Patent ID: 12210258

DETAILED DESCRIPTION

In general, according to one embodiment, there is provided a display device including a switching element, a common electrode, an insulating film covering the common electrode, a first pixel electrode electrically connected to the switching element in a first contact hole penetrating the insulating film, and a transparent conductive film electrically connected to the common electrode in a second contact hole penetrating the insulating film. The first pixel electrode and the transparent conductive film are arranged in a first direction in a same layer. The first pixel electrode is opposed to the common electrode in a display portion displaying an image. The transparent conductive film is opposed to the common electrode in a non-display portion surrounding the display portion. The common electrode is disposed over the display portion and the non-display portion. A size of the first contact hole and a size of the second contact hole are different from each other in planar view.

Embodiments will be described hereinafter with reference to the accompanying drawings. The disclosure is merely an example, and proper changes in keeping with the spirit of the invention, which are easily conceivable by a person of ordinary skill in the art, come within the scope of the invention as a matter of course. In addition, in some cases, in order to make the description clearer, the widths, thicknesses, shapes, and the like of the respective parts are illustrated schematically in the drawings, rather than as an accurate representation of what is implemented, but such schematic illustration is merely exemplary, and in no way restricts the interpretation of the invention. In addition, in the specification and drawings, constituent elements which function in the same or a similar manner to those described in connection with preceding drawings are denoted by the same reference numbers, and detailed explanations of them that are considered redundant may be appropriately omitted.

In the present embodiment, a liquid crystal display device is explained as an example of a display device DSP. The main configuration disclosed in the present embodiment can be applied to a self-luminous display device including an organic electroluminescent display element or the like, an electronic paper display device including an electrophoretic element or the like, a display device employing micro-electromechanical systems (MEMS), a display device employing electrochromism, and the like.

FIG.1is a plan view showing the external appearance of the display device DSP of the present embodiment. A first direction X, a second direction Y and a third direction Z are, for example, orthogonal to one another but may cross at an angle other than 90 degrees. The first direction X and the second direction Y correspond to directions parallel to the main surface of a substrate constituting the display device DSP, and the third direction Z corresponds to the thickness direction of the display device DSP. In the present specification, a position on the pointing end side of an arrow indicating the third direction Z is referred to as above, and a position on a side opposite to the pointing end of the arrow is referred to as below. In addition, an observation position at which the display device DSP is observed is assumed to be located on the pointing end side of the arrow indicating the third direction Z, and viewing from this observation position toward an X-Y plane defined by the first direction X and the second direction Y is referred to as planar view.

A plan view of the display device DSP in the X-Y plane is shown here. The display device DSP includes a display panel PNL, a flexible printed circuit board1and an IC chip2.

The display panel PNL is a liquid crystal display panel, and includes a first substrate SUB1, a second substrate SUB2, a liquid crystal layer LC which will be described later, a sealant SE and a light-shielding layer LS. The display panel PNL includes a display portion DA which displays an image, and a frame-shaped non-display portion NDA which surrounds the display portion DA. The second substrate SUB2is opposed to the first substrate SUB1in the third direction Z. The first substrate SUB1has a mounting portion MA extending in the second direction Y more than the second substrate SUB2.

The sealant SE is located in the non-display portion NDA, bonds the first substrate SUB1and the second substrate SUB2together, and seals in the liquid crystal layer LC. The light-shielding layer LS is located in the non-display portion NDA. The sealant SE is disposed at a position overlapping the light-shielding layer LS in planar view. InFIG.1, an area where the sealant SE is disposed and an area where the light-shielding layer LS is disposed are shown by different hatch lines, and an area where the sealant SE and the light-shielding layer LS overlap is shown by crosshatching. The light-shielding layer LS is disposed in the second substrate SUB2.

The display portion DA is located on an inner side surrounded by the light-shielding layer LS. The display portion DA includes a plurality of pixels PX arranged in a matrix in the first direction X and the second direction Y. The display portion DA has a pair of edge portions E1and E2extending along the first direction X, a pair of edge portions E3and E4extending along the second direction Y, and four round portions R1to R4. The display panel PNL has a pair of straight portions E11and E12extending along the first direction X, a pair of straight portions E13and E14extending along the second direction Y, and two round portions R11and R12. The round portions R11and R12are located on the outer sides of the round portions R1and R2, respectively. The radius of curvature of the round portion R11may be the same as or different from the radius of curvature of the round portion R1.

The flexible printed circuit board1and the IC chip2are mounted on the mounting portion MA. Note that the IC chip2may be mounted on the flexible printed circuit board1. The IC chip2includes a built-in display driver DD which outputs a signal required for displaying an image in a display mode of displaying an image. In the illustrated example, the IC chip2includes a built-in touch controller TC which controls a touch sensing mode of detecting approach or contact of an object to or with the display device DSP.

The display panel PNL of the present embodiment may be a transmissive type having a transmissive display function of displaying an image by selectively transmitting light from the rear surface side of the first substrate SUB1, a reflective type having a reflective display function of displaying an image by selectively reflecting light from the front surface side of the second substrate SUB2, or a transflective type having the transmissive display function and the reflective display function.

In addition, although the explanation of the detailed configuration of the display panel PNL is omitted here, the display panel PNL may have a configuration conforming to any one of a display mode using a lateral electric field along a substrate main surface, a display mode using a longitudinal electric field along a normal to a substrate main surface, a display mode using an inclined electric field inclined in an direction inclined with respect to a substrate main surface, and an appropriate combination of the lateral electric field, the longitudinal electric field and the inclined electric field. The substrate main surface here is a surface parallel to the X-Y plane defined by the first direction X and the second direction Y.

FIG.2is a plan view showing a configuration example of a touch sensor TS. Although the touch sensor TS of a self-capacitance method is explained here, the touch sensor TS may be of a mutual-capacitance method. The touch sensor TS includes a plurality of sensor electrodes Rx (Rx1, Rx2, etc.) and a plurality of sensor lines L (L1, L2, etc.). The sensor electrodes Rx are located in the display portion DA and are arranged in a matrix in the first direction X and the second direction Y. One sensor electrode Rx constitutes a sensor block which is the smallest unit which can perform touch sensing. The sensor lines L extend along the second direction Y and are arranged in the first direction X in the display portion DA. Each sensor line L is disposed at, for example, a position overlapping a signal line S which will be described later. In addition, each sensor line L is drawn to the non-display portion NDA and is electrically connected to the IC chip2.

Here, attention will be focused on the relationship between the sensor lines L1to L3arranged in the first direction X and the sensor electrodes Rx1to Rx3arranged in the second direction Y. The sensor line L1overlaps the sensor electrodes Rx1to Rx3and is electrically connected to the sensor electrode Rx1. The sensor line L2overlaps the sensor electrodes Rx2and Rx3and is electrically connected to the sensor electrode Rx2. A dummy line D20is apart from the sensor line L2. The dummy line D20overlaps the sensor electrode Rx1and is electrically connected to the sensor electrode Rx1. The sensor line L2and the dummy line D20are located on the same signal line. The sensor line L3overlaps the sensor electrode Rx3and is electrically connected to the sensor electrode Rx3. A dummy line D31overlaps the sensor electrode Rx1and is electrically connected to the sensor electrode Rx1. A dummy line D32is apart from the dummy line D31and the sensor line L3. The dummy line D32overlaps the sensor electrode Rx2and is electrically connected to the sensor electrode Rx2. The sensor line L3and the dummy lines D31and D32are located on the same signal line.

In the touch sensing mode, the touch controller TC applies a touch drive voltage to the sensor lines L. Accordingly, the touch drive voltage is applied to the sensor electrodes Rx, and sensing is performed in the sensor electrodes Rx. Sensor signals corresponding to the sensing results in the sensor electrodes Rx are output to the touch controller TC via the sensor lines L. The touch controller TC or an external host detects the presence or absence of the approach or contact of an object to or with the display device DSP and the coordinates of the position of an object based on the sensor signals.

Note that, in the display mode, the sensor electrodes Rx function as common electrodes CE to which a common voltage (Vcom) is applied. The common voltage is a voltage different from the touch drive voltage, and is applied from, for example, a voltage supply unit included in the display driver DD via the sensor lines L.

In the non-display portion NDA, the wiring lines WL1to WL3are disposed. In the illustrated example, the wiring lines WL1to WL3are disposed along the straight portion E13, the round portion R11, the straight line E11, the round portion R12and the straight line E14. The wiring line WL2is the closest of the wiring lines WL1to WL3to the display portion DA. The wiring line WL1is located between the wiring line WL2and the wiring line WL3. For example, the potential of the wiring line WL1is a fixed potential different from the potentials of the wiring lines WL2and WL3. In addition, the potential of the wiring line WL2is the same as the potential of the wiring line WL3. For example, the common voltage is applied to the wiring line WL2and the wiring line WL3. The potential of the wiring line WL1may be relatively lower or higher than the potential of the wiring line WL2. In a case where the potential of the wiring line WL1is lower than the potential of the wiring line WL2, the wiring line WL1functions as an ion trap line which traps impurity ions having positive polarity. Alternatively, in a case where the potential of the wiring line WL1is higher than the potential of the wiring line WL2, the wiring line WL1functions as an ion trap line which traps impurity ions having negative polarity.

FIG.3is a plan view showing the sensor electrode Rx shown inFIG.2and pixels PX. InFIG.3, a direction crossing at an acute angle counterclockwise with respect to the second direction Y is define as a direction D1, and a direction crossing at an acute angle clockwise with respect to the second direction Y is defined as a direction D2. Note that an angle θ1formed by the second direction Y and the direction D1is substantially the same as an angle θ2formed by the second direction Y and the direction D2.

One sensor electrode Rx is arranged over a plurality of pixels PX. In the illustrated example, the pixels PX located in odd-numbered rows along the second direction Y extend along the direction D1. In addition, the pixels PX located in even-numbered rows along the second direction Y extend along the direction D2. Note that the pixel PX here indicates the smallest unit which can be individually controlled according to a pixel signal and is referred to also as a sub-pixel. In addition, the smallest unit which realizes color display may be referred to as a main pixel MP. The main pixel MP is composed of a plurality of sub-pixels PX which display different colors. For example, the main pixel MP includes a red pixel which displays red, a green pixel which displays green and a blue pixel which displays blue as sub-pixels PX. In addition, the main pixel MP may include a white pixel which displays white.

For example, in one sensor electrode Rx,60to70main pixels MP are arranged along the first direction X, and60to70main pixels MP are arranged along the second direction Y.

FIG.4is an illustration showing the basic configuration and equivalent circuit of the pixel PX. A plurality of scanning lines G are connected to a scanning line drive circuit GD. A plurality of signal lines S are connected to a signal line drive circuit SD. Note that the scanning lines G and the signal lines S do not necessarily linearly extend but may be partly bent. For example, even if the signal lines S are partly bent, the signal lines S are assumed to extend in the second direction Y.

A common electrode CE is disposed in each sensor block B. Each common electrode CE is connected to a voltage supply unit CD of the common voltage (Vcom) and is arranged over a plurality of pixels PX. In addition, each common electrode CE is connected to the touch controller TC and functions as the sensor electrode Rx as described above.

Each pixel PX includes a switching element SW, a pixel electrode PE, the common electrode CE, a liquid crystal layer LC and the like. The switching element SW is composed of, for example, a thin-film transistor (TFT) and is electrically connected to the scanning line G and the signal line S. The scanning line G is electrically connected to a gate electrode GE of the switching element SW in each of the pixels PX arranged in the first direction X. The signal line S is electrically connected to a source electrode SE of the switching element SW in each of the pixels PX arranged in the second direction Y. The pixel electrode PE is electrically connected to a drain electrode DE of the switching element SW. Each pixel electrode PE is opposed to the common electrode CE and drives the liquid crystal layer LC by an electric field generated between the pixel electrode PE and the common electrode CE. A storage capacitance CS is formed between, for example, an electrode having the same potential as the common electrode CE and an electrode having the same potential as the pixel electrode PE.

FIGS.5A and5Bare enlarged views of an area AR1close to the straight portion E14shown inFIG.1. The respective layers of a semiconductor layer SC, the scanning line G and the signal line S included in the first substrate SUB1are illustrated inFIG.5A, and the respective layers of the scanning line G, the signal line S and the pixel electrode PE are illustrated inFIG.5B. Note that the layer of the common electrode CE is shown by a dotted line. The illustration of the configuration between the wiring line WL2and the straight portion E13is omitted.

As shown inFIG.5A, the scanning lines G11to G13linearly extend along the first direction X and are arranged at intervals in the second direction Y. The signal lines S11to S14extend along substantially the second direction Y and are arranged at intervals in the first direction X. The scanning lines G11to G13and the signal lines S11to S14cross each other. The common electrode CE is disposed over the display portion DA and the non-display portion NDA.

In the display portion DA, each of the scanning lines G11to G13and a plurality of semiconductor layers SC cross each other. In addition, each of the signal lines S11to S14is electrically connected to a plurality of semiconductor layers SC. Pixels PXE1to PXE3located between the signal lines S13and S14correspond to the outermost pixels in the display portion DA. That is, the pixels PXE1to PXE3are the closest pixels to the non-display portion NDA or the closest pixels to the straight portion E14. For example, a semiconductor layer SC11in the pixel PXE1crosses the scanning line G11at two positions, and is electrically connected to the signal line S14in a contact hole CH1.

In the non-display portion NDA, each of the scanning lines G11to G13and a plurality of dummy semiconductor layers DSC cross each other. Each dummy semiconductor layer DSC is not electrically connected to any of the signal lines S11to S14and is electrically floating. The dummy semiconductor layers DSC adjacent to the display portion DA overlap the common electrode CE. The dummy semiconductor layers DSC apart from the display portion DA overlap the wiring line WL2having a fixed potential.

The wiring line WL2is apart from the common electrode CE. The wiring line WL2includes a first layer WL21and a second layer WL22. The first layer WL21is a metal layer located in the same layer as the signal line S and formed of the same material as the signal line S. The second layer WL22is a transparent conductive layer located in the same layer as the common electrode CE and formed of the same material as the common electrode CE, and is overlaid on the first layer WL21. Note that an insulating film is interposed between the first layer WL21and the second layer WL22.

As shown inFIG.5B, the pixel electrodes PE are arranged in a matrix in the first direction X and the second direction Y in the display portion DA. In addition, each pixel electrode PE is opposed to the common electrode CE in the display portion DA. For example, a pixel electrode PE1located between the scanning lines G11and G12includes a plurality of strip electrodes Pa1extending along the direction D1. In addition, a pixel electrode PE2located between the scanning lines G12and G13includes a plurality of strip electrodes Pa2extending along the direction D2. The number of strip electrodes Pa1and the number of strip electrodes Pa2are two in the illustrated example but may be greater than or equal to three. In addition, the number of strip electrodes Pa1may be different from the number of strip electrodes Pa2.

A pixel electrode PE11of the pixel PXE1is electrically connected to the semiconductor layer SC11shown inFIG.5A. A pixel electrode PE12of the pixel PXE2has the same shape as the pixel electrode PE1. The pixel electrode PE11and a pixel electrode PE13of the pixel PXE3have the same shape as the pixel electrode PE2.

Wire electrodes EL11and EL13are located in the non-display portion NDA. Both of the wire electrodes EL11and EL13are transparent conductive films (or transparent electrodes) located in the same layer as the pixel electrode PE and formed of the same material as the pixel electrode PE. The wire electrodes EL11and EL13are opposed to the common electrode CE in the non-display portion NDA. The pixel electrode PE11and the wire electrode EL11are arranged in the first direction X. In addition, the pixel electrode PE12and the wire electrode EL13are arranged in the first direction X, and the pixel electrode PE13and the wire electrode EL13are arranged in the first direction X. The signal line S14is located between the pixel electrode PE11and the wire electrode EL11and between the pixel electrode PE12and the wire electrode EL13.

The wire electrode EL13will be more specifically explained. The wire electrode EL13crosses the scanning line G12and is adjacent to two pixels PXE2and PXE3arranged in the second direction Y. The wire electrode EL13includes an electrode portion131extending along the direction D1, an electrode portion132extending along the direction D2, and a base portion133. The pixel electrode PE12and the electrode portion131are arranged in the first direction X, and the pixel electrode PE13and the electrode portion132are arranged in the first direction X. The base portion133is located close to a portion in which the scanning line G13and the signal line S14cross each other, and is electrically connected to the common electrode CE in a contact hole CH13.

The wiring line WL2further includes a third layer WL23. The third layer WL23is a transparent conductive layer located in the same layer as the pixel electrode PE11, the wire electrode EL11and the like and formed of the same material as the pixel electrode PE.

In the example shown inFIG.5B, the pixel electrode PE11corresponds to the first pixel electrode. Alternatively, the pixel electrode PE12corresponds to the first pixel electrode, and the pixel electrode PE13corresponds to the second pixel electrode.

FIG.6is an enlarged plan view showing the pixel electrode PE11and the wire electrode EL11shown inFIG.5B.

The switching element SW is electrically connected to the scanning line G11and the signal line S14. The switching element SW in the illustrated example has a double-gate structure. The switching element SW includes the semiconductor layer SC11and a drain electrode DE11. Note that the drain electrode DE11may be referred to as a source electrode in the switching element SW. The semiconductor layer SC11overlaps the signal line S14in one portion, extends between the signal lines S13and S14in the other portion, and is formed in a substantially U shape. The semiconductor layer SC11crosses the scanning line G11in an area overlapping the signal line S14and in an area between the signal lines S13and S14. In the scanning line G11, the areas overlapping the semiconductor layer SC11function as gate electrodes GE. The signal line S14is electrically connected to one end portion SCA of the semiconductor layer SC11in the contact hole CH1. The drain electrode DE11is formed in the shape of an island and is disposed between the signal lines S13and S14. The drain electrode DE11is electrically connected to the other end portion SCB of the semiconductor layer SC11in the contact hole CH2.

The pixel electrode PE11includes a base portion BS which is integrally formed with the strip electrodes Pa2. The base portion BS overlaps the drain electrode DE11. The base portion BS is electrically connected to the drain electrode DE11. In the illustrated example, a structure of connection between the drain electrode DE11and the pixel electrode PE11will be briefly explained. A connection electrode RE11is disposed between the drain electrode DE11and the base portion BS. The connection electrode RE11is a transparent electrode formed of the same material as the common electrode CE and is formed in the same process as the common electrode CE. The connection electrode RE11is electrically connected to the drain electrode DE11in the contact hole CH3. The base portion BS is electrically connected to the connection electrode RE11in a contact hole CH10.

The wire electrode EL11includes an electrode portion112and a base portion113. The base portion113is electrically connected to the common electrode CE in a contact hole CH11. The base portion113overlaps the entire contact hole CH11in planar view. The contact hole CH11here is a hole penetrating an insulating film interposed between the common electrode CE and the base portion113, and indicates the boundary between the insulating film and the common electrode CE in planar view. That is, the base portion113covers the entire common electrode CE exposed from the contact hole CH11.

Attention will be focused on the pixel electrode PE11and the wire electrode EL11. When a width W11of the strip electrode Pa2and a width W12of the electrode portion112are compared with each other, the width W12is greater than the width W11. Note that the widths W11and W12here are lengths along the first direction X.

The electrode portion112extends in a direction parallel to the strip electrode Pa2. In the illustrated example, both the strip electrode Pa2and the electrode portion112extend along the direction D2.

A distance D11between the strip electrode Pa2and the signal line S14is equal to a distance D12between the electrode portion112and the signal line S14. The distances D11and D12are lengths along the first direction X.

The size of the contact hole CH10is different from the size of the contact hole CH11. In the illustrated example, the size of the contact hole CH11is greater than the size of the contact hole CH10in planar view. Note that the size of the contact hole CH10can be defined as, for example, the area of the connection electrode RE11in the contact hole CH10, and similarly, the size of the contact hole CH11can be defined as the area of the common electrode CE in the contact hole CH11.

One dummy semiconductor layer DSC overlaps the wire electrode EL11.

In the example shown inFIG.6, the pixel electrode PE11corresponds to the first pixel electrode, the contact hole CH10corresponds to the first contact hole, and the contact hole CH11corresponds to the second contact hole.

FIG.7is a cross-sectional view of the first substrate SUB1taken along line A-B shown inFIG.6. The illustrated example corresponds to a case where a fringe field switching (FFS) mode which is a display mode using a lateral electric field is applied.

The first substrate SUB1includes an insulating substrate10, insulating films11to15, the semiconductor layer SC11, the dummy semiconductor layer DSC, the drain electrode DE11, the signal line S14, the connection electrode RE11, the common electrode CE, the pixel electrode PE11, the wire electrode EL11, an alignment film AL1and the like.

The insulating substrate10is a substrate having optical transparency such as a glass substrate or a flexible resin substrate. The insulating film11is located on the insulating substrate10. The semiconductor layer SC11is located on the insulating film11and is covered with the insulating film12. The drain electrode DE11and the signal line S14are located on the insulating film13and are covered with the insulating film14. The connection electrode RE11and the common electrode CE are located on the insulating film14and are covered with the insulating film15. The connection electrode RE11is in contact with the drain electrode DE11in the contact hole CH3penetrating the insulating film14. The illustrated common electrode CE is located on a flat upper surface14A of the insulating film14and does not overlap any of the contact holes in the insulating films11to14. The pixel electrode PE11and the wire electrode EL11are located on the insulating film15and are covered with the alignment film AL1. The base portion BS of the pixel electrode PE11is in contact with the connection electrode RE11in the contact hole CH10penetrating the insulating film15. The base portion113of the wire electrode EL11is in contact with the common electrode CE in the contact hole CH11penetrating the insulating film15. The alignment film AL1is not in contact with the common electrode CE but is directly stacked on the wire electrode EL11in the contact hole CH11. Directly below the contact hole CH11, the insulating film14is directly stacked on the insulating film13, and no conductive layer is disposed in the same layer as the signal line S14. That is, between the dummy semiconductor layer DSC and the common electrode CE, the insulating film13is directly stacked on the insulating film12, the insulating film14is directly stacked on the insulating film13, and the common electrode CE is not in contact with the dummy semiconductor layer DSC. Directly above the signal line S14, the insulating film15is directly stacked on the insulating film14.

Each of the signal line S14and the drain electrode DE11is formed of a metal material such as aluminum (Al), titanium (Ti), silver (Ag), molybdenum (Mo), tungsten (W), copper (Cu) or chromium (Cr), an alloy obtained by combining these metal materials or the like, and may have a single-layer structure or a multilayer structure. Each of the connection electrode RE11, the common electrode CE, the pixel electrode PE11and the wire electrode EL11is a transparent electrode formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

Each of the insulating films11to13and the insulating film15is an inorganic insulating film formed of an inorganic insulating material such as silicon oxide, silicon nitride or silicon oxynitride, and may have a single-layer structure or a multilayer structure. The insulating film14is, for example, an organic insulating film formed of an organic insulating material such as acrylic resin.

As described above, the contact hole CH11is larger than the contact hole CH10. This is caused by a difference in underlying structure between the contact holes CH10and CH11. That is, since the contact hole CH10partly overlaps the contact hole CH3, the contact hole CH10is influenced by a difference in level of the insulating film14. On the other hand, the contact hole CH11overlaps the flat upper surface14A. Therefore, at the time of etching the insulating film14, a difference in etching conditions between the areas corresponding to the contact holes CH10and CH11causes a difference in size between the contact holes CH10and CH11.

In the present embodiment, even if the contact hole CH11is expanded, the common electrode CE exposed from the contact hole CH11is still entirely covered with the wire electrode EL11. Therefore, moisture intrusion from the contact hole CH11can be suppressed.

Moisture intrusion from the contact hole CH11may cause, for example, the common electrode CE and the insulating film15to peel away from each other. In the pixel PX of the display portion DA, if the common electrode CE and the insulating film15are peeled away from each other, a voltage applied to liquid crystal cannot be held between the pixel electrode PE and the common electrode CE, and display failure occurs (black display irregularities appear).

The inventors prepared the first sample in which the entire contact hole CH11is covered with the wire electrode and the second sample in which a part of the contact hole CH11is covered with the wire electrode, and conducted an experiment by exposing them to environment of high temperature and high humidity. As the experiment conditions, the temperature was 85° C., the humidity was 85%, and the amount of time for exposure was 240 hours. As a result of the experiment, black display irregularities appeared in the second sample but black display irregularities did not appear in the first sample. The experiment confirmed that covering of the entire contact hole CH11with the wire electrode is effective in suppressing black display irregularities caused by moisture intrusion.

Therefore, according to the present embodiment, degradation in display quality can be suppressed.

FIGS.8A and8Bare plan views showing a state where the wire electrode EL11overlaps the entire contact hole CH11. In each of the illustrated configuration examples, both an edge113E of the base portion113and an edge CHE of the contact hole CH11are formed in a rectangular shape, but are not limited to this shape, and may be formed in another shape such as a circular shape or an elliptical shape.

In the configuration example shown inFIG.8A, one end portion113A of the base portion113has a width W21, and the other end portion113B of the base portion113has a width W22. The widths W21and W22are lengths along the second direction Y. The width W21is equal to the width W22. The contact hole CH11is located between one end portion113A and the other end portion113B. The entire edge CHE overlaps the base portion113. That is, in planar view, the edge113E does not cross the edge CHE, and the entire edge113E is located more outward than the edge CHE. A shortest distance L between the edge113E and the edge CHE is greater than or equal to 1 μm, preferably, greater than or equal to 2 μm, more preferably, greater than or equal to 2.25 μm.

The configuration example shown inFIG.8Bis different from the configuration example shown inFIG.8Ain that the base portion113is expanded. More specifically, the other end portion113B is expanded along the second direction Y more than one end portion113A. The width W22is greater than the width W21. Therefore, as compared with the configuration example shown inFIG.8A, the entire edge113E is located even more outward than the edge CHE, and the shortest distance L between the edge113E and the edge CHE are expanded. According to such a configuration example, even if the wire electrode EL11and the contact hole CH11are relatively displaced from each other, the entire contact hole CH11is still covered with the wire electrode EL11, and moisture intrusion can still be suppressed.

FIG.9is a cross-sectional view of the display panel PNL taken along line C-D shown inFIG.5B. The configuration of the first substrate SUB1has been explained with reference toFIG.7. Note that, although illustrations and explanations are omitted inFIG.7, for example, the insulating film14may be formed of a double-layer structure of an insulating film141and an insulating film142, and metal lines ML13and ML14may be disposed between the insulating film141and the insulating film142. The metal line ML13is located directly above the signal line S13and extends parallel to the signal line S13. The metal line ML14is located directly above the signal line S14and extends parallel to the signal line S14. These metal lines ML13and ML14can form the sensor lines L (L1, L2, L3, etc.) of the touch sensor TS or the dummy lines D explained with reference toFIG.2. In this case, the common electrode CE formed in the display portion DA is formed on the insulating film142and is electrically connected to the sensor line L via a contact hole formed in the insulating film142. The insulating film141is located between the insulating film13and the insulating film142, covers the switching element, and forms a flat upper surface (a surface which is in contact with the insulating film142or a surface which is in contact with the sensor line L). The insulating film141is formed of an organic material, and the insulating film142may be formed of the same organic material as the insulating film141or be formed of an inorganic material. Furthermore, a connection electrode formed of the same material and formed in the same process as the sensor line L may be formed between the connection electrode RE11and the drain electrode DE.

The second substrate SUB2includes an insulating substrate20, a light-shielding layer BM, a color filter CF, an overcoat layer OC, an alignment film AL2and the like. Similarly to the insulating substrate10, the insulating substrate20is a substrate having optical transparency such as a glass substrate or a flexible resin substrate. The light-shielding layer BM and the color filter CF are located on a side opposed to the first substrate SUB1of the insulating substrate20. The color filter CF is opposed to the pixel electrode PE11in the third direction Z. The overcoat layer OC covers the color filter CF. The overcoat layer OC is formed of transparent resin. As the color filter CF, a red color filter, a green color filter, a blue color filter and the like are included. The alignment film AL2covers the overcoat layer OC. The alignment films AL1and AL2are formed of, for example, a material exhibiting horizontal alignment properties.

The first substrate SUB1and the second substrate SUB2described above are disposed such that the alignment films AL1and AL2are opposed to each other. The cell gap between the first substrate SUB1and the second substrate SUB2is, for example, 2 to 5 μm.

The liquid crystal layer LC is located between the first substrate SUB1and the second substrate SUB2and is held between the alignment film AL1and the alignment film AL2. The liquid crystal layer LC contains liquid crystal molecules LM. The liquid crystal layer LC is composed of a positive liquid crystal material (having positive dielectric anisotropy) or a negative liquid crystal material (having negative dielectric anisotropy).

An optical element OD1including a polarizer PL1is bonded to the insulating substrate10. An optical element OD2including a polarizer PL2is bonded to the insulating substrate20. Note that each of the optical elements OD1and OD2may include a retardation plate, a scattering layer, an antireflective layer or the like as needed. An illumination device IL illuminates the first substrate SUB1of the display panel PNL with white illumination light.

In this display panel PNL, in an off state where an electric field is not formed between the pixel electrode PE11and the common electrode CE, the liquid crystal molecules LM are initially aligned in a predetermined direction between the alignment films AL1and AL2. In the off state, the illumination light emitted from the illumination device IL toward the display panel PNL is absorbed in the optical elements OD1and OD2, and this results in dark display. On the other hand, in an on state where an electric field is formed between the pixel electrode PE11and the common electrode CE, the liquid crystal molecules LM are aligned in a direction different from the initial alignment direction by the electric field, and the alignment direction is controlled by the electric field. In the on state, a part of the illumination light from the illumination device IL is transmitted through the optical elements OD1and OD2, and this results in light display.

FIG.10is a plan view showing a configuration example of an area AR2close to the round portion R12shown inFIG.1.

As shown in the drawing, in the area AR2, the number of pixel electrodes PE arranged in the first direction X varies according to row. A row is composed of pixels arranged in the first direction X. In each row, the pixel electrode PEX in the outermost pixel and the wire electrode EL1are arranged in the first direction X. In the illustrated example, one wire electrode EL1is disposed in each row, and one wire electrode EL1and one pixel electrode PEX are arranged in the first direction X.

Between the wire electrode EL1and the wiring line WL2, an electrode EL2located in the same layer as the pixel electrode PEX and the wire electrode EL1is disposed. The electrode EL2is electrically connected to the common electrode CE in a plurality of contact holes CH20. That is, both the wire electrode EL1and the electrode EL2are electrically connected to the common electrode CE and have the same potential. The electrode EL2is apart from not only the pixel electrode PEX but also the other pixel electrode PE, and is also apart from the wiring line WL2. The electrode EL2spreads over a space between each of the pixel electrode PE and the wire electrode EL1and the wiring line WL2.

For example, the electrode EL2has a width W31between a first portion EL1A of the wire electrode EL1and the wiring line WL2, and has a width W32between a second portion EL1B of the wire electrode EL1and the wiring line WL2. The first portion EL1A is closer to the contact hole CH11than the second portion EL1B. The width W31is greater than the width W32. These widths W31and W32are lengths along the first direction X.

In addition, the electrode EL2has a width W41between the pixel electrode PEX and the wiring line WL2, and has a width W42between the wire electrode EL1and the wiring line WL2. The width W41is greater than the width W42. These widths W41and W42are lengths along the second direction Y.

The pixel electrode PE, the wire electrode EL1and the electrode EL2are formed by patterning the same transparent conductive film. According to the present configuration example, at the time of patterning, it is possible to suppress narrowing of the pixel electrode PEX of the outermost pixel relative to the pixel electrode PE close to the center of the display portion DA. Therefore, uniform dimensional accuracy can be achieved in the pixel electrodes PE.

FIG.11is a plan view showing another configuration example of the area AR2close to the round portion R12shown inFIG.1.

The configuration example shown inFIG.11is different from the configuration example shown inFIG.10in that the wire electrode EL1is omitted and the pixel electrode PEX and the electrode EL2are arranged in the first direction X. As described above, since the wire electrode EL1has the same potential as the electrode EL2, the wire electrode can be omitted. Note that a distance D21between the pixel electrode PEX and the electrode EL2is equal to a distance D22between the pixel electrode PE and the pixel electrode PEX. These distances D21and D22are lengths along the first direction X.

In this configuration example also, substantially the same effects as those of the configuration example shown inFIG.10can be obtained.

FIG.12is a plan view showing another configuration example of the area AR2close to the round portion R12shown inFIG.1.

The illustrated configuration example is different from the configuration example shown inFIG.10in that the electrode EL2is omitted and the wire electrode EL1is bent into a substantially L shape. That is, the wire electrode EL1includes a first electrode portion101and a second electrode portion102extending in a direction different from the first electrode portion101. The first electrode portion101is closer to the contact hole CH11than the second electrode portion102. The first electrode portion101extends parallel to the pixel electrode PEX. The pixel electrode PEX and the first electrode portion101are arranged in the first direction X. The second electrode portion102is continuous with the first electrode portion101. The second electrode portion102extends along the first direction X. The second electrode portion102and the pixel electrode PEX are arranged in the second direction Y. In addition, the second electrode portion102and the other pixel electrode PE are arranged in the second direction Y.

In this configuration example also, substantially the same effects as those of the configuration example shown inFIG.10can be obtained.

As explained above, according to the present embodiment, a display device which can suppress degradation in display quality can be provided.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

For example, the red pixel, the green pixel and the white pixel have the same pixel width in the present embodiment but may have different pixel widths from one another. In addition, the pixel electrodes of the red pixel, the green pixel and the white pixel have the same shape in the present embodiment but may have different shapes from one another.