TW201314535A - In-cell touch panel - Google Patents

Abstract

An in-cell touch panel is provided. The in-cell touch panel having a touch sensing signal transfer area and a touch sensing area includes a capacitive sensing electrode disposed on the touch sensing area of a first substrate and an opposite second substrate. A conductive layer is disposed on the touch sensing signal transfer area of the second substrate. A protrusion is disposed between the first and the second substrates and at the touch sensing signal transfer area, wherein the protrusion is electrically connected with the capacitive sensing electrode and contacts with the conductive layer on the second substrate, such that a touch sensing signal from the capacitive sensing electrode is transferred to the second substrate through the protrusion.

Description

In-line touch panel

The present invention relates to a touch panel, and more particularly to a signal transmission method of a capacitive in-cell touch panel.

The current touch panel can use a resistive, capacitive or other means, such as infrared or surface acoustic waves, to achieve the effect of touch sensing, wherein the capacitive touch panel utilizes between the monitoring touch and the capacitive sensing electrode. The generated capacitance value determines the position of the touch, because the capacitive touch panel can achieve the touch effect without applying pressure, which is the mainstream of the future development of the touch panel.

The current capacitive touch panel can be divided into two types. One is an external touch panel, which is a capacitive touch panel applied to the outside of the display panel, but this method causes an increase in the overall thickness of the touch display device. Another way is to make the capacitive touch element on the back of the color filter substrate, but this method will cause the first fabricated capacitive touch element to be scraped in the process of the subsequent color filter substrate. Injury damage.

Therefore, there is a need in the industry for a capacitive touch panel that overcomes the above problems, reduces the overall thickness of the touch display device, and prevents the capacitive touch element from being damaged in subsequent processes for making the display device.

According to an embodiment of the present invention, an in-cell touch panel has a touch signal transmission area and a touch sensing area, and the in-cell touch panel includes: a first substrate, and a capacitive sensing electrode On the touch sensing area of the first substrate, the second substrate is disposed opposite to the first substrate, the conductive layer is disposed on the touch signal transmission area of the second substrate, and the protrusion is disposed on the first substrate and the second substrate And being located on the touch signal transmission area, wherein the protrusion is electrically connected to the capacitive sensing electrode and is in contact with the conductive layer on the second substrate, so that the touch signal of the capacitive sensing electrode is transmitted to the touch via the protrusion The second substrate.

In order to make the above objects, features, and advantages of the present invention more comprehensible, the following detailed description is made in conjunction with the accompanying drawings.

Embodiments of the present invention provide a capacitive sensing in-cell touch panel in which a capacitive touch sensing electrode is disposed inside a color filter substrate, and the color filter layer is located on the color filter substrate. The side can be used to solve the scratch problem caused by the conventional touch panel manufacturing the capacitive touch element on the back of the color filter substrate, thereby avoiding damage to the capacitive touch sensing electrode, and at the same time The in-cell touch panel of the embodiment of the present invention can reduce the overall thickness of the touch display device.

However, in the in-cell touch panel of the embodiment of the invention, the touch signal of the capacitive touch sensing electrode on the side of the color filter substrate needs to be transmitted to the side of the thin film transistor substrate. In the conventional method, the signal on the side of the color filter substrate is transmitted to the side of the thin film transistor substrate through the conductive particles in the seal material in the peripheral region of the display panel. However, since the doping amount of the conductive particles in the sealant material is only 0.4 wt%, there may be no conductive particles in some regions, resulting in poor transmission of the touch signal; or each signal line transmitting the touch signal ( Signal trace) The number of conductive particles that are in contact with each other will be different, causing problems such as uneven transmission of touch signals. In addition, the conventional method utilizes the conductive particles in the sealant to transmit the touch signal, which will reduce the available area of the voltage (Vcom) signal of the common electrode of the original display panel, resulting in poor transmission or non-transmission of the Vcom signal of the display panel. Both of them further lead to the problem of poor display quality.

Therefore, in the in-cell touch panel of the embodiment of the present invention, the capacitive touch sensing electrode on the color filter substrate side is used by using the protrusion disposed between the color filter substrate and the thin film transistor substrate. The touch signal is transmitted to the side of the thin film transistor substrate.

Please refer to FIG. 1 , which is a plan view showing a touch panel according to an embodiment of the present invention. The touch panel 100 has a touch sensing area 100A and a touch signal transmitting area 100B, and a peripheral circuit area 100C for inputting a display signal. In addition, a sealant 134 is disposed on the periphery of the touch sensing area 100A and the touch signal transmitting area 100B of the touch panel 100.

In the touch sensing area 100A of the upper substrate of the touch panel 100, there are a plurality of capacitive sensing electrodes 108, such as diamond-shaped indium tin oxide (ITO) electrodes, and the capacitive sensing electrodes 108 are respectively The rows and columns are arranged in series, and the touch signals obtained by the capacitive sensing electrodes 108 of each row and each row can be transmitted to the lower substrate through the protrusions 114 on the touch signal transmitting region 100B, and the touch signals can be The conductive layer on the lower substrate is transferred to a flexible printed circuit (FPC) 136, and then transmitted to the integrated circuit (IC) (not shown) in the display device via the flexible circuit board 136 for touch signals. deal with.

Referring to FIG. 2, there is shown a cross-sectional view of a touch panel according to an embodiment of the present invention along a section line 2-2' of FIG. The touch panel 100 includes a first substrate 102, such as a color filter substrate. First, a capacitive touch sensing electrode structure S is formed on the inner side of the first substrate 102, and includes a first conductive layer 104, An insulating layer 106, a second conductive layer 108, and a second insulating layer 110, wherein the first conductive layer 104 may be a metal layer, such as gold, silver, copper, aluminum, titanium, molybdenum or aluminum-bismuth alloy (AlNd). For the metal material, the second conductive layer 108 is, for example, an indium tin oxide (ITO) layer or a transparent conductive layer of other materials. The materials of the first insulating layer 106 and the second insulating layer 110 are, for example, acrylic resin or tantalum nitride. , bismuth oxide or bismuth oxynitride and other materials. The second conductive layer 108 is a diamond-shaped capacitive sensing electrode of the same column (X direction) shown in FIG. 1 , and the first conductive layer 104 is a bridge structure connecting the rhombic capacitive sensing electrodes 108 of the same column. The rhombic capacitive sensing electrode 108 of the same row (Y direction) is not shown in FIG.

Next, a third insulating layer 112 is formed over the capacitive touch sensing electrode structure S of the first substrate 102. The material of the third insulating layer 112 is, for example, an acrylic resin, tantalum nitride, hafnium oxide or bismuth oxynitride. Then, a color filter layer CF is formed on the third insulating layer 112, which includes a black matrix (BM) 116 and color filters including three colors of red, green, and blue (R, G, B) ( The color filter: CF) 118 is located in the touch sensing area 100A of the touch panel 100.

According to an embodiment of the present invention, a protrusion 114 is formed in the touch signal transmission region 100B of the first substrate 102, and includes a photo spacer 115 and a first cover on the photosensitive spacer 115. The transparent conductive layer 120 is, for example, an indium tin oxide (ITO) layer, wherein the photosensitive spacer 115 is directly formed on the second conductive layer 108 by photoresist coating and lithography, and the first transparent conductive layer 120 is The photosensitive spacer 115 is covered and extended to the second conductive layer 108, so that the protrusion 114 is electrically connected to the capacitive touch sensing electrode structure S on the first substrate 102.

Next, the second substrate 130 is disposed opposite to the first substrate 102. The second substrate 130 is, for example, a thin-film transistor (TFT) array substrate, and has a plurality of thin film transistors (not shown). Formed on it. A conductive layer 132 is formed on the second substrate 130, and the material thereof is, for example, a metal material such as gold, silver, copper, aluminum, titanium, molybdenum or aluminum-niobium alloy (AlNd), and the conductive layer on the protrusion 114 and the second substrate 130 The touch is generated so that the touch signal generated by the capacitive touch sensing electrode structure S on the first substrate 102 can be transmitted to the second substrate 130 side via the protrusion 114.

As shown in FIG. 2, the conductive layer 132 on the second substrate 130 is electrically connected to the flexible circuit board (FPC) 136. Therefore, the touch signal generated by the capacitive touch sensing electrode structure S can be transmitted through the protrusion 114 and the conductive The layer 132 is transferred to the flexible circuit board 136, and then transmitted to the integrated circuit (IC) (not shown) in the display device via the flexible circuit board 136 for the processing of the touch signal, and the thin film electricity disposed on the second substrate 130. The crystal is electrically connected to the conductive layer 132 to read the touch signal generated by the capacitive touch sensing electrode structure S.

Next, a second transparent conductive layer 122, such as an indium tin oxide (ITO) layer, and a second transparent conductive layer 122 and a first transparent conductive layer 120 covering the surface of the photosensitive spacer 115 are formed on the color filter layer CF. The first transparent conductive layer 120 and the second transparent conductive layer 122 are electrically insulated from each other by a patterning process, and the first transparent conductive layer is electrically insulated from each other by a patterning process. The layer 120 is used to transmit the touch signal of the capacitive touch sensing electrode structure S, and the second transparent conductive layer 122 serves as a common electrode of the display device.

According to an embodiment of the present invention, a liquid crystal layer 128 may be interposed between the first substrate 102 and the second substrate 130 as a display element. In order to cause regular alignment of liquid crystal molecules in the liquid crystal layer 128, the first substrate 102 and the first substrate A liquid crystal layer 128 is interposed between the first alignment layer 124 and the second alignment layer 126, and the first alignment layer 124 and the second alignment layer 126 are usually made of polyimide (PI). In general, the thickness of the first alignment layer 124 and the second alignment layer 126 increases the contact resistance between the protrusion 114 and the conductive layer 132 on the second substrate 130, resulting in a decrease in the transmission performance of the touch signal. Therefore, in the embodiment of the present invention, the touch signal transmission area 100B of the touch panel 100 is disposed away from the positions of the first alignment layer 124 and the second alignment layer 126.

According to an embodiment of the present invention, the photosensitive spacer 115 in the protrusion 114 is formed through a photoresist coating and a lithography process. Therefore, the contact area of the protrusion 114 and the conductive layer 132 can be via the photosensitive spacer 115. The lithography process is fixed, so that each signal line of the capacitive sensing electrode can be fixed by the resistance of the electrical contact between the protrusion 114 and the conductive layer 132, thereby improving the sensing accuracy of the touch panel.

In accordance with another embodiment of the present invention, the protrusions 114 can be formed directly from a conductive material, such as via a deposited metal layer, and formed using a lithography and etching process. In this embodiment, the contact area of the protrusions 114 and the conductive layer 132 can also be fixed via a lithography process.

In other embodiments, the protrusions 114 may be made of an organic or inorganic material having electrical conductivity, such as an organic or inorganic material doped with conductive particles, such as gold, silver, or carbon black particles.

In the embodiment of the present invention, when the protrusions 114 themselves have electrical conductivity, the first transparent conductive layer 120 may not be required on the surface of the protrusions 114.

According to another embodiment of the present invention, the protrusions 114 may be formed on the conductive layer 132 of the second substrate 130 and electrically connected to the second conductive layer 108 of the first substrate 102.

Since the protrusions 114 in the embodiment of the present invention can transmit the electrical signals on the side of the first substrate 102 to the side of the second substrate 130, other protrusions can be additionally formed according to an embodiment of the present invention (not shown). The electrical connection is made to the common electrode 122 on the first substrate 102, and the voltage (Vcom) signal of the common electrode 122 is transmitted to the second substrate 130 side, so that the conductive material is not doped in the sealant material 134. Further, the manufacturing cost of the panel is reduced, wherein the protrusions 114 and the protrusions for transmitting the voltage required for the common electrode 122 are in non-electrical contact with each other.

In addition, according to an embodiment of the present invention, the protrusion 114 is formed by first forming the photosensitive spacer 115 and then forming the first transparent conductive layer 120. Therefore, the process of an embodiment of the present invention can be combined with the existing liquid crystal display panel. The process is combined to form the spacers 115 of the protrusions 114 at the same time when the spacers (not shown) in the liquid crystal layer 128 are formed, and the protrusions 114 are simultaneously formed when the common electrodes 122 of the liquid crystal display panel are formed. The first transparent conductive layer 120, and in this embodiment, the process sequence of the protrusions is the same as the process sequence of the pressure sensing structure of the in-line resistive touch panel, and thus, in an embodiment of the present invention, Capacitive and resistive touch panel processes can be combined to form a capacitive and resistive hybrid touch panel.

In summary, the in-cell touch panel of the embodiment of the present invention has a capacitive touch sensing electrode and a color filter layer disposed on the same side of the color filter substrate, compared to the external touch panel. Embodiments of the invention can reduce the overall thickness of the touch display device. In addition, the embodiment of the present invention can also avoid the scratch problem caused by the current double-sided process of the touch panel on the color filter substrate, thereby improving the manufacturing yield of the touch panel.

In the meantime, the in-cell touch panel of the embodiment of the present invention utilizes the protrusions to electrically connect the capacitive touch sensing electrodes on the first substrate and the conductive layer on the second substrate, thereby further touching the first substrate side. The control signal is transmitted to the second substrate side, thereby avoiding the problem of signal unevenness caused by the conventional signal transmission by the conductive particles in the sealant.

In addition, according to an embodiment of the present invention, the area of the transmission area of the voltage (Vcom) signal of the common electrode of the display device is not affected by the touch signal transmission area, so the touch display panel of the embodiment of the present invention can be improved. The problem that the quality of the display screen derived from the Vcom signal of the conventional touch display panel is not good.

Although the present invention has been disclosed in its preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached.

100. . . Touch panel

100A. . . Touch sensing area

100B. . . Touch signal transmission area

100C. . . Peripheral circuit area

102. . . First substrate

104. . . First conductive layer

106, 110, 112. . . Insulation

108. . . Second conductive layer

114. . . Protrusion

115. . . Photosensitive spacer

116. . . Black matrix layer

118. . . Color filter

120. . . First transparent conductive layer

122. . . Second transparent conductive layer (common electrode)

124, 126. . . Alignment layer

128. . . Liquid crystal layer

130. . . Second substrate

132. . . Conductive layer

134. . . Frame glue

136. . . Flexible circuit board (FPC)

S. . . Capacitive touch sensing electrode structure

CF. . . Color filter layer

1 is a schematic plan view showing a touch panel according to an embodiment of the invention.

Fig. 2 is a cross-sectional view showing a touch panel according to an embodiment of the present invention, taken along line 2-2' of Fig. 1.

100. . . Touch panel

100A. . . Touch sensing area

100B. . . Touch signal transmission area

102. . . First substrate

104. . . First conductive layer

106, 110, 112. . . Insulation

108. . . Second conductive layer

114. . . Protrusion

115. . . Photosensitive spacer

116. . . Black matrix layer

118. . . Color filter

120. . . First transparent conductive layer

122. . . Second transparent conductive layer (common electrode)

124, 126. . . Alignment layer

128. . . Liquid crystal layer

130. . . Second substrate

132. . . Conductive layer

134. . . Frame glue

136. . . Flexible circuit board (FPC)

S. . . Capacitive touch sensing electrode structure

CF. . . Color filter layer

Claims (13)

An in-cell touch panel having a touch sensing area and a touch signal transmission area includes: a first substrate; a capacitive touch sensing electrode; the touch feeling disposed on the first substrate a second substrate disposed opposite the first substrate; a conductive layer disposed on the touch signal transmission area of the second substrate; and a protrusion disposed on the first substrate and the Between the second substrate and the touch signal transmission area, wherein the protrusion is electrically connected to the capacitive touch sensing electrode and is in contact with the conductive layer on the second substrate, so that the capacitive type A touch signal of the touch sensing electrode is transmitted to the second substrate via the protrusion. The in-cell touch panel of claim 1, further comprising a color filter layer disposed on the capacitive touch sensing electrode facing the second substrate. The in-cell touch panel of claim 2, wherein the protrusion comprises a photosensitive spacer, and a first transparent conductive layer covers the photosensitive spacer, and wherein the first transparent The conductive layer is electrically connected to the capacitive touch sensing electrode and the conductive layer on the second substrate. The in-cell touch panel of claim 3, further comprising a second transparent conductive layer overlying the color filter layer, wherein the second transparent conductive layer and the first transparent conductive layer are The process is patterned and isolated from each other. The in-cell touch panel of claim 4, wherein the first transparent conductive layer transmits the touch signal of the capacitive touch sensing electrode, and the second transparent conductive layer is a common electrode . The in-cell touch panel of claim 5, further comprising a further protrusion disposed between the first substrate and the second substrate for providing a common voltage of the second transparent conductive layer, And the protrusion and the other protrusion are not electrically connected to each other. The in-cell touch panel of claim 1, wherein the protrusion comprises a conductive protrusion. The in-cell touch panel of claim 7, wherein the material of the conductive protrusion comprises a metal, an organic material doped with conductive particles or an inorganic material doped with conductive particles. The in-cell touch panel of claim 1, further comprising a sealant disposed between the first substrate and the second substrate, wherein no conductive particles are doped in the sealant. The in-cell touch panel of claim 1, further comprising: a first alignment layer disposed on the first substrate; a second alignment layer disposed on the second substrate, Facing the first alignment layer; and a liquid crystal layer interposed between the first alignment layer and the second alignment layer, wherein the position of the first alignment layer and the second alignment layer and the touch signal are transmitted Separated by zones. The in-cell touch panel of claim 10, wherein the liquid crystal layer includes a plurality of spacers, and the protrusions comprise a photosensitive spacer, wherein the spacers and the protrusions are Photosensitive spacers are formed simultaneously. The in-cell touch panel of claim 1, wherein the protrusion is formed on the first substrate or the second substrate. The in-cell touch panel of claim 1, wherein the capacitive touch sensing electrode has a plurality of signal lines, and each of the signal lines passes the protrusion and the conductive on the second substrate The contact areas of the layers are the same.