KR102316349B1 - Touch panel and touch display device having the same - Google Patents

Abstract

A touch panel according to an embodiment includes a CF substrate, a TFT substrate disposed on the CF substrate and touched by a user, and including sensing electrodes and driving electrodes to sense the touch, and between the CF substrate and the TFT substrate. It may include a liquid crystal layer disposed.
The embodiment has the effect of preventing the touch signal from being blocked by the ITO of the CF substrate by disposing the TFT substrate on the CF substrate.

Description

TOUCH PANEL AND TOUCH DISPLAY DEVICE HAVING THE SAME

The embodiment relates to a touch panel for improving touch sensitivity and a touch display device including the same.

In general, a touch panel is an input device that allows a user to input a user command by directly using a finger or selecting command content displayed on a screen such as an image display through an object. When the touch panel is directly touched by the user's finger or by an object, the touch panel detects the touch point and then drives the liquid crystal display according to the command indicated by the selected icon to display the content.

The touch panel is generally classified into an Add On Touch Panel and an In-Cell Touch Panel based on the arrangement of the touch panels in the liquid crystal display.

A conventional in-cell touch panel implements a touch operation by forming a touch sensor electrode on a thin film transistor (TFT) substrate and touching an upper portion of a color filter (CF) substrate.

However, a common electrode made of, for example, indium tin oxide (ITO) material is formed on the CF substrate, and the touch signal is blocked by the ITO, which causes a problem in that the touch sensitivity is lowered.

In order to solve the above problems, the embodiment aims to provide a touch panel for improving touch sensitivity and a touch display device including the same.

In order to achieve the above object, a touch panel according to an embodiment includes a CF substrate, a TFT substrate disposed on the CF substrate and touched by a user, and including sensing electrodes and driving electrodes to sense the touch, A liquid crystal layer disposed between the CF substrate and the TFT substrate may be included.

In addition, in order to achieve the above object, the touch display device according to the embodiment includes a CF substrate, and a TFT including sensing electrodes and driving electrodes disposed on the CF substrate and touched by a user to sense the touch. It may include a touch panel including a substrate, a liquid crystal layer disposed between the CF substrate and the TFT substrate, and a backlight unit disposed under the touch panel.

The embodiment has the effect of preventing the touch signal from being blocked by the ITO of the CF substrate by disposing the TFT substrate on the CF substrate.

1 is a cross-sectional view illustrating a display device according to an embodiment.
2 is a plan view showing an array of TFT substrates according to an embodiment.
3 to 5 are graphs illustrating a driving operation of the touch panel according to the embodiment.
6 is a cross-sectional view illustrating an operation of a touch panel of a touch panel according to an embodiment.

Hereinafter, the embodiment will be described in detail with reference to the drawings.

1 is a cross-sectional view showing a display device according to an embodiment, FIG. 2 is a plan view showing an array of a TFT substrate according to an embodiment, and FIGS. 3 to 5 are graphs showing a driving operation of a touch panel according to an embodiment, 6 is a cross-sectional view illustrating an operation of a touch panel of a touch panel according to an embodiment.

1 and 2 , the touch display apparatus according to the embodiment may include a touch panel 1000 and a backlight unit 2000 that provides light to the touch panel 1000 .

The touch panel 1000 includes a CF substrate 100 , a TFT substrate 200 disposed on the CF substrate 100 and including touch electrodes and driving electrodes, and the CF substrate 100 and the TFT substrate 200 . ) may include a liquid crystal layer 300 disposed between. Here, a column spacer 310 for confining the liquid crystal layer 300 may be disposed at an edge between the CF substrate 100 and the TFT substrate 200 . Although not shown, a polarizing plate may be further disposed on one surface of the CF substrate and the TFT substrate, respectively.

The CF substrate 100 includes a first glass substrate 110, a color filter 120 on the first glass substrate 100, an overcoat layer 130 covering the color filter 120, and the overcoat layer ( The first common electrode 140 disposed on the 130 may be included. The color filter 140 may include red, green, and blue. The color filter 140 may further include white.

The TFT substrate 200 may be disposed on the CF substrate 100 . The TFT substrate 200 may include driving electrodes 240 and sensing electrodes 220 . To this end, in the TFT substrate 200, a matrix-type TFT is formed, and a source electrode and a gate electrode of the TFTs are respectively connected to a data line and a gate line, and a pixel electrode is connected to a drain terminal.

A user may perform a touch on the upper portion of the TFT substrate 200 using a finger or an object. To this end, the sensing electrodes 220 and the driving electrodes 240 may be disposed to cross each other.

The sensing electrodes 220 may be disposed along the edge of one sub-pixel area P on a plane. The sensing electrodes 220 may be formed by being divided into a plurality of sections along the direction of the data line, and the sensing electrodes 220 may not be connected to each other on the boundary surface of each section. The sensing electrodes 220 may be formed in three sections.

The sensing electrodes 220 may be directly connected in the direction of the gate line GL within each section. That is, the sensing electrodes 220 disposed in the adjacent sub-pixel region P may be formed to be connected to each other in the same layer.

The sensing electrodes 220 may be bridge-connected to the sensing electrodes 220 adjacent in the direction of the data line DL. The sensing electrodes 220 may be partially bridge-connected to the adjacent sensing electrodes 220 disposed along the data line DL. The sensing electrodes 220 may be bridge-connected in the same layer as the sensing electrodes 220 adjacent in the direction of the data line DL. Since the sensing electrodes 220 are directly connected along the gate line GL direction, only some of the sensing electrodes 220 disposed along the data line DL direction may be bridge-connected. The sensing electrodes 220 block the non-opening area of the backlight unit 2000 to prevent light leakage.

In more detail, the TFT substrate 200 may include a second glass substrate 210 and a first electrode 220 formed under the second glass substrate 210 . The first electrode 220 may be formed of an ITO material that is a transparent conductor. The first electrode 220 may be a sensing electrode. Accordingly, the first electrode 220 will be given the same reference numerals as the above-described sensing electrodes.

A first passivation layer 230 may be disposed under the first electrode 220 . The first passivation layer 230 may be formed of an insulating material. A second electrode layer 240 may be disposed under the first passivation layer 230 . The second electrode 240 may be a gate electrode. The second electrode 240 may be a driving electrode. Accordingly, the second electrode 240 will be given the same reference numerals as the driving electrode described above.

An insulating layer 250 may be disposed under the second electrode 240 to cover the second electrode 240 . A source electrode 260 and a drain electrode 270 may be spaced apart from each other under the insulating layer 250 . An active layer ACT may be disposed on the source electrode 260 and the drain electrode 270 to partially overlap the source electrode 260 and the drain electrode 270 . A second passivation layer 280 may be disposed under the source electrode 260 and the drain electrode 270 . The second passivation layer 280 may be disposed to cover the source electrode 260 and the drain electrode 270 . The second passivation layer 280 may be formed of an insulating material. A pixel electrode 290 may be formed under the second passivation layer 280 . The pixel electrode 290 may be electrically connected to the drain electrode 280 through a hole formed in the second passivation layer 280 .

In the above description, the first electrode 220 is used as a sensing electrode and the second electrode 240 is used as a driving electrode, but the present invention is not limited thereto. ) can be used as a sensing electrode.

As shown in FIG. 3 , the touch display device may include a display period D and a sensing period T. The display period D and the sensing period T may be time-divided and driven within one frame. For example, the display period D and the sensing period T may be driven once within one frame.

In the display period D, the first electrode 220 may be used as a common electrode, and the second electrode 240 may be used as a gate electrode. In the sensing period T, the first electrode 220 may be used as a sensing electrode, and the second electrode 240 may be used as a driving electrode. Alternatively, in the sensing section T, the second electrode 240 may be used as a sensing electrode, and the first electrode 220 may be used as a driving electrode.

As shown in FIG. 4 , the touch display device may include a display period D and a sensing period T. The display period D and the sensing period T may be time-divided and driven within one frame. For example, the display period D and the sensing period T may be driven twice within one frame. The display period D and the sensing period T may be driven as a pair, and then the display period D and the sensing period T may be driven as a pair.

In the display period D, the first electrode 220 may be used as a common electrode, and the second electrode 240 may be used as a gate electrode. In the sensing period T, the first electrode 220 may be used as a sensing electrode, and the second electrode 240 may be used as a driving electrode. Alternatively, in the sensing section T, the second electrode 240 may be used as a sensing electrode, and the first electrode 220 may be used as a driving electrode.

As shown in FIG. 5 , the touch display device may include a display period D and a sensing period T. As shown in FIG. The display period D and the sensing period T may be time-divided and driven within one frame. For example, the display period D and the sensing period T may be driven twice or more, for example, N times within one frame.

In the display period D, the first electrode 220 may be used as a common electrode, and the second electrode 240 may be used as a gate electrode. In the sensing period T, the first electrode 220 may be used as a sensing electrode, and the second electrode 240 may be used as a driving electrode. Alternatively, in the sensing section T, the second electrode 240 may be used as a sensing electrode, and the first electrode 220 may be used as a driving electrode.

3 to 5 , the display period D and the sensing period T may be time-divided and driven by various methods. Of course, it is not limited to the features shown in FIGS. 3 to 5 , and the display section and the sensing section can be time-divided and driven in various ways.

As shown in FIG. 6 , when the upper portion of the TFT substrate 200 is pressed by the user, capacitance is generated between the driving electrode 240 and the sensing electrode 220 of the TFT substrate 200, and the touch is sensed. area can be detected.

As described above, the touch panel according to the embodiment has the effect of preventing the touch signal from being blocked by the ITO of the CF substrate by disposing the TFT substrate on the CF substrate.

1 , the backlight unit 2000 may be disposed under the touch panel 1000 . The backlight unit 2000 is disposed under the touch panel and serves to provide light to the touch panel. Although not shown, the backlight unit 2000 may include a light source, a light guide plate disposed on one side of the light source, optical sheets disposed on the light guide plate, and a reflective sheet disposed under the light guide plate. have.

The light source serves to generate light, and may include an LED device. The LED device may be an R, G, or B light emitting diode that emits monochromatic light of R (Red), G (Green), or B (Blue) or a light emitting diode that emits white light, and a side view device may be used. When an LED element emitting monochromatic light is used, the monochromatic light LED elements of R, G, and B are alternately arranged at regular intervals and the monochromatic light emitted therefrom is mixed into white light and then supplied to the touch panel 1000 . On the other hand, when an LED element emitting white light is used, a plurality of LED elements may be arranged at regular intervals to supply white light to the touch panel 1000 . The white light LED element consists of a blue LED element emitting blue light and a phosphor that absorbs blue monochromatic light and emits yellow light. (1000) can be supplied.

The light guide plate (LGP) serves to guide the light emitted from the light source to the touch panel 1000 . The light incident on one side of the light guide plate is repeatedly refracted and reflected by the diffusion agent added to the inside of the light guide plate, proceeds to the other side, and then is emitted to the upper portion of the light guide plate. Such a light guide plate serves to change light having an optical distribution in the form of a point light source or a linear light source into light having an optical distribution in the form of a surface light source.

The optical sheet is disposed on the light guide plate to improve the efficiency of light emitted from the light guide plate and to supply the light to the touch panel 1000 . The optical sheet may include a diffusion sheet for diffusing the light emitted from the light guide plate, and a plurality of prism sheets to collect the light diffused by the diffusion sheet to supply uniform light to the entire area of the touch panel 1000 .

The diffusion sheet is generally provided with one sheet, but the prism sheet may include a first prism sheet and a second prism sheet in which the prisms are perpendicular to the x and y axis directions. The first prism sheet and the second prism sheet may refract light in the x and y-axis directions to improve straightness of the light.

The reflective sheet is disposed under the light guide plate, and serves to reflect light emitted downward from the light guide plate toward the touch panel 1000 . Such a reflective sheet may adjust the amount of reflection of the entire incident light so that the entire light emitting surface has a uniform luminance distribution. As the reflective sheet, an Enhanced Specular Reflector (ESR) film having a very high reflectance may be used. The ESR film is a silver or white film having 98% reflectance and 2% transmittance, and most of the light incident on the reflective sheet is reflected toward the touch panel 1000 .

Although the above has been described with reference to the drawings and embodiments, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit of the present invention described in the claims below You will understand.

100: CF substrate 200: TFT substrate
210: second glass substrate 220: first electrode
230: first passivation layer 240: second electrode
280: second passivation layer 290: pixel electrode
300: liquid crystal layer 2000: backlight unit

Claims (11)

CF substrate;
a TFT substrate disposed on the CF substrate and touched by a user, the TFT substrate including sensing electrodes and driving electrodes to sense the touch; and
a liquid crystal layer disposed between the CF substrate and the TFT substrate;
The sensing electrodes are disposed along the edge of one sub-pixel area on a plane. The method of claim 1,
The TFT substrate includes a first substrate, a first electrode spaced apart from the first substrate, a first passivation layer disposed under the first electrode, and disposed under the first passivation layer a second electrode; layer, a second passivation layer disposed under the source and drain electrodes, and a pixel electrode disposed under the second passivation layer and electrically connected to the drain electrode through a hole formed in the second passivation layer. Including touch panel. 3. The method of claim 2,
A touch panel in which the first electrode functions as a common electrode and the second electrode functions as a gate electrode during a display period. 4. The method of claim 3,
During the sensing period, when the first electrode is used as a sensing electrode, the second electrode is used as a driving electrode, and when the first electrode is used as a driving electrode, the second electrode is used as a sensing electrode. 5. The method of claim 4,
The display section and the sensing section are a touch panel for performing time division driving within one frame. 5. The method according to any one of claims 2 to 4,
The first electrode is a touch panel formed by dividing a predetermined section along a gate line direction. 7. The method of claim 6,
The first electrode is a touch panel that is bridge-connected in the same layer as the first electrode adjacent in the direction of the data line. A CF substrate, a TFT substrate disposed on the CF substrate and touched by a user, the TFT substrate including sensing electrodes and driving electrodes to sense the touch, and a liquid crystal layer disposed between the CF substrate and the TFT substrate touch panel; and
Including; a backlight unit disposed under the touch panel;
The sensing electrodes are disposed along an edge of one sub-pixel area on a plane. 9. The method of claim 8,
The TFT substrate includes a first substrate, a first electrode spaced apart from the first substrate, a first passivation layer disposed under the first electrode, and disposed under the first passivation layer a second electrode; layer, a second passivation layer disposed under the source and drain electrodes, and a pixel electrode disposed under the second passivation layer and electrically connected to the drain electrode through a hole formed in the second passivation layer. A touch display device comprising a. 10. The method of claim 9,
During the sensing period, the first electrode is a sensing electrode and the second electrode is a driving electrode, or the first electrode is a driving electrode and the second electrode is a sensing electrode. 11. The method of claim 9 or 10,
The first electrode is a touch display device that is bridge-connected in the same layer as an adjacent first electrode along the direction of the data line.

Images