KR20110077233A - Liquid crystal display device including touch panel and method for fabricating the same - Google Patents

Abstract

PURPOSE: A touch panel embedded type liquid crystal display and method of manufacture thereof are provided to improve a touch function by using a contact method by a structure while using a method of port sensor. CONSTITUTION: A touch panel embedded type liquid display device includes as follows. An upper substrate and a lower substrate are facing each other. A plurality of gate line(GLi) and a data line(DLi) defines a pixel area by being crossed on the lower substrate. A first supply line(BL) and a second supply line(STL) are formed in parallel with the gate line on the upper substrate. A leat outline(RLk) is formed in parallel with the data lien on the lower substrate. A pixel TFT(T1) is formed on each crossing unit of the gate line and a data line. A storage capacitor(Cstg) is formed on a part that a pixel area and a second supply line is overlapped.

Description

Touch panel built-in liquid crystal display device and manufacturing method thereof {LIQUID CRYSTAL DISPLAY DEVICE INCLUDING TOUCH PANEL AND METHOD FOR FABRICATING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel embedded liquid crystal display, and more particularly, to a touch panel embedded liquid crystal display and a method of manufacturing the same, by using a method using a photo sensor and also using a contact method by a structure.

Recently, with the development of display device technology of flat panel displays, thin display devices such as liquid crystal displays (PDPs) and plasma display panels (PDPs) have begun to be used as display devices of flat panel displays. Among them, the liquid crystal display is most widely used among display methods because it can be applied to small devices and large devices.

Recently, there is an increasing demand for such a liquid crystal display device to add a touch panel capable of recognizing a touch portion through a human hand or a separate input means and correspondingly transmitting separate information.

The touch panel is simple, has less malfunctions, is easy to carry, can input characters without other input devices, and has been recently applied to various information processing apparatuses because the user can easily recognize how to use the touch panel.

As a method of implementing a conventional touch function in a panel, there is a method using a photo sensor, a method using capacitance, and a contact method using a structure such as a column space. But each has its drawbacks.

In particular, the method using the photo sensor has a disadvantage in that the touch error increases according to the color or external light of the touch object, and the contact method using the structure may affect the image quality by using the common upper electrode.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a touch panel-embedded liquid crystal display device and a method of manufacturing the same, by using a method using a photo sensor and simultaneously using a contact method by a structure. have.

In order to achieve the above object, a touch panel embedded liquid crystal display device includes: an upper substrate and a lower substrate facing each other; A plurality of gate lines and data lines crossing each other on the lower substrate to define pixel regions; First and second supply lines formed on the lower substrate in parallel with the gate lines; A lead-out line formed on the lower substrate in parallel with the data line; A pixel TFT formed at each intersection of the gate line and the data line; A storage capacitor formed at a portion where the pixel electrode connected to the drain electrode of the pixel TFT and the second supply line overlap each other; A sensor TFT formed at each intersection of the first supply line and the data line to output a photocurrent; A sensor capacitor formed at a portion where the drain electrode of the sensor TFT and the first supply line overlap each other to store a photocurrent of the sensor TFT; First and second conductive connection parts connected to the drain electrode and the first supply line of the sensor TFT and spaced apart from each other; A switch TFT formed at an intersection of a previous gate line and the lead-out line to output a photocurrent stored in the sensor capacitor or to output bias voltages of the first and second conductive connections; A contact switch formed on the upper substrate corresponding to the first and second conductive connecting portions; And it is characterized by having a liquid crystal layer filled between the upper substrate and the lower substrate.

In addition, a method of manufacturing a touch panel embedded liquid crystal display device according to the present invention for achieving the above object comprises the steps of forming an active semiconductor layer in each of the liquid crystal display area and the touch panel area on the substrate; Forming a first insulating film on an entire surface of the substrate including the active semiconductor layer; Forming a gate line, a first supply line, and a second supply line on the first insulating film such that the gate electrodes of the pixel TFT, the sensor TFT, and the switch TFT protrude so as to overlap the active semiconductor; Implanting impurities into the active semiconductor layer using the gate electrode as a mask to form source / drain regions of the pixel TFT, the sensor TFT, and the switch TFT; Forming a second insulating film on the entire surface including the gate line and the first and second supply lines; Forming a data line and a lead out line on the second insulating layer; Forming a third insulating film on an entire surface of the substrate including the data line and the lead-out line; Selectively removing the first to third insulating layers to form a plurality of contact holes; And forming a plurality of connection parts and first and second conductive connection parts on the third insulating film such that the respective parts are connected to each other through the contact hole.

The touch panel embedded liquid crystal display according to the present invention may improve touch performance by using not only a method using a photo sensor but also a contact method by a structure.

Hereinafter, a touch panel embedded liquid crystal display according to the present invention having the above characteristics will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram of a touch panel embedded liquid crystal display according to an exemplary embodiment of the present invention.

The touch panel embedded liquid crystal display of FIG. 1 includes a pixel circuit P1 formed at an intersection of an i-th gate line GLi and a j-th data line DLj, a first supply line BL, and a k-th readout. The sensor circuit P2 is formed at the intersection of the line RLk.

The pixel circuit P1 is formed at the intersection of the liquid crystal cell Clc, the gate line GLi, and the data line Di, and the pixel TFT T1 for driving the liquid crystal cell Clc, and the liquid crystal cell ( And a storage capacitor Cstg for maintaining the charging voltage of Clc for one frame.

The pixel TFT T1 supplies a data voltage supplied through the data line DLj to the pixel electrode of the liquid crystal cell Clc in response to a scan pulse from the gate line GLi. For this purpose, the gate electrode of the pixel TFT T1 is connected to the gate line GLi, the source electrode is connected to the data line DLj, and the drain electrode is connected to the pixel electrode of the liquid crystal cell Clc. The liquid crystal cell Clc is charged with a potential difference between the data voltage applied to the pixel electrode and the common voltage VCOM. The liquid crystal cell array is changed by an electric field formed by the potential difference to control the amount of light transmitted or to block light. Done. The storage capacitor Cstg is connected between the drain electrode of the pixel TFT T1 and the second supply line STL.

The touch sensor circuit P2 may include a sensor TFT T2 for generating a photocurrent differently depending on whether the touch point corresponds to a touch point during a period in which a driving voltage is supplied, a sensor capacitor Cstg2 for storing charges by the photocurrent; The contact switch CS conducts the bias voltage Vbias according to the external pressurization, and the photocurrent stored in the sensor capacitor Cstg2 and the conducted bias voltage Vbias to the kth lead-out line RLk. The switch TFT T3 which outputs is provided.

The gate electrode and the source electrode of the sensor TFT T2 are connected to the first supply line BL, and the drain electrode is connected to the first node N1.

Since the sensor TFT T2 is not covered by the black matrix of the upper substrate 32 unlike the pixel TFT T1 and the switch TFT T3, a photocurrent is supplied during a period in which a driving voltage is supplied in response to light incident from the outside. But generates a photocurrent of a different size depending on whether the touch point. In other words, the sensor TFT T2 generates a larger photocurrent at the touch point than the area not corresponding to the touch point in an illuminance environment (indoor environment) that is darker than the backlight 20, but is brighter than the backlight 20. In the (outdoor environment), a small photocurrent is generated at the touch point compared to the area not corresponding to the touch point. Charges by the photocurrent are stored in the sensor capacitor Cstg2 connected between the first node N1 and the first supply line BL.

The voltage VN1 of the first node is stored in the sensor capacitor Cst2 until the switch TFT T3 is turned on. The voltage VN1 of the first node has a different size depending on whether the driving voltage corresponds to the touch point during the supply period. In other words, the voltage VN1 of the first node has a larger value at the touch point than the area not corresponding to the touch point in an illuminance environment (indoor environment) that is darker than the backlight 20, and is brighter than the backlight 20. The environment (outdoor environment) has a smaller value at the touch point than the area that does not correspond to the touch point.

The contact switch CS or 40 conducts the bias voltage Vbias supplied from the first supply line BL to the first node N1 by an external pressure. At this time, the voltage of the first node N1 becomes the bias voltage Vbias.

The gate electrode of the switch TFT T3 is connected to the i-1 th gate line Gi-1, the source electrode is connected to the first node N1, and the drain electrode is connected to the k th readout line RLk. Connected. The switch TFT T3 is turned on in response to a scan pulse supplied to the i−1 th gate line Gi−1, so that the k th readout line RLk uses the voltage of the first node N1 as a light sensing signal. )

Meanwhile, the touch panel embedded liquid crystal display according to the present invention uses both a vertical electric field in which the common electrode 36 is formed on the upper substrate 32 and a transverse electric field in which the common electrode 36 is formed on the lower substrate 12. Applicable Here, the touch panel built-in liquid crystal display device to which the vertical electric field method is applied will be described as an example.

FIG. 2A is a layout view of a lower substrate implementing the circuit diagram of FIG. 1 by a semiconductor process, and FIG. 2B is a layout diagram of the upper substrate implementing the circuit diagram of FIG. 1 by a semiconductor process. 3 is a cross sectional view taken along line II ′ of FIG. 2A.

As shown in FIGS. 2 and 3, the touch panel embedded liquid crystal display according to the present invention includes an upper substrate 32 and a lower substrate 12 disposed at a predetermined distance from each other at a position spaced apart from the backlight 20. And a liquid crystal layer 10 filled between the upper substrate 32 and the lower substrate 12.

The upper substrate 32 may include a color filter layer 34, a common electrode 36, a contact switch 40 coated with a conductive film 39, and a partition wall that insulates the conductive film 39 from the common electrode 36. 37, 38). In addition, a black matrix (not shown) is formed in the non-pixel region between the color filter layer 34 and the color filter layer 34.

The lower substrate 12 crosses each other and is provided with a plurality of gate lines GLi and GLi-1 and a data line DLj and a first supply formed in parallel with the gate lines GLi and GLi-1. Each intersection of the line BL and the second supply line STL, the lead-out line RLk formed in parallel with the data line DLj, and the gate lines GLi and GLi-1 and the data line DLj. A storage capacitor Cstg and a first supply line BL formed at a portion where the pixel TFT T1 formed in the pixel TFT T1, the drain electrode (pixel electrode) and the second supply line STL of the pixel TFT T1 overlap each other. A sensor TFT (T2) formed at each intersection of the data line (DLi), a sensor capacitor (Cstg2) formed at a portion where the drain electrode of the sensor TFT (T2) and the first supply line (BL) overlap; A first conductive connection portion M3 connected to the drain electrode of the sensor TFT T2 and the first supply line BL, and spaced apart from each other; 2 conductive connection portion M4, switch TFT T3 formed at the intersection of previous stage gate line GLi-1 and lead-out line RLk, and a plurality of connection portions M1 for electrically connecting each line; M2 and M5).

 Hereinafter, the manufacturing method according to the semiconductor process of the lower substrate 12 will be described in detail.

Hereinafter, a method of manufacturing the touch panel embedded liquid crystal display device according to the present invention configured as described above will be described in detail.

First, active semiconductor layers 11 and 13 are formed in the liquid crystal display region and the touch panel region on the lower substrate 12, respectively.

An inorganic insulating film such as silicon nitride (SiNx) or silicon oxide (SiOx) is deposited on the entire surface of the substrate including the active semiconductor layers 11 and 13 to form a first insulating film (gate insulating film) 14.

A conductive material such as aluminum (Al) or Al alloy is deposited on the first insulating layer 14 and patterned by photolithography to form gate lines GLi-1 and GLi, first and second supply lines ( BL, STL).

In this case, the gate electrodes 15 of the pixel TFT T1, the sensor TFT T2, and the switch TFT T3 protrude from the gate lines GLi−1 and GLi and the first supply line BL, and the It is formed to overlap the active semiconductor layers 11 and 13. In addition, the first and second supply lines BL and STL protrude from the first and second supply lines BL and STL to form the storage capacitor Cstg and the sensor capacitor Cstg2.

Source / drain regions of the pixel TFT (T1), the sensor TFT (T2), and the switch TFT (T3) by implanting impurities into the active semiconductor layers 11 and 13 by using the gate electrode 15 as a mask. (13b, 13c) are formed. At this time, the active semiconductor layer between the source region 13b and the drain region 13c becomes the channel region 13a.

The width (W: Width) and length (L; Lengh) of the channel region 13b are gradually decreasing according to the trend of higher integration of the device, which means that the width of the junction between the channel region and the drain region is reduced. Thus, the threshold voltage for operating the TFT increases, and the resistance of the channel region increases, thereby reducing on-current during driving.

Of course, the storage capacitor Cstg and the sensor capacitor Cstg2 are formed before adding the mask process to form the gate lines GLi-1 and GLi, the first and second supply lines BL and STL. Impurity ions may be first implanted into the active semiconductor layers 11 and 13.

After the channel region is formed, an inorganic insulating film such as silicon nitride (SiNx) or silicon oxide (SiOx) is deposited on the entire surface including the gate electrode 15 to form a second insulating film 16.

A conductive material such as Al or Al alloy is deposited on the second insulating layer 16 and patterned by photolithography to form the data line DLi and the lead-out line RLk.

A third insulating film (not shown) is formed on the entire surface of the substrate including the data line DLi and the lead-out line RLk.

The third insulating film, the second insulating film 16 and the first insulating film 14 are selectively removed, so that the source region of the pixel TFT T1, the source region 13a of the sensor TFT T2, and the switch TFT A plurality of contact holes are formed in the drain region of the T3, the first supply line BL, the data line DLi, and the readout line RLk.

A conductive material such as Al or Al alloy is deposited on the third insulating layer and patterned by photolithography to connect the plurality of connection parts M1, M2 and M5 and the connection parts M3 and M4 so that the respective parts are connected to each other through the contact hole. ).

That is, the source region and the data line of the pixel TFT T1 are electrically connected by the connecting portion M1, and the first supply line BL and the sensor TFT T2 are electrically connected by the connecting portion M2. The source region 13a is electrically connected, and the lead-out line RLk and the drain region of the switch TFT T3 are electrically connected by the connection portion M5. Further, first and second conductive connection portions M3 and M4 are formed on the drain region of the sensor TFT T2 and the first supply line BL.

In addition, contact switches CS and 40 are formed at portions corresponding to the first and second conductive connection portions M3 and M4 on the upper substrate 32, and the upper and lower substrates 32 and 12 are formed. Stick together.

By such a process, a touch panel embedded liquid crystal display device according to the present invention is completed.

The touch panel embedded liquid crystal display according to the present invention is divided into a method of sensing light or a method of sensing external pressure according to a method of sensing a touch. It will be described in more detail as follows.

First, a method of sensing a touch by an optical sensor will be described.

In an illumination environment (indoor environment) darker than the backlight 20, the light emitted from the backlight 20 is reflected at the touch point of the user and transmitted to the sensor TFT T2. The sensor TFT T2 generates a photocurrent in response to incident light, and the sensor capacitor Cstg2 stores charges according to the photocurrent. The switch TFT T3 switches the stored photocurrent to the k-th readout line RLk. Therefore, in an illumination environment (indoor environment) darker than the backlight 20, a larger value is output at the touch point than in an area not corresponding to the touch point.

On the contrary, in an illuminance environment (outdoor environment) that is brighter than the backlight 20, since light of the surrounding is cut off at the touch point of the user, no photocurrent is generated in the sensor TFT T2 at the touch point, and the sensor capacitor Cstg2 is in the photocurrent. Less charge is stored and output to the k-th readout line RLk through the switch TFT T3. Therefore, in an illuminance environment (indoor environment) that is brighter than the backlight 20, a smaller value is output at the touch point than in an area not corresponding to the touch point.

Meanwhile, a method of sensing a touch by sensing an external pressure will be described with reference to FIG. 4.

When external pressure is applied, the contact switch 40 of the upper substrate 32 descends to contact the spaced apart conductive connecting portions M3 and M4 on the lower substrate 12. The contact switches CS or 40 contact and conduct the conductive connecting portions M3 and M4 spaced apart from each other to supply a bias voltage Vbias supplied from the first supply line BL to the switch TFT T3. The switch TFT T3 switches the supplied bias voltage Vbias to the k-th readout line RLk.

Therefore, in the touch panel embedded liquid crystal display according to the present invention, if the signal read out is smaller or larger than other regions, it is determined that the point is touched.

The touch panel embedded liquid crystal display according to the present invention may also be applied to a transverse electric field system. That is, it is possible to apply even when the upper substrate 32 does not need to include the common electrode 36. At this time, the upper substrate 32 includes contact switches CS and 40 coated with a conductive film 39 to contact and conduct each conductive connection portion M3 and M4 of the lower substrate 12. Accordingly, the touch panel embedded liquid crystal display device according to the present invention simplifies the structure and does not affect the image quality.

As described above, the touch panel embedded liquid crystal display according to the present invention can improve touch performance by using a contact method by a structure while using a method using a photo sensor. In addition, the touch panel embedded liquid crystal display according to the present invention may use a contact method by a structure even when the common electrode 36 is not required on the upper substrate 32. That is, the structure can be simplified by eliminating the need for a conductive seal or Ag Dot.

1 is a circuit diagram of a touch panel embedded liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2A is a layout diagram of a lower substrate implementing the circuit diagram of FIG. 1 by a semiconductor process. FIG.

FIG. 2B is a layout diagram of an upper substrate in which the circuit diagram of FIG. 1 is implemented by a semiconductor process. FIG.

3 is a cross sectional view taken along line II ′ of FIG. 2A;

FIG. 4 is a cross-sectional view when the upper substrate shown in FIG. 3 is pressurized. FIG.

* Brief description of symbols for the main parts of the drawings.

GLi: i th gate line DLj: j th data line

BL: 1st supply line STL: 2nd supply line

RLk: kth lead-out line CS: contact switch

Claims (6)

An upper substrate and a lower substrate facing each other; A plurality of gate lines and data lines crossing each other on the lower substrate to define pixel regions; First and second supply lines formed on the lower substrate in parallel with the gate lines; A lead-out line formed on the lower substrate in parallel with the data line; A pixel TFT formed at each intersection of the gate line and the data line; A storage capacitor formed at a portion where the pixel electrode connected to the drain electrode of the pixel TFT and the second supply line overlap each other; A sensor TFT formed at each intersection of the first supply line and the data line to output a photocurrent; A sensor capacitor formed at a portion where the drain electrode of the sensor TFT and the first supply line overlap each other to store a photocurrent of the sensor TFT; First and second conductive connection parts connected to the drain electrode and the first supply line of the sensor TFT and spaced apart from each other; A switch TFT formed at an intersection of a previous gate line and the lead-out line to output a photocurrent stored in the sensor capacitor or to output bias voltages of the first and second conductive connections; A contact switch formed on the upper substrate corresponding to the first and second conductive connecting portions; And And a liquid crystal layer filled between the upper substrate and the lower substrate. The method of claim 1, The touch switch and the first, second conductive connecting portion is spaced apart a predetermined interval, the touch switch built-in type, characterized in that the contact switch electrically connects the first, second conductive connecting portion by an external pressure. Liquid crystal display. Forming active semiconductor layers in the liquid crystal display area and the touch panel area on the substrate, respectively; Forming a first insulating film on an entire surface of the substrate including the active semiconductor layer; Forming a gate line, a first supply line, and a second supply line on the first insulating film such that the gate electrodes of the pixel TFT, the sensor TFT, and the switch TFT protrude so as to overlap the active semiconductor; Implanting impurities into the active semiconductor layer using the gate electrode as a mask to form source / drain regions of the pixel TFT, the sensor TFT, and the switch TFT; Forming a second insulating film on the entire surface including the gate line and the first and second supply lines; Forming a data line and a lead out line on the second insulating layer; Forming a third insulating film on an entire surface of the substrate including the data line and the lead-out line; Selectively removing the first to third insulating layers to form a plurality of contact holes; And And forming a plurality of connecting portions and first and second conductive connecting portions on the third insulating layer such that the respective portions are connected to each other through the contact hole. The method of claim 3, wherein When the gate line, the first and the second supply line are formed, a structure protruding from the first and second supply lines BL and STL to the active semiconductor layer is formed to form a storage capacitor and a sensor capacitor. The manufacturing method of the touch panel built-in liquid crystal display device characterized by the above-mentioned. The method of claim 3, wherein The plurality of contact holes are formed in a source region of the pixel TFT, a source region of the sensor TFT, a drain region of the switch TFT, a first supply line, a data line, and a readout line. Method of manufacturing the display device. The method of claim 3, wherein And forming a contact switch on the upper substrate corresponding to the first and second conductive connecting portions, and bonding the upper substrate and the lower substrate to each other.

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