KR20200002116A - Display device, driving device and control method thereof - Google Patents

Abstract

Provided is a display device. The display device according to an embodiment of the present invention comprises: a pixel electrode layer on which a pixel electrode is disposed; a liquid crystal layer in which liquid crystal is disposed; a common electrode layer disposed to face the pixel electrode layer while interposing the liquid crystal layer therebetween and including a plurality of divided common electrodes; a backlight unit projecting light onto the liquid crystal layer; and a black mattress layer in which a plurality of black mattresses are disposed to block the light from being output to the outside, wherein the black mattress is made of a conductive material and is connected to the common electrode, and a touch driving signal for driving the common electrode by a touch sensor is supplied to the black mattress.

Description

Display device, driving device and control method thereof {DISPLAY DEVICE, DRIVING DEVICE AND CONTROL METHOD THEREOF}

The present embodiment relates to a display device, a drive device for driving one configuration of the display device, and a control method thereof.

The technology of recognizing an object approaching or touching the touch panel is called a touch sensing technology.

The touch panel is positioned at the same position as the display panel on a plane, so that users can input a user manipulation signal to the touch panel while viewing an image of the display panel.

This method of generating a user manipulation signal provides surprising user intuition compared to other user manipulation signal input methods, for example, a mouse input method or a keyboard input method.

Accordingly, touch sensing technology is applied to various electronic devices including display panels.

On the other hand, when the display panel is implemented in an in-plane switching (IPS) method, since the common electrode is adjacent to the TFT (thin film transistor) layer, the common electrode is used as an electrode for realizing a common voltage and an electrode for a touch sensor. It is easy to apply in-cell touch technology. However, when the display panel is implemented in a VA (vertically aligned) method, the in-cell touch technology is not applied because the arrangement of the lines for applying the touch driving signal to the common electrode is not easy.

In this background, it is an object of the present embodiment to provide a technique for enabling in-cell touch in a display panel implemented in a VA method.

In order to achieve the above object, an embodiment includes a pixel electrode layer on which a pixel electrode is disposed; A liquid crystal layer in which liquid crystal is disposed; A common electrode layer disposed to face the pixel electrode layer with the liquid crystal layer interposed therebetween, and including a plurality of divided common electrodes; A backlight unit projecting light onto the liquid crystal layer; And a black mattress layer on which a plurality of black mattresses are arranged to block output of the light to the outside, wherein the black mattress is made of a conductive material, is connected to the common electrode, and drives the common electrode with a touch sensor. A touch driving signal is provided to the black mattress.

In the display device, a common voltage may be supplied to the black mattress in a first time period, and the touch driving signal may be supplied to the black mattress in a second time period.

In the display device, a color filter may be disposed around the black mattress in the black mattress layer.

In the display device, part or all of the pixel electrode may overlap the common electrode when viewed in the direction in which the light is projected.

In the display device, part or all of the black mattress may overlap the common electrode when viewed in the direction in which the light is projected.

In the display device, each pixel may include a plurality of subpixels, and the common electrode may be divided into units of N pixels (N is a natural number).

In the display device, a via hole is formed in the black mattress layer, and the black mattress and the common electrode are connected through the via hole.

In the display device, a plurality of the black mattresses disposed in a first direction are electrically connected, and two black mattresses adjacent to each other in a second direction, the second direction is perpendicular to the first direction, are electrically separated from each other. Can be.

In the display device, the common electrode may have a length in the second direction longer than a length in the first direction.

Another embodiment includes a pixel electrode layer on which a pixel electrode is disposed; A liquid crystal layer in which liquid crystal is disposed; A common electrode layer disposed to face the pixel electrode layer with the liquid crystal layer interposed therebetween and including a plurality of divided common electrodes; A backlight unit projecting light onto the liquid crystal layer; A black mattress layer on which a plurality of black mattresses are arranged to block the light from being output to the outside; And a common electrode line layer having a plurality of common electrode lines formed above or below the black mattress with respect to the projection direction of the light, wherein the common electrode line is connected to the common electrode and is connected to the common electrode. Provided is a display device in which a touch driving signal for driving a touch sensor to a touch sensor is supplied to the common electrode line.

In the display device, part or all of the common electrode line may overlap the black mattress when viewed in the direction in which the light is projected.

In the display device, the common electrode line may be made of a non-transparent or semi-transmissive material.

In the display device, a capacitance reduction signal whose phase is synchronized with the touch driving signal is supplied to another common electrode adjacent to the common electrode in a time period during which the touch driving signal is supplied to one common electrode. At least one of the gate line and the data line to be connected may be a predetermined constant voltage or the at least one line may be floated.

As described above, according to the present exemplary embodiment, in-cell touch is enabled in the display panel implemented in the VA method.

1 is a view schematically illustrating a display device according to the present disclosure.
2 is a configuration diagram of a liquid crystal panel of a general IPS method.
3 is a configuration diagram of a liquid crystal panel of a general VA method.
4 is a view for explaining the configuration of a liquid crystal panel of the VA method according to an embodiment.
FIG. 5 is a diagram illustrating a connection relationship between a common electrode and a black mattress in a general liquid crystal panel of a VA system.
6 is a view showing that the black mattress is made of a conductive material in the liquid crystal panel of the VA method according to an embodiment.
7 is a view illustrating a common electrode line formed separately from a black mattress in a VA type liquid crystal panel according to an exemplary embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

1 is a view schematically illustrating a display device according to the present disclosure.

Referring to FIG. 1, the display device 100 may include a panel 110, a data driver circuit 120, a gate driver circuit 130, a touch driver circuit 140, and the like.

In the panel 110, a plurality of data lines DL connected to the data driver circuit 120 may be formed, and a plurality of gate lines GL connected to the gate driver circuit 130 may be formed. In addition, a plurality of pixels P corresponding to intersection points of the plurality of data lines DL and the plurality of gate lines GL may be defined in the panel 110.

In each of the pixels P, a first electrode (for example, a source electrode or a drain electrode) is connected to the data line DL, a gate electrode is connected to the gate line GL, and a second electrode (for example, A transistor may be formed in which the drain electrode or the source electrode is connected to the pixel electrode.

In addition, the panel 110 may further include a plurality of common electrodes VE spaced apart from each other. One pixel P may be located or a plurality of pixels P may be located in an area where the common electrode VE is located. Alternatively, a plurality of common electrodes VE may be located in an area where the pixel P is located.

The panel 110 may include a display panel and a touch screen panel (TSP), where the display panel and the touch panel may share some components. For example, the plurality of common electrodes VE may receive a common voltage in one configuration of the display panel and simultaneously function as a touch sensor as one configuration of the touch panel. Although some components of the display panel and the touch panel are shared with each other, the panel 110 may be referred to as an integrated panel or an in-cell type panel, but the present invention is not limited thereto.

The data driver circuit 120 supplies a data signal to the data line DL to display the digital image on each pixel P of the panel 110.

The data driver circuit 120 may include at least one data driver integrated circuit. The at least one data driver integrated circuit may include a tape automated bonding (TAB) method or a chip on glass (COG). A chip on glass method may be connected to the bonding pad of the panel 110, or may be directly formed on the panel 110, and in some cases, may be integrated and formed on the panel 110. In addition, the data driving circuit 120 may be implemented by a chip on film (COF) method.

The gate driver circuit 130 sequentially supplies scan signals to the gate lines GL to turn on or off transistors positioned in each pixel P. FIG.

The gate driving circuit 130 may be located on only one side of the panel 110 as shown in FIG. 1, or may be divided into two and located on both sides of the panel 110, depending on the driving method.

In addition, the gate driver circuit 130 may include at least one gate driver integrated circuit. The at least one gate driver integrated circuit may be a tape automated bonding (TAB) method or a chip on glass (COG) method. The panel 110 may be connected to a bonding pad of the panel 110 or may be implemented as a GIP (Gate In Panel) type to be formed directly on the panel 110. In some cases, the panel 110 may be integrated with the panel 110. In addition, the gate driving circuit 130 may be implemented by a chip on film (COF) method.

The touch driver circuit 140 applies a touch driver signal to all or part of the plurality of common electrodes VE connected to the touch driver line TL.

As shown in FIG. 1, the touch driver circuit 140 has a configuration different from that of the data driver circuit 120 and the gate driver circuit 130, and is external to the data driver circuit 120 and the gate driver circuit 130. In some embodiments, depending on the implementation method, the data driver circuit 120 may be implemented as an internal configuration of another driver integrated circuit including at least one of the data driver circuit 120 and the gate driver circuit 130, or 120 or the internal structure of the gate driving circuit 130 may be implemented.

Therefore, the touch driver circuit 140 applies the touch driver signal to all or a part of the plurality of common electrodes VE, so that a separate driver integrated circuit including the touch driver circuit 140 includes the plurality of common electrodes VE. It can also be seen that the touch driving signal is applied to all or part of. In addition, according to the design method, the data driving circuit 120 or the gate driving circuit 130 including the touch driving circuit 140 applies the touch driving signal to all or part of the plurality of common electrodes VE. You can see.

The touch driver circuit 140 is not limited to the implementation and the design manner, and if only the same or similar to the performing function described herein, it may be another configuration itself or may be a configuration located inside or outside the other configuration. have.

In addition, although one touch driver circuit 140 is positioned in the display device 100 in FIG. 1, the display device 100 may include two or more touch driver circuits 140.

Meanwhile, in order for the touch driver circuit 140 to apply the touch driver signal to all or part of the plurality of common electrodes VE, the touch driver line TL connected to each of the plurality of common electrodes VE is required. Accordingly, the touch driving line TL connected to each of the plurality of common electrodes VE and transmitting the touch driving signal is connected to the panel 110 in the first direction (eg, vertical direction) or second direction (eg, horizontal direction). ) May be formed.

Meanwhile, the display device 100 may employ a capacitive touch method that detects proximity or touch of an object by sensing a change in capacitance through the common electrode VE.

For example, the capacitive touch method may be divided into a mutual capacitive touch method and a self-capacitive touch method.

The mutual capacitive touch method, which is a kind of capacitive touch method, applies a touch driving signal to one touch sensor (Tx electrode) and senses another touch sensor (Rx electrode) coupled to the Tx electrode. In the mutual capacitive touch method, the value sensed by the Rx electrode is changed according to the proximity or touch of an object such as a finger or a pen. And the like.

The self-capacitive touch method, which is another type of the capacitive touch method, senses the corresponding touch sensor again after applying the touch driving signal to the one touch sensor. In the self-capacitive touch method, a value sensed by the corresponding touch sensor is changed according to the proximity or touch of an object such as a finger or a pen. Detect. In the self-capacitive touch method, since the touch sensor applying the touch driving signal is the same as the touch sensor sensing, there is no distinction between the Tx electrode and the Rx electrode.

The display device 100 may employ one of the two capacitive touch methods described above (mutual capacitive touch method and self capacitance touch method). However, in the present specification, for convenience of description, the embodiment will be described assuming that a self-capacitive touch method is adopted.

The panel 110 may be a vertical alignment (VA) type liquid crystal panel. In the VA type liquid crystal panel, since the common electrode VE is located on the opposite side of the TFT (thin film transistor) layer with respect to the liquid crystal layer, the touch driving line TL connected to the common electrode VE is properly disposed. Can be problematic.

2 is a configuration diagram of a liquid crystal panel of a general IPS method.

Referring to FIG. 2, a substrate, a TFT layer, a common electrode layer, and a pixel electrode layer are sequentially disposed below the liquid crystal layer in the IPS (in-plane switching) liquid crystal panel, and the color filter layer and the cover are disposed on the liquid crystal layer. Glass may be disposed.

In the IPS type liquid crystal panel, a plurality of divided common electrodes may be disposed on the common electrode layer, and a touch driving line for supplying a touch driving signal to the common electrode may be disposed on the TFT layer.

3 is a configuration diagram of a liquid crystal panel of a general VA method.

Referring to FIG. 3, a substrate, a TFT layer, and a pixel electrode layer may be sequentially disposed on a lower side of the liquid crystal layer in a VA type liquid crystal panel, and a common electrode layer, a color filter layer, and a cover layer may be disposed above the liquid crystal layer. .

In the VA type liquid crystal panel, since the common electrode is disposed above the liquid crystal side, it is difficult to arrange the touch driving line to be connected to the common electrode.

4 is a view for explaining the configuration of a liquid crystal panel of the VA method according to an embodiment.

The left side of FIG. 4 is a block diagram of a liquid crystal panel of a general VA method, and the right side of FIG. 4 is a block diagram of a liquid crystal panel of a VA method according to an embodiment.

Referring to the right side of FIG. 4, the VA type liquid crystal panel according to the embodiment may include a backlight unit, a TFT layer, a pixel electrode layer, a liquid crystal layer, a common electrode layer, and a black mattress layer.

The pixel electrode may be disposed in the pixel electrode layer. The liquid crystal may be disposed in the liquid crystal layer.

The common electrode layer may be disposed to face the pixel electrode layer with the liquid crystal layer interposed therebetween. The common electrode layer may include a plurality of divided common electrodes.

The backlight unit may project light into the liquid crystal layer. The black mattress layer may include a plurality of black mattresses that block light from being output to the outside.

The common electrode disposed on the upper substrate may be divided into a plurality, and the touch driving line may be disposed by using a space of the black mattress. Each common electrode may be connected to the touch driving circuit through the touch driving line.

The black mattress and the common electrode may be spaced apart from each other. The black mattress and the common electrode or the touch driving line and the common electrode may be electrically connected through via holes formed in the black mattress layer.

FIG. 5 is a diagram illustrating a connection relationship between a common electrode and a black mattress in a general liquid crystal panel of a VA system.

Referring to FIG. 5, the black mattresses arranged in the first direction, for example, the column direction, may be electrically connected to each other. In addition, the black mattresses electrically connected in the first direction may be connected to the touch driving circuit through the MUX.

Black mattresses disposed adjacent to each other in a second direction, for example, in a row direction, may be electrically separated from each other.

In general, the black mattress is disposed to surround the edge of the pixel or subpixel, and the black mattress may be separated from each other in the pixels adjacent in the second direction.

When the black mattresses electrically connected in the first direction are referred to as black mattress connection groups, one black mattress connection group may be electrically connected to one common electrode.

The common electrode has a length in the second direction longer than the length in the first direction and may be disposed across two or more black mattress connection groups in the second direction, wherein the common electrode is one of two or more black mattress connection groups. It can be electrically connected via a black mattress connection group and via hole.

6 is a view showing that the black mattress is made of a conductive material in the liquid crystal panel of the VA method according to an embodiment.

6, the black mattress may be electrically connected to the common electrode through a via hole formed of a conductive material and formed in the black mattress layer.

7 is a view illustrating a common electrode line formed separately from a black mattress in a VA type liquid crystal panel according to an exemplary embodiment.

Referring to FIG. 7, a common electrode line made of a conductive material may be formed above or below the black mattress. The common electrode line may be electrically connected to the common electrode, and a touch driving signal for driving the common electrode with the touch sensor may be supplied to the common electrode line.

Some or all of the common electrode lines may overlap the black mattress in the direction in which the light is projected.

The common electrode line may be made of a conductive material and may also be made of a non-transmissive or semi-permeable material.

On the other hand, when the common electrode is used as a touch sensor in the VA type liquid crystal panel, some advantages may occur in driving than the IPS type liquid crystal panel.

First, in the case of the VA method, since the common electrode is disposed above the liquid crystal layer, capacitance formed by an object close to the surface, for example, a finger and the common electrode, may be larger than that of the IPS method. As the capacitance between the object and the common electrode-the touch sensor-increases, the sensitivity of the touch increases. When the capacitance is increased, the same touch performance can be obtained with a shorter driving time when the same driving voltage is used, and the same touch performance can be obtained by using a lower driving voltage when the same driving time is used. .

The touch driver circuit can operate in the IPS mode and the VA mode, the drive voltage in the VA mode can be controlled to be lower than the drive voltage in the IPS mode, and the drive time in the VA mode-the time for which the touch drive signal is supplied. It can be controlled shorter than the driving time of the IPS mode.

On the other hand, in the case of the VA method, since the common electrode is disposed above the liquid crystal layer, the capacitance between the common electrode and the display electrode may be smaller than that of the IPS method. Such capacitance reduces the sensitivity of the touch while operating as a parasitic component. In the case of the VA method, the sensitivity of the touch may be increased by decreasing the capacitance.

The touch driver circuit can drive to reduce this capacitance. For example, the touch driver circuit can supply the touch driving signal to the common electrode to be sensed, and can supply the auxiliary signal having the same phase as the touch driving signal to the surrounding common electrode.

The touch driver circuit may supply an auxiliary signal having the same phase as the touch driver signal to the display electrode (eg, data line, gate line, etc.) in the IPS method. On the other hand, in the VA method, the touch driving circuit may float the display electrode or supply a constant voltage (eg, a ground voltage) to the display electrode at a time period during which the touch driving signal is supplied. In the VA method, since the capacitance between the common electrode and the display electrode is small, the auxiliary signal may not be supplied to the display electrode.

As described above, according to the present exemplary embodiment, in-cell touch is enabled in the display panel implemented in the VA method.

The terms "comprise", "comprise" or "having" described above mean that a corresponding component may be included unless specifically stated otherwise, and thus does not exclude other components. It should be construed that it may further include other components. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (13)

A pixel electrode layer on which the pixel electrode is disposed;
A liquid crystal layer in which liquid crystal is disposed;
A common electrode layer disposed to face the pixel electrode layer with the liquid crystal layer interposed therebetween, and including a plurality of divided common electrodes;
A backlight unit projecting light onto the liquid crystal layer; And
A black mattress layer on which a plurality of black mattresses are arranged to block the light from being output to the outside;
The black mattress is made of a conductive material and connected to the common electrode,
And a touch driving signal for driving the common electrode with the touch sensor to the black mattress. The method of claim 1,
The common voltage is supplied to the black mattress in the first time period,
And a touch driving signal supplied to the black mattress in a second time period. The method of claim 1,
And a color filter arranged around the black mattress in the black mattress layer. The method of claim 1,
When viewed in the direction in which the light is projected,
Part or all of the pixel electrode overlaps the common electrode. The method of claim 1,
When viewed in the direction in which the light is projected,
Part or all of the black mattress overlaps the common electrode. The method of claim 1,
Each pixel is composed of a plurality of subpixels,
The common electrode is divided into units of N pixels (where N is a natural number). The method of claim 1,
A via hole is formed in the black mattress layer, and the black mattress and the common electrode are connected through the via hole. The method of claim 1,
A plurality of the black mattresses arranged in a first direction are electrically connected,
2. The display device of claim 2, wherein the two black matrices adjacent to each other in a second direction, the second direction is perpendicular to the first direction, are electrically separated from each other. The method of claim 8,
The common electrode is formed such that the length of the second direction is longer than the length of the first direction. A pixel electrode layer on which the pixel electrode is disposed;
A liquid crystal layer in which liquid crystal is disposed;
A common electrode layer disposed to face the pixel electrode layer with the liquid crystal layer interposed therebetween, and including a plurality of divided common electrodes;
A backlight unit projecting light onto the liquid crystal layer;
A black mattress layer on which a plurality of black mattresses are arranged to block the light from being output to the outside; And
A common electrode line layer on which a plurality of common electrode lines formed on an upper side or a lower side of the black mattress are arranged based on the projection direction of the light;
The common electrode line is connected to the common electrode,
And a touch driving signal for driving the common electrode with the touch sensor to the common electrode line. The method of claim 10,
When viewed in the direction in which the light is projected,
Part or all of the common electrode line overlaps the black mattress. The method of claim 10,
The common electrode line is formed of a non-transmissive or semi-transparent material. The method of claim 10,
In the time period when the touch driving signal is supplied to one common electrode,
A capacitance reduction signal whose phase is synchronized with the touch driving signal is supplied to another common electrode adjacent to the one common electrode,
And at least one of the gate line and the data line connected to each pixel is a predetermined constant voltage or the at least one line is floated.

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