, the second sensor electrodes116and the shield electrode126, and also includes the terminal portion106, a circuit element layer149, the organic EL elements134, and the sealing layer128provided on the transparent resin substrate124. The circuit element layer149includes circuit elements such as the driving transistor138, the selection transistor136, the capacitance element140, and the like.

In the terminal portion106, terminal electrodes118aand118bare formed in the same layer as that of the circuit element layer149. Namely, the terminal electrodes118aand118bare provided on the fourth transparent resin layer150d. In this case, the first sensor electrodes114are each connected with the terminal electrode118bvia a contact hole running through the fourth transparent resin layer150d, the third transparent resin layer150cand the second transparent resin layer150b. The second sensor electrodes116are each connected with the terminal electrode118avia a contact hole running through the fourth transparent resin layer150dand the third transparent resin layer150c. The terminal electrodes118aand118bare electrically connected with the flexible printed circuit board122, on which the second driving circuit112bis mounted. In this manner, the terminal electrodes located in the same layer and the sensor electrodes are connected with each other via contact holes having different depths, so that the terminal portion106has a high density. In this embodiment, the sensor electrodes114and116forming the touch sensor108are embedded in the transparent resin substrate124, so that the touch panel display100is thinned and is made flexible.

1-5. Method for Manufacturing the Touch Panel Display

An example of method for manufacturing the touch panel display100in an embodiment according to the present invention will be described with reference to the drawings. Hereinafter, the manufacturing method in this embodiment will be described by way of the structures of various manufacturing steps corresponding to the structure of the pixel110ashown inFIG.5AandFIG.5B.

FIG.10AandFIG.10Bshow a stage of forming the transparent resin substrate124. For manufacturing the touch panel display100in this embodiment, a support substrate200is used. The support substrate200may be a plate-like glass substrate having a first surface and a second surface opposite to the first surface. It is desired that the glass substrate has a high level of heat resistance. It is preferred that, for example, an alkali-free glass substrate having a strain point of 500° C., preferably 550° C. is used.

The first transparent resin layer150ais formed on the first surface of the support substrate200. The first transparent resin layer150ais formed of an insulating resin material. Examples of the insulating resin material include a transparent polyimide resin, a transparent polyethylenenaphthalate resin, a transparent para-polyamide resin, and the like. In the case where the transparent polyimide resin is used, the first transparent resin layer150ais formed as follows, for example. Diamine and acid anhydride are polymerized in the presence of a solvent to form a polyimide precursor resin. Then, the polyimide precursor resin is applied to the first surface of the support substrate200and is imidized by heat treatment. As a result, the first transparent resin layer150ais formed. In the case where the transparent para-polyamide resin is used, the first transparent resin layer150ais formed as follows. The transparent para-polyamide resin is copolymerized to have a better solubility in an organic solvent. The resultant transparent para-polyamide resin is applied to the first surface of the support substrate200, and is heat-treated to vaporize the solvent and thus is cured. As a result, the first transparent resin layer150ais formed. The first transparent resin layer150ais formed to have a thickness of 3 μm to 30 μm.

The first sensor electrodes114are formed on the first transparent resin layer150a. The first sensor electrodes114are formed of a transparent conductive film. The transparent conductive film is formed of a conductive metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO2), niobium-containing titanium oxide (TiNbOx), or the like; a conductive transparent film of a metal nitride or a metal oxide nitride such as titanium nitride (TiNx), titanium oxynitride (TiON) or the like; a metal nanowire of silver (Ag) or the like; or a conductive organic material such as polyaniline, graphene, carbon nanotube or the like. The first sensor electrodes114are formed as follows. The transparent conductive film is formed on the entirety of a first surface of the first transparent resin layer150a. Then, a resist mask is formed by lithography and etching is performed, so that the first sensor electrodes114are formed. The transparent conductive film formed on the first transparent resin layer150ais patterned to be, for example, flat plate-like (strip-like) as shown inFIG.6. Alternatively, the first sensor electrodes114may be formed of a metal film and patterned to be meshed with through-holes being located in positional correspondence with the pixels110aas described in another embodiment. The first sensor electrodes114are formed to have a thickness of 50 nm to 1000 nm.

The second transparent resin layer150bis formed on the first sensor electrodes114. The second transparent resin layer150bis formed in substantially the same manner as that of the first transparent resin layer150a. It is preferred that the second transparent resin layer150bis formed to embed the steps caused by the pattern of the first sensor electrodes114and thus to provide a flat surface. The second sensor electrodes116are formed on the second transparent resin layer150b. The second sensor electrodes116are formed in substantially the same manner as that of the first sensor electrodes114. The second sensor electrodes116are formed to be patterned to be, for example, flat plate-like (strip-like) as shown inFIG.6. In the second sensor electrodes116, an opening119is formed in positional correspondence with the first gate electrode154of the driving transistor138. The third transparent resin layer150cis formed on the second sensor electrodes116. The third transparent resin layer150cis formed in substantially the same manner as that of the first transparent resin layer150a. It is preferred that the third transparent resin layer150cis formed to embed the steps caused by the pattern of the second sensor electrodes116and thus to provide a flat surface.

FIG.11AandFIG.11Bshow a stage of forming the shield electrode126and the fourth transparent resin layer150don the third transparent resin layer150c. The shield electrode126is formed to cover substantially the entirety of the third transparent resin layer150c. The shield electrode126is formed of a transparent conductive film. The transparent conductive film is formed of a conductive metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO2), niobium-containing titanium oxide (TiNbOx) or the like. The shield electrode126is formed by sputtering. The shield electrode126may have a thickness of about 50 nm to about 500 nm. In the case where the shield electrode126is formed of silver (Ag) nanowire, carbon nanotube, graphene or the like, a solution having silver (Ag) nanowire dispersed therein, a solution having carbon nanotube dispersed therein, or a solution having graphene dispersed therein may be applied to the surface of the third transparent resin layer150c. Thus, the shield electrode126is formed.

In the shield electrode126, the first opening152ais formed in positional correspondence with the first gate electrode154of the driving transistor138, and the second opening152bis formed in positional correspondence with the first gate electrode156of the selection transistor136. The common line146is formed on the shield electrode126. The common line146is formed of a metal film of titanium (Ti), aluminum (Al), molybdenum (Mo), copper (Co) or the like.

The first gate electrode154is formed in the first opening152a. The first gate electrode154is formed to have a structure in which the first gate electrode layer154aformed of the same transparent conductive film as that of the shield electrode126and the first gate electrode layer154bformed of the same metal film as that of common line146are stacked on each other. The first gate electrode156is formed in the second opening152b. The first gate electrode156has substantially the same structure as that of the first gate electrode154. The first gate electrode154and the first gate electrode156are formed in the same conductive layer as that of the shield electrode126and the common line146, so that the structure and the manufacturing procedure are simplified. The openings152, the common line146and the first gate electrodes154and156in the shield electrode126are formed by multiple tone exposure. This step will be described in detail with reference toFIG.12AtoFIG.12E.

FIG.12AtoFIG.12Eeach show a cross-sectional structure of a region where the driving transistor138is located (corresponding to the cross-sectional view ofFIG.11A) in a lithography step of forming the shield electrode126, the first common line146a, the second common line146band the first gate electrode154.FIG.12AtoFIG.12Eomit the components below the third transparent resin layer150c.

FIG.12Ashows a stage of forming a transparent conductive film130and a metal film132on the third transparent resin layer150cand exposing a photoresist film304formed on the metal film132. In this step, multiple tone exposure (half-tone exposure) is adopted to form the first opening152ain the shield electrode126and also to form the first common line146a, the second common line146band the first gate electrode154(including the first gate electrode layer154aand the second gate electrode layer154b) on the shield electrode126as shown inFIG.12E, by use of one photomask. Hereinafter, the steps of the procedure will be described with reference toFIG.12AtoFIG.12E.

InFIG.12A, the photoresist film304is positive. As a result of development, a non-exposed region of the photoresist film304is left and an exposed region of the photoresist film304is removed. For exposing the photoresist film304, a multiple tone mask300is used. The multiple tone mask300has a multiple tone mask pattern302. As a multiple tone mask, a gray-tone mask and a half-tone mask are generally known. The gray-tone mask has slits of the resolution of the exposure device or less, and the slits block a part of the light to realize multiple tone exposure. The half-tone mask uses a semi-transmissive film to realize multiple tone exposure. In this embodiment, the half-tone mask is used. The multiple tone mask pattern302includes an exposed region, a semi-exposed region and a non-exposed region. In the example shown inFIG.12A, a region corresponding to the first opening152ais the exposed region except for the region where the first gate electrode154is to be formed, a region corresponding to the shield electrode126is the semi-exposed region, and a region corresponding to the first common line146a, the second common line146band the first gate electrode layer154bis the non-exposed region.

FIG.12Bshows a stage of exposing the photoresist mask304through the multiple tone mask300and developing the photoresist mask304. As a result of developing the photoresist mask304, a resist mask pattern306aincluding regions having different thicknesses in accordance with the amount of light used for the exposure is formed.FIG.12Bshows a form in which the resist mask pattern306aformed of a positive resist is thin in a region corresponding to the region where the first common line146a, the second common line146band the first gate electrode layer154bare to be formed, and is thick in a region corresponding to the region where the shield electrode126is to be formed.

FIG.12Cshows a stage of etching the metal film132and the transparent conductive film130to form the shield electrode126, the first opening152aand the first gate electrode layer154a. In the case where the metal film132is formed of a metal material such as titanium (Ti), molybdenum (Mo) or the like, dry etching using a fluorine-based etching gas such as CF4or the like may be performed. In the case where the transparent conductive film130is formed of a metal oxide such as ITO or the like, dry etching using a chlorine-based etching gas such as BCl3or the like may be performed. The transparent conductive film130is difficult to be etched by a fluorine-based etching gas such as CF4or the like. Therefore, the metal film132may be selectively etched on the transparent conductive film130. The metal film132, which may be selectively etched, and the transparent conductive film130are stacked on each other as described above, so that a complex shape is formed by use of one multiple tone mask300.

Then, as shown inFIG.12D, the resist pattern306ais treated with oxygen plasma or the like to remove a portion corresponding to the semi-exposed region, so that a resist mask pattern306bis formed. The resist mask pattern306bis used to selectively etch the metal film132. As a result, as shown inFIG.12E, the first common line146aand the second common line146bare formed on the shield electrode126, and the first gate electrode layer154bis formed on the first gate electrode layer154a. Then, the resist pattern306bis removed by ashing or the like.

In this manner, the shield electrode126having the first opening152a, the first common line146a, the second common line146band the first gate electrode154(including the first gate electrode layer154aand the second gate electrode layer154b) are formed by use of one photomask and one exposure step. Although not shown inFIG.12AtoFIG.12E, the second opening152gand the first gate electrode156(including the first gate electrode layer156aand the second gate electrode layer156b), are formed in substantially the same manner.

The fourth transparent resin layer150dis formed on the shield electrode126. The fourth transparent resin layer150dis formed in substantially the same manner as that of the first transparent resin layer150a. The fourth transparent resin layer150dflattens the top surface of the transparent resin substrate124.

FIG.13AandFIG.13Bshow a stage of forming the first insulating layer158, the transparent conductive layer160, the common line146. The first insulating layer158is formed by stacking the first silicon nitride film174aand the first silicon oxide film176afrom the side of the fourth transparent resin layer150d. The first silicon nitride film174ais formed by plasma CVD using, as a source gas, a gas such as SiH4, HN3, N2or the like. Similarly, the first silicon oxide film176ais formed by plasma CVD, optionally using SiH4, N2O, Si(OC2H5)4(tetraethoxysilane), Si(OCH3)4(tetramethoxysilane), or the like. The first insulating layer158is formed to cover substantially the entirety of the fourth transparent resin layer150d.

After the first insulating layer158is formed, the contact hole153aexposing the second common line146bis formed. The contact hole153aruns through the first insulating layer158and the fourth transparent resin layer150d.

The transparent conductive layer160(the first transparent conductive layer160a, the second transparent conductive layer160b, the third transparent conductive layer106cand the fourth transparent conductive layer160d), the first capacitance electrode170a, the data signal line144, the drain electrode169and the third common line146care formed on the first insulating layer158. The transparent conductive layer160and the first capacitance electrode170aare formed of a metal oxide material. Examples of the metal oxide material include indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO2), niobium-containing titanium oxide (TiNbOx), and the like. The data signal line144, the drain electrode169and the third common line146care formed of a metal material. Examples of the metal material include titanium (Ti), aluminum (Al), molybdenum (Mo), copper (Co), and the like. Such a line and such an electrode each have a structure in which aluminum (Al) or a core metal mainly formed of aluminum (Al) is covered with a high melting point metal material such as titanium (Ti), molybdenum (Mo), copper (Co) or the like provided above or below aluminum (Al) or the core metal.

The transparent conductive layer160(the first transparent conductive layer160a, the second transparent conductive layer160b, the third transparent conductive layer106cand the fourth transparent conductive layer160d), the first capacitance electrode170a, and the third common line146care formed as follows. The corresponding transparent conductive films and metal film are formed on the first insulating layer158, and then are patterned by multiple tone exposure in substantially the same manner as described above with reference toFIG.12AtoFIG.12E. As a result of this step, the second common line146band the third common line146care electrically connected with each other via the fourth transparent resin layer150din the region where the contact hole153ais formed. The data signal line144is formed on the third transparent conductive layer160c, and the drain electrode169is formed on the fourth transparent conductive layer160d.

FIG.14AandFIG.14Bshow a stage of forming the oxide semiconductor layers162(the first oxide semiconductor layer162aand the second oxide semiconductor layer162b). The first oxide semiconductor layer162ais formed to cover substantially the entirety of the first transparent conductive layer160aand the second transparent conductive layer160b. The second oxide semiconductor layer162bis formed to cover substantially the entirety of the third transparent conductive layer160cand the fourth transparent conductive layer160d. The first oxide semiconductor layer162aand the second oxide semiconductor layer162bare formed as follows. An oxide semiconductor film is formed by sputtering with an oxide semiconductor being used as a target, and then is patterned into island-like as shown inFIG.4by lithography. Thus, the first oxide semiconductor layer162aand the second oxide semiconductor layer162bare formed. The first oxide semiconductor layer162ais formed to be in contact with, and thus is electrically connected with, the first transparent conductive layer160aand the second transparent conductive layer160b. The second oxide semiconductor layer162bis formed to be in contact with, and thus is electrically connected with, the third transparent conductive layer160cand the fourth transparent conductive layer160d.

FIG.15AandFIG.15Bshow a stage of forming the electron transfer layer182, the second insulating layer164, the second gate electrodes166and168and the second capacitance electrode170bon the oxide semiconductor layers162(the first oxide semiconductor layer162aand the second oxide semiconductor layer162b).

As shown inFIG.15A, the electron transfer layer182is formed on the first oxide semiconductor layer162a. The electron transfer layer182is in contact with a top surface of the first oxide semiconductor layer162aand is individually provided for each pixel110a. The electron transfer layer182is formed in a region overlapping the first electrode180continuous from the first transparent conductive layer160a. Like the first oxide semiconductor layer162a, the electron transfer layer182is formed of an oxide semiconductor. The electron transfer layer182is formed of an oxide semiconductor material different from the oxide semiconductor material used to form the first oxide semiconductor layer162a, and thus is selectively processable on the first oxide semiconductor layer162a. More specifically, the electron transfer layer182is formed of an oxide semiconductor material having a higher etching rate than the oxide semiconductor material of the first oxide semiconductor layer162a, and thus is selectively processable. A multiple tone photomask is used for this process, so that the first oxide semiconductor layer162aand the electron transfer layer182are formed at the same time by one exposure step.

For example, it is preferred that the electron transfer layer182is formed of a zinc-based oxide semiconductor layer not containing tin (Sn) (e.g., ZnSiOx, ZnMgO, ZnGaOx, etc.), whereas the oxide semiconductor layer162is formed of a tin (Sn)-based oxide semiconductor layer not containing zinc (Zn), magnesium (Mg) or the like (e.g., InGaSnOx, InWSnOx, InSiSnOx, etc.). In other words, it is preferred that the electron transfer layer182contains zinc oxide and at least one selected from silicon oxide, magnesium oxide and gallium oxide, and that the oxide semiconductor layer162contains tin oxide, and at least one selected from indium oxide, gallium oxide, tungsten oxide and silicon oxide. With such an arrangement, the etching rates of the two layers are made different from each other to increase the selection ratio. More specifically, the etching rate of the electron transfer layer182is made higher than the etching rate of the oxide semiconductor layer162. In addition, the bandgaps of the oxide semiconductor layer162and the electron transfer layer182are optimized. More specifically, the bandgap of the electron transfer layer182is made larger than the bandgap of the oxide semiconductor layer162. For example, in the case where the bandgap of the oxide semiconductor layer162is 3.0 eV or larger, the bandgap of the electron transfer layer182is larger than, or equal to, the bandgap of the oxide semiconductor layer162, preferably 3.4 eV or larger. In the case of having a bandgap of 3.4 eV or larger, the electron transfer layer182does not absorb blue light and thus improves the reliability. It is preferred that the oxide semiconductor layer162has a thickness of 10 nm to 100 nm, whereas the electron transfer layer182has a thickness of 50 nm to 500 nm. In the case where the oxide semiconductor layer162and the electron transfer layer182each have a thickness in such a range, generation of plasmon in the first electrode180formed of a transparent conductive oxide is suppressed, which improves the light emission efficiency of the organic EL element134.

The second insulating layer164is formed to cover the oxide semiconductor layer162and the electron transfer layer182. The second insulating layer164is formed by, for example, stacking the second silicon oxide film176band the second silicon nitride film174bfrom the side of the oxide semiconductor layer162. As a result, the first silicon oxide film176ais formed below the oxide semiconductor layer162, and the second silicon oxide film176bis formed above the oxide semiconductor layer162. The oxide semiconductor layer162is held between the oxide insulating films, so that generation of a defect caused by oxygen deficiency (donor level) is suppressed.

As shown inFIG.15B, the contact hole153brunning through the second insulating layer164, the first insulating layer158and the fourth transparent resin layer150dand exposing the first common line146ais formed. The contact hole153crunning through the second insulating layer164and the first oxide semiconductor layer162aand exposing the drain electrode169is formed.

Then, the second gate electrodes166and168and the second capacitance electrode170bare formed. The second gate electrodes166and168and the second capacitance electrode170bare formed by performing lithography and etching on a metal film formed on a top surface of the second insulating layer164. The second gate electrode166is formed to include a region overlapping the first gate electrode154, and the second gate electrode168is formed to include a region overlapping the first gate electrode156. As a result, the driving transistor138and the selection transistor136are formed. The second gate electrode166is electrically connected with the drain electrode169via the contact hole153c. The second capacitance electrode170bis electrically connected with the first common line146avia the contact hole153b. The capacitance element140is provided in a region where the first capacitance electrode170aand the second capacitance electrode170boverlap each other with the second insulating layer164being located between the first capacitance electrode170aand the second capacitance electrode170b.

FIG.16AandFIG.16Bshow a stage of forming the flattening layer172and forming the opening178exposing the electron transfer layer182. The flattening layer172is formed to embed the selection transistor136, the driving transistor138and the capacitance element140. The flattening layer172is formed of an organic resin material such as, for example, an acrylic resin, a polyimide resin, an epoxy resin, a polyamide resin or the like. In the flattening layer172, the opening178exposing the electron transfer layer182is formed. In the case where the flattening layer172is formed of a photosensitive resin material, the opening178is formed by performing exposure by use of a photomask. In the second insulating layer164, an opening may be formed in a region corresponding to the opening178before the flattening layer172is formed. It is preferred that the opening178has a tapered inner surface for the formation of the organic EL element134.

Then, the electron injection layer184, the light emitting layer186, the hole transfer layer188, the hole injection layer190and the second electrode192are formed. The transparent resin substrate124is delaminated from the support substrate200. The transparent resin substrate124is delaminated by directing laser light toward the support substrate200. More specifically, ablation is caused between the transparent resin substrate124and the support substrate200to weaken the adherence force of the first transparent resin layer150aand thus to delaminate the transparent resin substrate124.

As a result of the above-described steps, the touch panel display100including the pixels110ashown inFIG.5AandFIG.5Bis manufactured. The electron injection layer184may be formed by sputtering method with C12A7 electride being used as a sputtering target. The electron injection layer184is commonly used for the plurality of pixels110a, and therefore, is formed in substantially the entirety of the region where the pixels110aare located. The light emitting layer186is formed of a different light emitting material for each of a red pixel, a green pixel and a blue pixel. In the case where the light emitted from the light emitting layer186has a white light emission spectrum, the light emitting layer186is formed, as a layer common for the plurality of pixels110a, in substantially the entirety of the region where the pixels110aare located. The hole transfer layer188and the hole injection layer190are each formed, as a layer common for the plurality of pixels110a, in substantially the entirety of the region where the pixels110aare located. The second electrode192is used as a common electrode for the plurality of pixels110a, and therefore, are formed in substantially the entirety of the region where the pixels110aare located.

In the above-described steps, as shown inFIG.17, the support substrate200may be a mother glass substrate (substrate on which a plurality of devices is to be formed), so that a plurality of display panels101are formed on the support substrate200. In this case, the transparent resin layers150are formed on substantially the entirety of a surface of the support substrate200except for an end portion thereof, and the plurality of display panels101are formed in the region where the transparent resin layers150are formed. In order to individually provide the plurality of display panels101formed on the support substrate200, the transparent resin substrate124including the transparent resin layers150is divided along a division region202. The division of the transparent resin substrate124may be performed by laser processing.

In this case, it is preferred that the shield electrode126of a transparent conductive film is not formed in the division region202. It is also preferred that neither the first insulating layer158nor the second insulating layer164formed of an inorganic insulating film such as a silicon oxide film, a silicon nitride film or the like is formed in the division region202. The transparent conductive film formed of an inorganic material is not formed in the division region202, so that the shield electrode126is not damaged at the time of division. Similarly, the inorganic insulating films are not formed in the division region202, so that neither the first insulating layer158nor the second insulating layer164is damaged at the time of division.

The method for manufacturing the touch panel display100in this embodiment uses a multiple tone mask to decrease the number of photomasks needed for the manufacturing. Use of the multiple tone mask allows a plurality of patterns (the shield electrode126and the first gate electrodes154and156, the second transparent conductive layer160band the third common line146c, the third transparent conductive layer160cand the data signal line144, the fourth transparent conductive layer160dand the drain electrode169, the first oxide semiconductor layer162aand the electrode transfer layer182) to be formed by one exposure step. This increases the productivity of the touch panel displays100and decreases the manufacturing cost thereof. In other words, even in the case where the electrodes forming an embedded-type touch panel (the first sensor electrodes114and the second sensor electrodes116) are formed in the display, the number of the photomasks needed for the manufacturing is decreased.

In this embodiment, the selection transistor136and the driving transistor138are both of a dual-gate structure. The present invention is not limited to this. For example, the selection transistor136may be of a top-gate type with the first gate electrode156being omitted. The pixel circuit is not limited to the circuit shown inFIG.3. The transistors and the organic EL element in this embodiment are applicable to a structure in which each pixel includes three or more transistors.

Second Embodiment

In this embodiment, regrading a touch panel display including a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen, differences in the pixel structure from the first embodiment will be described. In the following description, such differences from the first embodiment will be described.

FIG.18shows an equivalent circuit of a pixel110bin this embodiment. Unlike in the first embodiment, the first gate electrode156of the selection transistor136and the first gate electrode154of the driving transistor138are electrically connected with the first common line146a. Except for this, the equivalent circuit shown inFIG.18is substantially the same as the equivalent circuit shown inFIG.3.

FIG.19shows an example of planar structure of the pixel110bin the touch panel display in this embodiment.FIG.20Ashows a cross-sectional structure of the pixel110btaken along line A3-A4shown inFIG.19.FIG.20Bshows a cross-sectional structure of the pixel110btaken along line B3-B4shown inFIG.19. In the following description, these figures will be referred to, as necessary.

The shield electrode126is provided in the entirety of the pixel110b. The shield electrode126is provided to overlap the driving transistor138and the selection transistor136. In other words, the shield electrode126in the pixel110bthis embodiment does not have an opening, unlike the shield electrode126in the pixel110ain the first embodiment.

The driving transistor138includes a light blocking electrode155provided in a region overlapping the second gate electrode166. The light blocking electrode155is located between the shield electrode126and the fourth transparent resin layer150d, and is in contact with the shield electrode126. The light blocking electrode155is formed of a metal film, like the first gate electrode layer154bin the first embodiment. The shield electrode126is formed of a transparent conductive film whereas the light blocking electrode155is formed of a metal film, so that light incident on the transparent resin substrate124is prevented from being incident on the channel region of the driving transistor138. This suppresses the threshold voltage of the driving transistor138from being fluctuated.

The light blocking electrode155is supplied with the same potential as that of the shield electrode126. The shield electrode126is supplied with, for example, the ground potential, and thus the light blocking electrode155is also supplied with the ground potential. The driving transistor138is supplied, via the first insulating layer158, with a certain potential at a surface, of the first oxide semiconductor layer162awhere channel region is formed, opposite to the second electrode166(the surface opposite to the second electrode166is referred to as a “back channel”). Since the potential of the back channel is stabilized, the threshold voltage of the driving transistor138is suppressed from being fluctuated. In this embodiment, the light blocking electrode155may be omitted.

Like the driving transistor138, the selection transistor136includes a light blocking electrode157. Therefore, the selection transistor136is protected against light by the light blocking electrode157, and thus the potential of the back channel is stabilized. This suppresses the threshold voltage of the selection transistor136from being fluctuated.

The light blocking electrodes155and157on the shield electrode126may be patterned by use of multiple tone exposure, like in the first embodiment. More specifically, the light blocking electrodes155and157may be formed with no increase in the number of the photomasks, like in the first embodiment.

In this embodiment, the pixel110bhas substantially the same structure as that of the pixel110ain the first embodiment except for the light blocking electrodes155and157. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the first embodiment.

Third Embodiment

In this embodiment, regrading a touch panel display including a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen, differences in the pixel structure from the first embodiment will be described. In the following description, such differences from the first embodiment will be described.

FIG.21shows an equivalent circuit of a pixel110cin this embodiment. Unlike in the first embodiment, the first gate electrode154of the driving transistor138is electrically connected with the first common line146a. Except for this, the equivalent circuit shown inFIG.21is substantially the same as the equivalent circuit shown inFIG.3.

FIG.22shows an example of planar structure of the pixel110cin the touch panel display in this embodiment.FIG.23Ashows a cross-sectional structure of the pixel110ctaken along line A5-A6shown inFIG.22.FIG.23Bshows a cross-sectional structure of the pixel110ctaken along line B5-B6shown inFIG.22. In the following description, these figures will be referred to, as necessary.

In the pixel110c, the shield electrode126is provided to cover the driving transistor138. By contrast, the shield electrode126has the second opening152bin a region where the selection transistor136is provided. The driving transistor138includes the light blocking electrode155provided in a region overlapping the second gate electrode166. The light blocking electrode155is located between the shield electrode126and the fourth transparent resin layer150d, and is in contact with the shield electrode126. With such a structure, light incident on the transparent resin substrate124is prevented from being incident on the channel region of the driving transistor138. This suppresses the threshold voltage of the driving transistor138from being fluctuated.

The selection transistor136has a dual-gate structure in which the second semiconductor oxide layer162bis held between the first gate electrode156and the second gate electrode168. This improves the switching characteristics of, and decreases the off-current of, the selection transistor136.

In this embodiment, the pixel110chas substantially the same structure as that of the pixel110ain the first embodiment except for the shield electrode126and the light blocking electrode155. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the first embodiment.

Fourth Embodiment

In this embodiment, regrading a touch panel display including a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen, differences in the pixel structure from the first embodiment will be described. In the following description, such differences from the first embodiment will be described.

FIG.24shows an equivalent circuit of a pixel110din this embodiment. Unlike in the first embodiment, the first gate electrode156of the selection transistor136is electrically connected with the first common line146a. Except for this, the equivalent circuit shown inFIG.24is the same as the equivalent circuit shown inFIG.3.

FIG.25shows an example of planar structure of the pixel110din the touch panel display in this embodiment.FIG.26Ashows a cross-sectional structure of the pixel110dtaken along line A7-A8shown inFIG.25.FIG.26Bshows a cross-sectional structure of the pixel110dtaken along line B7-B8shown inFIG.25. In the following description, these figures will be referred to, as necessary.

In the pixel110d, the shield electrode126is provided to cover the selection transistor136. By contrast, the shield electrode126has the first opening152ain a region where the driving transistor138is provided. The selection transistor136includes the light blocking electrode157provided in a region overlapping the second gate electrode168. The light blocking electrode157is located between the shield electrode126and the fourth transparent resin layer150d, and is in contact with the shield electrode126. With such a structure, light incident on the transparent resin substrate124is prevented from being incident on the channel region of the selection transistor136. This suppresses the threshold voltage of the selection transistor136from being fluctuated.

Meanwhile, the driving transistor138has a dual-gate structure in which the first semiconductor oxide layer162ais held between the first gate electrode154and the second gate electrode166. The first gate electrode154and the second gate electrode166are electrically connected with each other and thus are supplied with the same potential. This improves the current driving capability of the driving transistor138, and thus the driving transistor138supplies a sufficient level of current to drive the organic EL element134.

In this embodiment, the pixel110dhas substantially the same structure as that of the pixel110ain the first embodiment except for the shield electrode126and the light blocking electrode157. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the first embodiment.

Fifth Embodiment

In this embodiment, a form in which the structures of the driving transistor138and the selection transistor136are different from those in the first embodiment will be described. Specifically, the driving transistor138and the selection transistor136are formed of a polycrystalline silicon film. In the following description, components that are the same as those in the first embodiment will not be described, and the above-described differences from the first embodiment will be mainly described.

FIG.27shows an example of planar structure of a pixel110ein a touch panel display in this embodiment.FIG.28Ashows a cross-sectional structure of the pixel110etaken along line A9-A10shown inFIG.28.FIG.28Bshows a cross-sectional structure of the pixel110etaken along line B9-B10shown inFIG.28. In the following description, these figures will be referred to, as necessary.

As shown inFIG.28AandFIG.28B, the organic EL element134, the driving transistor138, the selection transistor136, and the capacitance element140are located on the transparent resin substrate124. The structure of the transparent resin substrate124is substantially the same as that in the first embodiment.

As shown inFIG.27andFIG.28A, the driving transistor138includes a first semiconductor layer163a. The first semiconductor layer163ais formed of a tetrahedral semiconductor, for example, polycrystalline silicon. Below the first semiconductor layer163a, the first gate electrode154is located with the first insulating layer158and the fourth transparent resin layer150dbeing located between the first semiconductor layer163aand the first gate electrode154. Above the first semiconductor layer163a, the second gate electrode166is located with the second insulating layer164being located between the first semiconductor layer163aand the second gate electrode166. The structures of the first gate electrode154and the second gate electrode166are substantially the same as those in the first embodiment. The first semiconductor layer163aincludes impurity regions165aand165bcontaining impurity elements provided to control valence electrons. In the driving transistor138, the impurity region165bis connected with the second common line146b, and the impurity region165ais connected with a drain electrode169b. The drain electrode169bis electrically connected with the first electrode180of the organic EL element134. The first electrode180is formed of a transparent conductive film. A third insulating layer171is provided between the second gate electrode166and the flattening layer172. The second common line146band the drain electrode169bare provided between the third insulating layer171and the flattening layer172.

As shown inFIG.27andFIG.28B, the selection transistor136includes a second semiconductor layer163b. The second semiconductor layer163bis also formed of a tetrahedral semiconductor, for example, polycrystalline silicon. Below the second semiconductor layer163b, the first gate electrode156is located with the first insulating layer158and the fourth transparent resin layer150dbeing located between the second semiconductor layer163band the first gate electrode156. Above the second semiconductor layer163b, the second gate electrode168is located with the second insulating layer164being located between the second semiconductor layer163band the second gate electrode168. An impurity region165cof the second semiconductor layer163bis connected with the data signal line144, and an impurity region165dof the second semiconductor layer163bis connected with a drain electrode169c.

A polycrystalline silicon film used to form the semiconductor layer163is formed by crystallizing an amorphous silicon film formed by plasma CVD on the first insulating layer158. The amorphous silicon film is crystallized by directing laser light thereto (referred to as “laser annealing”). As a laser light source, for example, a third harmonic of an excimer laser or a YAG laser is usable. The laser light is ultrasonic light and is absorbed by an amorphous silicon film substantially entirety. Therefore, the transparent resin substrate124is not thermally damaged.

The capacitance element140includes the first capacitance electrode170aformed in the same layer as that of the second gate electrode168, the second capacitance electrode170bformed in the same layer as that of the drain electrode169c, and the third insulating layer171located between the first capacitance electrode170aand the second capacitance electrode170b. The drain electrode169cand the second capacitance electrode170bof the selection transistor136are electrically connected with each other.FIG.27andFIG.28Bshow a form in which the drain electrode169cand the second capacitance electrode170bare formed of one continuous conductive layer.

As shown inFIG.29A, the impurity region165dmay be extended to a region bellow the first capacitance electrode170a, so that the area size of the capacitance element140is enlarged to increase the capacitance without decreasing the aperture ratio of the pixel110e.FIG.29Bshows an equivalent circuit of the capacitance element140. As shown inFIG.29B, the capacitance element140has a structure in which a capacitance formed between the drain electrode169cand the first capacitance electrode170a, a capacitance formed between the impurity region165dhaving the same potential as that of the drain electrode169cand the first capacitance electrode170a, and a capacitance formed between the impurity region165dand the shield electrode126having the same potential as that of the first capacitance electrode170aare connected in parallel. With such a stack structure, the capacitance element140increases the capacitance thereof even though the area size of a projected area as seen in a plan view is not changed.

As shown inFIG.28A, the organic EL element134has the same structure as that in the first embodiment. In this embodiment, the driving transistor138and the selection transistor136each have an n-channel conductivity. In other words, since the impurity region165is formed of an n-type semiconductor, the driving transistor138and the selection transistor136each have an n-channel conductivity. Therefore, the touch panel display in this embodiment operates in substantially the same manner as that in the first embodiment.

The first gate electrode154and the second gate electrode166of the driving transistor138are electrically connected with each other and are supplied with the same gate voltage. The driving transistor138has such a dual-gate structure, and thus improves the current driving capability thereof. Therefore, the driving transistor138supplies a sufficient level of current to drive the organic EL element134. Even if the operation point of the organic EL element134is fluctuated, the constant current driving is performed in accordance with the fluctuation of the operation point. The first gate electrode156and the second gate electrode168of the selection transistor136are electrically connected with each other. The selection transistor136has such a dual-gate structure, and thus suppresses the threshold voltage thereof from being fluctuated and increases the on/off ratio thereof.

As described in this embodiment, the touch panel display including the touch panel108embedded in the transparent resin substrate124is also realized by use of transistors formed of polycrystalline silicon. The transistors including the channel region of polycrystalline silicon provide a high field effect mobility. Therefore, the current driving capability of the driving transistor138is improved, which advantageously contributes to increase in the precision of the pixels110e. The touch panel display in this embodiment has substantially the same structure as that in the first embodiment except that the transistors are formed of polycrystalline silicon. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the first embodiment.

Sixth Embodiment

In this embodiment, regrading a touch panel display including a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen, differences in the pixel structure from the fifth embodiment will be described. In the following description, such differences from the fifth embodiment will be described.

FIG.30shows an example of planar structure of a pixel110fin the touch panel display in this embodiment.FIG.31Ashows a cross-sectional structure of the pixel110ftaken along line A11-A12shown inFIG.30.FIG.31Bshows a cross-sectional structure of the pixel110ftaken along line B11-B12shown inFIG.30. In the following description, these figures will be referred to, as necessary.

The pixel110fhas substantially the same structure as that in the fifth embodiment except that the first opening152aand the second opening152bare omitted and that the shield electrode126is provided in the entirety of the pixel110f.

The driving transistor138includes the light blocking electrode155provided in a region overlapping the second gate electrode166. The light blocking electrode155is located between the shield electrode126and the fourth transparent resin layer150d, and is in contact with the shield electrode126. The light blocking electrode155is formed of a metal film, like in the second embodiment. The light blocking electrode155prevents light incident on the transparent resin substrate124from being incident on the channel region of the driving transistor138. This suppresses the threshold voltage of the driving transistor138from being fluctuated.

The light blocking electrode155is supplied with the same potential as that of the shield electrode126. The shield electrode126is supplied with, for example, the ground potential, and thus the light blocking electrode155is also supplied with the ground potential. The driving transistor138is supplied, via the first insulating layer158, with a certain potential in the back channel of the first semiconductor layer163awhere the channel region is formed. This suppresses the threshold voltage of the driving transistor138from being fluctuated.

Like the driving transistor138, the selection transistor136includes the light blocking electrode157. Therefore, the selection transistor136is protected against light by the light blocking electrode157, and thus the potential of the back channel is stabilized. This suppresses the threshold voltage of the selection transistor136from being fluctuated.

In this embodiment, the pixel110fhas substantially the same structure as that of the pixel110ein the fifth embodiment except for the light blocking electrodes155and157. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the fifth embodiment.

Seventh Embodiment

In this embodiment, regrading a touch panel display including a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen, differences in the pixel structure from the fifth embodiment will be described. In the following description, such differences from the fifth embodiment will be described.

FIG.32shows an example of planar structure of a pixel110gin the touch panel display in this embodiment.FIG.33Ashows a cross-sectional structure of the pixel110gtaken along line A13-A14shown inFIG.32.FIG.33Bshows a cross-sectional structure of the pixel110gtaken along line B13-B14shown inFIG.32. In the following description, these figures will be referred to, as necessary.

In the pixel110g, the shield electrode126is provided to cover the driving transistor138. By contrast, the shield electrode126has the second opening152bin a region where the selection transistor136is provided. The driving transistor138includes the light blocking electrode155provided in a region overlapping the second gate electrode166. The light blocking electrode155is located between the shield electrode126and the fourth transparent resin layer150d, and is in contact with the shield electrode126. With such a structure, light incident on the transparent resin substrate124is prevented from being incident on the channel region of the driving transistor138.

The selection transistor136has a dual-gate structure in which the second semiconductor layer163bis held between the first gate electrode156and the second gate electrode168. This improves the switching characteristics of, and decreases the off-current of, the selection transistor136. The first gate electrode156of the selection transistor136has a structure in which the first gate electrode layer156aformed of a transparent conductive film and the second gate electrode layer156bformed of a metal film are stacked on each other. Therefore, the selection transistor136also has a function of a light blocking film.

In this embodiment, the pixel110ghas substantially the same structure as that of the pixel110ein the fifth embodiment except for the shield electrode126and the light blocking electrode155. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the fifth embodiment.

Eighth Embodiment

In this embodiment, regrading a touch panel display including a touch sensor function of sensing a touch on a screen and a display function of displaying an image on the screen, differences in the pixel structure from the fifth embodiment will be described. In the following description, such differences from the fifth embodiment will be described.

FIG.34shows an example of planar structure of a pixel110hin the touch panel display in this embodiment.FIG.35Ashows a cross-sectional structure of the pixel110htaken along line A15-A16shown inFIG.34.FIG.35Bshows a cross-sectional structure of the pixel110htaken along line B15-B16shown inFIG.34. In the following description, these figures will be referred to, as necessary.

In the pixel110h, the shield electrode126is provided to cover the selection transistor136. By contrast, the shield electrode126has the first opening152ain a region where the driving transistor138is provided. The selection transistor136includes the light blocking electrode157provided in a region overlapping the second gate electrode168. The light blocking electrode157is located between the shield electrode126and the fourth transparent resin layer150d, and is in contact with the shield electrode126. With such a structure, light incident on the transparent resin substrate124is prevented from being incident on the channel region of the selection transistor136. This suppresses the threshold voltage of the selection transistor136from being fluctuated.

Meanwhile, the driving transistor138has a dual-gate structure in which the first semiconductor layer163ais held between the first gate electrode154and the second gate electrode166. The first gate electrode154and the second gate electrode166are electrically connected with each other and thus are supplied with the same potential. This improves the current driving capability of the driving transistor138, and thus the driving transistor138supplies a sufficient level of current to drive the organic EL element134.

In this embodiment, the pixel110hhas substantially the same structure as that of the pixel110ein the fifth embodiment except for the shield electrode126and the light blocking electrode157. Therefore, the touch panel display in this embodiment provides substantially the same function and effect as those in the fifth embodiment.

Ninth Embodiment

In this embodiment, an example of touch panel display in which the sensor electrodes embedded in the transparent resin substrate each have a diamond shape will be described. In the following embodiment, components that are the same as those in the first embodiment and the second embodiment will not be described, and differences therefrom will be mainly described.

FIG.36shows a planar structure of the first sensor electrodes114and the second sensor electrodes116forming a mutual capacitance-system electrostatic capacitance-type touch sensor. Each of the first sensor electrodes114is a receiver electrode (Rx electrode), and sequentially outputs detection signals (Vdet). By contrast, each of the second sensor electrodes116is a transmitter electrode (Tx electrode), and is supplied with a common driving signal (Vcom). The first sensor electrodes114are each of a diamond shape and are connected with each other in one direction (in the Y direction shown inFIG.36), whereas the second sensor electrodes116are each of a diamond shape and are connected with each other in a direction crossing the one direction (in the X direction shown inFIG.36). Although not shown inFIG.36, the first sensor electrodes114and the second sensor electrodes116are formed in different layers from each other with an insulating layer being located between the first sensor electrodes114and the second sensor electrodes116. The first sensor electrodes114and the second sensor electrodes116are each formed of a transparent conductive film or a metal film. In the case where a transparent conductive film is used, the first sensor electrodes114are formed in diamond patterns provided to spread two-dimensionally, and the second sensor electrodes116are also formed in diamond patterns provided to spread two-dimensionally. By contrast, in the case where a metal film is used, the first sensor electrodes114are formed in a mesh pattern with openings being formed in positional correspondence with the pixels, and the second sensor electrodes116are also formed in a mesh pattern with openings being formed in positional correspondence with the pixels. In either case, diamond-shaped electrodes are adopted, so that the first sensor electrodes114and the second sensor electrodes116are located densely.

FIG.37AandFIG.37Bshow an example of pixel110iof a touch panel display in which the diamond-shaped electrodes shown inFIG.36are embedded in a transparent resin substrate124b.FIG.37Ashows a cross-sectional structure of the pixel110icorresponding to the cross-sectional structure taken along line A1-A2shown inFIG.4.FIG.37Bshows a cross-sectional structure of the pixel110icorresponding to the cross-sectional structure taken along line B1-B2shown inFIG.4. The structure of the driving transistor138and the organic EL element134shown inFIG.37Aand the structure of the selection transistor136and the capacitance element140shown inFIG.37Bare substantially the same as those in the first embodiment.

The transparent resin substrate124bhas a structure in which the first transparent resin layer150a, the first sensor electrodes114, the inorganic insulating layer151, the second sensor electrodes116, the third transparent resin layer150c, the shield electrode126and the fourth transparent resin layer150dare stacked. In the case where the second sensor electrodes116used as the transmitter electrodes (Tx electrodes) provided to spread two-dimensionally are located as overlapping the driving transistors138, it is preferred that the second sensor electrodes116each have the opening119in positional correspondence with the corresponding driving transistor138. The opening119is provided, so that the electric field generated by a driving signal applied to the second sensor electrode116is prevented from influencing the first gate electrode154of the driving transistor138. In this embodiment also, it is preferred that the third transparent resin layer150chas a thickness of 10 μm or greater, preferably 15 μm or greater, in order to put the first gate electrode154far from the second sensor electrode116.

The first sensor electrodes114and the second sensor electrodes116are provided with the organic insulating layer151being located between the first sensor electrodes114and the second sensor electrodes116so as not to be short-circuited. It is preferred that the organic insulating layer151is formed of an insulating film that has a low moisture permeability and is visible light-transmissive such as a silicon nitride film, an aluminum oxide film or the like. The organic insulating layer151may have a thickness of 100 nm to 300 nm, and is formed on substantially the entirety of the transparent resin substrate124b. The organic insulating layer151provided in the transparent resin substrate124bimproves the barrier property against water vapor. This suppresses the organic EL element134provided on the transparent resin substrate124bfrom being deteriorated.

A silicon nitride film is considered to have a relative dielectric constant of 6 to 8, and an aluminum oxide is considered to have a relative dielectric constant of 8 to 10, which are both higher than that of a transparent resin layer (for example, a polyimide resin is considered to have a relative dielectric constant of 4 to 5). In addition, the inorganic insulating layer151is formed to have a thickness of 100 nm to 300 nm. Therefore, the capacitance formed between the first sensor electrodes114and the second sensor electrodes116is increased. This improves the sensitivity of the touch sensor108. As can be seen, the touch panel display in this embodiment increases the moisture resistance and the sensitivity of the touch panel108in addition to having the function and effect of the touch panel display100in the first embodiment.

FIG.38AandFIG.38Bshow an example of pixel110jof a touch panel display in which the diamond-shaped electrodes shown inFIG.36are embedded in the transparent resin substrate124b.FIG.38Ashows a cross-sectional structure of the pixel110jcorresponding to the cross-sectional structure taken along line A3-A4shown inFIG.19.FIG.38Bshows a cross-sectional structure of the pixel110jcorresponding to the cross-sectional structure taken along line B3-B4shown inFIG.19.

The structure of the driving transistor138and the organic EL element134shown inFIG.38Aand the structure of the selection transistor136and the capacitance element140shown inFIG.38Bare substantially the same as those in the second embodiment. The transparent resin substrate124bhas substantially the same structure as that shown inFIG.37AandFIG.37Bexcept that the shield electrode126is provided in substantially the entirety thereof. Therefore, the touch panel display in this embodiment increases the moisture resistance and the sensitivity of the touch panel108in addition to having the function and effect of the touch panel display100in the second embodiment.

Tenth Embodiment

In this embodiment, an example of touch panel display in which the sensor electrodes embedded in the transparent resin substrate each have a diamond shape will be described. In the following embodiment, components that are the same as those in the fifth embodiment and the sixth embodiment will not be described, and differences therefrom will be mainly described.

FIG.39AandFIG.39Bshow an example of pixel110kof a touch panel display in which the diamond-shaped electrodes shown inFIG.36are embedded in the transparent resin substrate124b.FIG.39Ashows a cross-sectional structure of the pixel110kcorresponding to the cross-sectional structure taken along line A9-A10shown inFIG.27.FIG.396shows a cross-sectional structure of the pixel110kcorresponding to the cross-sectional structure taken along line B9-B10shown inFIG.27. The structure of the driving transistor138and the organic EL element134shown inFIG.39Aand the structure of the selection transistor136and the capacitance element140shown inFIG.39Bare substantially the same as those in the fifth embodiment.

The transparent resin substrate124bhas substantially the same structure as that in the ninth embodiment. Therefore, the touch panel display in this embodiment increases the moisture resistance and the sensitivity of the touch panel108in addition to having the function and effect of the touch panel display100in the fifth embodiment.

FIG.40AandFIG.40Bshow an example of pixel110mof a touch panel display in which the diamond-shaped electrodes shown inFIG.36are embedded in the transparent resin substrate124b.FIG.40Ashows a cross-sectional structure of the pixel110mcorresponding to the cross-sectional structure taken along line A11-A12shown inFIG.30.FIG.406shows a cross-sectional structure of the pixel110mcorresponding to the cross-sectional structure taken along line B11-B12shown inFIG.30.

The structure of the driving transistor138and the organic EL element134shown inFIG.40Aand the structure of the selection transistor136and the capacitance element140shown inFIG.40Bare substantially the same as those in the sixth embodiment. The transparent resin substrate124bhas substantially the same structure as that shown inFIG.39AandFIG.39Bexcept that the shield electrode126is provided in substantially the entirety of the transparent resin substrate124b. Therefore, the touch panel display in this embodiment increases the moisture resistance and the sensitivity of the touch panel108in addition to having the function and effect of the touch panel display100in the sixth embodiment.

Eleventh Embodiment

In this embodiment, various forms of the first sensor electrodes114and the second sensor electrodes116forming the touch sensor108will be described.

FIG.41Ashows an example of first sensor electrodes114. The first sensor electrodes114shown inFIG.41Ainclude an electrode portion121and a connection portion123. The electrode portion121extends from a first end of the display portion102in a direction along the data signal line144to a second end facing the first end. The connection portion123is outer to the display portion102and is connected with the second driving circuit112b. The first sensor electrodes114are formed of a metal film of aluminum (Al), titanium (Ti), molybdenum (Mo), copper (Cu) or the like. In the first sensor electrodes114shown inFIG.41A, the electrode portion121includes linear patterns, whereas the connection portion123includes a two-dimensional solid pattern (the connection portion123is entirely formed of a metal material). The linear patterns each have a line width that is substantially equal to that of each of the data signal lines144provided in the display portion102, and are located at the same interval (or pitch) as that of the data signal lines144.

FIG.41Bshows another example of first sensor electrodes114. In the first sensor electrodes114shown inFIG.41B, the electrode portion121has a lattice pattern including a plurality of squares. The lattice pattern in the electrode portion121is provided such that lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142. The lattice pattern in the electrode portion121is provided such that lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at the same interval (or pitch) as that of the data signal lines144. Alternatively, the lattice pattern in the electrode portion121may be provided such that the lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142; and such that the lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at three times the interval (or pitch) of that of the data signal lines144.

FIG.42Ashows an example of second sensor electrodes116. The second sensor electrodes116shown inFIG.42Ainclude an electrode portion125and a connection portion127. The electrode portion125extends from a first end of the display portion102in a direction along the gate signal line142to a second end facing the first end. The connection portion127is outer to the display portion102and is connected with the third driving circuit112c. The second sensor electrodes116are formed of a metal film of aluminum (Al), titanium (Ti), molybdenum (Mo), copper (Cu) or the like. In the second sensor electrodes116shown inFIG.42A, the electrode portion125includes linear patterns, whereas the connection portion127includes a two-dimensional solid pattern (the connection portion127is entirely formed of a metal material). The linear patterns each have a line width that is substantially equal to that of each of the gate signal lines142provided in the display portion102, and are located at the same interval (or pitch) as that of the gate signal lines142.

FIG.42Bshows another example of second sensor electrodes116. In the second sensor electrodes116shown inFIG.42B, the electrode portion125has a lattice pattern including a plurality of squares. The lattice pattern in the electrode portion125is provided such that lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142. The lattice pattern in the electrode portion125is provided such that lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at the same interval (or pitch) as that of the data signal lines144. Alternatively, the lattice pattern in the electrode portion125may be provided such that the lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142; and such that the lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at three times the interval (or pitch) of that of the data signal lines144.

In each of the examples shown inFIG.41A,FIG.41B,FIG.42AandFIG.42B, the first sensor electrodes114and the second sensor electrodes116are embedded in the transparent resin substrate124. Therefore, for example, a metal film used to form the first sensor electrodes114and the second sensor electrodes116may be used to form an alignment marker. The alignment marker may be used to align the photomask used to form the data signal lines144in a later step, so that the first sensor electrodes114, the second sensor electrodes116, the gate signal lines142and the data signal lines144are positionally matched precisely with each other.

The first sensor electrodes114and the second sensor electrodes116in this embodiment have the same line width as that of the gate signal line122and the data signal line144, and are located at the same pitch as that of the gate signal lines142and the data signal lines144. Therefore, even in the case where the touch panel display is of a bottom emission-type, the touch sensor108is embedded in the transparent resin substrate124without decreasing the aperture ratio of the pixels. In addition, the first sensor electrodes114and the second sensor electrodes116are formed of a metal material, so that the resistance is decreased.

This embodiment may be appropriately combined with the touch sensor of the touch panel display in any of the first embodiment to the tenth embodiment.

Twelfth Embodiment

In this embodiment, various forms of the first sensor electrodes114and the second sensor electrodes116forming the touch sensor108will be described.

FIG.43Ashows an example of first sensor electrodes114. The first sensor electrodes114shown inFIG.43Ainclude an electrode portion121including diamond-shaped electrode patterns, and a connection portion123provided at an end of the electrode portion121. The electrode portion121extends from a first end of the display portion102in a direction along the data signal line144to a second end facing the first end. The connection portion123is outer to the display portion102and is connected with the second driving circuit112b. In the first sensor electrodes114shown inFIG.43A, the electrode portion121includes linear patterns, whereas the connection portion123has a two-dimensional solid pattern (the connection portion123is entirely formed of a metal material). The linear patterns each have a line width that is substantially equal to that of each of the data signal lines144provided in the display portion102, and are located at the same interval (or pitch) as that of the data signal lines144.

FIG.43Bshows another example of first sensor electrodes114. In the first sensor electrodes114shown inFIG.43B, the electrode portion121, including diamond-shaped electrode patterns, has a lattice pattern including a plurality of squares. The lattice pattern in the electrode portion121is provided such that lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142. The lattice pattern in the electrode portion121is provided such that lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at the same interval (or pitch) as that of the data signal lines144. Alternatively, the lattice pattern in the electrode portion121may be provided such that the lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142; and such that the lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at three times the interval (or pitch) of that of the data signal lines144.

FIG.44Ashows an example of second sensor electrodes116. The second sensor electrodes116shown inFIG.44Ainclude an electrode portion125including diamond-shaped electrode patterns, and a connection portion127. The electrode portion125extends from a first end of the display portion102in a direction along the gate signal line142to a second end facing the first end. The connection portion127is outer to the display portion102and is connected with the third driving circuit112c. In the second sensor electrodes116shown inFIG.44A, the electrode portion125includes linear patterns, whereas the connection portion127includes a two-dimensional solid pattern (the connection portion127is entirely formed of a metal material). The linear patterns each have a line width that is substantially equal to that of each of the gate signal lines142provided in the display portion102, and are located at the same interval (or pitch) as that of the gate signal lines142.

FIG.44Bshows another example of second sensor electrodes116. In the second sensor electrodes116shown inFIG.44B, the electrode portion125, including diamond-shaped electrode patterns, has a lattice pattern including a plurality of squares. The lattice pattern in the electrode portion125is provided such that lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142. The lattice pattern in the electrode portion125is provided such that lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at the same interval (or pitch) as that of the data signal lines144. Alternatively, the lattice pattern in the electrode portion125may be provided such that the lines of squares that are arrayed parallel to the gate signal line142each have a line width that is substantially equal to that of each of the gate signal lines142, and are located at the same interval (or pitch) as that of the gate signal lines142; and such that the lines of squares that are arrayed parallel to the data signal line144each have a line width that is substantially equal to that of each of the data signal lines144, and are located at three times the interval (or pitch) of that of the data signal lines144.

In this embodiment, the first sensor electrodes114and the second sensor electrodes116are formed of a metal film of aluminum (Al), titanium (Ti), molybdenum (Mo), copper (Cu) or the like. Therefore, the first sensor electrodes114and the second sensor electrodes116have a low resistance. In addition, like in the eleventh embodiment, an alignment marker may be formed in the transparent resin substrate124during the formation of the first sensor electrodes114and the second sensor electrodes116. Therefore, the first sensor electrodes114and the second sensor electrodes116are positionally matched precisely with the gate signal lines144and the data signal lines144. The first sensor electrodes114and the second sensor electrodes116in this embodiment have the same line width as that of the gate signal line142and the data signal line144, and are located at the same pitch as that of the gate signal lines142and the data signal lines144. Therefore, even in the case where the touch panel display is of a bottom emission-type, the touch sensor108is embedded in the transparent resin substrate124without decreasing the aperture ratio of the pixels. In addition, the first sensor electrodes114and the second sensor electrodes116are formed of a metal material, so that the resistance is decreased.

This embodiment may be appropriately combined with the touch sensor of the touch panel display in any of the first embodiment to the tenth embodiment.

Thirteenth Embodiment

In this embodiment, forms of the first sensor electrodes114and the second sensor electrodes116forming the touch sensor108will be described. The first sensor electrodes114and the second sensor electrodes116forming the touch sensor108in this embodiment correspond to a diamond PenTile matrix of the pixels.

FIG.45Ashows an example of first sensor electrodes114. The first sensor electrodes114shown inFIG.45Ais formed of a metal film, has a strip-like shape, and includes a connection portion123and an electrode portion121. The electrode portion121includes a mesh pattern corresponding to pixels located in a diamond PenTile matrix. The mesh of the metal material is located in positional correspondence with a region where light is not emitted from the pixels. The connection portion123includes a two-dimensional solid pattern of a metal film (the connection portion123is entirely formed of a metal material). In the example shown inFIG.45B, the electrode portion123of the first sensor electrodes114includes diamond-shaped electrode patterns, and also includes a mesh pattern corresponding to pixels located in a diamond PenTile matrix.

FIG.46Ashows an example of second sensor electrodes116. The second sensor electrodes116shown inFIG.46Ais formed of a metal film, has a strip-like shape, and includes a connection portion127and an electrode portion125. The electrode portion125includes a mesh pattern corresponding to pixels located in a diamond PenTile matrix. The mesh of the metal material is located in positional correspondence with a region where light is not emitted from the pixels. The connection portion127includes a two-dimensional solid pattern of a metal film (the connection portion127is entirely formed of a metal material). In the example shown inFIG.46B, the electrode portion125of the second sensor electrodes116includes diamond-shaped electrode patterns, and also includes a mesh pattern corresponding to pixels located in a diamond PenTile matrix.

The mesh patterns of the electrode portions121and125each merely need to have an opening pattern enclosing a set of two sub pixels corresponding to green, one sub pixel corresponding to red and one sub pixel corresponding to blue (one set of sub pixels). The mesh pattern may each have an opening pattern enclosing four or nine sets of the sub pixels.

The first sensor electrodes114shown inFIG.45Aand the second sensor electrodes116shown inFIG.46Aare located in an overlapping manner with an insulating layer being located between the first sensor electrodes114and the second sensor electrodes116. In this case, the mesh pattern of the electrode portion121of the first sensor electrodes114, and the mesh pattern of the electrode portion125of the second sensor electrodes116, may be located to overlapping each other. Alternatively, the mesh pattern of the electrode portion121and the mesh pattern of the electrode portion125may be shifted from each other. In any way, the mesh pattern is located so as not to overlap the light emitting regions of the pixels, so that the aperture ratio of the pixels is not decreased. The mesh pattern of a metal material encloses the pixels, and thus acts as a light blocking film (also referred to as a “black matrix”) to improve the image quality.

This embodiment may be appropriately combined with the touch sensor of the touch panel display in any of the first embodiment to the tenth embodiment.

Fourteenth Embodiment

In this embodiment, a form of connection structure between the first sensor electrodes114and the second sensor electrodes116with drawing wires will be described.

FIG.47Ashows an example of connection structure between the first sensor electrode114and a first drawing wire194a. The first sensor electrode114is connected with the first drawing wire194ain a region outer to the display portion102. The first sensor electrode114is provided between the first transparent resin layer150aand the second transparent resin layer150b, and the first drawing wire194ais provided on the fourth transparent resin layer150d.

As shown inFIG.47A, the first insulating layer158, the second insulating layer164and the flattening layer172are stacked on the fourth transparent resin layer150d, and the second electrode192is provided on the flattening layer172.FIG.47Ashows that the sealing layer128is further provided on the second electrode192. The sealing layer128may have any structure. In this embodiment, the sealing layer128includes a carbon nitride film196a, a silicon nitride film198and a carbon nitride film196bare stacked in this order. The carbon nitride film196is a polymerized film formed by plasma polymerization using, as material gas, hydrogen carbide gas such as methane (CH4) of the like and gas such as nitrogen (N2), ammonia (HN3) or the like. Meanwhile, the silicon nitride film198is formed by plasma CVD using, as material gas, silane (SiH4), ammonia (NH3), and nitrogen (N2). The plasma polymerized film such as the carbon nitride film196or the like has properties of having no pinhole, having a high level of step coverage, and having a small inner stress. The carbon nitride film196having such properties and the silicon nitride film198are combined, so that the sealing layer128having a high level of water vapor blocking property is provided.

The first drawing wire194ais electrically connected with the first sensor electrode114via a contact hole195running through the second transparent resin layer150b, the third transparent resin layer150cand the fourth transparent resin layer150d. The first drawing wire194ais drawn to the outside of the flattening layer172and the sealing layer128. The first drawing wire194amay be formed to be connected with the terminal electrode118in a region exposed from the sealing layer128.

FIG.47Ashows a form in which the transparent resin substrate124is provided on the support substrate200and the division region202is provided in the vicinity of the terminal electrode118(FIG.1). The division region202is an opening running through the transparent resin substrate124. The division region202is formed by, for example, laser processing. The division region202is formed as an open groove continuous so as to enclose the display panel. After the division region202is formed, the transparent resin substrate124may be delaminated from the support substrate200by laser ablation as described above in the first embodiment.

It is preferred that the first transparent resin layer150ais formed of a transparent polyimide resin. The transparent polyimide resin is softer than a transparent para-polyamide resin and has a high level of heat resistance, and therefore has an advantage of not generating a modified layer even by laser ablation. It is preferred that the fourth transparent resin layer150dis formed of a transparent para-polyamide resin. The first drawing wire194aand the terminal electrode118(shown inFIG.1) are provided on the fourth transparent resin layer150d. The transparent para-polyamide resin is harder than the transparent polyimide resin, and therefore, prevents the metal film used to form the first drawing wire194aand the terminal electrode118from coming off. The flexible printed circuit board122as shown inFIG.1may be thermally press-fit to the terminal electrode118, so that the deformation of the transparent resin substrate124is suppressed.

FIG.47Bshows an example of connection structure between the second sensor electrode116and a second drawing wire194b. The second sensor electrode116is connected with the second drawing wire194bin a region outer to the display portion102. The second sensor electrode116is provided between the second transparent resin layer150band the third transparent resin layer150c, and the second drawing wire194bis provided on the fourth transparent resin layer150d. It is preferred that the fourth transparent resin layer150dis formed of a transparent para-polyamide resin from the point of view of gas barrier property of preventing permeation of water vapor.

The second drawing wire194bis electrically connected with the second sensor electrode116via a contact hole195brunning through the third transparent resin layer150cand the fourth transparent resin layer150d. The second drawing wire194bis drawn onto the second information layer164so as to be connected with the third driving circuit112c. InFIG.47B, the third driving circuit112cis omitted.

As shown inFIG.48A, the first insulating layer158and the second insulating layer164may be extended to the outside of the flattening layer172. With such a structure, in a region where the first drawing wire194ais not provided as shown inFIG.48B, the second insulating layer164formed of an inorganic insulating film and the sealing layer128formed of an inorganic insulating film are provided in close contact with each other. The second insulating layer164and the sealing layer128are in close contact with each other in a region outer to the flattening layer172, so that entrance of moisture is prevented and the sealing capability is improved.

As shown inFIG.49, the first drawing wire194amay be electrically connected with the second drawing wire194b(including a transparent conductive film194b1and a metal film194b2) via a contact hole195cformed in the second insulating layer164, the first insulating layer158and the fourth transparent resin layer150d. The second drawing wire194bmay be electrically connected with a drawing wire194cvia the contact hole195bformed in the third transparent resin layer150c. The drawing wire194cmay be electrically connected with the first sensor electrode114via the first contact hole195aformed in the second transparent resin layer150b. The drawing wires194are coupled with each other via the contact holes formed in the transparent resin layers150, so that each of the contact holes is made shallow and thus the electrical connection is guaranteed.

In this embodiment, the contact holes195running through the transparent resin layers150are provided. Therefore, even in the case where the first sensor electrodes114and the second sensor electrodes116forming the touch sensor108are embedded in the transparent resin substrate124, the drawing wires194are drawn to an upper level and are connected with the terminal electrode118and the driving circuit112.

Supplementary Notes

The entirety of, or a part of, the illustrative embodiments disclosed above may be defined by the following supplementary notes. Any embodiment of the present invention is not limited to any of the following.

Supplementary Note 1

A method for manufacturing a touch panel display, the method include forming a transparent resin substrate including a touch sensor including a first sensor electrode extending in a first direction and a second sensor electrode extending in a second direction crossing the first direction, forming a shield electrode covering the touch sensor; and forming, on the transparent resin substrate, a display portion including pixels each including a transistor and an organic electroluminescence element electrically connected with the transistor.

Supplementary Note 2

The method for manufacturing a touch panel display according to supplementary note 1, in which the formation of the transparent resin substrate includes: forming a first transparent resin layer on a support substrate, forming the first sensor electrode extending in the first direction on the first transparent resin layer, forming a second transparent resin layer on the first transparent resin layer and the first sensor electrode, forming the second sensor electrode, extending in the second direction crossing the first direction, on the second transparent resin layer, forming a third transparent resin layer on the second transparent resin layer and the second sensor electrode, forming the shield electrode on the third transparent resin layer, and forming a fourth transparent resin layer on the shield electrode.

Supplementary Note 3

The method for manufacturing a touch panel display according to supplementary note 2, in which the first transparent resin layer, the second transparent resin layer, the third transparent resin layer and the fourth transparent resin layer are formed of a transparent para-polyamide resin or a transparent polyimide resin.

Supplementary Note 4

The method for manufacturing a touch panel display according to supplementary note 2, in which the first transparent resin layer is formed of a transparent polyimide resin, the fourth transparent resin layer is formed of a transparent para-polyamide resin, and the second transparent resin layer and the third transparent resin layer are formed of a transparent para-polyamide resin or a transparent polyimide resin.

Supplementary Note 5

The method for manufacturing a touch panel display according to supplementary note 2, in which the first transparent resin layer and the third transparent resin layer are formed of a para-polyamide resin or a polyimide resin, and the second transparent resin layer is formed of a silicon nitride film or an aluminum oxide film.

Supplementary Note 6

The method for manufacturing a touch panel display according to supplementary note 1, in which the first sensor electrode and the second first sensor electrode are each formed of a transparent conductive film.

Supplementary Note 7

The method for manufacturing a touch panel display according to supplementary note 1, in which the first sensor electrode and the second first sensor electrode are each formed of a transparent conductive film and formed to have a stripe pattern or a mesh pattern having openings at positions different from positions of the pixels.

Supplementary Note 8

The method for manufacturing a touch panel display according to supplementary note 1, in which the shield electrode is formed of a transparent conducive film.

Supplementary Note 9

The method for manufacturing a touch panel display according to supplementary note 1, in which the transistor is formed to include a first gate electrode, a first insulating layer on the first gate electrode, a semiconductor layer on the first insulating layer, a second insulating layer on the semiconductor layer, and a second gate electrode on the second insulating layer.

Supplementary Note 10

The method for manufacturing a touch panel display according to supplementary note 9, further including forming an opening in the shield electrode in a region overlapping the transistor, and forming the first gate electrode in the opening.

Supplementary Note 11

The method for manufacturing a touch panel display according to supplementary note 9, in which the first gate electrode is formed in contact with the shield electrode.

Supplementary Note 12

The method for manufacturing a touch panel display according to supplementary note 10, in which the opening of the shield electrode and the first gate electrode are formed by patterning by use of one photomask.

Supplementary Note 13 The method for manufacturing a touch panel display according to supplementary note 12, in which a multiple tone mask is used as the photomask.

Supplementary Note 14 The method for manufacturing a touch panel display according to supplemental note 2, further including an opening in the second sensor electrode in a region overlapping the transistor.

Supplementary Note 15

A touch panel display, including a display portion including a video signal line and a scanning signal line, a touch sensor electrode including a first sensor electrode (receiver electrode) and a second sensor electrode (transmitter electrode), and a driving circuit located outer to the display portion and the touch sensor. the driving circuit includes a video signal line driving circuit outputting a video signal to the video signal line, a scanning signal line driving circuit outputting a timing signal, synchronized to the video signal, to the scanning signal line, a sensing circuit receiving a detection signal output from the first sensor electrode (receiver electrode) and outputting a sensing signal, and a scanning circuit outputting a driving signal to the second sensor electrode (transmitter electrode). The driving circuit includes the video signal line driving circuit, the scanning signal line driving circuit, the sensing circuit and the scanning circuit in an integrated manner.

Supplementary Note 16

The touch panel display according to supplementary note 15, in which the driving circuit is included in a single semiconductor chip in an integrated manner.

Supplementary Note 17

The touch panel display according to supplementary note 15, in which the driving circuit includes the video signal line driving circuit, the scanning signal line driving circuit, the sensing circuit and the scanning circuit in an integrated manner as blocks.

Supplementary Note 18

The touch panel display according to supplementary note 15, in which the display portion includes a plurality of pixels, and the plurality of pixels each include an organic electroluminescence element.