JP2022002150A - Touch panel - Google Patents

Abstract

To deal with shapes of complicated display areas.SOLUTION: A touch panel has a notched area forming a concave part in a second direction. A first electrode disposed in a position overlapping the notched area is split and formed on both ends of the notched area as one first electrode and another first electrode. The one electrode and the other electrode are connected over a first bridge wiring disposed along the notched area. The first electrode disposed in a position whose one portion overlaps the notched area has, in an area overlapping the notched area, a concave part where a wiring width of the first electrode becomes narrow. In the concave part of the first electrode, a second bridge wiring disposed along the notched area is formed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a touch panel.

Liquid crystal display devices, which are typical flat display devices, are used in various fields as display devices for OA (Office Automation) devices such as personal computers and televisions, taking advantage of their features such as light weight, thinness, and low power consumption. In recent years, liquid crystal display devices have been used as display devices for mobile terminal devices such as mobile phones, car navigation devices, and game machines. The shape of the display area for displaying an image is required to correspond not only to a rectangle whose four corners are right angles, but also to a circle, an ellipse, and a complicated non-rectangle such as a part having unevenness. rice field.

Japanese Unexamined Patent Publication No. 2014-191650 Japanese Unexamined Patent Publication No. 2015-232819

Display devices such as liquid crystal displays and organic EL display devices in recent years often have a touch sensing function. Structures that realize the touch sensing function include optical type, resistance type, and capacitance type, but mobile devices such as smartphones use a drive electrode (Tx electrode) and a detection electrode (Rx electrode) for static electricity. A capacitance type that detects the touch position by changing the capacitance is often used. As shown in Patent Documents 1 and 2, a plurality of drive electrodes and detection electrodes are formed in order to detect a touch position, and the electrodes are arranged so as to be orthogonal to each other.

Further, in a method called an in-cell touch panel, a common electrode for displaying an image is also used as a drive electrode. In this case, the common electrode may be electrically divided in a direction parallel to the gate signal line or electrically divided in a direction parallel to the video signal line. When the common electrode is electrically divided in the direction parallel to the gate signal line, the detection electrode is electrically divided and arranged in the direction parallel to the video signal line, and the common electrode is placed in the video signal line. When electrically divided in the parallel direction, the detection electrode will be electrically divided and arranged in the direction parallel to the gate signal line.

On the other hand, recent display devices are required to have not only a simple rectangular display area but also a panel having a complicated outer shape such as having a dent like a notch in a part thereof.

If there is a notch in the display area, the detection electrode and the drive electrode arranged in the vicinity of the notch need to have a different shape from the detection electrode arranged in the other area. FIG. 8 shows an example of arrangement of the detection electrodes. In this example, the detection electrodes (Rx1 to Rxn) are extended in the D1 direction and arranged parallel to the D2 direction. One detection electrode is formed in a mesh shape or as an aggregate of zigzag wiring. In the example of FIG. 8, a notch 112 is formed in the center of the upper side of the display panel 110.

In the case of such a display device, various problems occur with respect to the detection electrode. In the example of FIG. 8, since the upper two rows of detection electrodes Rx1 and Rx2 are located at positions overlapping the notch 112, the detection electrodes overlapping the notch 112 have a different shape from the detection electrodes at other positions. There is a need. Normally, as shown in FIG. 8, it is conceivable to arrange separate detection electrodes on the left and right sides of the notch 112. For example, the detection electrodes in the first row are Rx1-1 and Rx1-2, and the detection electrodes in the second row are set. The electrodes are arranged as Rx2-1 and Rx2-2. In such a case, the terminal portion 141 for transmitting the output signal of the detection electrode to the outside and the wiring 140 between the detection electrodes are required for the detection electrode overlapping the notch portion, so that the number of wirings and the number of terminals are required. There is a problem that the number increases.

Further, since the length is different from that of other detection electrodes, the capacitance difference between the detection electrodes becomes large, and it becomes difficult to adjust the sensitivity as a touch panel.

An object of the present invention is to cope with the shape of a complicated display area.

The touch panel has a plurality of first electrodes extending in the first direction and parallel to the second direction orthogonal to the first direction, and a plurality of second electrodes extending in the second direction and parallel to the first direction. In the touch panel, the touch panel has a notch region that forms a recess in the second direction, and the first electrode arranged at a position overlapping the notch region is a notch region. It is divided and formed on both sides as one first electrode and the other first electrode, and the one first electrode and the other first electrode are connected by a first bridge wiring arranged along the notch region. The first electrode is arranged at a position where it partially overlaps the notch region, and has a recess in the overlap region of the notch region where the wiring width of the first electrode is narrowed. A second bridge wiring arranged along the notch region is formed in the recess of the electrode.

According to the present invention, it is possible to cope with the shape of a complicated display area.

It is a top view which shows the outline of the display panel to which this invention is applied. It is a circuit diagram of the display panel shown in FIG. It is a figure which shows a part of the circuit shown in FIG. 2 in detail. FIG. 6 is a sectional view taken along line IV-IV of the display device shown in FIG. It is a figure explaining the structure for touch sensing. It is an enlarged view around the notch. It is an enlarged view of the area VII of FIG. It is a top view which shows the outline of the display panel when this invention is not applied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be carried out in various embodiments without departing from the gist thereof, and is not construed as being limited to the description contents of the embodiments exemplified below.

The drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment in order to clarify the explanation, but the drawings are merely examples and limit the interpretation of the present invention. It's not something to do. In the present specification and each figure, elements having the same functions as those described with respect to the above-mentioned figures may be designated by the same reference numerals and duplicate description may be omitted.

Further, in the detailed description of the present invention, when defining the positional relationship between a certain component and another component, "above" and "below" are used only when they are located directly above or directly below a certain component. However, unless otherwise specified, it shall include the case where other components are intervened between them.

As the present embodiment, a liquid crystal display device will be described as an example. FIG. 2 is a circuit diagram of a display panel 10 included in the display device. FIG. 3 is a diagram showing a part of the circuit shown in FIG. 2 in detail. The display panel 10 includes a plurality of pixels PX in the display area DA. Here, the pixel PX indicates a minimum unit that can be individually controlled according to a video signal, and is, for example, in a region including a switching element SW arranged at a position where the scanning line G and the signal line S intersect. exist. The plurality of pixels PX are arranged in a matrix in the first direction D1 and the second direction D2. The scanning line G extends in the first direction D1 and is aligned with the second direction D2. The signal lines S each extend in the second direction D2 and are lined up in the first direction D1. The scanning line G and the signal line S do not necessarily have to extend linearly, and a part of them may be bent. The scanning line G and the signal line S are drawn out to a peripheral area PA (non-display area) outside the display area DA. In the peripheral region PA, the scanning line G is connected to the scanning line driving circuit GD, and the signal line S is connected to the signal line driving circuit SD.

The display panel 10 has a plurality of first electrodes 34 (pixel electrodes) and a plurality of second electrodes 36 (common electrodes) in order to drive the liquid crystal layer LC of each pixel PX. Each of the first electrodes 34 faces the second electrode 36, and the liquid crystal layer LC is driven by the electric field generated between the first electrode 34 and the second electrode 36. The holding capacity CS is formed, for example, between the second electrode 36 and the first electrode 34. The second electrode 36 is arranged over a plurality of pixels PX. The second electrode 36 is drawn out to the peripheral region PA and connected to the common electrode drive circuit CD.

The pixel PX includes a switching element SW. 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. More specifically, the switching element SW includes a gate electrode WG, a source electrode WS, and a drain electrode WD. The gate electrode WG is electrically connected to the scanning line G. In the illustrated example, the electrode electrically connected to the signal line S is referred to as a source electrode WS, and the electrode electrically connected to the first electrode 34 is referred to as a drain electrode WD. The scanning line G is connected to the switching element SW in each of the pixels PX arranged in the first direction D1. The signal line S is connected to the switching element SW in each of the pixels PX arranged in the second direction D2.

FIG. 4 is a cross-sectional view corresponding to one pixel PX of the display area DA. Specifically, it is a cross-sectional view at the position of the IV-IV line shown in FIG. The display panel 10 has a configuration corresponding to a display mode (Fringe-Field-Switching mode) using a lateral electric field substantially parallel to the main surface. Alternatively, the display panel 10 may have a configuration corresponding to a vertical electric field perpendicular to the main surface of the substrate, an electric field diagonal to the main surface of the substrate, or a display mode in which they are used in combination. good. In the display mode using the lateral electric field, for example, a configuration in which either one of the first substrate SUB1 and the second substrate SUB2 is provided with both the first electrode 34 and the second electrode 36 can be applied. In the display mode using a longitudinal electric field or an oblique electric field, for example, the first substrate SUB1 is provided with either the first electrode 34 or the second electrode 36, and the second substrate SUB2 is provided with the first electrode 34 and the second electrode 36. A configuration in which either one or the other is provided is applicable.

The first substrate SUB1 includes a first glass substrate GL1, a signal line S, a second electrode 36, a metal layer M, a first electrode 34, a first insulating film IN1, a second insulating film IN2, a third insulating film IN3, and a first. It is equipped with an alignment film AL1 and the like. It should be noted that the illustration of the switching element SW, the scanning line G, and various insulating films interposed between them is omitted here.

The first insulating film IN1 is located on the first glass substrate GL1. The semiconductor layer of the scanning line G and the switching element SW (not shown) is located between the first glass substrate GL1 and the first insulating film IN1. The signal line S is located on the first insulating film IN1. The second insulating film IN2 is located on the signal line S and the first insulating film IN1. The second electrode 36 is located on the second insulating film IN2. The metal layer M is in contact with the second electrode 36 directly above the signal line S. In the illustrated example, the metal layer M is located on the second electrode 36, but may be located between the second electrode 36 and the second insulating film IN2. The metal layer M is wiring provided for lowering the resistance of the second substrate 36, but at the time of touch sensing, a drive signal (Tx signal) for touch sensing is transmitted to the second electrode 36 via the metal layer M. Applied.

The third insulating film IN3 is located on the second electrode 36 and the metal layer M. The first electrode 34 is located on the third insulating film IN3. The first electrode 34 faces the second electrode 36 via the third insulating film IN3. Further, the first electrode 34 has a slit SL at a position facing the second electrode 36. The first alignment film AL1 covers the first electrode 34 and the third insulating film IN3.

The scanning line G, the signal line S, and the metal layer M are formed of a metal material such as molybdenum, tungsten, titanium, and aluminum, and may have a single-layer structure or a multi-layer structure. The second electrode 36 and the first electrode 34 are formed of a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The first insulating film IN1 and the third insulating film IN3 are inorganic insulating films, and the second insulating film IN2 is an organic insulating film.

The second substrate SUB2 includes a second glass substrate GL2, a light-shielding layer BM, a color filter CF, an overcoat layer OC, a second alignment film AL2, and the like. The light-shielding layer BM and the color filter CF are located on the side of the second glass substrate GL2 facing the first substrate SUB1. The light-shielding layer BM partitions the pixel PX and is located directly above the signal line S. The color filter CF faces the first electrode 34, and a part thereof overlaps the light-shielding layer BM. The color filter CF includes a red color filter, a green color filter, a blue color filter, and the like. The overcoat layer OC covers the color filter CF. The second alignment film AL2 covers the overcoat layer OC.

The detection electrode 22 is located on the main surface (the surface on which the viewer recognizes the image) of the second glass substrate GL2. The detection electrode 22 may be formed of a metal or a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), or the transparent conductive material may be laminated on the metal. , May be formed of a conductive organic material, a dispersion of fine conductive substances, or the like. The shape of the detection electrode 22 is formed as an aggregate of wiring in a mesh shape or in a zigzag manner.

The first optical element OD1 including the first polarizing plate is located between the first glass substrate GL1 and the lighting device BL. The second optical element OD2 including the second polarizing plate is located on the detection electrode 22. The first optical element OD1 and the second optical element OD2 may include a retardation plate, if necessary.

FIG. 5 is a diagram illustrating a structure for touch sensing. In the present embodiment, the plurality of second electrodes 36 are shared for touch sensing together with the plurality of detection electrodes 22. The detection electrodes 22 extend in the first direction D1 and are arranged at intervals in the second direction D2. The detection electrode 22 faces the second electrode 36. The second electrodes 36 each have a band-like shape extending in the second direction D2, and are arranged at intervals in the first direction D1. Each of the second electrodes 36 is electrically connected to the common electrode drive circuit CD shown in FIG. The common electrode drive circuit CD supplies a common drive signal to the second electrode 36 at the time of display drive for displaying an image in the display area DA.

The common electrode drive circuit CD supplies a sensor drive signal (Tx signal) to the second electrode 36 at the time of sensing drive for touch sensing. The detection electrode 22 changes the capacitance between the second electrode 36 and the detection electrode 22 with the sensor signal required for sensing (that is, the change in the electrostatic capacitance between the second electrode 36 and the detection electrode 22) as the sensor drive signal is supplied to the second electrode 36. The based detection signal (Rx signal)) is output.

As described above, the second electrode 36 has a function of generating an electric field for display between the second electrode 36 and the first electrode 34, and has a capacitance between the second electrode 36 and the detection electrode 22 in order to detect the touch position of the object to be detected. It has a function to generate.

FIG. 1 is a plan view of the display panel 10 to which the present invention is applied. The display panel 10 has a notch 12. The notch 12 is formed in the middle of the display panel 10 in the first direction D1 (horizontal direction in FIG. 1), and is formed at both ends in the second direction D2 (vertical direction in FIG. 1) orthogonal to the first direction D1. It is formed on one side (upper side of FIG. 1). The notch 12 is not simply an area where the image is not displayed, but an area where the space is physically vacant. When the display panel 10 is applied to a smartphone, a speaker, a camera, or the like is arranged in this space.

The display panel 10 has a display area DA on which an image is displayed. It is an outer edge portion of the display panel 10, and has a peripheral region PA around the display region DA.

A plurality of detection electrodes (Rx electrodes) 22 are arranged on the display panel 10 for touch sensing. The plurality of detection electrodes 22 in the present embodiment extend in the first direction D1 and are parallel to the second direction D2. For example, 17 detection electrodes 22 are arranged on the display region DA.

A terminal portion 41 for transmitting the signal of the detection electrode 22 to the outside is formed on the lower side of the display region DA. The terminal portion 41 has a plurality of terminals. The terminal portion 41 and each detection electrode 22 are connected by wiring 40. The wiring 40 is arranged in the peripheral area PA of the display panel 10 which is outside the display area DA.

In the case of the display panel 10 of FIG. 1, the notch 12 overlaps with two detection electrodes Rx1 and Rx2 of the detection electrodes 22. In this embodiment, there are bridge wirings 330 and 331 connecting the detection electrodes 22 arranged on the left and right sides of the notch 12 at a position where the detection electrode 22 overlaps the notch 12.

FIG. 6 shows an enlarged view around the notch 12. Further, FIG. 7 shows an enlarged view of the region VII shown in FIG. As shown in FIG. 6, in one detection electrode 22, a wiring group configured in a mesh shape is extended in the D1 direction. The width of the wiring constituting the detection electrode 22 is about 5 μm. The width of one detection electrode 22 in the D2 direction is about 600 μm. One detection electrode may be formed by being divided into two, and in that case, the wiring width of the detection electrode 22 after the division is about 300 μm. Since the detection electrode 22 is configured in a mesh shape, it is wide like this, but since the wiring itself is 6 (3 × 2 at the time of division), the total width of the wiring only in the D2 direction is , About 30 μm, which is the substantial wiring width of the detection electrode 22.

In the detection electrode 22 (Rx1), the left and right sides are completely separated by the notch 12. Therefore, the bridge wiring 330 is arranged on the peripheral region PA surrounding the notch 12, and the left and right detection electrodes 22 (Rx1) are electrically connected. As a result, the wiring 40 connected to the detection electrode 22 (Rx1) can be handled by only one of them. Therefore, even in the case of the display panel having the notch 12, the number of terminals of the terminal portion 41 may be the same as in the case of the simple rectangular display panel.

In the present embodiment, the width of the bridge wiring 330 is 30 μm, which is 6 times as thick as the width of 5 μm of the wiring constituting the other detection electrodes 22. Since the substantial wiring width of the detection electrode 22 is 30 μm as described above, the ratio of the wiring width becomes 6 times and becomes too large when the normal wiring width is 5 μm. Therefore, in this embodiment, in order to make the ratio of the wiring widths the same, the width of the bridge wiring 330 is set to 30 μm or more. With this width, there is no practical problem in terms of electrical resistance, and it is possible to arrange the wiring without any problem in terms of wiring layout.

In the detection electrode 22 (Rx2), only the upper half of the detection electrode overlaps the notch 12, so that the width of the mesh-shaped electrode is narrowed along the notch 12 in the overlapping portion. The left and right sides of the detection electrode 22 (Rx2) are not completely separated, but a bridge wiring 331 is formed along the notch 12 in the portion where the width of the detection electrode 22 (Rx2) is narrowed. As a result, an electric conductive path on the notch 12 side of the detection electrode 22 (Rx2) is secured. The width of the bridge wiring 331 is 5 μm. In the detection electrode 22 (Rx2), the width in the D2 direction is about half that in the other portion at the place where it overlaps with the notch 12. Therefore, the actual wiring width of the detection electrode 22 (Rx2) at the position of the notch 12 is about 15 μm, which is about half the width of the other portion. Therefore, there is no practical problem in terms of electrical resistance, and there is no problem in using the wiring width of 5 μm constituting the detection electrode 22 as it is for the bridge wiring 331.

As described above, in the present embodiment, even if the detection electrode is divided by these bridge wirings, it is possible to make the state so that there is not much difference electrically from the other detection electrodes. Therefore, even when the shape of the display area becomes complicated, the wiring 40 and the terminal portion 41 similar to the rectangular display area can be used. In addition, the capacitance difference between the detection electrodes can be reduced.

The present invention is not limited to the above-described embodiment, and can be replaced with a configuration that has substantially the same configuration, a configuration that exhibits the same action and effect, or a configuration that can achieve the same object. For example, the configuration described in the embodiment shows an example of an in-cell touch panel, but an external touch panel is formed outside the display area together with a touch sensing drive electrode (Tx electrode) and a detection electrode (Rx electrode) outside the display device. Also, the structure of the detection electrode (Rx electrode) of the present invention can be used. Further, in the above embodiment, the liquid crystal display device has been described as an example, but the shape of the detection electrode can also be applied to the organic EL display device.

10 Display panel, 12 notch, 22 detection electrode, 34 1st electrode, 36 2nd electrode, 40 wiring, 41 terminal part, display panel 110, notch 112, wiring 140, terminal part 141, 330 bridge wiring, 331 bridge Wiring, AL1 1st alignment film, AL2 2nd alignment film, BL lighting device, BM shading layer, CD common electrode drive circuit, CF color filter, CS holding capacity, D1 1st direction, D2 2nd direction, DA display area, G scanning line, GD scanning line drive circuit, GL1 first glass substrate, GL2 second glass substrate, IN1 first insulating film, IN2 second insulating film, IN3 third insulating film, LC liquid crystal layer, M metal layer, OC over Coat layer, OD1 1st optical element, OD2 2nd optical element, PA peripheral area, PX pixel, S signal line, SD signal line drive circuit, SL slit, SUB1 1st substrate, SUB2 2nd substrate, SW switching element, WD Drain electrode, WG gate electrode, WS source electrode.

Claims (7)

A plurality of first electrodes extending in the first direction and parallel to the second direction orthogonal to the first direction,
A plurality of second electrodes extending in the second direction and parallel to the first direction,
It is a touch panel with
The touch panel has a notched region that forms a recess in the second direction.
The first electrode arranged at a position overlapping the notch region is divided and formed as one first electrode and the other first electrode on both sides of the notch region.
The one first electrode and the other first electrode are connected by a first bridge wiring arranged along the notch region.
The first electrode arranged at a position partially overlapping the notch region has a recess in the overlapping region of the notch region where the wiring width of the first electrode is narrowed.
A touch panel characterized in that a second bridge wiring arranged along the notch region is formed in the recess of the first electrode. In the touch panel according to claim 1,
A touch panel characterized in that a peripheral region of a display panel is arranged between the first electrode and the notch region, and the first bridge wiring is arranged in the peripheral region. In the touch panel according to claim 1 or 2.
The first electrode is a touch panel characterized by having a mesh-like shape. In the touch panel according to any one of claims 1 to 3.
A touch panel characterized in that the width of the first bridge wiring is wider than the width of the wiring constituting the first electrode. In the touch panel according to any one of claims 1 to 4.
A touch panel characterized in that the width of the second bridge wiring is the same as the width of the wiring constituting the first electrode. In the touch panel according to any one of claims 1 to 5.
A touch panel characterized by having a plurality of connection wirings connected to each of the plurality of first electrodes and a plurality of terminals connected to the plurality of connection wirings. In the touch panel according to any one of claims 1 to 6.
A touch panel characterized in that the first electrode is a detection electrode and the second electrode is a drive electrode.

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