TWI667602B - Capacitive touchscreen and the driving method thereof - Google Patents

Abstract

A capacitive touch display device includes a light source driving stack, at least one light source, and a screen printing stack. The light source is arranged on the light source driving stack, and the screen printing stack is printed on the light source and the light source driving stack. The light source driving stack includes at least one light source switch, a first power source, and a data line connected to the gate of the light source switch. The light source switch and the light source are connected in series between the first power source and the second power source. The screen printing stack includes an extended conductive layer adjacent to the touch surface of the capacitive touch display device, which is electrically connected to the first power supply or the second power supply, and is located between the touch surface and the light source driving stack. The first power source, the second power source, or the data line output at least one touch signal to sense the position where the user touches the touch surface. A driving method of a capacitive touch display device is also proposed.

Description

Capacitive touch display device and its driving method

The invention relates to a touch device and a driving method thereof; in particular, to a capacitive touch display device and a driving method thereof.

In the development of the existing display technology, the miniature light emitting diode (Micro LED) which has made the light emitting diode (Light Emitting Diode, LED) miniaturized has become one of the main development topics in the flat display technology. The miniature light-emitting diode is different from the organic light-emitting diode. It is a technology developed from the point of view of the inorganic light-emitting diode. It inherits the high efficiency, high brightness, high reliability, and high-speed response time of the inorganic light-emitting diode. Other features, such as self-luminous display technology without additional backlight, are helpful in saving energy, reducing volume and thickness.

Although the thickness of the backlight module can be omitted for the miniature light-emitting diode display device belonging to the self-luminous display technology, when this display device is to incorporate an input technology such as a touch function, it is inevitable that an additional touch module is required Attached. The high-resolution thin and light flat-panel display with touch function has always been the development goal of the current display technology, how to make a A display device with a small volume and thickness is still one of the topics currently devoted to development.

The invention provides an integrated capacitive touch display device and a driving method thereof, which can reduce the thickness and circuit complexity required for the touch function.

The capacitive touch display device of the present invention includes a light source driving stack, at least one light source and a screen printing stack. The light source is disposed on the light source driving stack, and the screen printing stack is printed on the light source and the light source driving stack. The light source driving stack includes at least one light source switch, a first power source, and a data line connected to the gate of the light source switch. The light source switch and the light source are connected in series between the first power source and the second power source. The screen printing stack includes an extended conductive layer adjacent to the touch surface of the capacitive touch display device, which is electrically connected to the first power supply or the second power supply, and is located between the touch surface and the light source driving stack. The first power source, the second power source, or the data line output at least one touch signal to sense the position where the user touches the touch surface.

The method for driving the capacitive touch display device of the present invention includes: in a display mode, the first power supply and the second power supply provide power to drive the light source, the data line output signal controls the light source switch; and in a touch mode, the first A power supply, a second power supply, or a data line output touch signals to sense the position of the user touching the touch surface.

C1‧‧‧Capacitance

119‧‧‧dielectric layer

D1, D2‧‧‧ji

1110‧‧‧conductive layer

Data1 ~ Data3‧‧‧Data line

1111‧‧‧flat layer

DS‧‧‧Touch surface

120‧‧‧Light source

G1, G2 ‧‧‧ gate

122, 124‧‧‧ contact

Gate1 ~ Gate3‧‧‧Gate line

130‧‧‧ Screen printing stack

S1, S2‧‧‧Source

131‧‧‧Extended conductive layer

SW1‧‧‧Light source switch

132‧‧‧Transparent filling layer

SW2‧‧‧Data switch

TS1, TS2‧‧‧‧touch signal

Vdd1 ~ Vdd3‧‧‧First power supply

Vss1Vss3‧‧‧second power supply

50‧‧‧Contact

100, 200, 300 ‧‧‧ capacitive touch display device

110‧‧‧Layer driven stack

111‧‧‧ substrate

112A, 112B ‧‧‧ pixel circuit

113‧‧‧conductive layer

114‧‧‧ shading layer

115‧‧‧Buffer layer

116, 117‧‧‧ semiconductor layer

118‧‧‧Gate insulation

1A is a schematic cross-sectional view of a capacitive touch display device according to a first embodiment of the invention; 1B is a circuit schematic diagram corresponding to FIG. 1A; FIG. 2A is a circuit schematic diagram of a capacitive touch display device according to a second embodiment of the present invention; FIG. 2B is a signal schematic diagram of a capacitive touch display device according to a second embodiment of the present invention; 3A is a circuit schematic diagram of a capacitive touch display device according to a third embodiment of the invention; FIG. 3B is a signal schematic diagram of a capacitive touch display device according to a third embodiment of the invention.

The capacitive touch display device proposed by the present invention is applied to display devices such as inorganic light emitting diodes (Light Emitting Diode, LED) and other self-luminous technology of semiconductor light sources, preferably using micro LEDs (Micro LED ) And other self-luminous technology display devices. The capacitive touch display device and method of the present invention can display high-brightness and high-resolution images by the above-mentioned technology, and the electrodes required for the touch function can be integrated into the display device, without significantly increasing the overall thickness Provide touch function under the premise of.

FIG. 1A is a schematic cross-sectional view of a capacitive touch display device according to a first embodiment of the present invention. For the sake of clear description, the capacitive touch display device 100 of this embodiment is specifically depicted as a pixel or sub-pixel light source and its related A schematic cross-sectional view of the device. In other words, the capacitive touch display device 100 of the present invention is composed of a plurality of light sources 120 as pixels or sub-pixels and the light source switch SW1 connected thereto to selectively emit light and form a display screen, and each light source will be described in detail below And related elements to illustrate the technical features of the present invention.

1A, in the first embodiment of the present invention, the capacitive touch display device 100 includes a light source driving stack 110, a light source 120, and a screen printing stack 130, wherein the light source driving stack 110 is It is formed by optical etching, and the screen printing stack 130 is printed on the light source 120 and the light source driving stack 110 via screen printing. Specifically, the light source 120 is preferably a Micro LED, because the driving circuit of the bottom layer of the Micro LED can be a thin film transistor (Thin Film Transistor, TFT), a metal oxide semiconductor field effect transistor (Metal-Oxide-Semiconductor Filed-Effect Transistor, MOSFET), LTPS (Low Temperature Poly-silicon) or other devices suitable for switching functions, so the light source driving stack 110 of the capacitive touch display device 100 of this embodiment may be manufactured by a yellow light process, but the present invention does not It is limited to the manufacturing method of the light source driving stack 110.

FIG. 1B is a schematic circuit diagram of FIG. 1A. 1B, the light source driving stack 110 of this embodiment includes a light source switch SW1, a first power source Vdd1 and a second power source Vss1. The light source switch SW1 is, for example, a transistor, preferably a thin-film transistor (Thin-Film Transistor) , TFT), in other embodiments of the present invention, it may be a metal-oxide field semiconductor (Metal-Oxide-Semiconductor Field-Effect Transistor), an n-channel MOSFET (N-channel MOSFET, NMOS), LTPS, The invention is not limited to the types of transistors. The light source 120 is disposed on the light source driving stack 110, and the light source 120 and the light source switch SW1 are connected in series between the first power supply Vdd1 and the second power supply Vss1. The light source driving stack 110 further includes a data line Data1, and the gate G1 of the light source switch SW1 can receive the signal from the data line Data1.

In the present embodiment, the first power supply Vdd1 is, for example, a line to which power is input, and the second power supply Vss1 is, for example, a line to be grounded. The light source switch SW1 can control whether the light source 120 receives the power signal from the first power source Vdd1, and the signal of the data line Data1 controls the light source switch SW1.

Referring to FIG. 1A, the screen printing stack 130 is printed on the light source 120 and the light source driving stack 110, and the screen printing stack 130 includes an extended conductive layer 131. The extended conductive layer 131 is electrically connected to the above mentioned The first power supply Vdd1 or the second power supply Vss1 for power signals. For example, the extended conductive layer 131 of this embodiment is connected between the light source 120 and the light source switch SW1, that is, to the first power supply Vdd1, and the extended conductive layer 131 is adjacent to the touch surface DS of the capacitive touch display device 100 (That is, the side away from the substrate 111 of the capacitive touch display device 100).

When the user touches the contact point 50 of the touch surface DS, the extended conductive layer 131 can more effectively allow the user to effect the capacitive coupling effect (Capacitive Coupling Effect) generated at the contact point 50 on the first power supply Vdd1 or the second power supply Vss1 The capacitance changes. Specifically, the capacitive touch display device 100 of this embodiment may be driven in a display mode or a touch mode.

In the display mode, the power transmitted between the first power supply Vdd1 and the second power supply Vss1 can drive the light source 120, and in conjunction with the switching of the signal from the data line Data1 to emit the light required by a pixel or sub-pixel, thereby forming a display In the touch mode, the first power supply Vdd1, the second power supply Vss1 or the data line Data1 is used to transmit a touch signal to sense the position where the user touches the touch surface DS (eg, contact point 50).

1B, since the extending direction of the first power supply Vdd1 and the second power supply Vss1 is perpendicular to the extending direction of the data line Data1, whether it is a self-capacitance (Self Capacitance) touch or a mutual capacitance (Mutual Capacitance) touch The first power supply Vdd1, the second power supply Vss1 and the data line Data1 can all be used as appropriate touch electrodes, and the extended conductive layer 131 can further improve the detection sensitivity of the touch signal.

Since the capacitive touch display device 100 of this embodiment has the above-mentioned touch mode and display mode, a display screen with a touch function can be provided. At the same time, the sensing electrodes required in the touch mode and the electrodes required in the display mode are integrated with each other, which can reduce the complexity of the circuit and The overall thickness, in turn, provides a thinner and lighter volume. The following further describes other elements proposed by the embodiments of the present invention and their provided functions.

Please refer to FIG. 1A. In this embodiment, the screen printing stack 130 of the capacitive touch display device 100 further includes a light-transmitting filling layer 132. The light-transmitting filling layer 132 is formed of a transparent material, for example, preferably by a mesh.印 形成 的 光 填 填 层 132。 The transparent filling layer 132 formed by printing. The light-transmissive filling layer 132 can fill the gap between the light source driving stack 110 and the light source 120 to fill the height difference formed by the light source 120 on the light source driving stack 110, and provide a plane to form the extended conductive layer 131. Meanwhile, the transparent filling layer 132 of this embodiment is formed with a contact hole, and the extended conductive layer 131 is connected to the second power source Vss1 through the transparent filling layer 132 from the side close to the touch surface DS through the contact hole. In other embodiments, the extended conductive layer 131 may also be connected to the first power supply Vdd1.

The extended conductive layer 131 is a light-transmitting electrode, preferably a transparent electrode, and its material may be, for example, a transparent conductive film such as ITO, PEDOT, CNT, or a transparent metal conductive material such as nano silver. Both the extended conductive layer 131 and the transparent filling layer 132 can be formed on the light source driving stack 110 by screen printing, wherein the extended conductive layer 131 is preferably subjected to high-precision screen printing with a precision of, for example, 10 to 30 microns (micro meter, μm) to form a high-precision touch electrode shape to improve the sensitivity of capacitive touch sensing.

The capacitive touch display device 100 of this embodiment further includes pixel circuits 112A and 112B. The light source 120 is connected to the conductive layer 113 forming the source S1 through the pixel circuit 112A to receive power signals. In detail, the pixel circuit 112A is used as a contact on the light source driving stack 110 for the contact 124 of the light source 120 to be connected, and the pixel circuit 112B can be extended to a conductive layer (not shown) connected to the second power supply Vss1, And as a contact point for the light source 120 to connect the contact 122, thereby providing the light source 120 with a connection Access interface.

Please refer to FIG. 1A again. In detail, the light source driving stack 110 of this embodiment is completed by, for example, seven yellow light manufacturing processes. The semiconductor layers 116 and 117 of polysilicon, the gate insulating layer 118, the conductive layer 113, the dielectric layer 119, the conductive layer 1110, and the flat layer 1111. The above-mentioned components can be completed through a yellow light process, and then a light source 120 such as a Micro LED is connected to the light source driving stack by using a transfer-bonding method, for example. Since the Micro LED 120 can be completed through an inorganic material and has high temperature resistance, the above screen printing stack 130 can be further screen printed on the light source driving stack 110 and the light source 120.

On the other hand, please refer to FIG. 1B together. The light source driving stack 110 of this embodiment further includes a data switch SW2, the data line Data1 outputs a signal to the drain D2 of the data switch SW2, the source S2 of the data switch SW2 and the light source switch The gate G1 of SW1 is connected. The light source driving stack 110 further includes a gate line Gate1, the gate G2 of the data switch SW2 is connected to the gate line Gate1, and the light source driving stack 110 further includes a capacitor C1 to maintain the potential difference of the light source 120. In other words, the light source 120 of this embodiment is driven by a 2T1C circuit, and the data line Data1, the first power supply Vss1, and the second power supply Vdd1 can also be used as sensing electrodes for capacitive touch. The implementation of the driving method proposed by the present invention in different embodiments will be further described below based on the above circuit and device design.

2A, in the second embodiment of the present invention, the capacitive touch display device 200 is similar to the capacitive touch display device 100 described above, and in the touch mode, for example, a plurality of first power supplies Vdd2 and second The power supply Vss2 outputs touch signals and receives signals through multiple data lines Data2 No., that is, by measuring the mutual capacitance change between the first power supply Vdd2 and the data line Data2 to sense the position of the user touching the touch surface of the capacitive touch display device 200 (the present invention is not limited to the first power supply and data Mutual capacitance sensing between the power line or the second power supply and the data line. In this embodiment, the mutual capacitance sensing between the first power supply and the data line is used as an example).

Please also refer to the signal schematic diagram corresponding to FIG. 2A shown in FIG. 2B, where Gate2n to Gate2n + 2 are the gate signals output by the capacitive touch display device 200 in each gate line Gate2 in sequence, and Data2n is the data line The signal output by Data2, Vdd2n is the signal output by the first power supply Vdd2, and Vss2n is the signal output by the second power supply Vss2.

In the display stage Display 1, the data line Data2 sequentially outputs data signals according to the pixels turned on by the gate lines Gate2 to display the screen; in the touch stage Touch 1, the first power supply Vdd2 and the second power supply Vss2 output touch signals TS1 senses the position where the user touches the touch surface; where the touch signal TS1 is an AC signal, and the oscillation frequencies of the first power supply Vdd2 and the second power supply Vss2 are synchronized with each other. Therefore, when the capacitive touch display device 200 is in the touch stage, it can not only sense the position where the user touches the touch surface, but also avoid the flickering of the screen caused by the touch signal TS1.

The present invention is not limited to the above-mentioned touch sensing method by sensing mutual capacitance changes. In other embodiments, the above capacitive touch display device 200 can also output touches from the first power supply Vdd2 and the second power supply Vss2 During the signal TS1, the user touches the capacitive touch display by sensing the electrical signal caused by the capacitance change of the first power supply Vdd2 or the second power supply Vss2 and the electrical signal caused by the capacitance change of the data line Data2 The location of the touch surface of the device 200. In other words In other words, the touch signal TS1 is an AC signal, and the first power supply Vdd2 and the second power supply Vss2 each output the touch signal TS1 at the same frequency and phase. The driving method proposed by the present invention can also be controlled by the first in the touch mode. The power supply Vdd2 and the second power supply Vss2 simultaneously output touch signals, and sense the position where the user touches the touch surface of the capacitive touch display device 200 by self-capacitance touch sensing.

On the other hand, outside the viewable area of the display device 200, the first power supply Vdd2, the second power supply Vss2, and the data line Data2 can also be extended to each display pixel by cluster traces (Cluster trace), so In the touch stage, multiple first power supply Vdd2, second power supply Vss2 or data line Data2 can be used to sense the capacitance change and adjust the resolution of touch.

3A, in the third embodiment of the present invention, the capacitive touch display device 300 is similar to the capacitive touch display device 100 described above, and in the touch mode, for example, multiple data lines Data3 output touch signals , And receive signals by multiple first power supply Vdd3 or second power supply Vss3, that is, by sensing the change in mutual capacitance between the first power supply Vdd3 and the data line Data3 to sense the user ’s contact with the capacitive touch display device 300 The position of the touch surface (the present invention is not limited to the mutual capacitance sensing between the first power supply and the data line or the second power supply and the data line. In this embodiment, the mutual capacitance sensing of the first power supply and the data line is used as an example).

Please also refer to the signal schematic diagram corresponding to FIG. 3A shown in FIG. 3B, where Gate3n to Gate3n + 2 are the gate signals output by the capacitive touch display device 300 in sequence for each gate line Gate3, and Data3n is the data line The signal output by Data3, Vdd3n is the signal output by the first power supply Vdd3, and Vss3n is the signal output by the second power supply Vss3.

In the display stage Display 2, the data line Data3 sequentially outputs data signals according to the pixels opened by these gate lines Gate3 to display the screen; In the touch stage Touch 2, the data line Data3 outputs a touch signal TS2 to sense the position where the user touches the touch surface; where the touch signal TS2 is an AC signal. Therefore, when the capacitive touch display device 200 is in the touch stage, the touch position of the user can be sensed by the touch signal TS2 output by the data line Data3.

The present invention is not limited to the above-mentioned touch sensing method by sensing mutual capacitance changes. In other embodiments, the above capacitive touch display device 300 may also output the touch signal TS2 through the data line Data3 by Sensing the electrical signal caused by the capacitance change of the first power supply Vdd3 or the second power supply Vss3, and sensing the electrical signal caused by the capacitance change of the data line Data3 to sense the user touching the touch surface of the capacitive touch display device 300 s position. In other words, the driving method proposed by the present invention can also output a touch signal from the data line Data3 in the touch mode, and sense the user's touch on the capacitive touch display device 300 by self-capacitive touch sensing The location of the surface.

In summary, the capacitive touch display device proposed by the present invention can be driven in different modes, and provides a display screen with a touch function under the switch between the display mode and the touch mode. At the same time, since the capacitive touch display device proposed by the present invention can integrate the circuits required for the touch function into the light source driving stack for driving the light source of each pixel, the overall circuit complexity, volume, and thickness can be reduced. Provide a thin and light touch display device.

Claims (12)

A capacitive touch display device includes: a light source driving stack, including: at least one light source switch; a first power source; a second power source; and a data line; at least one light source, disposed on the light source driving stack, The light source and the light source switch are connected in series between the first power source and the second power source, the gate of the light source switch is connected to the data line; and a screen printing stack printed on the light source and the light source driving stack , The screen printing stack includes: an extended conductive layer electrically connected to the first power source or the second power source, the extended conductive layer is adjacent to the touch surface of the capacitive touch display device, and is located on the touch surface and The light source drives between the stacks; wherein the first power supply, the second power supply, or the data line outputs at least one touch signal to sense the position of the user touching the touch surface. The capacitive touch display device as described in item 1 of the patent application range, wherein the screen printing stack further comprises: a light-transmitting filling layer, which is filled on the light source driving stack and covering the light source, wherein the light-transmitting filling layer A contact hole is formed, and the extended conductive layer is electrically connected to the first power source or the second power source through the light-transmissive filling layer from the side close to the touch surface through the contact hole. The capacitive touch display device as described in item 1 of the patent application range, wherein the light source driving stack is formed by optical etching, and the screen printing stack is printed on the light source and the light source driving stack via screen printing. The capacitive touch display device as described in item 1 of the patent application range, wherein the light source driving stack further includes: a pixel circuit, the light source is connected to the light source switch through the pixel circuit, and the extended conductive layer passes through the The pixel circuit is connected to the first power supply or the second power supply. The capacitive touch display device as described in item 1 of the patent scope, wherein the light source driving stack further includes: at least one data switch, the data line outputs a signal to the drain of the data switch; and a gate line, connected The gate of the data switch. The capacitive touch display device as described in item 1 of the patent scope, further includes: a plurality of pixels, each pixel of the plurality of pixels includes: the light source; and the light source switch. A method for driving a capacitive touch display device as described in any one of claims 1 to 6 includes: in a display mode, the first power supply and the second power supply provide power to drive the light source, the The data line output signal controls the light source switch; and in a touch mode, the first power source, the second power source, or the data line outputs the touch signal to sense the position where the user contacts the touch surface. According to the driving method described in item 7 of the patent application scope, the first power supply and the second power supply simultaneously output the touch signal; when the user touches the touch surface, according to the first power supply or the second power supply The electrical signal changed by a capacitance change and the electrical signal changed by the data line due to the capacitance change provide the position where the user contacts the touch surface. According to the driving method described in item 7 of the patent application scope, the first power supply and the second power supply simultaneously output the touch signal; when the user touches the touch surface, according to the first power supply or the second power supply One of the and the data signal that the data line changes due to the change in mutual capacitance provides the position where the user contacts the touch surface. The driving method as described in item 8 or 9 of the patent application scope, wherein the touch signal is an AC signal, and the first power supply and the second power supply each output the touch signal at the same frequency and phase. The driving method as described in item 7 of the patent application scope, wherein in the touch mode, the data line transmits the touch signal; when the user touches the touch surface, according to the first power supply or the second The electrical signal changed by the power source due to the change in self capacitance and the electrical signal changed by the data line due to the change in self capacitance provide the position where the user contacts the touch surface. The driving method as described in item 7 of the patent application scope, wherein in the touch mode, the data line transmits the touch signal; when the user touches the touch surface, according to the first power supply or the second The electrical signal changed by one of the power source and the data line due to the change in mutual capacitance provides the position where the user contacts the touch surface.