JP2018010026A - Liquid crystal display with touch sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display with a touch sensor that can reduce display unevenness.SOLUTION: A second substrate 10 includes an inner surface S2 that faces a first substrate 20 at an interval and an outer face S1 on the opposite side of the inner face S2, and has translucency. A liquid crystal layer 30 is provided between the first substrate 20 and second substrate 10. An outside touch sensor electrode 1 is provided on the outer face S1 of the second substrate 10. A black matrix layer 11 is provided on the inner face S2 of the second substrate 10, includes an opening, has a light blocking property, and is made of resin. An inner touch sensor electrode 2 is provided on the black matrix layer 11 and is made of metal. An insulating layer 12 is provided on the inner touch sensor electrode 2. A shield electrode 3 is provided on the insulating layer 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid crystal display device with a touch sensor.

  In recent years, not only a vertical electric field mode but also a horizontal electric field mode is widely used as a liquid crystal display panel. In the horizontal electric field mode, a desired display is performed by applying a horizontal electric field generated from the pixel electrode of the thin film transistor (TFT) substrate to the liquid crystal layer. On the other hand, an electric field that affects the potential of the counter substrate (typically a color filter (CF) substrate) can also be generated from the TFT substrate. An undesired electric field can be applied to the liquid crystal layer by unintentionally changing the potential of the counter substrate. As a result, display unevenness such as light leakage or white spots may occur. For example, according to Patent Document 1, a liquid crystal display panel is provided with a gate wiring, a gate terminal outside the display area, and a tapered gate wiring portion that connects them to each other. The tapered gate wiring portion is a lead wiring group outside the display area, and has a wiring pitch that becomes narrower as it is closer to the gate terminal. An electric field generated from the tapered gate wiring portion induces a potential fluctuation of the counter substrate. As a result, white spots may occur in the liquid crystal display near the gate terminal. In order to prevent this, a conductive layer is disposed above the tapered gate wiring portion via an insulating film. Thereby, the electric field generated from the lead-out wiring is shielded, and the potential fluctuation of the counter substrate is prevented.

  In recent years, liquid crystal display devices provided with a touch sensor have been widely used. One type of touch sensor is a projected capacitive touch sensor. The projected capacitive touch sensor includes a detection row direction wiring that detects the coordinates of the touch position in the row direction and a detection column direction wiring that detects the touch position in the column direction. In order to reduce the thickness or weight of the device, an in-cell method in which the functions of the touch sensor are integrated in the display panel or an on-cell method in which the functions of the touch sensor are integrated on the surface of the display panel can be used. With the in-cell method, a decrease in the accuracy of touch detection can be a problem. On the other hand, in the on-cell method, degradation of display visibility due to the presence of a touch sensor can be a problem. In view of both of these problems, a hybrid system in which the functions of the touch sensor are integrated on the surface and inside of the display panel may be useful. For example, according to Patent Document 2, an X detection electrode extending in the X direction is provided on one surface of the substrate, and a Y detection electrode extending in the Y direction is provided on the other surface of the substrate.

JP 2005-275054 A JP 2013-97704 A

  When the touch sensor is a hybrid type and the liquid crystal display panel is a horizontal electric field mode display type, due to the influence of the electric field generated between the touch sensor electrode and the pixel electrode of the TFT substrate on the liquid crystal layer, Display unevenness such as light leakage or white spots may occur.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a liquid crystal display device with a touch sensor capable of suppressing display unevenness.

  The liquid crystal display device of the present invention includes a first substrate, a second substrate, a liquid crystal layer, an outer touch sensor electrode, a black matrix layer, an inner touch sensor electrode, an insulating layer, and a shield electrode. doing. The second substrate has an inner surface facing the first substrate at an interval and an outer surface opposite to the inner surface, and has translucency. The liquid crystal layer is provided between the first substrate and the second substrate. The outer touch sensor electrode is provided on the outer surface of the second substrate. The black matrix layer is provided on the inner surface of the second substrate, has an opening, has light shielding properties, and is made of resin. The inner touch sensor electrode is provided on the black matrix layer and is made of metal. The insulating layer is provided on the inner touch sensor electrode. The shield electrode is provided on the insulating layer.

  According to the present invention, the electric field generated from the inner touch sensor electrode is shielded by the shield electrode. Thereby, display unevenness due to the electric field generated from the inner touch sensor electrode can be suppressed.

It is a fragmentary sectional view which shows schematically the structure of the liquid crystal display panel with a touch sensor which the liquid crystal display device in Embodiment 1 of this invention has. It is a figure which shows schematically the structure of the liquid crystal display device in Embodiment 1 of this invention. FIG. 2 is a partial plan view schematically showing the configuration of each picture element provided on a color filter substrate included in the liquid crystal display panel with a touch sensor of FIG. 1. It is a figure which shows typically the structure of the TFT substrate which the liquid crystal display panel with a touch sensor of FIG. 1 has. It is a partial top view which shows roughly each structure of the pixel provided in the color filter board | substrate which the liquid crystal display panel with a touch sensor which the liquid crystal display device in Embodiment 2 of this invention has has. It is a fragmentary sectional view which shows schematically the structure of the liquid crystal display panel with a touch sensor which the liquid crystal display device in Embodiment 3 of this invention has.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a partial cross-sectional view schematically showing a configuration of a liquid crystal display panel 51 with a touch sensor included in the liquid crystal display device 60 (FIG. 2) in the present embodiment. A liquid crystal display panel with a touch sensor 51 includes a TFT substrate (first substrate) 20, a CF substrate (second substrate) 10, a liquid crystal layer 30, an outer touch sensor electrode 1, and a BM layer (black matrix layer). 11, inner touch sensor electrode 2, color material layer (insulating layer) 12, shield electrode 3, overcoat layer 13, CF side polarizing plate 31, and TFT side polarizing plate 32. .

  The CF substrate 10 has translucency and is made of, for example, glass. The CF substrate 10 has an inner surface S2 and an outer surface S1 opposite to the inner surface S2. The outer surface S1 is a surface that faces the observer. The inner surface S2 faces the TFT substrate 20 with a gap. The liquid crystal layer 30 is provided between the TFT substrate 20 and the CF substrate 10.

  The BM layer 11 is provided on the inner surface S <b> 2 of the CF substrate 10. The BM layer 11 has an opening OP (FIG. 3). The BM layer 11 has a light shielding property. The BM layer 11 is made of a resin and can be charged.

  By providing the outer touch sensor electrode 1 and the inner touch sensor electrode 2, the liquid crystal display panel 51 with a touch sensor has a function of receiving an input from an observer. The outer touch sensor electrode 1 is provided on the outer surface S1 of the CF substrate 10. The inner touch sensor electrode 2 is provided on the BM layer 11. The inner touch sensor electrode 2 is made of metal. The color material layer 12 is provided on the inner touch sensor electrode 2. A CF substrate 10 and a BM layer 11 are disposed between the outer touch sensor electrode 1 and the inner touch sensor electrode 2.

  The shield electrode 3 is provided on the color material layer 12. The overcoat layer 13 is provided on the color material layer 12. The overcoat layer 13 is made of an insulator. In particular, in the present embodiment, the shield electrode 3 is disposed on the color material layer 12 via the overcoat layer 13.

  The CF side polarizing plate 31 is provided on the outer surface S <b> 1 of the CF substrate 10. The outer touch sensor electrode 1 is disposed between the CF side polarizing plate 31 and the CF substrate 10. The TFT side polarizing plate 32 is provided on the surface of the TFT substrate 20 opposite to the surface facing the liquid crystal layer 30. Cross Nicol is used for the arrangement of the CF side polarizing plate 31 and the TFT side polarizing plate 32. Of the outer touch sensor electrode 1 and the outer touch sensor electrode 1, the former is closer to the CF side polarizing plate 31 and the latter is closer to the TFT side polarizing plate 32.

  FIG. 2 is a diagram schematically showing the configuration of the liquid crystal display device 60, and mainly shows the configuration related to the input function. In the drawing, a planar layout of the liquid crystal display panel 51 with a touch sensor is shown. In order to make the drawing easy to see, a region having a shield electrode 3 is provided with a grain pattern.

  In the display area 40 of the liquid crystal display panel 51 with a touch sensor, the outer touch sensor electrodes 1 extending in the column direction (vertical direction in FIG. 2) are arranged on the outer surface S1 (FIG. 1) of the CF substrate 10 in the row direction (horizontal in FIG. 2). Direction). In the display region 40, the inner touch sensor electrodes 2 extending in the row direction are arranged in the column direction on the inner surface S2 (FIG. 1) of the CF substrate 10. In the display region 40, the shield electrodes 3 extending in the row direction are arranged in the column direction on the inner surface S2 (FIG. 1) of the CF substrate 10.

  The liquid crystal display device 60 includes an input function control board 41, a liquid crystal display control / input function control board 42, and an inter-substrate conduction member 43 in addition to the liquid crystal display panel 51 with a touch sensor. The outer touch sensor electrode 1 and the input function control board 41 are connected to each other by a lead wiring in a region outside the display region 40. The inner touch sensor electrode 2 is electrically connected to the lead wiring of the TFT substrate 20 through the inter-substrate conducting member 43 and further connected to the liquid crystal display control / input function control substrate 42. Similarly, the shield electrode 3 is electrically connected to the lead wiring of the TFT substrate 20 via the inter-substrate conducting member 43 and further connected to the liquid crystal display control / input function control substrate 42.

  FIG. 3 is a partial plan view schematically showing the configuration of each of the plurality of picture elements PE provided in the display area 40 of the CF substrate 10. The BM layer 11 is disposed in an area that needs to be shielded from light. On the BM layer 11, the inner touch sensor electrode 2 made of a low resistance metal is formed. The inner touch sensor electrode 2 is disposed on the inner side of the BM layer 11 in the planar layout in order to prevent a decrease in transmittance.

  The shield electrode 3 is disposed so as to completely cover the inner touch sensor electrode 2 in a planar layout so that the electric field from the inner touch sensor electrode 2 does not leak. In the present embodiment, the shield electrode 3 is disposed so as to directly face the liquid crystal layer 30 (FIG. 1). The shield electrode 3 is disposed so as to cover a part of the BM layer 11 in the planar layout.

  The color material layer 12 typically includes a red layer 12R, a green layer 12G, and a blue layer 12B. In FIG. 3, the red layer 12R, the green layer 12G, and the blue layer 12B are arranged without a gap, but a gap may be provided therebetween.

  FIG. 4 is a diagram schematically illustrating a configuration of the TFT substrate 20 included in the liquid crystal display panel 51 with a touch sensor. The TFT substrate 20 includes a plurality of pixel electrodes 21 to which a pixel potential Vp is supplied, and a common electrode 22 that is provided away from the pixel electrode 21 and to which a common potential Vc is supplied.

  In the case of a horizontal electric field mode liquid crystal display panel, the pixel electrode 21 and the common electrode 22 (FIG. 4) for modulating the liquid crystal layer 30 (FIG. 1) are both provided on the TFT substrate 20 instead of the CF substrate 10. The liquid crystal layer 30 (FIG. 1) is modulated by the electric field generated by these electrodes. If the potential of the CF substrate 10 is maintained at the common potential Vc in the display area 40, the electric field for liquid crystal modulation is not disturbed. Conversely, when the potential of the CF substrate 10 deviates from the common potential Vc, an electric field is generated between the pixel electrode 21 on the TFT substrate 20 and the CF substrate 10, and the electric field for liquid crystal modulation may be disturbed. In the case of a liquid crystal display panel that does not have a touch sensor, in the display region 40, the potential of the CF substrate 10 becomes the common potential Vc due to the charging effect, and thus the above-described disturbance is unlikely to occur. On the other hand, in the liquid crystal display panel with a touch sensor having the inner touch sensor electrode 2, the inner touch sensor electrode 2 can take a potential different from the common potential, and thus the above-described disturbance can occur. That is, display unevenness (whiteout) may occur due to an error electric field generated between the inner touch sensor electrode 2 and the pixel electrode 21 (FIG. 4).

  According to the present embodiment, the shield electrode 3 is provided on the inner touch sensor electrode 2 via the color material layer 12. Thereby, the electric field generated from the inner touch sensor electrode 2 is shielded by the shield electrode 3. Therefore, display unevenness due to the electric field generated from the inner touch sensor electrode 2 can be suppressed. When the shield electrode 3 completely covers the inner touch sensor electrode 2, the error electric field to the liquid crystal layer 30 can be more sufficiently shielded.

  The shield electrode 3 is disposed on the color material layer 12 via an overcoat layer 13. The overcoat layer 13 can ensure electrical insulation between the shield electrode 3 and the inner touch sensor electrode 2 more reliably.

  The shield electrode 3 has a portion overlapping the BM layer 11 in plan view. Thereby, the electric field generated from the charged BM layer 11 can be shielded to some extent. Therefore, display unevenness due to the electric field generated from the BM layer 11 can be suppressed.

  The inner touch sensor electrode 2 is made of metal. Thereby, the electrical resistance of the inner touch sensor electrode 2 can be lowered.

  Preferably, the shield electrode 3 is electrically connected to the common electrode 22 via the inter-substrate conducting member 43 (FIG. 2). Thereby, the potential of the shield electrode 3 can be held at the common potential Vc. Therefore, the electric field generated from the inner touch sensor electrode 2 can be more effectively shielded by the shield electrode.

(Embodiment 2)
FIG. 5 is a partial plan view schematically showing the configuration of each of the plurality of picture elements PE provided on the color filter substrate included in the liquid crystal display panel with a touch sensor included in the liquid crystal display device according to the present embodiment. In the present embodiment, a shield electrode 3v is provided instead of the shield electrode 3 (FIG. 3). The shield electrode 3v has a portion that overlaps the opening OP of the BM layer 11 in plan view. Furthermore, the shield electrode 3v has translucency. The width of the shield electrode 3v is made wider than the width of the BM layer 11.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  According to the present embodiment, the shield electrode 3v has a portion that overlaps the opening OP of the BM layer 11 in plan view. Thereby, as compared with the first embodiment, the shield electrode 3 can more fully cover the BM layer 11. Therefore, the electric field generated from the charged BM layer 11 can be shielded more effectively. Therefore, display unevenness due to the electric field generated from the BM layer 11 can be suppressed.

  Furthermore, the shield electrode 3 has translucency. Thereby, it is avoided that the light passing through the opening OP is shielded by the shield electrode 3. Therefore, it is possible to avoid that the effective aperture ratio is lowered due to the presence of the shield electrode 3.

(Embodiment 3)
FIG. 6 is a partial cross-sectional view schematically showing a configuration of a liquid crystal display panel 53 with a touch sensor included in the liquid crystal display device according to the third embodiment. In the present embodiment, unlike the first embodiment (FIG. 1), the overcoat layer 13 is disposed between the shield electrode 3 and the liquid crystal layer 30.

  Since the configuration other than the above is substantially the same as the configuration of the first or second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

  According to the present embodiment, the overcoat layer 13 made of an insulator is disposed between the shield electrode 3 and the liquid crystal layer 30. Thereby, the conductive foreign matter from the shield electrode 3 is prevented from entering the liquid crystal layer 30. Therefore, a short circuit between the pixel electrode 21 and the common electrode 22 (FIG. 4) due to the conductive foreign matter is prevented. Therefore, it is possible to prevent the occurrence of a display error due to this short circuit.

  In addition, since the distance between the inner touch sensor electrode 2 and the shield electrode 3 is closer than that in the first embodiment, more effective electric field shielding can be achieved without increasing the area of the shield electrode 3.

  In the configuration of FIG. 6, electrical insulation between the inner touch sensor electrode 2 and the shield electrode 3 is ensured only by the color material layer 12. For this reason, in the region where the inner touch sensor electrode 2 and the shield electrode 3 overlap, the color material layer 12 is provided so that there is no gap when the red layer 12R, the green layer 12G, and the blue layer 12B are in contact with each other. There is a need. Therefore, it is preferable to fill the gaps between the color materials more reliably by arranging the color materials in an overlapping manner.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  OP opening, PE picture element, S1 outer surface, S2 inner surface, Vc common potential, Vp pixel potential, 1 outer touch sensor electrode, 2 inner touch sensor electrode, 3, 3v shield electrode, 10 CF substrate (second substrate), 11 BM layer (black matrix layer), 12 color material layer (insulating layer), 12B blue layer, 12G green layer, 12R red layer, 13 overcoat layer, 20 TFT substrate (first substrate), 21 pixel electrode, 22 Common electrode, 30 liquid crystal layer, 31 CF side polarizing plate, 32 TFT side polarizing plate, 40 display area, 41 input function control board, 42 liquid crystal display control / input function control board, 43 inter-substrate conductive member, 51, 53 touch sensor Liquid crystal display panel, 60 liquid crystal display device.

Claims (5)

A first substrate;
A second substrate having an inner surface facing the first substrate at an interval and an outer surface opposite to the inner surface and having translucency;
A liquid crystal layer provided between the first substrate and the second substrate;
An outer touch sensor electrode provided on the outer surface of the second substrate;
A black matrix layer provided on the inner surface of the second substrate, having an opening, having a light shielding property, and made of a resin;
An inner touch sensor electrode provided on the black matrix layer and made of metal;
An insulating layer provided on the inner touch sensor electrode;
A shield electrode provided on the insulating layer;
A liquid crystal display device comprising:   The liquid crystal display device according to claim 1, wherein the shield electrode has a portion that overlaps with the opening of the black matrix layer in a plan view and has a light-transmitting property.   The first substrate includes a plurality of pixel electrodes to which a pixel potential is supplied and a common electrode that is provided away from the pixel electrode and to which a common potential is supplied, and the shield electrode is electrically connected to the common electrode. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is connected. The insulating layer is a color material layer;
The liquid crystal display device further includes an overcoat layer provided on the color material layer and made of an insulator.
The shield electrode is disposed on the color material layer via the overcoat layer,
The liquid crystal display device according to any one of claims 1 to 3. The insulating layer is a color material layer;
4. The liquid crystal display device according to claim 1, further comprising an overcoat layer provided on the shield electrode and made of an insulator. 5.

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