Patent ID: 12242698

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In addition, constituent elements with the same function are given the same reference numeral throughout the drawings for describing the embodiments, and repeated description thereof will be omitted. Further, the following embodiment is not intended to construe the claims of the present invention in a limited sense.

Schematic Configuration of Display Device with Touchscreen

FIG.7is a side view illustrating a schematic configuration of a display device with a touchscreen. In addition,FIG.7shows a case where the display panel is a liquid crystal display panel30.

The display device with a touchscreen shown inFIG.7includes the liquid crystal display panel30, a capacitance coupling type touchscreen20disposed on a surface on an observer side of the liquid crystal display panel30, and a backlight40disposed under a surface on an opposite side to the observer side of the liquid crystal display panel30.

As the liquid crystal display panel30, a liquid crystal display panel of, for example, an IPS type, a TN type, a VA type, or the like, is used.

The touchscreen20includes a plurality of X electrodes which extend in a first direction and are arranged in parallel with a predetermined arrangement pitch in a second direction intersecting the first direction, and a plurality of Y electrodes which extend in the second direction so as to intersect the X electrodes and are arranged in the first direction with a predetermined arrangement pitch.

Further,FIG.7schematically shows a case where capacitors C1and C3are formed between the finger50of an observer and the X electrodes, and a capacitor C2is formed between the finger50of the observer and the Y electrode. The touchscreen20shown inFIG.7detects a capacitance difference between coupling capacitances of the X electrode and the Y electrode, and detects touched position coordinates in a touch plane of the touchscreen20, which are touched by the finger50of the observer.

[Touchscreen in the Related Art]

FIGS.4to6are diagrams illustrating a capacitance coupling type touchscreen in the related art, whereinFIG.4is a plan view illustrating an electrode pattern of the capacitance coupling type touchscreen in the related art;FIG.5is a cross-sectional view illustrating a cross-sectional structure taken along the line V-V′ shown inFIG.4; andFIG.6is a cross-sectional view illustrating a cross-sectional structure taken along the line VI-VI′ shown inFIG.4.

The capacitance coupling type touchscreen in the related art includes a plurality of X electrodes which extend in a first direction (for example, the X direction) and are arranged in parallel with a predetermined arrangement pitch in a second direction (for example, the Y direction) intersecting the first direction, and a plurality of Y electrodes which extend in the second direction so as to intersect the X electrodes and are arranged in the first direction with a predetermined arrangement pitch.

The plurality of Y electrodes are formed in an electrode pattern where an intersection portion2aand an electrode portion2bwider than the intersection portion2aare alternately disposed in a plurality in the second direction. The plurality of Y electrodes are disposed on a surface of a substrate11on the observer side and are covered by an insulating layer12which is formed thereon. As the substrate11, a transparent insulating substrate such as, for example, glass is used.

The plurality of X electrodes are formed in an electrode pattern where an intersection portion1aand an electrode portion1bwider than the intersection portion1aare alternately disposed in a plurality in the first direction. The intersection portion la of each of the plurality of X electrodes is formed in a layer different from the Y electrode and planarly intersects the intersection portion2aof each of the Y electrodes. The electrode portion1bof the plurality of X electrodes is formed in the same layer as the electrode portion2bof each of the Y electrodes so as to be separated from the Y electrodes. Here, the electrode portion1bof the X electrode and the electrode portion2bof the Y electrode have a rhombic shape when viewed from the direction perpendicular to the substrate11.

The electrode portion1bof each of the plurality of X electrodes is covered by the insulating layer12in the same manner as the Y electrode. The intersection portion1aof each of the plurality of X electrodes is disposed on the insulating layer12and is covered by a protective layer13which is formed thereon.

The intersection portion1aof the X electrode planarly intersects the intersection portion2aof the Y electrode, and is electrically and mechanically connected to two adjacent electrode portions1bwith the intersection portion2ainterposed therebetween via contact holes12aformed in the insulating layer12which is an insulating interlayer between the intersection portion1aof the X electrode and the Y electrode.

In plan view, the electrode portion2bof the Y electrode is disposed between the two adjacent intersection portions1aof the X electrode, and the electrode portion1bof the X electrode is disposed between the two adjacent intersection portions2aof the Y electrode.

In addition, the X electrode and the Y electrode are made of a material having high transmittance, for example, a transparent conductive material such as ITO (Indium Tin Oxide).

However, in the capacitance coupling type touchscreen in the related art, there is a problem in that, when the touchscreen is viewed from a specific direction, the contact hole portion is recognized by a user due to reflection at the contact hole portion, and thus visual quality deteriorates.

EMBODIMENT

FIGS.1A and1Bare diagrams illustrating a touchscreen according to an embodiment of the present invention, whereinFIG.1Ais a plan view of an electrode intersection portion, andFIG.1Bis a cross-sectional view illustrating a cross-sectional structure taken along the line1B-1B′ ofFIG.1A.

In the present embodiment as well, as shown inFIG.4, the touchscreen includes a plurality of X electrodes which extend in a first direction (for example, the X direction) and are arranged in parallel with a predetermined arrangement pitch in a second direction (for example, the Y direction) intersecting the first direction, and a plurality of Y electrodes which extend in the second direction so as to intersect the X electrodes and are arranged in the first direction with a predetermined arrangement pitch.

The plurality of Y electrodes are formed in an electrode pattern where an intersection portion2aand an electrode portion2bwider than the intersection portion2aare alternately disposed in a plurality in the second direction. The plurality of Y electrodes are disposed on a surface of a substrate11on the observer side and are covered by a protective layer13which is formed thereon. As the substrate11, a transparent insulating substrate such as, for example, glass is used.

The plurality of X electrodes are formed in an electrode pattern where an intersection portion1aand an electrode portion1bwider than the intersection portion1aare alternately disposed in a plurality in the first direction. The intersection portion1aof each of the plurality of X electrodes is formed so as to stride over a pedestal layer15and planarly intersects the intersection portion2aof each of the Y electrodes. The electrode portion1bof each of the plurality of X electrodes is formed in the same layer as the electrode portion2bof each of the Y electrodes so as to be separated from the Y electrodes.

The plurality of X electrodes are covered by the protective layer13which is formed thereon. In addition, the electrode portion1bof the X electrode and the electrode portion2bof the Y electrode have a rhombic shape when viewed from the direction perpendicular to the substrate11.

In the present embodiment, the pedestal layer15is formed at a part where the intersection portion1aof the X electrode intersects the intersection portion2aof the Y electrode. The pedestal layer15has a profile of an elliptical shape in plan view.

As described above, the intersection portion1aof the X electrode is formed so as to stride over the pedestal layer15. Thereby, the intersection portion1aof the X electrode planarly intersects the intersection portion2aof the Y electrode, and is electrically and mechanically connected to two adjacent electrode portions1bof the X electrode with the intersection portion2ainterposed therebetween.

In plan view, the electrode portion2bof the Y electrode is disposed between the two adjacent intersection portions1aof the X electrode, and the electrode portion1bof the X electrode is disposed between the two adjacent intersection portions2aof the Y electrode. In addition, the X electrode and the Y electrode are made of a material having high transmittance, for example, a transparent conductive material such as ITO (Indium Tin Oxide).

As described above, the present embodiment is characterized in that the pedestal layer15is provided at the part where the intersection portion1aof the X electrode intersects the intersection portion2aof the Y electrode in order to omit the contact hole12aformed in the insulating layer12in the touchscreen in the related art.

Here, the pedestal layer15is formed in a tapered shape where the thickness of the side surface15bgradually increases toward the planarized portion15aon an opposite side to the surface coming into contact with the substrate11.

In the present embodiment, the contact hole12aformed in the insulating layer12is omitted from the touch panel in the related art by providing the pedestal layer15at the portion where the intersection portion1aof the X electrode intersects the intersection portion2aof the Y electrode. Therefore, it is possible to solve the problem that, when viewed from a specific direction, the contact hole portion is recognized by a user due to reflection at the contact hole portion and thereby visual quality deteriorates.

However, at the side surface15bwith a tapered shape of the intersection portion1aof the X electrode formed so as to cover the pedestal layer15, reflectance is increased than the surroundings and reflection becomes obvious, including optical interference, and particularly, it is expected that visual quality in the reflection deteriorates.

As shown inFIG.1B, it is possible to reduce the interference by adding an index matching layer16; however, visual quality deterioration at the side surface15bwith a tapered shape due to reflection cannot be reduced.

The deterioration in the visual quality due to reflection is caused by the side surface15bwith a tapered shape, and is caused by reflected light at each side surface15bhaving directionality in a direction perpendicular to each side surface15b, in a case where a profile of the pedestal layer15is a rectangular shape, as shown inFIG.3B.

Therefore, in the present embodiment, a profile of the pedestal layer15when viewed from the direction perpendicular to the substrate11is characterized in an elliptical shape of which the long axis direction is an extending direction of the intersection portion1aof the X electrode. Thereby, the side surface15bwith a tapered shape becomes a nonlinear shape which is a convex shape with respect to the reflection direction so as to diffuse reflected light at the side surface15band decrease a difference between luminance due to the reflected light at the side surface15band surrounding luminance, and thereby it is possible to reduce that the pattern of the electrode intersection portion is seen.

Here, preferably, the smaller the area of the pedestal layer is, the further achieved the improvement effect is; however, the area cannot be too small due to a restriction of a resistance value of the X electrode.

Further, in the present embodiment, for the above-described reasons, when viewed from the direction perpendicular to the substrate11, it is clear that a shape of the part intersecting the intersection portion1aof the X electrode in the pedestal layer is preferably a nonlinear shape.

Further, a profile of the pedestal layer15when viewed from the direction perpendicular to the substrate11is not limited to an elliptical shape, and may be an obtuse polygonal shape, or may be a circular shape as shown inFIG.2. In addition,FIG.2is a diagram illustrating a modified example of the pedestal layer15according to the present embodiment and is a plan view of the electrode intersection portion.

Further, although the intersection portion2aof the Y electrode is formed under the pedestal layer15, and the intersection portion1aof the X electrode is formed on the pedestal layer15inFIG.1B, the intersection portion1aof the X electrode may be formed under the pedestal layer15, and the intersection portion2aof the Y electrode may be formed on the pedestal layer as shown inFIG.3B. A configuration in this case is shown inFIGS.3A and3B.

However, as shown inFIGS.3A and3B, since it is necessary for both ends of the electrode portion1bof the X electrode in the extending direction of the X electrode to be formed so as to cover a part of the planarized portion15aand the side surface15bof the pedestal layer15in terms of manufacturing processes, a reflection region is further increased than that of the configuration shown inFIGS.1A and1B, which thus is not preferable. In addition,FIGS.3A and3Bare diagrams for describing effects of the touchscreen according to the present embodiment.

In addition, although, in the above-described embodiment, the display device with a touchscreen where the touchscreen is provided on the liquid crystal display panel which is an example of the display panel, the present invention is not limited thereto, and may be applied to a display device with a touchscreen where the touchscreen is provided on other display panels such as an organic EL display panel or an inorganic EL display panel.

As above, although the invention made by the present inventor has been described in detail based on the embodiment, the present invention is not limited to the embodiment and may be variously modified without departing from the spirit thereof.

In other words, while there have been described what are at present considered to be certain embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.