KR20130030167A - Device for sensing user input and electronic device including the same - Google Patents

Abstract

PURPOSE: A user input sensing device using a voltage change and an electronic device including the same are provided to raise the accuracy and resolution of touch and to calculate a touch area. CONSTITUTION: Electrode pads(110) of a transparent material are placed in a matrix form. A driving unit(210) includes a first storage battery and a switch connected with the electrode pads. The driving unit charges and floats the electrode pads by using the switch and outputs a voltage change corresponding to a voltage signal applied to the first storage battery. A detecting unit(220) outputs a touch detection value based on a difference between voltage changes of touch. A signal processing unit(230) calculates a touch area by using the touch detection value and calculates touch coordinates by using the touch area. [Reference numerals] (210) Driving unit; (220) Detecting unit; (230) Signal processing unit; (240) Memory

Description

DEVICE FOR SENSING USER INPUT AND ELECTRONIC DEVICE INCLUDING THE SAME}

The present invention relates to a user input sensing device and an electronic device including the same. More particularly, the present invention relates to a touch sensing device and an electronic device including the same.

The touch panel is an input device that allows a user to input a command of a user by touching with a human hand or other contact means based on the content displayed by the video display device.

To this end, the touch panel is provided on the front face of the image display device and converts the contact position, which is directly in contact with a human hand or other contact means, into an electrical signal. Accordingly, the instruction selected at the contact position is received as an input signal.

Since such a touch panel can replace an input device such as a keyboard and a mouse, its use range is gradually expanding.

As a method of implementing a touch panel, a resistive film type, a light sensing type, and a capacitive type are known. Among them, the capacitive touch panel converts the contact position into an electrical signal by sensing a change in the capacitance that the conductive sensing pattern forms with other peripheral sensing patterns or the ground electrode when a human hand or an object touches.

Here, in order to determine the contact position on the contact surface, the sensing pattern includes a first sensing pattern (X pattern) formed to be connected along the first direction and a second sensing pattern (Y pattern) formed to be connected along the second direction .

1 is an exploded plan view of a conventional touch panel.

The conventional touch panel 10 includes a transparent substrate 11, a first sensing pattern 12 formed in sequence on the transparent substrate 11, a first insulating layer 13, a second sensing pattern 14, a metal pattern 15, And a second insulating film 16.

The first sensing patterns 12 are formed to be connected to one surface of the transparent substrate 11 along a first direction. For example, the first sensing patterns 12 may be formed on the transparent substrate 11 in a regular pattern in which a plurality of diamond shapes are connected in a line.

The first sensing patterns 12 may be formed of a plurality of X patterns formed so that the first sensing patterns 12 located in one row having the same X coordinate are connected to each other.

The first sensing pattern 12 includes a pad 12a so as to be electrically connected to the metal pattern 15 on a row basis. The pads 12a of the first sensing patterns 12 may be formed in a row unit.

The second sensing patterns 14 are formed to be connected to the first insulating layer 13 along the second direction and alternately arranged with the first sensing patterns 12 so as not to overlap with the first sensing patterns 12. For example, the second sensing patterns 14 may be formed in the same diamond pattern as the first sensing patterns 12, and the second sensing patterns 14 located on one row having the same Y coordinate are connected to each other .

The second sensing pattern 14 includes a pad 14a so as to be electrically connected to the metal pattern 15 on a row-by-row basis. The pads 14a of the second sensing patterns 14 may be formed in units of rows.

The first and second sensing patterns 12 and 14 are made of a transparent conductive material such as indium tin oxide (ITO), and the first insulating layer 13 is made of a transparent insulating material.

Unit sensing patterns 12 and 14 are electrically connected to position detection lines (not shown), respectively, and supply contact position signals to a driving circuit (not shown) or the like.

When a hand or an object touches the touch panel 10 shown in Fig. 1, the first and second sensing patterns 12 and 14, the metal pattern 15, and the position detection line are connected to the driving circuit side, A change in capacity is delivered. And the contact position is grasped | ascertained as the change of capacitance is converted into an electrical signal by X and Y input processing circuits (not shown) etc.

However, in the conventional touch panel 10, each layer for X and Y must have an ITO pattern, and an insulating layer must be provided between the X layer and the Y layer, thereby increasing the thickness. In addition, since capacitive changes generated by touch are accumulated several times, touch detection is required to detect capacitive changes at a high frequency. This requires complex computational and statistical processing.

In addition, the difference in electrical signals before and after the touch is extremely small, so that it is influenced by wiring resistance. Therefore, a metal wiring such as the metal pattern 15 is required to maintain a low resistance. An additional mask process is required to form such a metal pattern 15. [

In addition, since touch detection of the conventional touch panel 10 is highly dependent on the resistance value and sensitive to noise, there are many difficulties in increasing the touch detection sensitivity.

Moreover, the conventional touch panel 10 can not calculate an accurate touch area because a touch is detected using a minute change of capacitance accumulated several times by complicated calculation. Therefore, it is practically impossible for the user to use the touch area as one means of user input.

The problem to be solved by the present invention is to calculate the correct touch area and touch coordinates of the touch sensing device.

According to an aspect of the present invention, a user input sensing device includes: a plurality of electrode pads of a transparent material disposed in a matrix form; A driving unit including a switch and a first capacitor electrically connected to the plurality of electrode pads, and configured to output a voltage change in response to a voltage signal applied to the first capacitor after charging and floating the electrode pad using the switch. ; A detector configured to output a touch detection value based on a difference between the output voltage change before and after the touch; And a signal processor configured to calculate a touch area using the touch detection value and calculate touch coordinates using the touch area.

The signal processor may calculate the touch area by extracting a touch cell group corresponding to touched adjacent electrode pads and summing touch detection values of the touched touch cell group.

The signal processor may calculate multi-touch coordinates using touch areas of a plurality of touch cell groups.

The signal processor may calculate the touch coordinates based on a position of the electrode pad on the matrix and a touch area occupying the electrode pad.

The signal processor may calculate touch coordinates based on the position of the electrode pads on the matrix and the distribution of the touch areas in the X-axis and Y-axis directions.

The signal processor may calculate touch coordinates by using a center point of the touch area in the X and Y axis directions.

According to a second aspect of the present invention, there is provided a method of detecting a user input, comprising: driving a touch cell corresponding to an electrode pad of a transparent material arranged in a matrix; Outputting a touch detection value based on a difference in voltage change generated from the driven touch cell before and after the touch; Calculating a touch area based on the touch detection value; And calculating touch coordinates by using the calculated touch area and position information of the touched electrode pad.

The driving of the touch cell may include charging and floating the electrode pad using a switch electrically connected to the electrode pad, and outputting a voltage change generated by applying a voltage signal to a first capacitor electrically connected to the electrode pad. The touch detection value outputting step may include detecting a difference of the output voltage change before and after the touch as a touch detection value.

The method may further include extracting a touch cell group including the adjacent cell from which the touch is detected, based on the touch detection value.

The calculating of the touch coordinates may include calculating touch coordinates based on the coordinates of the center point of the touch area.

Here, the center point coordinates of the touch area may be calculated based on the distribution of the touch area occupying the electrode pad.

The center point coordinates of the touch area may be calculated using an area center point in the X axis direction and an area center point in the Y axis direction of the touch area.

An integrated circuit (IC) used in a user input sensing device according to a third aspect of the present invention includes a switch and a first capacitor electrically connected to a plurality of electrode pads arranged in a matrix form. A driving unit configured to output a voltage change in response to a voltage signal applied to the first capacitor after charging and floating an electrode pad; A detector configured to output a touch detection value based on a difference between the output voltage change before and after the touch; And a signal processor configured to calculate a touch area using the touch detection value and calculate touch coordinates using the touch area.

The signal processor may calculate the touch area by extracting a touch cell group corresponding to touched adjacent electrode pads and summing touch detection values of the touched touch cell group.

The signal processor may calculate the touch coordinates based on the position of the electrode pad and the touch area occupying the electrode pad.

The signal processor may calculate touch coordinates using the position of the electrode pad and the center point of the touch area in the X and Y axis directions of the touch panel.

As described above, according to the exemplary embodiment of the present invention, the resolution and accuracy of the touch can be increased, and the touch area can be calculated.

1 is an exploded plan view of a conventional touch panel.
2 is a block diagram of a touch sensing apparatus according to an embodiment of the present invention.
3 is an equivalent circuit diagram of a touch cell according to an embodiment of the present invention.
4 is a waveform diagram of a touch cell according to an embodiment of the present invention.
5 is a schematic block diagram of a touch cell and a detector according to an embodiment of the present invention.
6 is a graph for explaining an operation of a detector according to an exemplary embodiment of the present invention.
7 is a graph showing a voltage difference between a touch cell and a reference cell as a function of touch capacitance according to an embodiment of the present invention.
8 is a schematic diagram illustrating a correspondence relationship between a touch cell and a memory in a touch sensing apparatus according to an embodiment of the present invention.
9 is a flowchart illustrating a method of calculating a contact area and a contact position according to an embodiment of the present invention.
10 to 13 are views illustrating a method of calculating a contact area and a contact position according to an embodiment of the present invention.
14 to 17 are schematic diagrams illustrating a touch operation of a user.
18 is a flowchart illustrating an operation according to a contact area in an electronic device according to an embodiment of the present disclosure.
19 is a flowchart illustrating an operation of changing an area of a contact in an electronic device according to an embodiment of the present disclosure.

DETAILED DESCRIPTION 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. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. 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.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless otherwise stated.

Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

Throughout the specification, when a part is "connected" to another part, this includes not only a case where the part is directly connected, but also a case where another system is connected in the middle.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a touch sensing apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a block diagram of a touch sensing apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the touch sensing device according to the present embodiment includes a touch panel and a driving device.

The touch panel includes a plurality of electrode pads 110 formed on a substrate 100 such as glass or plastic film made of transparent material and a plurality of signal wires 120 connected thereto.

The plurality of electrode pads 110 may be, for example, rectangular or rhombic, but is not limited thereto. The electrode pads 110 may be formed in a polygonal shape having a uniform shape. The electrode pads 110 may be arranged in the form of a matrix of substantially adjacent polygons.

Each signal line 120 has one end connected to the electrode pad 110 and the other end extending to the bottom edge of the substrate 100. The line width of the signal wire 120 may be designed to be quite narrow, on the order of several tens to several tens of micrometers.

The electrode pad 110 and the signal line 120 may be made of a transparent conductive material such as ITO (Indium Tin Oxide), IZO (indium-zinc-oxide), CNT (carbon nanotube), or graphene .

The electrode pad 110 and the signal wiring 120 can be formed at the same time by, for example, laminating an ITO film on the substrate 100 by sputtering or the like and then patterning the same using an etching method such as photolithography.

The electrode pad 110 and the signal wiring 120 may be covered with a transparent insulating film (not shown).

The driving device for driving the touch panel may be directly mounted on a part of the substrate 100 or may be formed on a circuit board 200 such as a printed circuit board or a flexible circuit film. The driving device may include a driver 210, a detector 220, a signal processor 230, a memory 240, and the like, and may be implemented as one or more integrated circuit (IC) chips.

The driving unit 210 is connected to the signal line 120 and receives signals from the signal processing unit 230 to drive circuits for touch detection and outputs a voltage corresponding to a result of the touch detection determination. The driving unit 210 may include a plurality of switches and a capacitor connected to the electrode pad 110.

The detector 220 is connected to the driver 210 and converts, amplifies, or digitizes the difference in the voltage change of the electrode pad 110 received from the driver 210 to be stored in the memory 240. The detection unit 220 may include an amplifier and an analog-to-digital converter.

The signal processing unit 230 applies a signal for controlling the driving unit 210 or processes the digital voltage stored in the memory 240 to generate necessary information. The signal processing unit 230 may be implemented as an analog signal processing unit and a digital signal processing unit. The analog signal processor may control the driver 210, and the digital signal processor may calculate the touch area and the touch coordinates based on the difference in the voltage change detected by the detector 220. The signal processing unit 230 may include a microcontroller unit (MCU) and may perform predetermined signal processing through the firmware.

The memory 240 stores predetermined data used for touch detection, area calculation, touch calculation, or data received in real time according to a command of the signal processing unit 230. [

As described above, the driver 210, the detector 220, the signal processor 230, and the memory 240 may be separated from each other, or two or more components may be integrated and implemented.

A detailed embodiment of the touch panel and the driver shown in FIG. 2 and its operation will be described in detail with reference to FIGS. 3 and 4.

3 is an equivalent circuit diagram of a touch cell according to an embodiment of the present invention, and FIG. 4 is a waveform diagram of a touch cell according to an embodiment of the present invention.

Referring to FIG. 3, the driving unit 210 may include a plurality of transistors Q and a plurality of first capacitors C1 that perform a switching operation, and may further include a plurality of pad capacitors Cp. The transistor Q, the first capacitor C1 and the pad capacitor Cp may be grouped one by one for the electrode pad 110 and the signal wire 120, and in the future, the electrode pad 110, the signal wire 120, The transistor Q, the first capacitor C1 and the pad capacitor Cp are collectively referred to as a "touch cell". The touch cell is a concept including a case where each component is electrically connected by a multiplexer.

The transistor Q may be a field effect transistor, for example, a control voltage Vc applied to its gate, a data voltage Vd applied to its source (or drain), and a drain (or source) 120, respectively. The control voltage Vc and the data voltage Vd may be applied under the control of the signal processing unit 230. [ Here, other elements capable of switching in place of the transistor Q may be used.

The first capacitor C1 may be formed between the gate and the drain of the transistor Q, and may be formed separately from the transistor Q by a designer to secure a necessary capacity. The voltage signal applied to the first capacitor C1 may be the same signal as the voltage signal applied to the gate of the transistor Q, but a separate voltage signal if the first capacitor C1 is formed separately from the transistor Q May be applied. The voltage signal applied to the first capacitor C1 is preferably a square wave signal.

The pad capacitor Cp is a kind of parasitic capacitance formed by the electrode pad 110 or the signal wiring 120 or the like. The pad capacitor Cp may include any parasitic capacitance generated by the driver 210, the touch panel, and the image display device. In FIG. 3, reference numeral Ct denotes a capacitance formed between the electrode pad 110 and the user's finger when the user touches the electrode pad 110.

On the other hand, the cell can be arranged in a position that the user can not touch, or a cell having an electrical characteristic that is not always touched, which will be referred to as a "reference cell". The "reference cell" may exist physically, but may be a virtual cell having only data values.

Referring to FIG. 4, the signal processor 230 may apply the data voltage Vd and the control voltage Vc to the source and gate of the transistor Q, respectively.

After the data voltage Vd rises, the transistor Q is turned on when the control voltage Vc applied to the gate rises from the low voltage VL to the high voltage VH. Accordingly, the electrode pad is charged with the data voltage Vd, and the output voltage Vo will be the data voltage Vd.

Next, when the control voltage Vc falls from the high voltage VH to the low voltage VL, the transistor Q is turned off, and the electrode pad 110 is in a floating state. At this time, the voltage level of the output voltage Vo of the electrode pad 110 may drop instantaneously due to the level drop of the square wave applied to the first capacitor C1. This voltage drop is sometimes called "kick-back."

In the case where there is no touch on the touch cell or the reference cell (Case 1), that is, when the capacitors connected to the electrode pad 110 are only the first capacitor C1 and the pad capacitor Cp, these capacitors C1, The voltage drop (V1) of the output voltage (Vo)

. For convenience, the reference numerals of the capacitor and its capacity are used the same.

Equation (1) is easily derived from the equations for obtaining the total amount of charge before and after the voltage drop.

However, as shown in FIG. 3, when the user is touching the electrode pad 110 (Case 2), a capacitor Ct is formed between the electrode pad 110 and the user's finger or the contact means, thereby forming an electrode. In the capacitor connected to the pad 110, a touch capacitor Ct is added in addition to the first capacitor C1 and the pad capacitor Cp. The voltage drop V2 of the electrode pad 110 by these three capacitors C1, Cp, and Ct becomes equal to the following formula (2).

As a result, the voltage drop (V2) in the case of the touch (Case 2) becomes smaller than the voltage drop (V1) of the case without the touch (Case 1). The difference between the voltage drop (V2) and the voltage drop (V1) depends on the touch capacitance (Ct).

In general, the capacitance C of the capacitor is proportional to the area A of the electrode and proportional to the distance d between the electrodes, that is, C = εA / d (ε is the dielectric constant). Accordingly, the larger the touch area, the larger the touch capacitance Ct. Using this relationship, the touch area can be calculated using the difference in voltage drop between the electrode pads 110 before and after the touch. A detailed description of the touch area calculation will be described later.

As shown in FIG. 4, when a variation of the control voltage Vc applied to the first capacitor C1 occurs when the transistor Q is turned off, a voltage change of the output voltage Vo occurs. In the embodiment of the present invention, the touch can be detected from the difference of the variation value of the output voltage Vo before and after the touch (that is, the difference between the voltage drop V2 and the voltage drop V1).

On the other hand, when the voltage applied to the first capacitor C1 rises from the low voltage (VL) to the high voltage (VH) when the transistor Q is turned off and becomes a floating state, although not shown, A phenomenon occurs. In this case, since the total capacitance when there is a touch (Case 2) is larger than the total capacitance when there is no touch (Case 1), a small increase in voltage will occur (see Equations 1 and 2). Therefore, even when the voltage applied to the first capacitor C1 in the floating state increases, the touch can be detected on the same principle as in the above-described embodiment. The designer can select which of the voltage rising / falling points is used for touch detection.

Hereinafter, for convenience, a description will be mainly given of a configuration for detecting a touch when the voltage applied to the first capacitor C1 falls from VH to VL in a floating state.

Next, a detailed example and operation of the detector shown in FIG. 2 will be described in detail with reference to FIGS. 5 to 7.

5 is a schematic block diagram of a touch cell and a detector according to an embodiment of the present invention.

Referring to FIG. 5, the detector according to the present embodiment may include an amplifier 222 and an analog-digital converter (ADC) 224.

The two inputs of the amplifier 222 may be an output voltage Vo of the touch cell 250 and an output voltage Vr of the reference cell 260, and the amplifier 222 may have a difference between the two output voltages Vo and Vr. It may be a differential amplifier for amplifying and outputting. In FIG. 5, Va represents the output voltage of the amplifier 222, and VaD represents the digitization of the output voltage of the amplifier 222.

In this case, the touch cell 250 includes the electrode pad 110, the signal wire 120, the transistor Q, the first capacitor C1, and the pad capacitor Cp shown in FIG. 3, and there is a touch. Refers to a typical touch cell further including a touch capacitor Ct, and the reference cell 260 refers to a touch cell that does not include a touch capacitor Ct because a user's touch does not occur as mentioned above.

The voltage difference (? V = Vo - Vr) between the output voltage Vo of the touch cell 250 and the output voltage Vr of the reference cell 260 is such that the control voltage Vc changes from the high voltage VH to the low voltage VL The voltage difference when it falls.

The voltage difference? V between the touch cell Vo and the reference cell Vr at the time when the control voltage Vc falls from the high voltage VH to the low voltage VL is expressed by the following equation (3).

6 is a graph illustrating an output of an amplifier in an embodiment of the present invention.

When the amplifier 222 is a differential amplifier, the difference voltage ΔV is linearly amplified, but is saturated and outputs a constant value above a specific value.

Referring to FIG. 6, the output voltage Va of the amplifier 222 may be Vas when the difference voltage ΔV is greater than or equal to the saturation voltage ΔVs, and when it is smaller than this, the output voltage Va may have a magnitude proportional to the difference voltage ΔV. have. For example, if the difference voltage ΔV is 0, the output voltage Va is also 0, if the difference voltage ΔV is ΔV1, the output voltage Va is Va1, and if the difference voltage ΔV is ΔV2, the output voltage Va is When Va2 and the difference voltage ΔV are ΔV3, the output voltage Va may be Va3.

Meanwhile, when the electrode pad 110 according to an embodiment of the present invention is sufficiently small and the electrode pad 110 is completely covered by a finger when a touch is generated, the difference voltage? V has a maximum value, Or more.

Thus, by designing the amplifier 222 such that the saturation voltage ΔVs is greater than or equal to the maximum value of the difference voltage ΔV, linearity may be imparted to the amplifier. The linearity can be used to calculate an accurate touch area.

The output voltage Va of the amplifier 222 is input to the ADC 224 and the ADC 224 can output the converted analog voltage Va to the digital signal VaD.

For example, the ADC 224 may divide the output voltage Va of the amplifier 222 into four sections and give a two-bit digital value in order of magnitude to each section. Referring to FIG. 7, the output voltage Va of the amplifier 222 is about 0 to Va1, 00 for Va1 to Va2, 01 for Va1 to Va2, 10 for Va2 to Va3, and 11 for Va3 or more. Can be given.

However, setting the digital value to 2 bits is just one example. Other examples are 4 bits, 8 bits, and 10 bits.

7 is a graph illustrating a relationship between a difference voltage and a touch capacitance in an embodiment of the present invention.

Equation (3) is rearranged as a function of the difference voltage ΔV as follows.

(Where K1 = C1 (VH-VL), K2 = C1 + Cp,

Thus, K1 and K2 are constants, and are greater than zero)

As shown in FIG. 7, when the difference voltage ΔV is zero, the touch capacitance Ct is zero, and as the difference voltage ΔV increases, the touch capacitance Ct increases.

Here, since the touch capacitance Ct is proportional to the touch area A and inversely proportional to the distance d between the touch means and the electrode pad 110, that is, since Ct = εA / d (ε is a dielectric constant), the distance ( When d) is constant, the touch area A and the touch capacitance Ct are linearly proportional.

As a result, it can be understood that the larger the difference voltage? V, the larger the touch area A is.

As described above, when the entire area of the electrode pad 110 is completely covered by the touch of a finger or the like, the difference voltage? V becomes the maximum value and the touch area A becomes the maximum value. This is because the touch area A can not be larger than the area of the electrode pad 110.

As a result, the graph of FIG. 7 shows that the difference voltage ΔV is effective in a range between 0 and the maximum value ΔV_max, and the linearity between the difference voltage ΔV and the touch area A may be given using this characteristic. have.

For example, a linear function may be generated in the valid period and the output value of the generated linear function may be matched for each difference voltage ΔV.

Alternatively, linearity can be given between the differential voltage? V and the touch area A by applying a predetermined weight to the output of each differential voltage? V and correcting it.

Or linearity can be imparted by using the inverse function of the differential voltage? V and the touch area A, such as gamma correction.

This correction for linearity can reduce the amount of computation since the number of samples to be processed is limited if processed after or simultaneously with the analog-to-digital conversion.

Alternatively, even if the relationship between the touch area A and the difference voltage ΔV is not a perfect linear proportion, if the slope is sufficiently gentle to provide sufficient accuracy for calculating the area, it is treated as being substantially linear proportional, and special correction processing The difference voltage [Delta] V can be used to calculate the touch area A without any change.

As described in the embodiment related to FIG. 6, since the difference voltage ΔV and the amplification value Va are also linear by the amplifier 222, the amplification value Va of the difference voltage ΔV is also the touch area A. ) And linearity. Naturally, the digitized value VaD of the amplification value Va also has a linearity with the touch area A.

The relationship between the difference voltage ΔV defined by the various embodiments described above, its amplification value Va or VaD, and the touch area A is referred to as "substantially linear proportionality". Using this "substantially linear proportional" relationship, the touch sensing device according to an embodiment of the present invention can detect a very accurate touch area and coordinates.

8 is a schematic diagram illustrating a correspondence relationship between a touch cell and a memory in a touch sensing apparatus according to an embodiment of the present invention.

The memory 240 illustrated in FIG. 2 may be, for example, a plurality of memories having addresses corresponding to the touch cells 250 (strictly speaking, the electrode pads 110 should be used as the touch cells 250 for convenience of description). Cells, each memory cell may store amplified and digitized difference voltage VaD through the amplifier 222 and the ADC 224.

As described above, the amplified and digitized difference voltage VaD is substantially linearly proportional to the touch area with respect to the electrode pad 110. Therefore, the amplified and digitized difference voltage VaD is treated to be equal to the touched digital area value.

In the present specification, the amplified and digitized difference voltage VaD is a value related to touch detection and is referred to as " touch detection value VaD " for convenience. When the touch detection value VaD is digitized to 2 bits, the touch detection value VaD may have four values of 00, 01, 10, and 11. Here, 00 means no touch, and 11 means that the entire electrode pad is touched and covered. As described above, the size of the touch detection value VaD corresponds to the size of the touch area for one electrode pad.

8 illustrates a touch cell of C1 to C16 and a memory cell of M1 to M16, and M1 to M16 correspond to C1 to C16, respectively. Touch occurs in touch cells C6, C7, C10, C11, C14, and C15, C6 is about 2/5 of the total area, C7 is about 3/5, C10 and C11 are all, C14 and C15 are about 1 Suppose that / 10 or less touched your finger.

Then, 00 is stored in memory cells C1 to C5, C8, C9, and C12 to C16 corresponding to touch cells C1 to C5, C8, C9, and C12 to C16 having little or no touch, and 01 and M7 to M6. 11 may be stored in 10, M10, and M11.

The signal processing unit 230 reads the digital area values of the touch cells C1 to C16 from the memory 240 to determine the contact area and the contact position. This will be described in detail with reference to FIGS. 9 to 13.

9 is a flowchart illustrating a method of calculating touch area and touch coordinates according to an embodiment of the present invention.

Referring to FIG. 9, the touch sensing apparatus according to the present embodiment first measures the touch detection value VaD of each touch cell (S10). In order to measure the touch detection value VaD, each electrode pad 110 is scanned in a predetermined frequency and order. A touch cell whose touch detection value VaD is not 0 is determined to have occurred a touch, and the touch detection value VaD is recorded in the memory 240 corresponding to each touch cell.

Next, a touch cell group consisting of adjacent touch cells whose touch detection value VaD is not 0 is extracted (S20). According to an embodiment of the present invention, since the electrode pads 110 are each implemented in an isolated matrix form, the multi-touch sensing function is provided. Therefore, when multi-touch occurs, it is necessary to group touch cells in which touch occurs in order to calculate respective touch areas and coordinates.

Next, the area of the touch area is calculated based on the touch detection value VaD of the touch cell group (S30). As described above, since the touch detection value VaD and the touch area are proportional to each other, the touch area may be calculated by summing the touch detection values VaD in the touch cell group.

Next, the coordinates of the touch area are calculated from the calculated area of the touch area (S40). In the touch panel according to the exemplary embodiment of the present invention, the electrode pad 110 has a polygonal shape having a uniform size, and is densely arranged in a matrix form. Thus, the image display device is covered with the predetermined area and address of each of the electrode pads 110. Accordingly, the occupied area of the electrode pad 110 can be matched with the coordinates of the image display device.

If information on the touch occupancy area is calculated for each electrode pad from the touch area calculated in step S30, the touch area distribution of the X-axis and Y-axis of the electrode pad matrix can be obtained. By calculating the area center points of the X and Y axes based on the area distribution, it is possible to calculate the touch coordinates corresponding to the center points of the entire touch areas.

The touch coordinates can be calculated very accurately using the structure of the touch panel and the calculated touch area.

The process illustrated in FIG. 9 may be performed by a signal processor disposed inside and outside the touch sensing apparatus.

10 to 13 illustrate a process of calculating a contact area and a contact position according to an embodiment of the present invention.

When the contact position of FIG. 8 is indicated as an area, it becomes the hatched area of FIG. At this time, for example, a group consisting of four adjacent touch cells having a digital area value other than 00, for example, 2 × 2 cells, and the sum of the digital area values of the touch cells belonging to this group, ie, 01, 10, 11, It can be regarded as a touch area.

The area value can be calculated because the touch detection value VaD and the touch area have a substantially linear proportional relationship.

Although a 2x2 cell group has been described as an example, a group consisting of more or fewer cells may be selected depending on the size of the electrode pad and the size of the touch area. In the case where the value of the touch cell is displayed as 2 bits of the digitized touch detection value VaD, a total of four area values may be obtained for one cell, and 16 area values may be obtained in a 2 × 2 cell group.

By digitizing the difference of the digitized voltage change value into a higher bit, the calculated area value can be more accurate, and the size of the adjacent touch cell group having a non-zero digital area value can be larger.

11 is a diagram illustrating a method of calculating touch coordinates according to an embodiment of the present invention.

Referring to FIG. 11, the center position of the touch area illustrated in FIG. 10 may be a point indicated by X. FIG. For the 2x2 touch cell group, the digital area value of the touch cells at the top left, top right, bottom left and bottom right, that is, 01101111, which is a value in which 01, 10, 11, and 11 are consecutively described, is defined as a value indicating a contact position. The coordinates of the corresponding center position X can be shaped into a lookup table and stored in internal or external memory.

Alternatively, when the touch cell group in which the touch is generated is determined, the touch coordinates may be calculated in real time based on a mutual relationship between the coordinates of the touch cell and the digital area value of the touch cell.

12 illustrates a method of calculating touch coordinates according to another embodiment of the present invention.

Referring to FIG. 12, the digital area values of the touch cells are summed and graphed for each row X axis and each column Y axis of the touch cell group in the form of a 2 × 2 matrix. For example, FIG. 12 shows graphs at the bottom and the right, respectively.

In the lower graph, the sum of the digital area values corresponding to the first column is 01 + 11 and the sum of the digital area values corresponding to the second column is 10 + 11. The graph then finds the X coordinate that bisects the value integrated on the X axis (that is, the area of the area between the horizontal axes).

For example, if the width of the touch cell is 1 and the block's left border is 0, then in the range of 0 to 1, a straight line parallel to the horizontal axis will be drawn with a height of 4 (= 01 + 11) in decimal. In this 1 to 2 range, a straight line parallel to the abscissa will be drawn with a height of 5 (= 10 + 11) in decimal. The area between the horizontal axis and these straight lines will be a stepped figure as in Fig. 12, and the area of this figure is 9 (= 4 + 5). If the abscissa of the vertical line dividing the area of the figure is (1 + x), then (4 + 5x) = 5 (1-x), so x = 0.1. Therefore, the horizontal coordinate of the vertical line becomes 1.1.

Similarly, in the graph on the right, the digital area value for the first row is 01 + 10 and 11 + 11, the sum of the digital area values for the second row. Again in this case, the Y coordinate is found to bisect the value integrated on the Y axis (that is, the area of the area between the vertical axes).

For example, if the height of the touch cell is 1 and the upper boundary of the block is 0, and the coordinate value increases as the number goes down, the height is 3 (= 01 + 10) in decimal format and the vertical axis and Parallel straight lines will be drawn, and in the range where the vertical axis is 1-2, a straight line parallel to the vertical axis will be drawn with a height of 6 (= 11 + 11) in decimal. The area between the vertical axis and these straight lines will be a stepped figure, as in FIG. 12, with an area of 9 (= 3 + 6). (3 + 6x) = 6 (1-x) when the ordinate of the horizontal line bisecting the area of the figure is set to (1 + x). Therefore, the ordinate of the horizontal line is 1.25.

In this way, the touch coordinates can be calculated by obtaining the x coordinates and the y coordinates as the centers of the touch areas.

Since the electrode pads are arranged on the image display device in the form of a matrix, the coordinates in the electrode pad matrix can be matched with the coordinates of the image display device. Therefore, by using the coordinates of the center position of the area distribution of the X axis and the Y axis in the touch cell group in which the touch occurs, the center position of the entire touch area can be calculated in the image display apparatus.

The signal processor 230 may determine the touch position by using the touch area occupying each cell in this manner. Even when the value of the touch cell is displayed as 2 bits, a total of 256 positions can be obtained for one block, and thus a touch coordinate resolution higher than the number of touch cells can be obtained.

If the digitized area value is provided with higher bits, the resolution of the touch coordinates will be much higher. That is, if the digitized area value is provided with a higher bit, it is possible to detect a change in the fine touch area distribution and use it to detect a change in the fine touch coordinates.

12 has been described with a fairly simple example, further statistical processing may be further performed to yield a more accurate area distribution within the touch cell group.

FIG. 13 is a diagram illustrating touch coordinates and a touch area together based on an embodiment of the present invention.

Referring to FIG. 13, when a touch occurs in a predetermined area, an accurate contact area is calculated by adding the digital area values of touch cells belonging to a touch cell group, which is a set of touch cells having a digital area value other than 00, and the digital area. By properly processing the distribution of area values, the exact center position of the contact can be found.

In addition, shape information of a region in which a touch occurs may be provided using coordinate information of a touch cell in which a touch occurs. For example, in FIG. 13, since a touch occurs in a 2 × 2 touch cell group, a circular touch area having a detected area may be calculated. However, if a touch occurs in a 2 × 3 touch cell group, an elliptical touch area having a long vertical axis may be calculated. Therefore, according to the embodiment of the present invention, the shape of the touch region may be used as one of the user inputs.

In addition, if the touch area value in the touch cell of the touch cell group is considered, a more precise shape of the touch area may be calculated.

The obtained touch area and the touch position can be used as an input gesture for driving an electronic device including a display device related to the touch sensing device, for example, a smart phone or the like.

This will be described in detail with reference to FIGS. 14 to 19.

14 to 17 are schematic diagrams illustrating a touch operation of a user, and FIG. 18 is a flowchart illustrating an operation according to a contact area in an electronic device according to an embodiment of the present disclosure, and FIG. 19 is an embodiment of the present disclosure. According to the change of the contact area in the electronic device according to the present invention.

Referring to FIG. 14, a user may lightly tap or press firmly on a specific graphic interface displayed on the touch panel. That is, the contact area between the touch panel and the finger may be smaller than the threshold value, the contact area may be larger than the threshold value, and accordingly, the user's touch intention may be different. In this case, even when the same graphic interface is touched, when the touch area is small, the electronic device performs an operation A, but when the touch area is large, an operation B may be performed instead of A.

Referring to FIG. 15, a user may scroll left and right or up and down while being in contact with a touch panel, and the display device may perform an operation different from that of FIG. 14. At this time, different operations may be performed according to the contact area. For example, when the area of the touch panel is large, the scroll speed may be slowed or touch-slided with a stronger force.

In the embodiment illustrated in FIG. 16, when the touch area is greater than or equal to a threshold, a new operation may be performed. For example, if a contact area on a document or a picture is larger than a certain area and the contact surface moves, the operation of deleting a part of the document or picture may be performed.

Referring to FIG. 17, a user may drive an electronic device by using a change in touch angle.

In general, when the user changes the touch area, the angle of the touched finger that is touching changes. This tendency is stronger because most handheld electronic devices are touch driven with the electronic device held.

For example, in order to reduce the touch area, the angular change of the finger joint occurs while raising the finger tip. On the contrary, in order to increase the touch area, the angle of the finger joint is changed while lying on the tip of the finger.

In this case, a change in touch coordinates and a change in area are accompanied. Accordingly, when the touch coordinate is moved upward while the touch area is reduced while the touch is maintained, it may be recognized that the finger is bent up. Conversely, if the touch area increases while the touch coordinate moves downward, it is possible to recognize that the finger is extended.

By using this, it is possible to provide various user interfaces (eg, change of viewpoint of a 3D object) in which the user can intuitively recognize the angle of the finger.

Here, the user intention may be more accurately determined by using the direction information in which the touch area is increased / decreased in addition to the change in the touch coordinates and the touch area.

If it is necessary to perform different operations according to the contact area as illustrated in FIGS. 14 and 15, the operations may be performed in the same order as illustrated in FIG. 18. The operation illustrated in FIG. 18 is an example in which the contact area is divided into three types of large, medium, and small, and accordingly, three different operations are performed, and the operations occurring in the electronic device including the touch sensing device and the display device are shown.

First, the contact is detected according to the above-described process (S210), the contact area is calculated (S220), and it is determined whether the contact area is larger than the set value A1 (S230). If the contact area is larger than the set value A1, it is determined whether the contact area is larger than the set value A2 (S230). Otherwise, an instruction corresponding to the small area contact is executed (S250). If the contact area is larger than the set value A2 in step S230, a command corresponding to the large area contact is executed (S270), otherwise, a command corresponding to the medium area contact is executed (S260).

Among the operations, steps S210 and S220 may be performed by the touch sensing device, and the remaining operations may be performed by another part of the electronic device, for example, a command processor or software (not shown).

As shown in FIGS. 17 and 18, when other operations are to be performed according to a change in contact area, the operations may be performed in the same order as shown in FIG. 19.

First, the contact is detected according to the above-described process (S310), the contact area is calculated (S320), and it is determined whether the contact area changes (S330).

If the contact area changes, it is determined whether the contact is maintained (S340), otherwise, another predetermined operation is performed.

If the contact area is maintained in step S340, a command corresponding to the change of the contact area is executed (S350), otherwise, another operation may be performed.

Meanwhile, a virtual image corresponding to the contact area may be generated at the contact position, and a corresponding operation may be performed or displayed on the display device. The virtual image may also be operated depending on whether the virtual image is stationary or moved. This may vary.

As described above, according to the present embodiment, the contact area can be accurately obtained and various operations can be performed accordingly.

It is to be understood that the foregoing description of the disclosure is for the purpose of illustration and that those skilled in the art will readily appreciate that other embodiments may be readily devised without departing from the spirit or essential characteristics of the disclosure will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

It is to be understood that the scope of the present invention is defined by the appended claims rather than the foregoing description and that all changes or modifications derived from the meaning and scope of the claims and equivalents thereof are included in the scope of the present invention .

100: substrate, 110: electrode pad,
120: signal wiring, 200: circuit board,
210: driver, 220: detector,
222: amplifier, 224: analog-to-digital converter,
230: signal processing unit, 240: memory,
250: touch cell, 260: reference cell

Claims (16)

A user input sensing device,
A plurality of electrode pads of a transparent material disposed in a matrix form;
A driving unit including a switch and a first capacitor electrically connected to the plurality of electrode pads, and configured to output a voltage change in response to a voltage signal applied to the first capacitor after charging and floating the electrode pad using the switch. ;
A detector configured to output a touch detection value based on a difference between the output voltage change before and after the touch; And
A signal processor that calculates a touch area using the touch detection value and calculates touch coordinates using the touch area.
User input detection device comprising a. The method of claim 1,
And the signal processor is configured to calculate the touch area by extracting a touch cell group corresponding to touched adjacent electrode pads and summing touch detection values of the touched touch cell group. The method of claim 2,
And the signal processor is configured to calculate multi-touch coordinates by using touch areas of a plurality of touch cell groups. The method of claim 1,
And the signal processor calculates the touch coordinates based on a position of the electrode pad on the matrix and a touch area occupying the electrode pad. 5. The method of claim 4,
And the signal processor calculates touch coordinates based on a position of the electrode pads on the matrix and a distribution of touch areas in the X-axis and Y-axis directions. The method of claim 5,
And the signal processor is configured to calculate touch coordinates by using a center point of touch areas in the X and Y axis directions. In the user input detection method,
Driving touch cells corresponding to electrode pads of a transparent material arranged in a matrix;
Outputting a touch detection value based on a difference in voltage change generated from the driven touch cell before and after the touch;
Calculating a touch area based on the touch detection value; And
And calculating touch coordinates using the calculated touch area and position information of the touched electrode pad. The method of claim 7, wherein
The touch cell driving step,
Charging and floating the electrode pad by using a switch electrically connected to the electrode pad, and outputting a voltage change generated by applying a voltage signal to a first capacitor electrically connected to the electrode pad,
The touch detection value output step,
Detecting the difference in the output voltage change before and after the touch as a touch detection value. The method of claim 7, wherein
And extracting a touch cell group including adjacent cells from which a touch is detected, based on the touch detection value. 10. The method according to claim 8 or 9,
And calculating the touch coordinates based on the coordinates of the center point of the touch area. The method of claim 10,
The center point coordinate of the touch area is calculated based on the distribution of the touch area occupying the electrode pad. The method of claim 11,
And a center point coordinate of the touch area is calculated using an area center point in the X axis direction and an area center point in the Y axis direction of the touch area. In the integrated circuit (IC) used in the user input sensing device,
And a switch and a first capacitor electrically connected to the plurality of electrode pads arranged in a matrix form, wherein the voltage change is responsive to a voltage signal applied to the first capacitor after charging and floating the electrode pad using the switch. A driving unit for outputting;
A detector configured to output a touch detection value based on a difference between the output voltage change before and after the touch; And
A signal processor that calculates a touch area using the touch detection value and calculates touch coordinates using the touch area.
Integrated circuit comprising a. The method of claim 13,
And the signal processor is configured to calculate the touch area by extracting a touch cell group corresponding to touched adjacent electrode pads and summing touch detection values of the touched touch cell group. The method of claim 13,
And the signal processing unit calculates the touch coordinates based on the position of the electrode pad and the touch area occupying the electrode pad. 16. The method of claim 15,
And the signal processor calculates touch coordinates by using the position of the electrode pad and the center point of the touch area in the X and Y axis directions of the touch panel.

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