The present application claims priority to Korean Patent Application No. 10-2007-0099704 filed on Oct. 4, 2007, and all benefits accruing therefrom under 35 U.S.C. §119, the contents of which are incorporated herein by reference in their entirety.
1. Field of the Invention
The present disclosure relates to a display, and more particularly, to a display with a built-in touch screen panel and a method of manufacturing the same.
2. Related Art
In general, a touch screen panel is a device enabling a specific operation by touching a screen directly over a character, an icon, etc., with a human hand or an object without using a keyboard. A conventional touch screen panel is separately prepared from a display and then attached to the display, which increases a total thickness of the display. Therefore, in order not to increase the thickness, there has been proposed a display with a built-in touch screen panel in which a touch screen panel function is provided in the fabrication of the display.
In the conventional display with the built-in touch screen panel, a sensing electrode is disposed on a lower substrate where a thin film transistor (TFT) and a pixel electrode are provided, and a conductive spacer is disposed on an upper substrate where a color filter and a common electrode are provided. Therefore, the conductive spacer and the sensing electrode sense a touch position by a pressure applied thereto.
In the conventional display, when the upper and lower substrates are attached to each other, they are slightly misaligned, which leads to a misalignment between the sensing electrode and the conductive spacer. In particular, a surface of the conductive spacer contacting the sensing electrode does not have a flat shape but a substantially curved shape, so that an actual contact area between the conductive spacer and the sensing electrode is reduced. Therefore, the misalignment between the upper and lower substrates results in a sensing failure caused by insufficient contact of the sensing electrode and the conductive spacer.
Embodiments of the present disclosure provide a display (and method of manufacturing the same) with a built-in touch screen panel capable of preventing a sensing failure of a sensing electrode and a conductive spacer caused by a misalignment therebetween.
In accordance with an embodiment of the present disclosure, a display includes a first substrate and a second substrate facing each other, a first sensing electrode and a second sensing electrode disposed on the first substrate, and a conductive spacer disposed on the second substrate. The first and second sensing electrodes are spaced apart from each other, and the conductive spacer is disposed so as to correspond to each of the first and second sensing electrodes.
In various implementations, the first substrate may include a first sensing line arranged in one direction of the first substrate and a second sensing line intersecting the first sensing line, wherein the first and second sensing lines may be insulated from each other. The first and second sensing electrodes may be connected to the first and second sensing lines, respectively. The second sensing line may be provided for one or more unit pixels. The cross section of the conductive spacer may become wider as it extends from a region corresponding to a center of each of the first and second sensing electrodes toward a region corresponding to outer edges of the first and second sensing electrodes. The cross section of the conductive spacer may include a small width at a region between the first and second sensing electrodes. The cross section of the conductive spacer may include a maximum width at a region corresponding to the each center of the first and second sensing electrodes. The conductive spacer may include cross sections that may be spaced apart from each other and the cross sections may have wider regions corresponding to the each central portions of the first and second sensing electrodes. The conductive spacer may include two spacers that may be spaced apart from each other. The conductive spacer may be provided for one or more unit pixels and may be disposed on a black matrix. Portions of the first and second sensing electrodes may extend to cross each other.
In accordance with an embodiment of the present disclosure, a method of manufacturing a display includes forming first and second sensing lines and first and second sensing electrodes connected to the first and second sensing lines, respectively, on a first substrate. The first and second sensing lines extend in a first direction and a second direction, respectively, and are insulated from each other. The method may include forming a conductive spacer on a second substrate. The conductive spacer may be formed on a region corresponding to each of the first and second sensing electrodes. The method may include forming a cell gap spacer between the first and second substrates and forming a liquid crystal layer between the first and second substrates.
In accordance with an embodiment of the present disclosure, a display includes a lower substrate and an upper substrate facing each other, a first sensing electrode and a second sensing electrode disposed on the lower substrate, which are spaced apart from each other, and a conductive spacer disposed on the upper substrate to be corresponding to each of the first and second sensing electrodes.
In various implementations, the lower substrate may include a first sensing line arranged in one direction of the lower substrate and a second sensing line intersecting the first sensing line, wherein the first and second sensing lines may be insulated from each other. The first and second sensing electrodes may be connected to the first and second sensing lines, respectively. The second sensing line may be provided for every one or more unit pixels.
In various implementations, the conductive spacer may become wider from a region corresponding to each of the first and second sensing electrodes toward a region corresponding to outer edges of the first and second sensing electrodes. The conductive spacer may have a small width at a region between the first and second sensing electrodes. The conductive spacer may have a maximum width at a region corresponding to the centers of the outer edges of the first and second sensing electrodes. The conductive spacer may have cross sections that are spaced apart from each other and become wider from regions corresponding to the central portions of the first and second sensing electrodes toward outer edges of the first and second sensing electrodes. The conductive spacer may include two spacers that are spaced apart from each other, the two spacers respectively becoming wider from regions corresponding to the central portions of the first and second sensing electrodes toward outer edges of the first and second sensing electrodes. The conductive spacer may be provided for every one or more unit pixels, and is disposed on a black matrix. Portions of the first and second sensing electrodes may extend to cross each other.
In accordance with another embodiment of the present disclosure, a method of manufacturing a display includes forming first and second sensing lines and first and second sensing electrodes connected to the first and second sensing lines, respectively, on a first substrate, wherein the first and second sensing lines extend in one direction and another direction, respectively, and are insulated from each other. The method includes forming a conductive spacer on a second substrate, wherein the conductive spacer is wider from a region corresponding to each of the first and second sensing electrodes. The method includes forming a cell gap spacer between the first and second substrates and forming a liquid crystal layer between the first and second substrates.
In various implementations, forming the first and second sensing lines may include forming a plurality of gate lines extending in the one direction and the first sensing line spaced apart from the plurality of gate lines on the first substrate forming a gate insulating layer on the first substrate, and forming an active layer and an ohmic contact layer on a predetermined region of the gate insulating layer. forming a plurality of data lines extending in a direction intersecting the plurality of gate lines, and the second sensing line spaced apart from the plurality of data lines on the gate insulating layer, forming a passivation layer on the substrate, and etching a predetermined region of the passivation layer to form a plurality of contact holes, and forming a pixel electrode on the passivation layer, and forming the sensing electrode connected to the first and second sensing lines.
In various implementations, forming the conductive spacer may include forming a black matrix on a predetermined region of the second substrate, forming a protrusion extending along the sensing electrode in a region corresponding to the sensing electrode on the second substrate, and forming a color filter, and forming a conductive layer on the second substrate, and patterning the conductive layer to form a common electrode and a conductive spacer. The protrusion may be formed by a photolithography process using a mask exposing regions corresponding to respective central portions of the first and second sensing electrodes. The protrusion may include two protrusions spaced apart from each other.
These and other features and advantages of the present disclosure are more readily apparent from the detailed description of the embodiments set forth below taken in conjunction with the accompanying drawings.
Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the concept of the invention to those skilled in the art.
In the lower substrate 200, a plurality of gate lines GL1 through GLn extend in one direction and a plurality of data lines DL1 through DLm extend in another direction. Pixels are disposed at every intersection of the plurality of gate lines GL1 through GLn and the plurality of data lines DL1 through DLm. In each of the pixels, a TFT (T) acting as a switching component and a pixel electrode 280 are disposed. The TFT (T) includes a gate electrode connected to the gate line GL, a source electrode connected to the data line DL and a drain electrode connected to the pixel electrode 280. The lower substrate 200 further includes a plurality of first sensing lines (not shown), a plurality of second sensing lines (not shown) and a plurality of sensing electrodes (not shown) connected to the first and second sensing lines for performing a touch screen panel function. The first sensing line may extend in the same direction as the gate line GL, and the second sensing line may extend in the same direction as the data line DL. Here, the first and second sensing lines intersect each other, and are electrically insulated from each other. An initial driving voltage Vid having a predetermined voltage level is applied to the first and second sensing lines, and the first and second sensing lines are connected to the touch position determination unit 500. The first and second sensing lines may be provided for each of red (R), green (G) and blue (B) pixels or for every predetermined number of pixels. For example, the first and second sensing lines may be provided for every one or more unit pixels, wherein the unit pixel may include, for example, three pixels.
The upper substrate 300 provided with the color filter and the common electrode is disposed facing the lower substrate 200 and is attached to the lower substrate 200. The liquid crystal layer (not shown) is disposed between the upper and lower substrates. The upper substrate 330 may include a color filter substrate where color filters corresponding to respective pixels are provided. However, the color filters may be disposed on the lower substrate 200. The upper substrate 300 further includes a plurality of conductive spacers (not shown) so as to perform a touch screen panel function. The conductive spacer electrically contacts the sensing electrode on the lower substrate 200 by an external pressure applied from the above. The conductive spacer may be provided for each of red (R), green (G) and blue (B) pixels or for every three pixels.
In one implementation, as the sensing electrodes connected to the first and second sensing lines on the lower substrate 200 electrically contact the conductive spacers of the upper substrate 300 by an external pressure, x and y coordinates of a touch position to which the external pressure is applied may be determined by a voltage level variation of the initial driving voltage Vid applied to the first and second sensing lines.
The panel driver 400, in one embodiment, includes a timing controller 410, a power supplier 420, a gradation voltage generator 430, a data driver 440 and a gate driver 450.
The timing controller 410 controls an overall operation of the display. As an original data signal DATA_0 of R, G and B and a first control signal CNTL1 are supplied from a host system such as a graphic controller (not shown), the timing controller 410 outputs a first data signal DATA 1, a second control signal CNTL2, a third control signal CNTL3, a fourth control signal CNTL4 for displaying an image on the display panel 100. Specifically, the first control signal CNTL1 may include a main clock signal MCLK, a horizontal synchronization signal HSYNC and a vertical synchronization signal VSYNC. The second control signal CNTL2 includes a horizontal start signal STH, an inversion signal REV and a data load signal TP for controlling the data driver 440. The third control signal CNTL3 includes a vertical start signal STV, a clock signal CK and an output enable signal OE for controlling the gate driver 450. The fourth control signal CNTL4 includes a clock signal CLK and an inversion signal REV for controlling the power supplier 420.
In one implementation, the timing controller 410 applies the first data signal DATA1 of R′, G′ and B′, which is obtained by controlling an output timing of the original data signal DATA_0 of R. G and B, to the data driver 440. The timing controller 410 further outputs a fifth control signal CNTL5 for controlling the touch position detector 500. The fifth control signal CNTL5 includes a clock signal controlling the initial driving voltage Vid outputted from the power supplier 420 to be supplied to the first and second sensing lines.
The power supplier 420 is responsive to the fourth control signal CNTL4 outputted from the timing controller 410, thereby outputting common voltages Vcom and Vcst to be supplied to the display panel 100, the initial driving voltage Vid to be supplied to the lower substrate 200 so as to perform the touch screen function, an analog driving voltage AVDD to be supplied to the gradation voltage generator 430, and gate on/off voltages Von and Voff to be supplied to the gate driver 450.
In one implementation, by using the analog driving voltage AVDD supplied from the power supplier 420 as a reference voltage, the gradation voltage generator 430 outputs a plurality of reference gradation voltages VGMA_R corresponding to gradation levels based on division resistors having a resistance ratio to which gamma curve is applied.
The data driver 440 generates a gradation voltage VGMA on the basis of the reference gradation voltage VGMA_R outputted from the gradation voltage generator 430. Further, the data driver 440 converts the digital type first data signal DATA1 supplied per line into a data signal on the basis of the second control signal CNTL2 and the gradation voltage VGMA; and controls an output timing of the data signal and outputs them to the data lines DL1 through DLm.
The gate driver 450 generates gate signals according to the third control signal CNTL3 outputted from the timing controller 410 and the gate on/off voltages Von and Voff outputted from the power supplier 420, and then outputs the generated gate signals to the gate lines GL1 through GLm in sequence.
The touch position detector 500 detects a position coordinate of a point to which an external pressure is applied. That is, the conductive spacer disposed on the upper substrate 300 contacts the sensing electrode of the lower substrate 200 by the external pressure, and detects the voltage level variation of the initial driving voltage Vid applied to the first and second sensing lines. In this way, x and y coordinates are determined. As such, the touch position detector 500 includes a voltage supply control unit (not shown) configured to supply the initial driving voltage Vid to the first and second sensing lines according to the fifth control signal CNTL5, and a data sampling unit (not shown) configured to detect the variation of the initial driving voltage Vid in each of the first and second sensing lines to output a first detection signal DS1 and a second detection signal DS2, respectively. The touch position detector 500 may be provided in the data driver 440.
In one implementation, the position determination unit 600 is adapted to determine a touch position of the display panel to which the external pressure is applied by combining the x and y coordinates that are respectively determined by the first and second detection signals DS1 and DS2 outputted from the touch position detector 500.
Referring to
In one embodiment, the lower substrate 200 includes: a plurality of gate lines 221 extending in one direction over a first insulating substrate 210; a plurality of data lines 260 extending in another direction intersecting the gate lines 221; a pixel electrode 280 provided in each pixel region defined by the gate lines 221 and the data lines 260; and a TFT (T) connected to the gate line 221, the data line 260 and the pixel electrode 280. The lower substrate 200 further includes: a first sensing line SL1 spaced apart from the gate line 221 and extending in one direction; a second sensing line SL2 spaced apart from the data line 260 and extending in another direction; a first sensing electrode 291 connected to the first sensing line SL1; and a second sensing electrode 292 connected to the second sensing line SL2.
The gate line 221 may extend, for example, in a horizontal direction, and a portion of the gate line 221 protrudes to form a gate electrode 222. A gate insulating layer 230 is disposed on an entire surface including the gate line 221. The gate insulating layer 230 may have a mono-layered structure or a multilayered structure including silicon oxide (SiO2) or a silicon nitride (SiNx).
An active layer 241 formed of a semiconductor material such as amorphous silicon is disposed on the gate insulating layer 230 over the gate electrode 222. An ohmic contact layer 251 is disposed on the active layer 241. The ohmic contact layer 251 is formed of a semiconductor material such as silicide or n+ hydrogenated amorphous silicon heavily doped with n-type impurities. The ohmic contact layer 251 may be removed at a channel region between a source electrode 261 and a drain electrode 262.
The data line 260 is disposed over the gate insulating layer 230. The data line 260 extends in a direction intersecting the gate line 221. A region where the data line 260 and the gate line 221 intersect each other is defined as a pixel region. A portion of the data line 260 protrudes to an upper portion of the ohmic contact layer 251 to form the source electrode 261. The drain electrode 262 is disposed on the ohmic contact layer 251 such that it is spaced apart from the source electrode 261.
A passivation layer 270 is disposed over an entire surface including the gate line 221 and the data line 260. The passivation layer 270 may include an inorganic insulating layer or an organic insulating layer. First to third contact holes 271, 272 and 273 are provided in the passivation layer 270. The first contact hole 271 exposes a predetermined portion of the drain electrode 262, the second contact hole 272 exposes a portion of the first sensing line SL1, and the third contact hole 273 exposes a portion of the second sensing line SL2.
The pixel electrode 280 is disposed on the passivation layer 270. The pixel electrode 280 is formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The pixel electrode 280 is connected to the drain electrode 262 through the first contact hole 271.
The first sensing line SL1 is disposed to be spaced apart from the gate line 221 by a predetermined distance. The first sensing line SL1 may be simultaneously formed with the gate line 221. A branch line BR branched from the first sensing line SL1 may be spaced apart from the second sensing line SL2 by a predetermined distance and extend in the same direction as the extension direction of the second sensing line SL2. However, the branch line BR does not extend as far as the second sensing line SL2 and extends only to be connected to the first sensing electrode 291.
The second sensing line SL2 is disposed to be spaced apart from the data line 260 by a predetermined distance, and the second sensing line SL2 is provided for every predetermined number of pixels. For example, the second sensing line SL2 may be disposed between a blue pixel and a red pixel. The second sensing line SL2 may be simultaneously formed with the data line 260.
The first sensing electrode 291 is connected to the branch line BR of the first sensing line SL1 through the second contact hole 272, and the second sensing electrode 292 is connected to the second sensing line SL2 through the third contact hole 273. The first and second sensing electrodes 291 and 292 may be simultaneously formed with the pixel electrode 280 to be spaced apart from the pixel electrode 280 by predetermined distances.
The upper substrate 300, in one embodiment, includes a black matrix 320, a color filter 330 and a common electrode 340 disposed on a second insulating substrate 310. The upper substrate 300 further includes a cell gap spacer 350 and a conductive spacer 360.
The black matrix 320 is provided on the upper substrate 300 except for a sub pixel region. For example, the black matrix 320 is disposed on a region of the upper substrate 300 corresponding to the gate line 221, the data line 260, the TFT (T) and the first and second sensing lines SL1 and SL2 of the lower substrate 200. Hence, the black matrix 320 prevents light leakage through regions other than the pixel region, and also prevents light interference between adjacent pixel regions. The black matrix 320 is formed of a photosensitive organic material with black pigment added. The black pigment may include carbon black or titanium oxide.
In one implementation, the red (R), green (G) and blue (B) filters of which boundaries are the black matrices 320 are repeatedly arranged to form the color filter 330. The color filter 330 gives a corresponding color to light which is incident from a light source and passes through the liquid crystal layer (not shown). The color filter 330 may be formed of a photosensitive organic material.
The common electrode 340 may be formed of a transparent conductive material, e.g., ITO or IZO, and provided on the second insulating substrate 310 including the black matrix and the color filter 330.
The cell gap spacer 350 maintains a space between the lower and upper substrates 200 and 300. The cell gap spacer 350 is arranged for each pixel or for every predetermined number of pixels, for example, three pixels. The cell gap spacer 350 may be disposed on the black matrix 320 between the blue color filter 330 and the red color filter 330.
The conductive spacer 360, in one embodiment, is arranged for every predetermined number of pixels. For instance, the conductive spacer 360 is disposed on the black matrix 320 between the blue pixel and the red pixel, and is positioned corresponding to the first and second sensing electrodes 291 and 292 of the lower substrate 200. The conductive spacer 360, in one embodiment, extends from regions corresponding to respective central portions of the first and second sensing electrodes 291 and 292 toward regions corresponding to four edges of each of the first and second sensing electrodes 291 and 292. The conductive spacer 360 extends from the regions corresponding to the respective central portions of the first and second sensing electrodes 291 and 292 toward the center of each of the four edges of the first and second sensing electrodes 291 and 292, whereby the conductive spacer 360 has the maximum width. Therefore, a width of the conductive spacer 360 is small at a region between the first and second sensing electrodes 291 and 292, and gradually increases toward each of the first and second sensing electrodes 291 and 292. Two spacers spaced apart from each other may be disposed such that they respectively correspond to the central portions of the first and second sensing electrodes 291 and 292 and may be connected to each other through a conductive layer. Various shapes of the conductive spacer 360 are exemplarily illustrated in
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In various implementations, if the conductive spacer 360 is designed such that two conductive spacers are spaced apart from each other like the separated first and second sensing electrodes 291 and 292, each may also have the shape of diamond, rectangle and circle, as illustrated in
In a sectional view of the conductive spacer 360, a portion of the conductive spacer 360 corresponding to one end of the first sensing electrode 291 and another portion corresponding to the other end of the second sensing electrode 292 may have the same height as illustrated in
Consequently, in one embodiment, even if the misalignment occurs between the conductive layer and the first and second sensing electrodes 291 and 292, a sensing failure will not occur because the conductive spacer 360 is shaped such that it extends from regions corresponding to the central portions of the first and second sensing electrodes 291 and 292 toward regions corresponding to outer edges of the first and second sensing electrodes 291 and 292. In other words, even though the conductive spacer 360 is misaligned with the first and second sensing electrodes 291 and 292 to the above, below, left or right side thereof, as illustrated in
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In one embodiment, light is incident through the light transmitting part 380a of the second mask 380 to expose a predetermined region of the photosensitive layer 370. An exposed region 370a may be formed according to a shape of the light transmitting part 380a of the second mask 380 and a distance between the second mask 380 and the photosensitive layer 370. For example, if the distance between the second mask 380 and the photosensitive layer 370 corresponds to a distance that enables light incident through two light transmitting parts 380a to be superimposed, the photosensitive layer 370 disposed in a region between the two light transmitting parts 380a is also exposed. This results in formation of a conductive spacer having shapes such as the ones shown in
In a case where the light transmitting part 380a is formed in the shape of a diamond, the exposed region 370a may be formed in diamond shape such that it is rather narrow at a region corresponding to the central portions of the two light transmitting parts 380a, gradually increases toward both sides thereof, and then gradually decreases again. In another embodiment, the exposed region 370a may be formed in the shape of a rectangle such that it extends from one side of the photosensitive layer 370 to the other side. In yet another embodiment, the exposed region 370a may be formed in the shape of a circle such that its width is small at a region corresponding to the central portions of the two light transmitting parts 380a and gradually increases toward both sides thereof.
On the other hand, if the distance between the second mask 380 and the photosensitive layer 370 corresponds to a distance that does not enable the light incident through the two light transmitting parts 380a to be superimposed, the photosensitive layer 370 between the two light transmitting parts 380a is not exposed. This method results in formation of conductive spacers having shapes such as the ones shown in
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In the various embodiments of the present disclosure, although the photosensitive layer 370 is formed on the insulating layer 360a which is not photosensitive, the insulating layer 360a itself may be photosensitive. In this case, an exposure process may be performed on the insulating layer 360a without the formation of the photosensitive layer 370. Further, the various embodiments presented herein illustrate that the color filter 330 is formed after the protrusion 360a is formed, but the present disclosure is not limited thereto. That is, the protrusion 360b may be formed after the color filter is formed first.
Although the foregoing embodiments illustrate that the cell gap spacer 350 is formed on the upper substrate 300, the cell gap spacer 350 may be formed on the lower substrate 200. Moreover, the embodiments illustrate that the sensing electrode is divided into the first and second sensing electrodes 291 and 292 which are spaced apart from each other, but the sensing electrode may be a single electrode that is not divided or separated. Furthermore, the first and second sensing electrodes 291 and 292 have a shape of rectangle but they may also be shaped so that they contact each other. For example, portions of the first and second sensing electrodes 291 and 292 may protrude from an upper region and a lower region thereof, respectively, and the protruding portions of the first and second sensing electrodes 291 and 292 may face each other, as illustrated in
In accordance with various embodiments, a contact surface between a conductive spacer and first and second sensing electrodes can be increased by forming the conductive spacer such that it extends from regions corresponding to central portions of the first and second sensing electrodes that are spaced apart from each other. Therefore, it is possible to prevent a sensing failure caused by misalignment between the sensing electrode and the conductive spacer, thus improving touch sensitivity and reliability of a display.
Although the display and the method of manufacturing the same have been described with reference to the specific embodiments, they are not limited thereto. Therefore, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention defined by the appended claims.
Number | Date | Country | Kind |
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10-2007-0099704 | Oct 2007 | KR | national |