KR20110087153A - Capacitance touch screen and operation method thereof - Google Patents

Abstract

PURPOSE: An electrostatic capacity touch screen and driving method thereof are provided to recognize the size of the power by the touch and touch location. CONSTITUTION: A substrate locates in the lower part of an electrostatic capacity touch screen. A flexible layer(26) is transformed into the direction of force. A lower electrode(34) is installed in the upper part of the substrate. An upper electrode is installed in the lower part of the flexible layer.

Description

Capacitive touch screen and its driving method {CAPACITANCE TOUCH SCREEN AND OPERATION METHOD THEREOF}

The present invention relates to a capacitive touch control display panel. In particular, the present invention relates to a capacitive touch screen and a driving method thereof for detecting a touch by a conductor or a non-conductor through a capacitive method.

The present invention is derived from the research conducted as part of the core technology development project of the customized IT package for the Ministry of Knowledge Economy. [Task management number: 2009-S-001-01, Title: Development of next generation input device technology for information appliances] .

In general, a display product has at least one configuration for receiving a user's command. Examples of the configuration include a button, a remote controller, a touch pad, and a touch screen.

Among these, the touch screen (or touch pad) is mainly used for PDA (Personal Digital Assistant) products (e.g., smartphones, PDA phones, etc.), Palm-Size PCs, ATMs (Automated Teller Machine) devices, etc. have.

The touch screen (or touch pad) displays characters or icons on the screen, and allows a user to touch a character or an icon with a finger or a styler (or a touch pen) to input or manipulate a desired function.

Such touch screens (touch pads) are typically resistive, electro-magnetic, and capacitive.

An example of a capacitive type is described in US Pat. No. 5,942,733. The capacitive method described in US Pat. No. 5,942,733 will be described with reference to FIG. 1 is an exemplary view illustrating a structure of a touch pad to which a capacitive method according to the related art is applied.

As shown in FIG. 1, the conventional capacitance method has three electrodes, namely, an electrode ground plane 24, an upper electrode 18, and a lower electrode 34 orthogonal to the upper electrode 18. The electrode ground surface 24 is positioned directly below the upper flexible layer 26 and deforms toward the upper electrode 18 and the lower electrode 34 as the stylus 28 is pressed (ie, touched).

Thus, the conventional capacitive method has a capacitance between the electrode ground surface 24 and the upper electrode 18 and a capacitance between the ground surface 24 and the lower electrode 14 generated when the finger or the stylus 28 is pressed down. The change in capacitance is measured to recognize the X-axis (horizontal) position and the Y-axis (vertical) position pressed by the stylus 28.

However, since the capacitive touch pad structure described in No. 5,942,733 does not use a transparent electrode and a transparent substrate, it cannot be applied as a touch screen for display.

In addition, even if the capacitive touch pad structure described in No. 5,942,733 is applied to a touch screen for display using a transparent electrode, since the transparent electrode film is formed in three or more layers, the overall transmittance of the touch screen is lowered, and the manufacturing cost is reduced. There is a disadvantage that increases.

In addition, although the conventional capacitive method can recognize the position, that is, coordinates by two-dimensionally, it cannot recognize the force or pressure pressed by the user. This is a disadvantage that it is difficult to cope with the case that requires more contact to implement a three-dimensional user interface or to display a variety of menus on the display screen.

US Registration No. 5,942,733

The technical problem to be achieved by the present invention is to provide a capacitive touch screen that lowers the manufacturing cost while increasing the overall transmittance of the touch screen.

Another object of the present invention is to provide a capacitive touch screen capable of simultaneously recognizing the touch position and the magnitude of the force pressed by the touch.

Another object of the present invention is to provide a method of driving a capacitive touch screen which reduces a recognition error of a touch position.

Another object of the present invention is to provide a capacitive touch screen driving method capable of varying a range of location recognition according to a situation.

According to an aspect of the present invention, there is provided a substrate positioned on a lower side, a flexible layer positioned on an upper side, and deformed in a direction of a pressing force, a plurality of lower electrodes installed side by side at regular intervals on an upper surface of the substrate, A plurality of upper electrodes disposed side by side at regular intervals on the lower surface of the flexible layer and intersecting the plurality of lower electrodes, and between the lower electrode and the upper electrode interposed between the substrate and the flexible layer It provides a capacitive touch screen comprising an elastic layer for generating a capacitance.

The capacitive touch screen according to an aspect of the present invention may further include a lower passivation layer for protecting the plurality of lower electrodes and an upper passivation layer for protecting the plurality of upper electrodes.

The elastic layer may include a transparent elastic body positioned between the plurality of upper electrodes and the plurality of lower electrodes to generate a capacitance, and a gap between the transparent flexible layer and the transparent glass substrate, wherein the transparent elastic body is external. It characterized in that it comprises a dam installed at a constant height on the edge of the touch screen so as not to leak. At this time, the transparent elastomer is a gel of a gel-based, the dam is characterized in that the elastic material such as silicone rubber or polyurethane. At this time, the transparent elastomer and the dam is characterized in that the elastic material, such as a gel-based gel (gel), silicone-based rubber or poly uripan.

The flexible layer uses a PET (Polyethylene Terephthalate) film having a hard coating on its top surface.

Each of the plurality of upper electrodes and each of the plurality of lower electrodes has the same width, and the gap between the upper electrode and the lower electrode is 0.5 mm to 0.001 mm, and indium tin oxide (ITO), metallic Single-Walled Carbon NanoTube (SWCNT), or a conductive polymer PEDOT (Poly 3,4-ethylenedioxythiophene) is characterized in that it is made of one material.

The lower passivation layer and the upper passivation layer are transparent films, characterized in that the OCA (Optical Clear Adhesive) tape.

In addition, the present invention according to another aspect to achieve the technical problem is a capacitive touch screen for determining the user's touch position by driving a touch screen in which N first electrodes and M second electrodes are crossed in a matrix form A driving method comprising: (a) forming and selecting neighboring K first electrodes from one of the N first electrodes into one vertical scan group, and (b) while the one vertical scan group is selected, Forming and selecting the neighboring J second electrodes as one horizontal scan group among the M second electrodes, and (c) in the touch cell intersecting the vertical scan group and the horizontal scan group in (b) Collecting a signal corresponding to the generated capacitance value, (d) repeating steps (b) and (c) sequentially so that all of the M second electrodes are selected; Step (e) sequentially repeating steps (a) to (c) such that all of the N first electrodes are selected, and (f) occurring in all touch cells collected by step (e) And determining a touch position by using the capacitive value, wherein (K-1) or less first electrodes are overlapped between neighboring vertical scan groups, and (J−) between neighboring horizontal scan groups. It provides a capacitive touch screen driving method, characterized in that less than one second electrode overlaps.

In step (f), the signals corresponding to the capacitive values collected from all the touch cells are compared with each other to determine the position of the first touch cell having the largest capacitance as the touch position. . At this time, the step (f) is a step of extracting a touch cell having a change in capacitance value from the capacitance values measured from all the touch cells, and comparing the capacitance values of the extracted touch cells the largest capacitance value And identifying the first touch cell.

The capacitive touch screen driving method may further include converting the capacitance value of the first touch cell into a force or a pressure.

Meanwhile, in the above, K and J are greater than 2 and less than or equal to 8, but the K and the J may be the same number or different numbers. Wherein K and J are the same number, the K and the J is 3, the first electrode overlapping between the neighboring vertical scanning group is two, the second overlapping between the neighboring horizontal scanning group It is characterized by two electrodes.

According to an exemplary embodiment of the present invention, the touch screen may be made of a transparent material to increase overall transmittance, and thus, manufacturing cost may be reduced by generating capacitance using two electrodes.

In addition, according to an embodiment of the present invention, it is possible to simultaneously recognize the touch position and the magnitude of the force pressed by the touch.

In addition, according to an embodiment of the present invention, the touch position recognition resolution and the force recognition resolution may be increased to increase the capacitance change while reducing the recognition error of the touch position.

1 is an exemplary view illustrating a structure of a touch pad to which a capacitive method according to the related art is applied.
2 is a structural diagram of a capacitive touch screen according to an embodiment of the present invention.
3 is a plan view illustrating an arrangement of an upper transparent electrode and a lower transparent electrode of a capacitive touch screen according to a first embodiment of the present invention.
4 is a plan view illustrating an arrangement of an upper transparent electrode and a lower transparent electrode of a capacitive touch screen according to a second embodiment of the present invention.
5 is a block diagram illustrating an apparatus for driving a capacitive touch screen according to an exemplary embodiment of the present invention.
6 is a diagram for describing a method of driving a capacitive touch screen according to a first embodiment of the present disclosure with reference to an electrode.
FIG. 7 is a diagram illustrating the number of touch cells for which a capacitance measurement value is obtained according to the capacitive touch screen driving method according to the first embodiment of the present invention.
FIG. 8 is a diagram illustrating the number of touch cells for which a capacitance measurement value is obtained according to the capacitive touch screen driving method according to the second embodiment of the present invention.
9 is a flowchart illustrating a method of driving a capacitive touch screen according to a first embodiment of the present invention.
10 is a timing diagram of a scan control signal for a capacitive touch screen driving method according to a first embodiment of the present invention.
11 is a timing diagram of a scan control signal for a capacitive touch screen driving method according to a second embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Now, a capacitive touch screen and a driving method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.

First, a capacitive touch screen according to an embodiment of the present invention will be described with reference to FIG. 2. 2 is a structural diagram of a capacitive touch screen according to an embodiment of the present invention.

As shown in FIG. 2, in the capacitive touch screen according to the embodiment of the present invention, the transparent glass substrate 17 is positioned on the lower side, and the transparent flexible layer 11 pressed by a finger or a stylus is positioned on the upper side. In this case, the transparent flexible layer 11 is formed of a transparent flexible film so that it is easily deformed by a force applied through a finger, a stylus, or a touch pen. The flexible film may be, for example, a hard coating on the upper surface thereof. PET (Polyethylene Terephthalate) film is used, and the thickness is within 0.125mm to 0.3mm.

A plurality of lower transparent electrodes 16 are disposed on the upper surface of the transparent glass substrate 17 at regular intervals, and a plurality of upper transparent electrodes 12 are disposed on the lower surface of the transparent flexible 11 at regular intervals. The transparent electrode 12 and the plurality of lower transparent electrodes 16 are installed to cross each other perpendicularly.

The width of the upper and lower transparent electrodes 12, 16 is appropriate from 1mm to 5mm, and the gap with neighboring electrodes is maintained within 0.5mm to 0.001mm. Indium tin oxide (ITO), metallic single-walled carbon nanotube (SWCNT), or conductive polymer PEDOT (Poly 3,4-ethylenedioxythiophene) is used as the material of the lower transparent electrode 16 and the upper transparent electrode 12.

A lower transparent protective film 15 for protecting the lower transparent electrode 16 is formed on the upper surface of the lower transparent electrode 16, and an upper transparent protective film for protecting the upper transparent electrode 12 on the lower surface of the upper transparent electrode 12. (13) is formed. In this case, the lower transparent protective layer 15 and the upper transparent protective layer 13 are formed in a transparent film form, and prevent cracking or cracking due to mechanical impact of ITO, and the transparent flexible layer 11 of metallic SWCNT or conductive polymer PEDOT material or In order to improve adhesion to the lower transparent electrode 16 and to protect the electrode, it is preferable to be formed of an optical clear adhesive (OCA) tape.

Since the upper transparent protective layer 13 and the lower transparent protective layer 15 are necessary for improving adhesion and protecting the electrode, they may not be used in some cases.

A constant capacitance is formed between the upper transparent electrode 12 and the lower transparent electrode 16 so that a constant capacitance is formed, and an elastic layer 14 deformed by external pressure is provided. The elastic layer 14 fills between the transparent flexible layer 11 having the plurality of upper transparent electrodes 12 formed of the transparent elastic body 41 and the transparent glass substrate 17 having the plurality of lower transparent electrodes 16 formed therein, and is transparent. The dam 42 is formed at a constant height at the edge of the touch screen so that the elastic body 41 does not leak out.

Specifically, the transparent elastic body 41 is positioned between the plurality of upper transparent electrodes and the plurality of lower transparent electrodes to generate capacitance. At this time, the transparent elastomer 41 has a high transparency and excellent restoring power by using a gel of a silicone-based gel, and improves the softness and the touch feeling.

And the thickness of the transparent elastic body 41 is 0.1 mm to 0.8 mm or less. When the thickness of the transparent elastic body 41 is too thin, it is difficult to maintain the uniformity of the thickness, and when the thickness of the transparent elastic body 41 is large, the distance between the upper transparent electrode 12 and the lower transparent electrode 16 that crosses is increased, thereby decreasing the initial capacitance value. Problems occur in signal processing. In addition, if the thickness of the transparent elastic body 41 is too thick, there is a problem that the mismatch between the display image on the bottom of the touch screen and the touch position of the touch screen becomes large.

The dam 42 has a height within 0.1 mm to 0.8 mm corresponding to the thickness of the transparent elastic body 41 and is formed of an elastic material such as silicone rubber or polyurethane, and the dam 42 located at the edge of the touch screen. Even if the surroundings are pressed, the position and force recognition can be made smooth.

As described above, in the capacitive touch screen according to the exemplary embodiment of the present invention, since each component 11 to 17 is made of a transparent material, the screen displayed on the lower side of the transparent glass substrate 17 can be easily seen by the user.

Meanwhile, in the above-described embodiment, each component (11 to 17, except for the dam) has been described as being made of a transparent material, but the present invention is not limited thereto, and at least one may be made of a translucent or opaque material.

Hereinafter, a brief description of a method of detecting a touch position in a capacitive touch screen according to an embodiment of the present invention configured as described above.

As illustrated in FIG. 2, when the upper surface of the transparent flexible layer 11 is pressed with a stylus (or a finger), the transparent flexible layer 11 is deformed around the contact portion. This deformation causes the at least one upper transparent electrode 12 located at the contact portion to move downward to narrow the distance between the upper transparent electrode 12 and the lower transparent electrode 16.

Therefore, a change in capacitance in which the capacitance becomes large is generated between the upper transparent electrode 12 and the lower transparent electrode 16 positioned at the contact portion.

Therefore, when the touch screen according to the embodiment of the present invention measures the change of the capacitance at the intersection between all of the upper transparent electrode 12 and the lower transparent electrode 16, the touch screen may be placed in contact with the stylus (or a finger, etc.). The capacitance between the above-described upper transparent electrode 12 and the lower transparent electrode 16 has a large capacitance value measured compared to the capacitance at other measured intersection points, so that the point where the large capacitance value is measured is moved to the touch position. Figure out.

In addition, the touch screen according to the embodiment of the present invention can measure only the capacitance change between the two electrodes, that is, the upper transparent electrode 12 and the lower transparent electrode 16 and determine the capacitance value. The degree can be used to determine the force (pressure) pressed by the stylus (or finger).

When the force (pressure) pressed by the stylus (or the finger) can be grasped, the touch screen according to the embodiment of the present invention is a simple touch or a touch for another operation, for example, a click. You will know. For example, when a user uses a mouse touch pad in a notebook computer, when a touch screen according to an exemplary embodiment of the present invention is applied to a mouse touch pad, a touch for moving a direction of a user and a touch for clicking may be distinguished. Will be.

Hereinafter, an arrangement state between a plurality of upper transparent electrodes 12 and a plurality of lower transparent electrodes 16 in a capacitive touch screen according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3 and 4.

3 is a plan view illustrating an arrangement of an upper transparent electrode and a lower transparent electrode of a capacitive touch screen according to a first embodiment of the present invention, and FIG. 4 is an upper transparent of the capacitive touch screen according to a second embodiment of the present invention. It is a top view which shows arrangement | positioning of an electrode and a lower transparent electrode. 3 and 4 are plan views showing the arrangement of the upper transparent electrode and the lower transparent electrode disposed in the same screen area.

As shown in FIGS. 3 and 4, the plurality of upper transparent electrodes 12 and the plurality of lower transparent electrodes 16 according to the embodiment of the present invention cross each other perpendicularly, that is, in a matrix form. Is installed.

In detail, each of the plurality of upper transparent electrodes 12 is arranged side by side at regular intervals in the vertical direction, and each of the plurality of lower transparent electrodes 16 is arranged side by side at regular intervals in the horizontal direction.

Hereinafter, for convenience of description, the upper transparent electrode 12 is referred to as a vertical electrode, and the lower transparent electrode 13 is referred to as a horizontal electrode.

Of course, according to another exemplary embodiment, the plurality of upper transparent electrodes 12 may be arranged in the vertical direction, and the plurality of lower transparent electrodes 16 may be arranged in the horizontal direction.

In FIG. 3, four vertical electrodes x101, x102, x103, x104 and five horizontal electrodes y101, y102, y103, y104, and y105 are arranged to intersect. In FIG. 4, 12 vertical electrodes x1 to x 12 and 15 horizontal electrodes y1 to y15 are arranged to intersect.

At this time, the area A and the area B of the unit crossing point (hereinafter referred to as "touch cell") where one vertical electrode and one horizontal electrode intersect and can sense the touch position by the user are inversely proportional to the number of electrodes arranged. . That is, area A is larger than area B. In this case, the touch cell is a minimum unit for sensing a user's touch on the touch screen, and is an intersection area of a horizontal electrode and a vertical electrode that generate capacitance.

In general, the magnitude of the capacitance between two parallel conductor plates is geometrically proportional to the cross-sectional area of the two conductor plates and inversely proportional to the two conductor plate spacings. Therefore, as the area of the unit crossing point is wider, the change in capacitance value can be increased, which is advantageous for recognizing the change in force.

Therefore, in the case of applying a conventional driving method according to the related art, the first embodiment of the present invention shown in FIG. 3 having a small number of vertical electrodes and a horizontal electrode is one of the present invention shown in FIG. It is advantageous to recognize a change in capacitance value than the second embodiment.

However, the larger the area of the unit crossing point, the wider the electrode width, and thus, the larger the error in position recognition. Accordingly, the second embodiment of the present invention shown in FIG. An error in recognizing a change in capacitance value is smaller than that of the first embodiment of the present invention shown in FIG.

As a result, according to the conventional conventional driving method, the smaller the area of the unit crossing point is, the smaller the error in recognition of the position at which the intersection point is pressed, but there is a disadvantage in that the change of the capacitance value is not recognized. have.

Here, the method of driving the capacitive touch screen according to the embodiment of the present invention, when applied to the touch screen having the electrode arrangement according to the second embodiment of the present invention, the electrode arrangement according to the first embodiment of the present invention It is possible to recognize a change in capacitance value at least as much as a touch screen with an electrode arrangement according to the first embodiment of the present invention, while reducing an error in recognition of the position at which the intersection point is pressed than the touch screen.

Hereinafter, a method of driving a capacitive touch screen according to an exemplary embodiment of the present invention will be described with reference to FIGS. 5 to 9.

First, referring to FIGS. 5 and 6, a driving apparatus of a capacitive touch screen and an electrode state of a touch screen will be described.

FIG. 5 is a block diagram illustrating a device for driving a capacitive touch screen according to an embodiment of the present invention, and FIG. 6 is a diagram for describing a method of driving a capacitive touch screen according to an embodiment of the present invention with reference to electrodes. Drawing.

As shown in FIG. 5, a device for driving a touch screen according to an exemplary embodiment of the present invention includes a touch screen 100, an X-axis scan unit 200, a Y-axis scan unit 300, and a touch sensing unit 400. The control unit 500 is included.

Of course, the driving device of the capacitive touch screen according to the embodiment of the present invention, the power supply for supplying power to the horizontal electrode and the vertical electrode through each of the scanning unit (200, 300), the operation of each of the scanning unit (200, 300) Although a signal generator for generating a synchronization signal required for synchronizing the signal generator is included, such a configuration is omitted since it is conventional.

In the touch screen 100, twelve vertical electrodes x1 to x12 are arranged side by side at regular intervals and side by side at regular intervals such that the fifteen horizontal electrodes y1 to y15 cross perpendicularly to the vertical electrodes x1 to x12. Arranged (see FIG. 4).

The X-axis scan unit 200 sequentially applies a first set signal (eg, AC voltage, AC current, frequency, etc.) to each vertical scan group GX according to the scan control signal of the controller 500. In the following description, the first set signal is a voltage.

As illustrated in FIG. 6, the vertical scan group GX includes an analog switch including three adjacent vertical electrodes x1, x2, x3, or x2, x3, x4, etc. in the X-axis scan unit 200. One scan group GX is formed by the multiplex MUX, and two vertical electrodes overlap each other between neighboring vertical scan groups.

Accordingly, in the example illustrated in FIG. 6, the X-axis scan unit 200 forms ten vertical scan groups GX1 to GX10 corresponding to the twelve vertical electrodes x1 to x12.

Specifically, the ten vertical scanning groups GX1 to GX10 sequentially include (x1, x2, x3), (x2, x3, x4), (x3, x4, x5), (x4, x5, x6), and (x5). , x6, x7), (x6, x7, x8), (x7, x8, x9), (x8, x9, x10), (x9, x10, x11) and (x10, x11, x12).

Accordingly, the X-axis scan unit 200 sequentially applies the first set voltage in the order of the first vertical scan group GX1 to the last vertical scan group GX10 according to the scan control signal. The first set voltage applied in this way is simultaneously applied to three vertical electrodes forming one vertical scan group.

Next, the Y-axis scan unit 300 applies a second set signal (eg, AC voltage, AC current, frequency, etc.) to each horizontal scan group GY according to the scan control signal of the controller 500. In the following description, the second set signal is a voltage.

As illustrated in FIG. 6, the horizontal scan group GY includes an analog switch including three adjacent horizontal electrodes y1, y2, y3, or y2, y3, y4, and the like, in the Y-axis scan unit 300. One scan group GY is formed by the multiplex MUX, and two horizontal electrodes overlap each other between neighboring horizontal scan groups.

 Referring to FIG. 6, the Y-axis scanning unit 300 forms 13 horizontal scanning groups GY1 to GY13 corresponding to the 15 horizontal electrodes y1 to y15.

Specifically, the thirteen horizontal scanning groups GY1 to GY13 are sequentially (y1, y2, y3), (y2, y3, y4), (y3, y4, y5), (y4, y5, y6), ( y5, y6, y7), (y6, y7, y8), (y7, y8, y9), (y8, y9, y10), (y9, y10, y11), (y10, y11, y12), (y11, y12, y13), (y12, y13, y14), and (y13, y14, y15).

Therefore, the Y-axis scan unit 300 sequentially applies the second set voltage in the order of the first horizontal scan group GY1 to the last horizontal scan group GY13 according to the scan control signal. The second set voltage applied in this way is simultaneously applied to three vertical electrodes forming one horizontal scan group.

The touch detection unit 400 instructs the control unit 500 to apply the scan control signal to recognize the touch position and the force, and according to the application of the set voltage through the X-axis scan unit 200 and the Y-axis scan unit 300. By measuring the capacitance value of each touch cell, and comparing the measured capacitance value of each touch cell to determine the position of the touch cell of the maximum capacitance value, and converts the measured maximum capacitance value into force (or pressure) Know the force exerted on touch.

In this case, the area of the touch cell detected by the touch sensing unit 400 through the capacitance value is an area A where one horizontal scan group and one vertical scan group cross each other.

The area A is larger than the area B where one vertical electrode and one horizontal electrode cross each other, and thus the capacitance value is larger than the area B. Therefore, the touch sensing unit 400 can easily recognize the change in the capacitance value, and can differentiate and grasp the degree of change in the capacitance value.

In addition, the touch sensing unit 400 has a position recognition resolution and a force recognition resolution. That is, the touch sensing unit 400 measures the capacitance value of each touch cell having an area A, but measures the capacitance value by spaced at least one electrode between neighboring touch cells, thereby recognizing detailed touch position. And enable power awareness.

In addition, the touch sensing unit 400 compares capacitance values with respect to at least one or more touch cells (touch cells whose capacitance values have changed), and then extracts one touch cell having the largest capacitance value. The touch cell of is determined as a touch cell touched by a finger or a stylus.

As a result, the touch detector 400 extracts one touch cell having an area A, but obtains the same result as extracting a touch cell substantially corresponding to the area B by sequential overlapping scans of the same touch cell.

When the touch detector 400 extracts one touch cell, the touch detector 400 provides the controller 500 with a position and a capacitance value corresponding to the extracted touch cell.

The controller 500 transmits a scan control signal to the X-axis scan unit 200 and the Y-axis scan unit 300 to sense a touch by a stylus or a finger.

In this case, the scan control signal transmitted from the controller 500 is a signal for sequentially scanning 10 vertical scan groups formed by 12 vertical electrodes and sequentially scanning 13 horizontal scan groups formed by 15 horizontal electrodes. Therefore, whenever one vertical scan group is sequentially selected according to the scan control signal, the second setting signal is sequentially applied to the 13 horizontal scan groups.

Meanwhile, as another embodiment of the present invention, the vertical scan group GX and the horizontal scan group GY may be configured differently from the example shown in FIG. 6.

In detail, the vertical scan group GX includes three adjacent vertical electrodes (x1, x2, x3 or x2, x3, x4, etc.) included in the X-axis scan unit 200 as shown in FIG. One scan group GX is formed by a switch or multiplex MUX, but there is no vertical electrode overlapping (overlapping) between neighboring vertical scan groups. Therefore, in this case, the vertical scan group is composed of (x1, x2, x3), (x4, x5, x6), (x7, x8, x9), (x10, x11, x12), and there are four scan groups in total. .

The horizontal scan group GY is also formed on the same principle as the vertical scan group GY. Accordingly, the horizontal scan group GY is formed of (y1, y2, y3), (y4, y5, y6), (y7, y8). , y9), (y10, y11, y12), and (y13, y14, y15) to form a total of five horizontal scanning groups.

In another embodiment of the present invention, the vertical scan group and the horizontal scan group may include N scan electrodes adjacent to one scan group, and at least one or (N-1) electrodes overlap between the scan scan groups. Can be formed. For example, four neighboring electrodes may be one scan group, and three, two, or one electrodes may overlap each other.

However, for accurate touch position recognition and fast processing, the number N of scan electrodes included in the scan group is preferably larger than 2 and 8 or less, and the number of electrodes overlapping between neighboring scan groups is preferably N-1. Do.

According to another embodiment of the present invention, the number of electrodes forming the vertical scan group and the number of electrodes forming the horizontal scan group may be different. For example, the vertical scan group may have three electrodes as one group, and the horizontal scan group may have four electrodes as one group.

Next, a capacitive touch screen driving method according to a first embodiment of the present invention will be described with reference to FIGS. 7, 9, and 10.

FIG. 7 is a diagram illustrating the number of touch cells for which a capacitance measurement value is obtained according to the capacitive touch screen driving method according to the first embodiment of the present invention. 9 is a flowchart illustrating a method of driving a capacitive touch screen according to a first embodiment of the present invention. 10 is a timing diagram of a scan control signal for a capacitive touch screen driving method according to a first embodiment of the present invention.

First, suppose that the user touches a point (area of (x5, y8) based on the position of the electrode) of the area B shown in FIG. 6 with a finger or a stylus.

The controller 500 transmits a scan control signal as shown in FIG. 10 to the X-axis scan unit 200 and the Y-axis scan unit 300 at regular intervals in response to the input from the touch sensor 400.

The X-axis scan unit 200 simultaneously turns on an analog switch connected to three vertical electrodes x1, x2, and x3 according to the received scan control signal, or turns on signals for the three vertical electrodes x1, x2 and x3. The first one vertical electrode group GX1 is formed and selected by the method of inputting the multiplexer to the multiplexer (S901 and S902).

At the same time, the Y-axis scan unit 300 simultaneously turns on the analog switch or multiplexer connected to the three horizontal electrodes according to the scan control signal, from the first horizontal electrode group GY1 to the last horizontal electrode group GY13. ) Are sequentially selected (S903)

Then, capacitance is generated at each point where the vertical electrode group GX1 and the horizontal electrode groups GY1 to GY13 cross each other, and the touch sensing unit detects the capacitance at the intersection point of the horizontal electrode group and the vertical electrode group. Measure at 400.

Here, the capacitance value at the intersection point is larger as the distance between the electrode groups is closer, and the larger capacitance value means that the deformation of the flexible layer 11 is large due to a large pressing force by the user, on the other hand, It means that the touch point is pressed.

Next, the X-axis scan unit 200 simultaneously turns on the analog switch or multiplexer connected to the three vertical electrodes x2, x3, and x4 according to the scan control signal. ) Is selected to form a second one vertical electrode group (GX2).

At the same time, the Y-axis scan unit 300 sequentially selects the first horizontal electrode group GY1 to the last horizontal electrode group GY3 according to the scan control signal.

Then, at each point where the vertical electrode group GX2 and the horizontal electrode groups GY1 to GY13 intersect, the touch sensing unit 400 measures the capacitance at the intersection point between the horizontal electrode group and the vertical electrode group.

By repeating the above method (S905, S906, S907, S908), as shown in Fig. 7, the capacitance values are collected at the intersections of all the vertical electrode groups and the horizontal electrode groups.

In Fig. 7, the touch cells (intersection points) are (GX1, GY1), ..., (GX1, G13), (GX2, GY1), ..., (GX2, GY13), ..., (GX10). , GY1), ..., (GX10, GY13), totaling 130 intersection points.

The touch sensing unit 400 identifies a touch cell whose capacitance has changed from the distribution of capacitance values collected from all touch cells compared to the capacitance value (set value) when it is not pressed by a finger or a stylus. (S909).

Here, since the user presses the (x5, y8) point with a finger or a stylus, the touch cell including the (x5, y8) point causes a change in capacitance value. In detail, the touch cell having the changed capacitance has a cross point (GX3, GY6), (GX3, GY7), (GX3, GY8), which are intersections of the vertical electrode groups GX3, GX4, GX5 and the horizontal electrode groups GY6, GY7, and GY8. ), (GX4, GY6), (GX4, GY7), (GX4, GY8), (GX5, GY6), (GX5, GY7), (GX5, GY8).

Of course, even if the user presses the (x5, y8) point, the touch force does not act only on the (x5, y8) point but also around the (x5, y8) point. You will be more than a dog.

The touch sensing unit 400 compares the capacitance value with respect to the touch cells having the change in the capacitance value and identifies the touch cell with the largest change in the capacitance value or one touch cell with the largest capacitance value in operation S910. ).

One of the touch cells thus identified is a touch cell having an intersection point of (GX4, GY7) at the center of the (x5, y8) point.

The touch sensing unit 400 identifies the center position of the touch cell and calculates the center position and the capacitance value of the touch cell, converts the capacitance value into force or pressure, and recognizes the touch position touched by the user. (S911).

Then, the touch sensing unit 400 determines the recognized touch position and the converted force (or pressure) as the position and force touched by the user (S912).

Here, the touch position determined by the touch sensing unit 400 may determine what the user has selected on the screen, and the force calculated by the touch sensing unit 400 may be oriented by the user through comparison with a reference value for the set force. Allows you to determine whether you have touched to move or touched to select (or click). For example, a touch for directional movement has a weak touch force, and a selection (or click) has a strong touch force.

Here, as another embodiment of the present invention, instead of the controller 500, the touch sensing unit 400 may convert the capacitance value into force or pressure.

Next, a capacitive touch screen driving method according to a second embodiment of the present invention will be described with reference to FIGS. 8 and 11.

FIG. 8 is a diagram illustrating the number of touch cells for which a capacitance measurement value is obtained according to the capacitive touch screen driving method according to the second embodiment of the present invention. 11 is a timing diagram of a scan control signal for a capacitive touch screen driving method according to a second embodiment of the present invention.

In the capacitive touch screen driving method according to the second embodiment of the present invention, as shown in the timing diagram of FIG. 11, the vertical electrode group GX and the horizontal electrode group GY may be formed as another embodiment of the present invention. This is the method to apply when configured.

Specifically, in the capacitive touch screen driving method according to the second embodiment of the present invention, the vertical scan group GX and the horizontal scan group GY are divided into three scan electrodes with three electrodes as shown in FIG. 6. However, the present invention is applied to a case in which there is no overlapping electrode between neighboring scan groups.

The capacitive touch screen driving method according to the second embodiment of the present invention has the same process as that shown in FIG. 9.

However, unlike the first embodiment of the present invention, the capacitive touch screen driving method according to the second embodiment of the present invention has three scanning electrodes in three electrodes forming a group without overlapping with each electrode as shown in FIG. It is input at the same time.

Therefore, according to the capacitive touch screen driving method according to the second embodiment of the present invention, the number of touch cells capable of measuring the capacitance is 20 as shown in FIG. It is much smaller than the number of touch cells that can be measured by the touch screen driving method according to the example (see FIG. 7).

The capacitive touch screen driving method according to the second embodiment of the present invention is applied when an icon or a menu displayed on a screen occupies a large screen area, and in this case, the capacitance according to the first embodiment of the present invention. Compared to the touch screen driving method, quick touch position recognition and force recognition can be performed.

Of course, the driving device of the capacitive touch screen according to an embodiment of the present invention is manufactured to selectively switch the capacitive touch screen driving method according to the first and second embodiments of the present invention. The conversion can be easily implemented by those skilled in the art, such as the operation of an analog switch or the operation of a multiplexer, so detailed description thereof will be omitted.

The embodiments of the present invention described above are not only implemented by the apparatus and method but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, The embodiments can be easily implemented by those skilled in the art from the description of the embodiments described above.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

100: touch screen 200: X-axis scanning unit
300: Y-axis scanning unit 400: touch detection unit
500 control unit 11: transparent flexible layer
12: upper transparent electrode 13: upper transparent protective film
14 elastic layer 15 lower transparent protective film
16: lower transparent electrode 17: transparent glass substrate
41: transparent elastomer 42: dam

Claims (18)

The lower substrate,
A flexible layer which is located on the upper side and deforms in the direction of the pressing force,
A plurality of lower electrodes disposed side by side at regular intervals on the upper surface of the substrate,
A plurality of upper electrodes installed side by side at regular intervals on the lower surface of the flexible layer, intersecting the plurality of lower electrodes, and
The capacitive touch screen includes an elastic layer that generates capacitance when a signal is applied to the lower electrode and the upper electrode that are positioned between the substrate and the flexible layer and cross each other. The method of claim 1,
And a lower passivation layer for protecting the plurality of lower electrodes, and an upper passivation layer for protecting the plurality of upper electrodes. The method of claim 2,
And the substrate, the flexible layer, the plurality of upper electrodes, the plurality of lower electrodes, the elastic layer, the lower passivation layer and the upper passivation layer are made of a transparent material. The method according to claim 1 or 3,
The elastic layer is positioned between the plurality of upper electrodes and the plurality of lower electrodes transparent capacitance is generated by the capacitance and deformed by external pressure;
And a dam interposed between the flexible layer and the substrate and provided at a constant height at an edge of the touch screen so that the transparent elastic body does not leak out. The method of claim 4, wherein
The flexible layer is a capacitive touch screen, characterized in that the upper surface (hard) hard coated polyethylene terephthalate (PET) film. The method of claim 5,
The upper electrode and the lower electrode capacitive touch screen, characterized in that the gap between the neighboring electrode is within 0.5mm to 0.001mm. The method of claim 6,
The lower electrode and the upper electrode are capacitive touch, characterized in that made of one material of indium tin oxide (ITO), metallic single-walled carbon nanotube (SWCNT), or conductive polymer PEDOT (Poly 3,4-ethylenedioxythiophene) screen. The method of claim 2,
The transparent elastic body is a capacitive touch screen, characterized in that the gel of the gel (gel). The method of claim 8,
The dam is a capacitive touch screen, characterized in that the elastic material such as silicone rubber or polyurethane. The method of claim 3,
The lower protective layer and the upper protective layer is a transparent film, capacitive touch screen, characterized in that the optical clear adhesive (OCA) tape. In the capacitive touch screen driving method for determining a user's touch position by driving a touch screen in which N first electrodes and M second electrodes intersect in a matrix form,
(a) selecting and forming neighboring K first electrodes into one vertical scan group among the N first electrodes,
(b) while the one vertical scan group is selected, forming and selecting neighboring J second electrodes as one horizontal scan group from the M second electrodes,
(c) collecting a signal corresponding to a capacitance value generated in a touch cell intersecting the vertical scan group and the horizontal scan group in step (b);
(d) repeating steps (b) and (c) sequentially so that all of the M second electrodes are selected;
(e) sequentially repeating steps (a) to (c) such that all of the N first electrodes are selected, and
(f) determining a touch position by using the capacitance values generated in all touch cells collected by step (e),
(K-1) or less of the first electrodes overlap between the adjacent vertical scan groups,
And (J-1) or less of the second electrodes overlap between adjacent horizontal scanning groups. The method of claim 11,
In the step (f), the signals corresponding to the capacitance values collected from all the touch cells are compared with each other, and the position of the first touch cell having the largest capacitance value is determined as the touch position. How to drive touch screen. The method of claim 11,
The step (f) may include extracting a touch cell having a change in capacitance value from the capacitance values received from all the touch cells;
And comparing the capacitive values of the extracted touch cells to identify the first touch cell having the largest capacitance value. The method according to any one of claims 11 to 13,
And converting the capacitance value of the first touch cell into a force or a pressure. The method of claim 14,
And K and J are greater than 2 and less than or equal to 8. 16. The method of claim 15,
And the K and J are the same number. The method of claim 16,
The capacitive touch is characterized in that K and J are 3, the first electrode overlapping with the neighboring vertical scan group is two, and the second electrode overlaps with the neighboring horizontal scan group. Screen drive method. 16. The method of claim 15,
And the K and J are different numbers.

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