CN102375603A - Display device with touch tablet - Google Patents

Abstract

Disclosed is a display device having a touch panel that effectively intercepts noise generated from the display panel to prevent the touch panel from being disabled. A display device having a touch panel includes: a display panel; a touch panel attached to the display panel through an adhesive layer; a noise intercepting layer on the entire rear surface of the touch panel to prevent noise from the touch panel. The electrical noise of the display panel is introduced into the touch panel; the metal ring pattern is on the noise intercepting layer to surround the edge of the noise intercepting layer, and the resistance of the metal ring pattern is lower than a resistance of the noise intercepting layer; and a ground terminal electrically connected to the noise intercepting layer and the metal ring pattern.

Description

Display device with touch panel

technical field

The present invention relates to a display device having a touch panel, and more particularly, to a display device having a touch panel that effectively intercepts noise generated from the display panel to prevent the touch panel from being disabled.

Background technique

This application claims priority from Korean Patent Application No. 10-2010-0080547 filed on Aug. 19, 2010, which is hereby incorporated by reference as if fully set forth herein.

Recently, touch screens capable of inputting information by touching the screens of various display devices are widely used as information input units of computer systems. Simply by a user touching with a finger or a stylus, the touch screen moves or selects displayed information, so that anyone regardless of age or gender can easily use the touch screen.

The touch screen senses a touch or a touch position generated on a screen of a display device, and outputs touch information, and a computer system analyzes the touch information, and then executes a command. As the display device, a flat panel display device such as a liquid crystal display device, a plasma display panel, or an organic light emitting diode display device is generally used.

Touch screen technologies are classified as resistive, capacitive, infrared, ultrasonic, or electromagnetic based on the sensing method. Among these types, the resistive type and the capacitive type are advantageous in terms of manufacturing cost, and thus are widely used.

The resistive touch screen recognizes a touch by sensing a voltage change generated by contact between upper and lower resistive films (transparent conductive films) due to touch pressure. However, the resistive touch screen has disadvantages that the touch screen or display device is easily damaged due to touch pressure, and the touch screen has low light transmittance due to scattering in the air layer between the resistive films.

The capacitive touch screen, which overcomes these disadvantages of the resistive touch screen, recognizes a touch by sensing a change in capacitance generated when a small amount of charge moves to a touch point when a conductor such as a human body or a stylus touches the touch screen. The capacitive type touch screen has high durability due to the use of tempered glass, has high light transmittance and excellent touch sensing capability, and is capable of multi-touch, thereby attracting a lot of attention.

Generally, a touch screen is manufactured as a panel attached to an upper portion of a display device so as to enable touch input. However, a display device having a touch panel has a disadvantage in that a touch sensor in the touch panel may fail due to electromagnetic interference (EMI) caused by noise (ie, static electricity) generated by the display device.

Contents of the invention

Accordingly, the present invention relates to a display device with a touch panel.

An object of the present invention is to provide a display device having a touch panel that effectively intercepts noise generated from the display panel to prevent the touch panel from being disabled.

To achieve this object and other advantages, and in accordance with the object of the present invention, as embodied and broadly described herein, a display device having a touch panel includes: a display panel; a touch panel attached to the the display panel; a noise interception layer on the entire rear surface of the touch panel to prevent electrical noise from the display panel from being introduced into the touch panel; a metal ring pattern, the metal ring pattern on the noise intercepting layer to surround an edge of the noise intercepting layer, and the resistance of the metal ring pattern is lower than that of the noise intercepting layer; and a ground terminal electrically connected to the noise intercepting layer and the metal ring pattern.

The touch panel may include: a lower substrate provided with the noise interception layer, the metal ring pattern, and the ground terminal on an outer surface; a capacitive type touch sensor formed on an inner surface of the lower substrate; and a cover A substrate is formed on the touch sensor.

The display device may further include: a circuit film for electrically connecting the touch sensor to a touch controller to drive the touch sensor; and a circuit film extension extending from an inner surface of the lower substrate along the lower substrate. The sides of the surface are bent and connected to ground terminals formed on the rear surface of the lower substrate.

The circuit film extension may be configured such that a first portion of the circuit film extension connected to the ground terminal has a larger width than a second portion of the circuit film extension bent along a side surface of the lower substrate. width.

The metal ring pattern and the ground terminal are integrally formed in the same metal layer.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Description of drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve as Explain the principles of the invention. In the attached picture:

1 is a schematic longitudinal sectional view of a display device having a touch panel according to an embodiment of the present invention;

2A and 2B are diagrams illustrating noise discharge paths according to the presence or absence of a metal ring pattern;

3 is a plan view of an electrode structure of a part of the capacitive touch sensor shown in FIG. 1; and

4 is a longitudinal sectional view illustrating a connection structure between an FPC and a ground terminal on the rear surface of the touch panel shown in FIG. 3 .

Detailed ways

Hereinafter, a display device with a touch panel according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic longitudinal sectional view of a display device having a touch panel according to one embodiment of the present invention.

The display device shown in FIG. 1 includes a display panel 40 and a touch panel 10 attached to the surface of the display panel 40 through an adhesive layer 30 .

As the display panel 40, a flat display device such as a liquid crystal display device, a plasma display panel, or an organic light emitting diode display device is generally used. For example, if a liquid crystal display device is used as the display panel 40, the liquid crystal display device includes a color filter substrate on which a color filter array is formed, a thin film transistor substrate on which a thin film transistor array is formed, and between the color filter substrate and the thin film transistor array. The liquid crystal layer formed between them, and the polarizing plates respectively attached to the outer surface of the color filter substrate and the outer surface of the thin film transistor substrate. The liquid crystal display device displays an image by driving a liquid crystal layer using a horizontal electric field or a vertical electric field according to an image signal.

A transparent adhesive layer 30 is applied to the entire surface of the display panel 40 , and the touch panel 10 is attached to the display panel 40 through the adhesive layer 30 . The adhesive layer 30 is formed of an optical elastic resin, for example, Super View Resin (SVR: Super View Resin), which is an acrylic UV curable resin, can be used. SVR has improved visibility and impact resistance.

The touch panel 10 includes a touch sensor 14 formed on a lower substrate 16 and a cover substrate 12 on an upper surface of the touch sensor 14 . The lower substrate 16 and the cover substrate 12 are formed of glass or transparent polymer. In addition, the cover substrate 12 may be formed of tempered glass having high durability. The touch panel 10 uses a capacitive type touch sensor 14 that recognizes a touch by sensing a change in capacitance generated when a conductor such as a human body or a stylus touches the touch panel 10 and a small amount of charge moves to a touch point. The touch sensor 14 is electrically connected to a touch controller mounted on a circuit film (for example, a flexible printed circuit (FPC)) through a circuit film. The touch controller provides a driving signal to the touch sensor 14 and receives a sensing signal from the touch sensor 14, thereby determining whether there is a touch and a touch position.

Between the touch panel 10 and the display panel 40 , that is, on the entire rear surface of the touch panel 10 , a noise interception layer 18 for preventing noise radiated from the display panel 40 from being introduced into the touch panel 10 is formed. The noise blocking layer 18 is formed by depositing a transparent conductive layer on the rear surface of the touch panel 10 , ie, the outer surface of the lower substrate 16 , using a deposition method such as sputtering or chemical vapor deposition (CVD). The transparent conductive layer is formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO or antimony tin oxide (ATO). The noise intercepting layer 18 is electrically connected to a ground terminal 22, for example Shown in 2A and 2B. Ground terminal 22 is connected to ground power supply by FPC.Therefore, noise interception layer 18 discharges to ground terminal 22 and then introduces into the noise of noise interception layer 18 from display panel 40 radiation, that is, static electricity, prevents thus from Noise radiated from the display panel 40 is introduced into the touch panel 10. The noise interception layer 18 is formed on the entire rear surface of the lower substrate 16, so that touch sensing introduced to the touch panel 10 from the display area and the peripheral driving circuit area of the display panel 40 can be intercepted. All electrical noise in the area and outside areas.

In particular, as shown in FIG. 2B , a metal ring image 20 having a resistance lower than that of the noise intercepting layer 18 is formed at the edge of the noise intercepting layer 18 in order to shorten a discharge delay time of noise. The metal ring image 20 is electrically connected to the ground terminal 22 together with the noise interception layer 18 , thereby quickly releasing the noise released from the noise interception layer 18 to the ground terminal 22 . The metal ring pattern 20 is formed on the edge of the noise intercepting layer 18 by sputtering or printing. The metal ring pattern 20 is formed of a metal having relatively low resistance, for example, molybdenum (Mo), copper (Cu), silver (Ag), chromium (Cr), aluminum (Al), aluminum neodymium alloy (AlNd), and molybdenum titanium ( Alloy MoTi). In addition, the metal ring pattern 20 is formed in the same metal layer as the ground terminal 22 formed under the noise interception layer 18 and is electrically connected to the ground terminal 22 . For example, the metal ring pattern 20 is formed in the shape of a closed rectangular strip by printing on the edge of the noise intercepting layer 18 using Ag paste. In addition, the ground terminal 22 is electrically connected to the metal ring pattern 20 and is formed under the noise interception layer 18 by printing using Ag paste, like the metal ring pattern 20 .

The transparent conductive layer used as the noise interception layer 18 has relatively high resistance. Therefore, if there is no metal ring pattern 20, as shown in FIG. In , that is, in the upper part B, the time for releasing noise through the ground terminal 22 is delayed due to high resistance, thereby possibly introducing noise into the touch panel 10 . In this case, some areas of the touch panel 10, ie, the upper portion B, recognize noise as a normal sensing signal, or no touch is sensed due to noise, and thus the touch panel 10 may fail.

On the other hand, if the metal ring pattern 20 with lower resistance than the transparent conductive layer is additionally formed on the edge of the noise intercepting layer 18, as shown in FIG. Noise is quickly released through this metal ring pattern 20 . That is, the noise interception layer 18 quickly releases noise to the ground terminal 22 through the metal ring pattern 20 regardless of the distance from the ground terminal 22 . Thereby, it is possible to effectively prevent noise from the display panel 40 from being introduced into some areas of the touch panel 10 due to the noise release delay of the noise interception layer 18 . As a result, failure of the touch panel 10 due to introduction of noise from the display panel 40 to the touch panel 10 can be prevented.

FIG. 3 is a plan view of an electrode structure in a part of the capacitive touch sensor 14 shown in FIG. 1 .

The capacitive touch sensor 14 shown in FIG. 3 includes a plurality of first sensing electrode lines 142 in the touch sensing area TSA, wherein the plurality of sensing electrode lines are connected in the horizontal direction (that is, along the X-axis direction) through the first connection electrodes 143 . a first sensing electrode 141 ; and a plurality of second sensing electrode lines 146 , wherein the plurality of second sensing electrodes 145 are connected vertically (ie, along the Y-axis direction) via second connecting electrodes 147 . The plurality of first sensing electrode lines 142 are arranged vertically (along the Y-axis direction), and the plurality of second sensing electrode lines 146 are arranged horizontally (along the X-axis direction). The first sensing electrodes 141 and the second sensing electrodes 145 are formed in a diamond shape, but may also be formed in various other shapes. The first connection electrodes 143 and the second connection electrodes 147 cross each other under the condition that an insulating layer (not shown) is interposed between the first connection electrodes 143 and the second connection electrodes 147 . The first sensing electrode 141, the second sensing electrode 145 and the second connecting electrode 147 are formed by the same transparent conductive layer, while the first connecting electrode 143 is formed by a metal layer, and the metal layer is formed so that the insulating layer is sandwiched between the transparent conductive layer. and between metal layers. The first connection electrode 143 is electrically connected to the first sensing electrode 141 through a contact hole penetrating the insulating layer. Alternatively, the first sensing electrode 141 and the second sensing electrode 145 may be formed of the same transparent conductive layer as the first connection electrode 143, and the second connection electrode 147 may be formed of a metal layer formed such that the second The connection electrode 147 is electrically connected to the second sensing electrode 145 through the contact hole. The first sensing electrode 141 and the second sensing electrode 145 form a capacitor together with the conductive touch body of the touch cover substrate 12 , and change capacitance to output a sensing signal.

In addition, in the outer area OA surrounding the touch sensing area TSA, the capacitive touch sensor 14 further includes: a plurality of first lead wires 148 respectively electrically connected to the first sensing electrode lines 142 located in the touch sensing area TSA, The plurality of second leads 160 are respectively electrically connected to the second sensing electrode lines 146 located in the touch sensing area TSA, and the pads 170 are respectively electrically connected to the first lead 148 and the second lead 160 . The first lead wires 148 are connected to left and right ends of the first sensing electrode line 142, respectively, and are connected to corresponding pads 170 in a pad area located at a lower portion of the outer area OA. The second lead wires 160 are connected to lower ends of the second sensing electrode lines 146, respectively, and are connected to corresponding pads 170 located in pad regions. The first lead 148 , the second lead 160 and the pad 170 are formed in the same metal layer as one of the first connection electrode 143 and the second connection electrode 147 in the touch sensing area TSA.

For example, one of the first connection electrode 143 and the second connection electrode 147 included in the touch sensing area TSA and the first lead 148, the second lead 160 and the pad in the outer area OA are formed on the lower substrate 16. After the metal pattern of 170, an insulating layer provided with a contact hole is formed on the metal pattern, and the other one of the first connection electrode 143 and the second connection electrode 147, the first sensing The transparent conductive pattern of the electrode 141 and the second sensing electrode 145 .

The plurality of pads 170 formed in the pad region are electrically connected to the FPC 180, thereby being electrically connected to a touch controller (not shown) mounted on the FPC 180. The touch controller not only drives the first sensing electrode lines 142 and the second sensing electrode lines 146 of the touch sensor 14, but also receives sensing signals output from the first sensing electrode lines 142 and the second sensing electrode lines 146 and Integrate these sensing signals according to unit time to sense whether there is a touch, and sense according to the X-axis and Y-axis positions of the first sensing electrode line 142 and the second sensing electrode line 146 that output these sensing signals. Touch location.

An extension 180A extending from one side end of the FPC 180 is electrically connected to a ground terminal 22 formed on the rear surface of the touch panel 10, as shown in FIG. 2B. That is, the extension 180A of the FPC 180 is bent along the side of the lower substrate 16 of the touch panel 10, as shown in FIG. The extension portion 180A of the FPC 180 includes a small-width portion bent along the side surface of the lower substrate 16 and a large-width portion connected to the ground terminal 22. The FPC 180 discharges the noise discharged from the noise interception layer 18 through the metal ring pattern 20 and the ground terminal 22 to the ground power, thereby canceling the noise.

As described above, in the display device having a touch panel according to the present invention, the noise interception layer 18 formed of a transparent conductive layer is formed on the entire rear surface of the touch panel 10 attached to the display panel 40, and the metal ring pattern 20 is formed At the edge of the noise intercepting layer 18 , the noise introduced from the display panel 40 is effectively intercepted regardless of the distance between the noise intercepting layer 18 and the ground terminal 22 . Thereby, the noise introduced from the display panel 40 to the touch panel 10 is minimized, thereby preventing the failure of the touch panel 10 due to noise, and the noise introduced to the touch controller through the touch sensor 10 is minimized, thereby expanding the sensing signal driving range , thereby improving the sensing performance of the touch controller.

As apparent from the above description, in the display device having a touch panel according to the present invention, a metal ring pattern having low resistance is formed between the touch panel and the display panel at the edge of the noise intercepting layer formed of the transparent conductive layer, thereby Noise from the display panel is quickly released through the ground terminal regardless of the distance between the noise intercepting layer and the ground terminal.

Therefore, the noise from the display panel is effectively intercepted, thereby preventing the failure of the touch sensor, and the noise introduced into the touch controller is reduced, thereby expanding the driving range of the sensing signal, thereby improving the recognition rate of the sensing signal.

It will be apparent to those skilled in the art that various modified embodiments and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modified embodiments and variations of this invention that come within the scope of the appended claims and their equivalents.

Claims (6)

1. A display device comprising: display board; a touchpad attached to the display panel by an adhesive layer; a noise intercepting layer on the entire rear surface of the touch panel to prevent electrical noise from the display panel from being introduced into the touch panel; a metal ring pattern on the noise intercepting layer to surround an edge of the noise intercepting layer, and the resistance of the metal ring pattern is lower than that of the noise intercepting layer; and and a ground terminal electrically connected to the noise interception layer and the metal ring pattern. 2. The display device according to claim 1, wherein the touch panel comprises: a lower substrate, the outer surface of which is the rear surface of the touchpad; a capacitive touch sensor formed on an inner surface of the lower substrate; and A cover substrate is formed on the touch sensor. 3. The display device according to claim 2, further comprising: a circuit film for electrically connecting the touch sensor to a touch controller to drive the touch sensor; and A circuit film extension bent from the inner surface of the lower substrate along a side surface of the lower substrate and connected to a ground terminal formed on an outer surface of the lower substrate. 4. The display device according to claim 3 , wherein the circuit film extension is configured such that a width of a first portion of the circuit film extension connected to the ground terminal is larger than that of the circuit film extension. The width of the second portion bent along the side of the lower substrate. 5. The display device of claim 1, wherein the metal ring pattern and the ground terminal are integrally formed in the same metal layer. 6. The display device according to claim 1, wherein the noise interception layer is formed of a transparent conductive layer.

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