CN105182588A - A built-in touch panel - Google Patents

Abstract

The invention provides an embedded touch panel which comprises a light filtering substrate, a black matrix layer positioned below the light filtering substrate, a touch sensing layer, a color filter layer, a common electrode layer and a photoresist spacer. The touch sensing layer is located below the black matrix layer, the color filter layer is located below the touch sensing layer, the common electrode layer is located below the color filter layer, and the photoresist spacer is located below the common electrode layer. The common electrode layer is provided with a preset pattern, the preset pattern comprises a through hole corresponding to the photoresist spacer in the vertical direction, and the parasitic capacitance of the touch sensing layer is reduced through the through hole. Compared with the prior art, the patterned common electrode layer is characterized in that the through hole is formed by hollowing out the position corresponding to the photoresist spacer in the vertical direction, so that the parasitic capacitance between the touch sensing layer and the common electrode layer is effectively reduced, and the optical effect of liquid crystal display is not influenced.

Description

A built-in touch panel

technical field

The present invention relates to a touch panel, in particular to an in-cell touch panel.

Background technique

In recent years, with the continuous advancement of image display technology, the touch display panel has become one of the commonly used displays in the market due to its advantages of direct input of commands through touch, and is widely used. in various electronic products. In the prior art, touch panels are roughly divided into two types: on-cell and in-cell. Among them, the plug-in touch panel is to make the touch sensor on the surface of the color filter, add the touch sensor to the glass to make the touch panel module, and then combine it with the thin film transistor liquid crystal display (TFT-LCD ) panel module fit. The in-cell touch panel is to make the touch sensor in the panel structure, and directly place the touch sensor in the TFT-LCD panel module. The touch function is integrated in the display, and there is no need for an external touch panel. Therefore, the thickness of the built-in touch panel is lighter and thinner than that of the plug-in touch panel.

In addition, touch panels can be divided into capacitive touch panels, resistive touch panels, optical touch panels, etc. according to their types. Taking the capacitive touch panel as an example, the touch technology mainly utilizes the current sensing technology of pressing force to work. For example, when a finger touches the metal layer, the electric field of the human body, the user and the surface of the touch screen form a coupling capacitor. For high-frequency currents, since the capacitor is a direct conductor, the finger absorbs a small current from the contact point. This current flows from electrodes on the four corners of the touch screen. The current flowing through the four electrodes is proportional to the distance from the finger to the four corners, and the controller can accurately calculate the ratio of these four currents to finally obtain the specific position information of the touch point on the screen. From the above, it can be seen that when the respective functions of the projected capacitive touch panel and the in-cell touch panel are integrated, an in-cell projected capacitive touch panel can be formed.

For a touch panel sensor in a touch panel, its parasitic capacitance is often directly affected by the common electrode layer (such as ITO material), for example, the distance between the plane where the touch sensor is located and the common electrode layer. Generally, the smaller the parasitic capacitance, the better the touch sensing accuracy; the larger the parasitic capacitance, the poorer the touch sensing accuracy. However, the above-mentioned parasitic capacitance in the existing touch panel is still too large, which will significantly reduce the touch sensing accuracy.

In view of this, how to design a new in-cell touch panel, by adjusting the distance between the touch sensor and the common electrode layer, to reduce the parasitic capacitance of the touch sensor, so as to overcome the above-mentioned defects in the prior art , is an urgent problem to be solved by relevant technical personnel in the industry.

Contents of the invention

Aiming at the above defects of the in-cell touch panel in the prior art, the present invention provides a novel in-cell touch panel that can reduce the parasitic capacitance of the touch sensor.

According to one aspect of the present invention, an in-cell touch panel is provided, including a filter substrate and a black matrix layer located below the filter substrate, wherein the in-cell touch panel also includes:

A touch sensing layer, located below the black matrix layer;

A color filter layer, located below the touch sensing layer, which includes a plurality of filters of different colors distributed at intervals;

a common electrode layer, located below the color filter layer; and

a photoresist spacer, located below the common electrode layer,

Wherein, the common electrode layer has a predetermined pattern, and the predetermined pattern includes a through hole corresponding to the photoresist spacer in the vertical direction, and the touch sensor is reduced by the through hole. The parasitic capacitance of the sensing layer.

In one embodiment, the in-cell touch panel further includes an insulating layer located between the touch sensing layer and the common electrode layer, one end of the photoresist spacer is connected to the insulating layer. layers in direct contact.

In one embodiment, the common electrode layer is made of transparent indium tin oxide (ITO).

In one embodiment, the projection of the photoresist spacer in the vertical direction completely falls within the range of the patterned touch sensing layer.

In one embodiment, the touch sensing layer has a ring-shaped square pattern, and the projection of the photoresist spacer is located at the apex of the square pattern.

In one of the embodiments, the color filter layer includes a red filter, a green filter and a blue filter in sequence, and the photoresist spacer is arranged between adjacent filters of any different colors .

In one embodiment, the in-cell touch panel is a projected capacitive touch panel. Further, the touch sensing layer includes a sending electrode, a receiving electrode and a floating area, and the preset pattern of the common electrode layer only corresponds to the vertical projection area of the area where the sending electrode and the receiving electrode are located.

The embedded touch panel of the present invention comprises a filter substrate, a black matrix layer located below the filter substrate, a touch sensing layer, a color filter layer, a common electrode layer and a photoresist spacer thing. The touch sensing layer is located under the black matrix layer, the color filter layer is located under the touch sensing layer, the common electrode layer is located under the color filter layer, and the photoresist spacer is located under the common electrode layer. Wherein, the common electrode layer has a predetermined pattern, and the predetermined pattern includes a through hole corresponding to the photoresist spacer in the vertical direction, and the parasitic capacitance of the touch sensing layer is reduced by the through hole. Compared with the prior art, the present invention provides a patterned common electrode layer, hollowing out the place corresponding to the photoresist spacer in the vertical direction to form a through hole, so that the touch sensing layer and the common electrode layer The parasitic capacitance value can be effectively reduced without affecting the optical effect of the liquid crystal display.

Description of drawings

Readers will have a clearer understanding of various aspects of the present invention after reading the detailed description of the present invention with reference to the accompanying drawings. in,

FIG. 1 shows a schematic structural view of an in-cell touch panel in the prior art;

FIG. 2 shows a schematic diagram of the positional relationship between the touch sensing layer and the common electrode layer located on one side of the filter substrate in the in-cell touch panel of FIG. 1;

FIG. 3 shows a schematic structural diagram of an in-cell touch panel that can reduce the parasitic capacitance of the touch sensing layer according to an embodiment of the present invention;

FIG. 4A shows a schematic diagram of a preset pattern of a common electrode layer of the in-cell touch panel of FIG. 3;

4B shows a schematic diagram of the preset pattern of the common electrode layer and the distribution pattern of the photoresist spacers in the in-cell touch panel of FIG. 3; and

4C is a schematic diagram showing the relationship between the projection of the photoresist spacer in the vertical direction and the position of the touch sensing layer in the in-cell touch panel of FIG. 3 .

Detailed ways

In order to make the technical content disclosed in this application more detailed and complete, reference may be made to the drawings and the following various specific embodiments of the present invention, and the same symbols in the drawings represent the same or similar components. However, those skilled in the art should understand that the examples provided below are not intended to limit the scope of the present invention. In addition, the drawings are only for schematic illustration and are not drawn according to their original scale.

The specific implementation manners of various aspects of the present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic structural diagram of an in-cell touch panel in the prior art. FIG. 2 is a schematic diagram showing the positional relationship between the touch sensing layer and the common electrode layer on one side of the filter substrate in the in-cell touch panel of FIG. 1 .

Referring to FIG. 1 , an existing in-cell touch panel includes a color filter substrate 100 and an array substrate 102 . On one side of the array substrate 102 , the upper surface includes a thin film transistor array (thin film transistor array) 104 , and the lower surface is provided with a lower polarizer (lower polarizer) 118 . On one side of the filter substrate 100 , an upper polarizer 116 is disposed on the upper surface, and a black matrix layer (black matrix) 106 is disposed on the lower surface. A touch sensor layer (touch panel sensor layer) 108 is located below the black matrix layer 106 . A color filter layer (color filter layer) 110 is located below the touch sensing layer 108, and it includes, for example, a red filter, a green filter and a blue filter in sequence. A common electrode layer (common electrodedelayer) 112 is located below the color filter layer 110 . In addition, a photospacer (PS) 114 is disposed between the common electrode layer 112 and the TFT array 104 . The liquid crystal layer is also located between the common electrode layer 112 and the TFT array 104 , and the flip direction of the liquid crystal molecules can be changed by the change of the voltage potential on the TFT array 104 .

As mentioned above, for the touch sensor on the touch sensing layer, its parasitic capacitance is often directly affected by the common electrode layer, for example, when the distance between the touch sensing layer and the common electrode layer is relatively short When , the impact of the parasitic capacitance of the touch sensor due to the common voltage is more obvious. As shown in FIG. 2 , the hatched area represents the patterned common electrode layer 112, the grid lines represent the photoresist spacers 114, and an insulation layer (insulation layer) is also included between the touch sensing layer 108 and the common electrode layer 112. 120. The photoresist spacer 114 is inserted into the concave portion of the common electrode layer 112 . When a certain voltage is applied to the transmitting electrode or the receiving electrode on the touch sensing layer 108, between the touch sensing layer 108 and the common electrode layer 112 at the position of the photoresist spacer 114 (such as the dotted circle S1) will be There are parasitic capacitance effects. In FIG. 2 , it is easy to know that a part of the common electrode layer above the photoresist spacer 114 still causes a large parasitic capacitance value, which makes the touch sensing accuracy worse.

In order to solve the above defects in the prior art, the present invention provides an improved touch panel which can reduce the parasitic capacitance of the touch sensing layer. Wherein, FIG. 3 shows a schematic structural diagram of an in-cell touch panel that can reduce the parasitic capacitance of the touch sensing layer according to an embodiment of the present invention. FIG. 4A is a schematic diagram of a preset pattern of a common electrode layer of the in-cell touch panel of FIG. 3 . FIG. 4B is a schematic diagram of the preset pattern of the common electrode layer and the distribution pattern of the photoresist spacers in the in-cell touch panel of FIG. 3 . 4C is a schematic diagram showing the relationship between the projection of the photoresist spacer in the vertical direction and the position of the touch sensing layer in the in-cell touch panel of FIG. 3 .

Referring to FIG. 3, in this embodiment, similar to FIG. 2, the in-cell touch panel includes a filter substrate 100, a black matrix layer 106 located under the filter substrate, a touch sensing layer 108, an insulating Layer 120, a color filter layer (including red filter R, green filter G and blue filter B), a common electrode layer 112 (such as ITO material), a photoresist spacer 114 and the array substrate 102. The touch sensing layer 108 is located under the black matrix layer 106, the color filter layer is located under the touch sensing layer 108, the common electrode layer 112 is located under the color filter layer, and the photoresist spacer 114 is located on the common electrode layer 112 below.

Different from the prior art, the common electrode layer 112 of the present invention has a predetermined pattern, and the predetermined pattern includes a through hole corresponding to the photoresist spacer 114 in the vertical direction, and the touch control is reduced by the through hole. The parasitic capacitance of the sensing layer 108 . As shown by the dashed circle S2 in FIG. 3 , the photoresist spacer 114 penetrates the upper and lower surfaces of the common electrode layer 112 and is in direct contact with the insulating layer 120 . In this way, since the common electrode layer 112 is hollowed out in the vertical direction of the photoresist spacer 114 , the parasitic capacitance value of the touch sensing layer 108 there can be reduced.

In a specific embodiment, the above-mentioned color filter layer includes a red filter R, a green filter G, and a blue filter B in sequence, and the black matrix 106 is arranged at the border area between two adjacent color filters, to avoid color mixing. In addition, photoresist spacers 114 are disposed between adjacent filters of any different colors, such as between the green filter G and the blue filter, or between the blue filter B and the red filter. between.

In a specific embodiment, the in-cell touch panel of the present invention can be a projected capacitive touch panel. Preferably, the touch sensing layer 108 includes a sending electrode, a receiving electrode and a floating area, and the preset pattern of the common electrode layer 112 only corresponds to the vertical projection area of the area where the sending electrode and the receiving electrode are located.

4A and 4B, wherein, FIG. 4A shows the preset pattern shape of the common electrode layer 112, and FIG. The area corresponding to the photoresist spacer 114 is hollowed out so as to reduce the parasitic capacitance of the touch sensing layer at this position. In addition, in order to achieve a better effect of reducing parasitic capacitance, the projection of the photoresist spacer 114 in the vertical direction can completely fall within the range of the patterned touch sensing layer 108 . As shown in FIG. 4C , the touch sensing layer 108 has a ring-shaped square pattern, and the projection of the photoresist spacer 114 can be located at the apex of the square pattern.

The embedded touch panel of the present invention comprises a filter substrate, a black matrix layer located below the filter substrate, a touch sensing layer, a color filter layer, a common electrode layer and a photoresist spacer thing. The touch sensing layer is located under the black matrix layer, the color filter layer is located under the touch sensing layer, the common electrode layer is located under the color filter layer, and the photoresist spacer is located under the common electrode layer. Wherein, the common electrode layer has a predetermined pattern, and the predetermined pattern includes a through hole corresponding to the photoresist spacer in the vertical direction, and the parasitic capacitance of the touch sensing layer is reduced by the through hole. Compared with the prior art, the present invention provides a patterned common electrode layer, hollowing out the place corresponding to the photoresist spacer in the vertical direction to form a through hole, so that the touch sensing layer and the common electrode layer The parasitic capacitance value can be effectively reduced without affecting the optical effect of the liquid crystal display.

Hereinbefore, specific embodiments of the present invention have been described with reference to the accompanying drawings. However, those skilled in the art can understand that without departing from the spirit and scope of the present invention, various changes and substitutions can be made to the specific embodiments of the present invention. These changes and substitutions all fall within the scope defined by the claims of the present invention.

Claims (8)

1. An in-cell touch panel includes a filter substrate and a black matrix layer under the filter substrate, the in-cell touch panel further includes:

the touch sensing layer is positioned below the black matrix layer;

the color filter layer is positioned below the touch sensing layer and comprises a plurality of filters with different colors which are distributed at intervals;

the common electrode layer is positioned below the color filter layer; and

a photoresist spacer located below the common electrode layer,

the common electrode layer is provided with a preset pattern, the preset pattern comprises a through hole corresponding to the photoresist spacer in the vertical direction, and the parasitic capacitance of the touch sensing layer is reduced by the through hole.

2. The in-cell touch panel of claim 1, further comprising an insulating layer between the touch sensing layer and the common electrode layer, wherein one end of the photoresist spacer is in direct contact with the insulating layer.

3. The in-cell touch panel of claim 1, wherein the common electrode layer is a transparent ITO material.

4. The in-cell touch panel of claim 1, wherein a vertical projection of the photo-resist spacers falls entirely within the patterned touch sensor layer.

5. The in-cell touch panel of claim 4, wherein the touch sensing layer has a circular stripe-shaped square pattern, and the photoresist spacers are projected at the vertices of the square pattern.

6. The in-cell touch panel according to claim 1, wherein the color filter layer comprises a red filter, a green filter and a blue filter in sequence, and the photo spacers are disposed between adjacent filters of any color.

7. The in-cell touch panel of claim 1, wherein the in-cell touch panel is a projected capacitive touch panel.

8. The in-cell touch panel of claim 7, wherein the touch sensing layer comprises a transmitting electrode, a receiving electrode and a floating area, and the predetermined pattern of the common electrode layer only corresponds to a vertical projection area of the areas where the transmitting electrode and the receiving electrode are located.