KR101493494B1 - User device including fingerprint sensing region in touch screen - Google Patents

Abstract

A user terminal is provided. The user terminal comprises a plurality of electrostatic sensors arranged in a matrix on a substrate of transparent material, a switch electrically connected to the plurality of electrostatic sensors, and a capacitor, wherein the electrostatic sensor is charged and floating using the switch, A detection unit for outputting a touch detection value based on a difference between the voltage changes before and after the touch, and a controller for outputting a touch detection value based on the output touch detection value, And a signal processing unit for calculating a touch area and touch coordinates, wherein a part of the plurality of electrostatic sensors is a fingerprint recognition area in which electrostatic sensors of a specific size are densely arranged so as to recognize a fingerprint.

Description

USER DEVICE INCLUDING FINGERPRINT SENSING REGION IN TOUCH SCREEN < RTI ID = 0.0 >

The present invention relates to a user terminal, and more particularly, to a user terminal including a fingerprint recognition area within a touch screen.

2. Description of the Related Art In recent years, various additional functions utilizing personal information such as mobile banking have been provided as well as communication functions such as telephone or text message transmission service through a mobile communication terminal.

Accordingly, the need for a locking device of a mobile communication terminal is becoming more important.

Conventional locking devices applied to mobile communication terminals are mostly conventional methods using passwords.

For example, a lock device is applied to a telephone function, an additional function, or an international telephone function, and the user must input the password in order to use the function.

However, this method is inconvenient in that the password becomes useless when the password is exposed, the password must be periodically changed to secure stability, and the password must be remembered from the user's point of view.

Therefore, in recent years, a terminal equipped with a locking device through fingerprint recognition has been developed in earnest in order to supplement such a method and improve the locking effect.

In order to mount such a fingerprint recognition device on a small-sized mobile communication terminal, the size of the sensor must be minimized. If necessary, the fingerprint recognition device may recognize a fingerprint 'Sliding type' fingerprint sensor is being developed.

Meanwhile, as the fingerprint recognition sensor is mounted on the mobile communication terminal, efforts have been made to combine it with other functions.

SUMMARY OF THE INVENTION The present invention is directed to provide a user terminal including a fingerprint recognition area in a touch screen.

In order to achieve the above object, a user terminal including a fingerprint recognition area in a touch screen of the present invention includes a plurality of electrostatic sensors arranged in a matrix form on a substrate of a transparent material, a plurality of electrostatic sensors electrically connected to the plurality of electrostatic sensors A driver for charging and floating the electrostatic sensor using the switch and outputting a voltage change that varies according to a voltage signal applied to the capacitor, And a signal processing unit for calculating a touch area and a touch coordinate based on the output touch detection value, wherein a part of the plurality of the electrostatic sensors is capable of recognizing a fingerprint A fingerprint recognition area in which electrostatic sensors of a specific size are densely arranged.

According to an aspect of the present invention, the signal processing unit recognizes the touched fingerprint when a touch occurs in the fingerprint recognition area for a specific time or longer and an area of the touch generated in the fingerprint recognition area is equal to or greater than a threshold value.

Further, in one aspect of the present invention, the interval between the adjacent electrostatic sensors among the plurality of electrostatic sensors disposed in the fingerprint recognition area is equal to or less than the interval between the ridge of the fingerprint and neighboring valleys.

According to an aspect of the present invention, the signal processing unit generates fingerprint information based on whether or not each electrostatic sensor disposed in the fingerprint recognition area is touched, the touch area, and the touch coordinates.

Further, in one aspect of the present invention, the fingerprint recognition area is highlighted and displayed when a fingerprint input request due to the execution of a specific application is displayed.

According to an embodiment of the present invention, the size of the touch screen can be enlarged to the space where the conventional fingerprint sensor is located.

Further, according to an embodiment of the present invention, it is possible to reduce power consumption for operating the conventional fingerprint sensor, thereby contributing to reduction of power consumption of the touch screen device.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a block diagram illustrating a configuration of a user terminal according to an embodiment of the present invention.
2 is an equivalent circuit diagram of a touch cell according to an embodiment of the present invention.
3 is a waveform diagram of a touch cell according to an embodiment of the present invention.
4 is a schematic block diagram of a touch cell and a detection unit according to an embodiment of the present invention.
5 is a graph showing the output of an amplifier according to an embodiment of the present invention.
6 is a graph showing a relationship between a difference voltage and a touch capacitance in an embodiment of the present invention.
7 is a schematic diagram for explaining a correspondence relationship between a touch cell and a memory according to an embodiment of the present invention.
8 is a flowchart illustrating a method of calculating a touch area and touch coordinates according to an embodiment of the present invention.
9 to 12 are diagrams illustrating a process of calculating a contact area and a contact position according to an embodiment of the present invention.
13 is a diagram illustrating use of a user terminal in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. 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 order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "indirectly connected" . Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

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

1 is a block diagram illustrating a configuration of a user terminal according to an embodiment of the present invention.

A user terminal according to an embodiment of the present invention may include a touch panel and a driving device.

The touch panel may include a plurality of electrostatic sensors 110 formed on a substrate 100 such as a transparent glass or plastic film, and a plurality of signal lines 120 connected thereto.

In addition, the plurality of electrostatic sensors 110 may be, for example, rectangular or rhombic, but are not limited thereto. The electrostatic sensors 110 may be implemented as a uniform polygonal shape, and may be arranged in a matrix form of substantially adjacent polygonal shapes.

Here, some of the plurality of electrostatic sensors 110 may be a fingerprint recognition area 111 in which electrostatic sensors of a specific size are closely arranged to recognize fingerprints.

For example, the fingerprint recognition area 111 may be an area in which 128 x 128 pixels are densely arranged with an electrostatic sensor having a size of 50 mu m and 50 mu m as one pixel, and the size of the pixel and the degree the fingerprint sensing accuracy for the fingerprint recognition area 111 can be varied depending on the number of pixels.

For reference, the signal lines of the fingerprint recognition area 111 can be connected to the respective electrostatic sensors, and are shown in gray area for convenience in FIG.

In addition, the fingerprint recognition area 111 can be touched and can recognize fingerprints like the plurality of electrostatic sensors 110, depending on the touch connection time and contact area.

Hereinafter, the electrostatic sensor of a specific size disposed in the fingerprint recognition area 111 will be referred to as a 'pixel'.

Each signal line 120 has one end connected to the electrostatic sensor 110 and the other end extending to the lower edge of the substrate 100.

For reference, the line width of the signal wiring 120 can be designed to be quite narrow to the order of several to several tens of micrometers (占 퐉).

The electrostatic sensor 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. have.

The electrostatic sensor 110 and the signal wiring 120 can be simultaneously formed by, for example, laminating an ITO film on the substrate 100 by a method such as sputtering and then patterning using an etching method such as photolithography.

In addition, the electrostatic sensor 110 and the signal wiring 120 may be covered with a transparent insulating film (not shown).

On the other hand, the driving device for driving the touch panel may be directly mounted on a part of the substrate 100, or formed on a circuit board 200 such as a printed circuit board or a flexible circuit film.

Here, the driving device may include a driving unit 210, a detecting unit 220, a signal processing unit 230, a memory 240, and the like, and may be implemented by one or more integrated circuit (IC) chips.

The driving unit 210 is connected to the signal line 120. The driving unit 210 receives signals from the signal processing unit 230 and drives circuits for touch detection. Can be output.

The driving unit 210 may include a plurality of switches and capacitors electrically connected to the electrostatic sensor 110. The electrostatic sensor 110 may be charged and floated by using a switch, A voltage change responding to the signal can be output.

The detecting unit 220 is connected to the driving unit 210 and may convert the difference in voltage of the electrostatic sensor 110 received from the driving unit 210 into a digital signal.

In addition, the detector 220 may include an amplifier and an analog-to-digital converter.

The signal processing unit 230 may apply a signal for controlling the driving unit 210 or may process the digital voltage stored in the memory 240 to generate necessary information. (Not shown) and a digital signal processor (not shown).

Here, the analog signal processing unit (not shown) controls the driving unit 210, and the digital signal processing unit (not shown) can calculate the touch area and the touch coordinates based on the difference in the voltage change detected from the detection unit 220.

Also, the signal processing unit 230 can generate fingerprint information by recognizing the touched fingerprint when the touched fingerprint area 111 is touched for a specific time or more and the area of the touch is equal to or greater than a threshold value.

For reference, a fingerprint consists of a valley, which is the space between the ridge and the ridge, as raised ridges in the fingertip of a person.

When such a fingerprint is touched to the fingerprint recognition area 111, the ridge comes into contact with some pixels of the fingerprint recognition area 111, and the valley does not contact the pixels of the fingerprint recognition area 111 .

Therefore, the signal processing unit 230 determines whether or not the pixel of the fingerprint recognition area 111 is in contact with the ridge, or based on the area and coordinate of the ridge contacted with the pixel of the fingerprint recognition area 111 Fingerprint information can be generated.

In addition, the signal processing unit 230 may include a microcontroller unit (MCU), and may perform predetermined signal processing through the firmware.

Meanwhile, the memory 240 may store predetermined data or real-time data to be used for touch detection, area calculation, and touch calculation according to an instruction of the signal processing unit 230.

As described above, the driving unit 210, the detection unit 220, the signal processing unit 230, and the memory 240 may be separated, or two or more components may be integrated.

Hereinafter, a specific embodiment of the touch panel and the driving unit shown in FIG. 1 and its operation will be described in detail with reference to FIG.

2 is an equivalent circuit diagram of a touch cell according to an embodiment of the present invention.

2, the driving unit 210 includes a plurality of transistors Q and a plurality of first capacitors C1 for performing a switching operation, and may further include a plurality of sensor capacitors Cp.

Here, the transistor Q, the first capacitor C1, and the sensor capacitor Cp can be grouped one by one for each of the electrostatic sensor 110 and the signal line 120, and the electrostatic sensor 110, the signal line 120 ), The transistor Q, the first capacitor C1, and the sensor capacitor Cp are collectively referred to as a "touch cell ".

For reference, 'touch cell' is a concept that includes the case where each component is electrically connected by a multiplexer.

The transistor Q of the driving unit 210 may be a field effect transistor, for example, a control voltage Vc may be applied to the gate, a data voltage Vd may be applied to the source (or drain) (Or source) may be coupled to the signal line 120.

Here, the control voltage Vc and the data voltage Vd may be applied under the control of the signal processing unit 230, and other elements that can perform switching instead of the transistor Q may be used.

Meanwhile, 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 in order to secure a necessary capacity.

The voltage signal applied to the first capacitor C1 may be the same as the voltage signal applied to the gate of the transistor Q. However, if the first capacitor C1 is formed separately from the transistor Q, A voltage signal may be applied.

For reference, the voltage signal applied to the first capacitor C1 is preferably a square wave signal.

The sensor capacitor Cp is a kind of parasitic capacitance formed by the electrostatic sensor 110 or the signal wiring 120 and includes any parasitic capacitance generated by the driving unit 210, the touch panel, .

For reference, a cell having an electrical characteristic that is placed at a position that the user can not touch or is not always touched can be disposed, which is referred to as a "reference cell ".

Here, the "reference cell" may physically exist, but it may be a virtual cell having only a data value.

2, reference character Ct denotes a capacitance formed between the electrostatic sensor 110 and the user's finger when the user touches the electrostatic sensor 110. [

3 is a waveform diagram of a touch cell according to an embodiment of the present invention.

3, the signal processing unit 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, when the control voltage Vc applied to the gate rises from the low voltage VL to the high voltage VH, the transistor Q is turned on.

Accordingly, the electrostatic sensor is charged with the data voltage Vd, and the output voltage Vo will be the data voltage Vd.

Thereafter, when the control voltage Vc falls from the high voltage VH to the low voltage VL, the transistor Q is turned off, and the electrostatic sensor 110 is in a floating state.

At this time, the voltage level of the output voltage Vo of the electrostatic sensor 110 is instantaneously dropped due to the level drop of the square wave applied to the first capacitor C1. Such a voltage drop phenomenon is 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 electrostatic sensor 110 are only the first capacitor C1 and the sensor capacitor Cp, these capacitors C1, The voltage drop (V1) of the output voltage (Vo)

[Equation 1]

 .

For the sake of convenience, the same reference numerals are used for the capacitors and their capacitances.

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

However, as shown in FIG. 2, when the user touches the electrostatic sensor 110 (Case 2), a capacitor Ct is formed between the electrostatic sensor 110 and the finger or contact means of the user, The capacitors connected to the sensor 110 may be added with the touch capacitors Ct in addition to the first capacitors C1 and the sensor capacitors Cp.

The voltage drop V2 of the electrostatic sensor 110 by these three capacitors C1, Cp, and Ct can be expressed by the following equation (2).

&Quot; (2) "

As a result, the voltage drop V2 in Case 2 is smaller than the voltage drop V1 in Case 1 where no touch occurs, and the voltage drop V2 and the voltage drop V1, May vary depending on the touch capacitance Ct.

In general, the capacitance C of the capacitor is proportional to the area A of the electrode and is proportional to the distance d between the electrodes, that is, C = εA / d (ε is the dielectric constant).

Accordingly, as the touch area increases, the touch capacitance Ct increases. Using this relationship, it is possible to calculate the touch area using the difference in the voltage drop of the electrostatic sensor 110 before and after the touch. Details of the calculation of the touch area will be described later.

As shown in Fig. 3, when the control voltage Vc applied to the first capacitor C1 changes when the transistor Q is turned off, a change in the voltage 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).

3, 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, The voltage level may rise.

In this case, the total capacitance of Case 2 (Case 2) is larger than the total capacitance of Case 1 (Case 1), so that the voltage rise will be small (see Equations 1 and 2).

Therefore, even when the voltage applied to the first capacitor C1 rises in the floating state, the touch can be detected on the same principle as in the above-described embodiment, and the point of time during which the voltage rise / Is selectable.

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

Hereinafter, a specific example of the detection unit shown in FIG. 2 and its operation will be described in detail with reference to FIG. 4 to FIG.

4 is a schematic block diagram of a touch cell and a detection unit according to an embodiment of the present invention.

Referring to FIG. 4, the detector according to the present embodiment may include an amplifier 222 and an analog-to-digital converter (ADC) 224.

The two inputs of the amplifier 222 may be the output voltage Vo of the touch cell 250 and the output voltage Vr of the reference cell 260 and the amplifier 222 may be controlled by the difference between the two output voltages Vo and Vr And outputs the amplified signal.

In Fig. 4, Va represents the output voltage of the amplifier 222, and VaD represents the output voltage of the amplifier 222 digitized.

Here, the touch cell 250 may include the electrostatic sensor 110, the signal wiring 120, the transistor Q, the first capacitor C1, and the sensor capacitor Cp shown in FIG. Refers to a normal touch cell that further includes a touch capacitor Ct. The reference cell 260 refers to a touch cell that does not include a touch capacitor Ct because no user touch occurs as described above do.

The difference (? V = Vo - Vr) between the output voltage Vo of the touch cell 250 and the output voltage Vr of the reference cell 260 indicates that the control voltage Vc is lower than the high voltage VH ) Of the voltage drop.

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 can be expressed by the following equation 3 .

&Quot; (3) "

5 is a graph showing the output of an amplifier according to an embodiment of the present invention.

When the amplifier 222 is a differential amplifier, the differential voltage? V is amplified linearly, and saturated at a specific value or more and output a constant value.

5, the output voltage Va of the amplifier 222 is Vas when the difference voltage? V is equal to or higher than the saturation voltage? Vs, and has a magnitude proportional to the difference voltage? have.

For example, if the difference voltage V is 0, the output voltage Va is 0 and the difference voltage V is? V1, the output voltage Va is Va1 and the difference voltage? V is? Va2 and the difference voltage? V is? V3, the output voltage Va can be Va3.

When the electrostatic sensor 110 is sufficiently small in size such as an electrostatic sensor disposed in the fingerprint recognition area 111 and the electrostatic sensor 110 is completely covered by a finger when a touch is generated, May have a maximum value, and may not increase any more.

Therefore, by designing the amplifier 222 such that the saturation voltage? Vs is greater than or equal to the maximum value of the difference voltage? V, linearity can be imparted to the amplifier, and 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 outputs the 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 apply a digital value of 2 bits in the order of magnitude to each section.

5, 00 is output when the output voltage Va of the amplifier 222 is about 0 to Va1, 01 is selected when Va1 to Va2, 10 when Va2 to Va3, and 11 when Va3 or more. Can be given.

However, the digital value of 2 bits is only an example, and other examples such as 4 bits, 8 bits, and 10 bits are possible

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

Equation (3) is rewritten as a function of the difference voltage (V) as follows.

&Quot; (4) "

(Where K1 = C1 (VH-VL), K2 = C1 + Cp, where K1 and K2 are constants,

As shown in FIG. 6, when the differential voltage V is 0, the touch capacitance Ct is 0 and the touch capacitance Ct increases as the difference voltage V 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 electrostatic sensor 110, that is, Ct =? A / d (? Is a dielectric constant) the touch area A and the touch capacitance Ct are linearly proportional to each other and the larger the difference voltage V is, the larger the touch area A is.

As described above, when the entire area of the electrostatic sensor 110 is completely covered by the touch of a finger or the like, the touch area A can not be larger than the area of the electrostatic sensor 110, And the touch area A becomes the maximum value.

As a result, in the graph of FIG. 6, the difference voltage? V is effective in a section between 0 and the maximum value? V_max, and the linearity between the difference voltage? V and the touch area A is given .

For example, a linear function may be generated in the valid period and an output value of the generated linear function may be matched to each of the difference voltages? V.

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.

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

Alternatively, when the relationship between the differential voltage and the touch area A of the voltage difference? Is not perfectly linear, the inclination is sufficiently gentle to provide sufficient accuracy for area calculation, and is treated as being substantially linear proportional, The differential voltage DELTA V can be used for calculating the touch area A.

5, since the difference voltage V and the amplified value Va also have a linearity by the amplifier 222, the amplified value Va of the differential voltage V is also changed to a touch And the digitized value VaD of the amplification value Va can have a linearity with the touch area A. [

The relation between the differential voltage (? V) and its amplification value (Va or VaD) defined by the various embodiments described above and the touch area (A) is referred to as "substantially linear proportional ".

Using this "substantially linear proportional" relationship, a user terminal according to an embodiment of the present invention can detect a very accurate touch area and coordinates.

7 is a schematic diagram for explaining a correspondence relationship between a touch cell and a memory according to an embodiment of the present invention.

The memory 240 shown in FIG. 1 includes a plurality of memories 240 having addresses corresponding to, for example, the touch cell 250 (strictly speaking, the electrostatic sensor 110) And each memory cell may store a difference voltage VaD that is amplified and digitized through the amplifier 222 and the ADC 224.

As described above, since the amplified and digitized difference voltage VaD can be substantially linearly proportional to the touch area for the electrostatic sensor 110, the amplified and digitized difference voltage VaD is equal to the tapped digital area value .

Therefore, the amplified and digitized difference voltage VaD is a value related to the touch detection, and will be referred to as "touch detection value VaD" for convenience of explanation.

For reference, the magnitude of the touch detection value VaD can correspond to the magnitude of the touch area with respect to one electrostatic sensor. When the touch detection value VaD is digitized to 2 bits, four values of 00, 01, 10, Value. ≪ / RTI >

Here, 00 means that no touch is made, and 11 means that the entire electrostatic sensor is covered by touching.

In FIG. 7, the touch cells C1 to C16 and the memory cells M1 to M16 are shown, and M1 to M16 correspond to C1 to C16, respectively.

Touches are generated in the 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 Let's say that less than 10 touches your finger.

00 is stored in the memory cells C1 to C5, C8, C9, and C12 to C16 corresponding to the touch cells C1 to C5, C8, C9, and C12 to C16 11, 10 for M10 and 11 for M11.

Therefore, the signal processing unit 230 can read the digital area values of the touch cells (C1 to C16) from the memory 240 to determine the contact area and the contact position.

In addition, the signal processing unit 230 may read the touch detection values from the memory 240 to generate shape information of the touch region, and may generate a predetermined control signal according to whether the shape of the touch region is changed.

In addition, the signal processing unit 230 can generate fingerprint information based on whether each pixel disposed in the fingerprint recognition area 111 is touched.

More specifically, FIG. 7 shows the arrangement of the touch cells for detecting the touch generation area at the time of occurrence of the touch, and the pixels arranged in the fingerprint recognition area 111 can be arranged more finely than shown in FIG. 7 For example, the spacing between neighboring pixels among the pixels disposed in the fingerprint recognition area 111 may be less than the interval between the ridge of the fingerprint and neighboring valleys.

Therefore, when the user's finger touches the fingerprint recognition area 111, each pixel disposed in the fingerprint recognition area 111 is in contact with a ridge of the fingerprint or due to a valley of the fingerprint, The signal processing unit 230 may generate fingerprint information by combining information on pixels in contact with ridges of the fingerprint.

At this time, the signal processing unit 230 may generate fingerprint information based on whether or not each pixel is simply touched according to the size and layout interval of each pixel disposed in the fingerprint recognition area 111, Fingerprint information may be generated based on the coordinates.

Here, the touch area of each pixel means a contact area of a ridge to each pixel, and the touch coordinates of each pixel may be a coordinate in which a ridge is contacted.

For example, when the size of each pixel disposed in the fingerprint recognition area 111 is smaller than the thickness of a ridge, the signal processing unit 230 can generate fingerprint information based on whether or not each pixel is in contact, When the size of each pixel disposed in the fingerprint recognition area 111 is larger than the thickness of the ridge, the signal processing unit 230 can generate fingerprint information based on the contact area and coordinate of the ridge contacted to each pixel have.

For reference, the signal processing unit 230 can perform the fingerprint recognition for the touch touched to the fingerprint recognition area 111 if a touch occurs for a specific time or longer with respect to the fingerprint recognition area 111 and the area of the touch is equal to or greater than a threshold value have.

A method of determining the contact area and the contact position of the signal processing unit 230 will be described in detail with reference to FIGS. 9 to 12. FIG.

9 to 12 can be applied not only to the electrostatic sensor 110 but also to the electrostatic sensor disposed in the fingerprint recognition area 111. [

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

8 can be performed in the signal processing unit 230. Hereinafter, the flowchart of FIG. 8 will be described with a user terminal including the signal processing unit 230 as a main unit.

First, the user terminal measures a touch detection value (VaD) of each touch cell (S10).

At this time, each electrostatic sensor 110 is scanned in order with a predetermined frequency in order to measure the touch detection value VaD.

A touch cell having a non-zero touch detection value (VaD) is determined to have generated a touch, and a touch detection value (VaD) is recorded corresponding to each touch cell in the memory (240).

After step S10, the user terminal extracts a touch cell group including adjacent touch cells whose touch detection value (VaD) is not 0 (S20).

For reference, since the electrostatic sensors 110 are implemented in the form of an isolated matrix, they can provide a multi-input sensing function. Accordingly, when multi-touch occurs, a step of grouping the touch cells in which the touch occurs is required to calculate the respective touch areas and coordinates.

After S20, the user terminal calculates the area of the touch area based on the touch detection value VaD of the touch cell group (S30).

Here, since the touch detection value VaD and the touch area are mutually proportional, the touch area can be calculated by summing the touch detection values VaD in the touch cell group.

After S30, the user terminal calculates coordinates of the touch area from the area of the calculated touch area (S40).

When the information about the touch occupied area is calculated for each electrostatic sensor from the touch area, the touch area distribution of the X axis and the Y axis of the electrostatic sensor matrix can be obtained. Based on the area distribution, the X axis and Y axis When the area center point is found, the touch coordinates corresponding to the center point of the entire touch area can be calculated.

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

9 to 12 are diagrams illustrating a process of calculating a contact area and a contact position according to an embodiment of the present invention.

When the contact position shown in Fig. 7 is displayed in Fig. 9, it becomes a hatched area in Fig.

At this time, for example, a group consisting of four adjacent touch cells having a digital area value other than 00, for example, 2X2 cells is held and the sum of the digital area values of the touch cells belonging to this group, i.e., 01, 10, 11, It can be regarded as an area.

The area value can be calculated because the touch detection value VaD and the touch area are substantially linearly proportional to each other.

Although a 2x2 cell group has been described as an example, a group consisting of more or less cells may be selected depending on the size of the electrostatic sensor and the size of the touch area.

When the digitized touch detection value (VaD) of the touch cell is represented by 2 bits, a total of 4 area values can be obtained for one cell and 16 area values can be obtained from the 2X2 cell group.

Further, if the difference between the digitalized voltage variation values is digitized to 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.

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

Referring to FIG. 10, the center position of the touch region shown in FIG. 9 may be a point indicated by X. FIG.

01101111, which is a successive value of the digital area values of the upper left, upper right, lower left, and lower right touch cells for the 2x2 touch cell group, is defined as a value indicating the contact position, and this value and the corresponding The coordinates of the center position X can be stored in the internal or external memory in the form of a look-up table.

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

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

Referring to FIG. 11, the digital area values of the touch cells can be summed and plotted for each row X-axis and each column Y-axis of the touch cell group in the form of a 2x2 matrix.

11, 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.

In this graph, an X coordinate is obtained by bisecting 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 left boundary of the block is 0, a straight line parallel to the horizontal axis will be drawn with a height of 4 (= 01 + 11) in decimal notation in the range of 0 to 1, In the range of 1 ~ 2, the height will be 5 (= 10 + 11) in decimal and a straight line parallel to the horizontal axis will be drawn.

At this time, the horizontal axis and the area between these straight lines will be a stepped shape as shown in Fig. 11, and the area of this figure is 9 (= 4 + 5).

(4 + 5x) = 5 (1-x) when the abscissa of the vertical line bisecting the area of the figure is set to (1 + x). Therefore, the horizontal coordinate of the vertical line becomes 1.1.

Similarly, in the right graph, the digital area value for the first row is 01 + 10, which is the sum of the digital area values for the second row, 11 + 11.

In this case as well, a Y coordinate that bisects the value integrated in the Y axis (i.e., the area of the area between the vertical axes) is found.

For example, if the height of the touch cell is 1, the upper boundary of the block is 0, and the coordinate value becomes larger toward the lower side, the height is 3 (= 01 + 10) A parallel straight line will be drawn. In the range of 1 to 2 on the vertical axis, the height will be 6 (= 11 + 11) in decimal and a straight line parallel to the longitudinal axis will be drawn.

Here, the vertical axis and the area between these straight lines will be a stepped shape as shown in Fig. 11, and the area of this figure is 9 (= 3 + 6).

(3 + 6x) = 6 (1-x), x = 0.25, and the ordinate of the horizontal line is 1.25, when the ordinate of the horizontal line bisecting the area of the figure is set to (1 + x).

In this manner, touch coordinates can be calculated by obtaining the x-coordinate and the y-coordinate which are the centers of the touch area.

Since the electrostatic sensor 110 is disposed on the image display device in a matrix form, the coordinates in the electrostatic sensor 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 processing unit 230 can determine the touch position using the touch area occupying each cell in this manner.

Even if the value of the touch cell is represented by 2 bits, since a total of 256 positions can be obtained for one block, a touch coordinate resolution higher than the number of touch cells can be obtained.

If the digitized area value is provided with a higher bit, the resolution of the touch coordinates will be much higher.

That is, if the digitized area value is provided with a higher bit, the change of the fine touch area distribution can be detected, and the change of the fine touch coordinates can be detected using the digitized area value.

FIG. 11 illustrates a fairly simple example, and additional statistical processing may be performed to produce a more accurate area distribution within the touch cell group.

FIG. 12 is a diagram showing touch coordinates and a touch area according to an embodiment of the present invention.

Referring to FIG. 12, when a touch occurs in a predetermined area, an accurate contact area is calculated by adding 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, The exact center position of the contact can be found.

In addition, by using the coordinate information of the touch cell in which the touch occurs, the shape information of the area where the touch is generated can be provided.

For example, in FIG. 12, since a touch occurs in a 2x2 touch cell group, a circular touch area having a detected area can be calculated.

However, if a touch occurs in the 2x3 touch cell group, a long oval touch region having a vertical axis can be calculated.

Therefore, according to an embodiment of the present invention, the shape of the touch region may also 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 taken into consideration, a more precise shape of the touch area can be calculated.

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

13 is a diagram illustrating use of a user terminal in accordance with an embodiment of the present invention.

As shown in FIG. 13, the fingerprint recognition area 111 is included in the touch screen, and the user can select a specific menu of the user terminal (application installed in the user terminal) through the touch screen including the fingerprint recognition area 111 You can select or run specific functions.

At this time, when a specific application is executed and a fingerprint input is required, the user terminal can display the fingerprint recognition area 111 by displaying or highlighting a specific color in the fingerprint recognition area 111 as shown in FIG. 13 , The display method of the fingerprint recognition area 111 of the user terminal is not limited to the above example.

Then, when the user's fingerprint is input to the fingerprint recognition area 111, the user terminal can determine whether the corresponding touch is a fingerprint input based on the touch time and the touched area of the input fingerprint, and sense the input fingerprint .

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. 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.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: substrate
110: electrostatic sensor
111: fingerprint recognition area
120: Signal wiring
200: circuit board
210:
220:
230: Signal processor
240: Memory

Claims (5)

A user terminal comprising a fingerprint recognition area within a touch screen,
A plurality of electrostatic sensors arranged in a matrix on a substrate of a transparent material;
And a switch and a capacitor electrically connected to the plurality of electrostatic sensors, wherein the electrostatic sensor is charged and floating using the switch, and then a voltage change varying according to a voltage signal applied to the capacitor is outputted A driving unit;
A detection unit for outputting a touch detection value proportional to a magnitude of a touch area of each of the plurality of electrostatic sensors based on a difference between the output voltage changes before and after the touch; And
A signal processing unit for calculating a touch area and touch coordinates based on the output touch detection value;
Wherein some of the plurality of electrostatic sensors are fingerprint recognition areas in which electrostatic sensors of the same type having a specific size are densely arranged so that fingerprints can be recognized.
The method according to claim 1,
Wherein the signal processor recognizes the touched fingerprint when a touch occurs in the fingerprint recognition area for a predetermined time or longer and an area of the touch generated in the fingerprint recognition area is equal to or greater than a threshold value.
The method according to claim 1,
Wherein an interval between adjacent electrostatic sensors among the plurality of electrostatic sensors disposed in the fingerprint recognition area is equal to or less than an interval between a ridge of a fingerprint and neighboring valleys.
The method according to claim 1,
Wherein the signal processing unit generates fingerprint information based on whether or not each electrostatic sensor disposed in the fingerprint recognition area is touched, based on the touch area and the touch coordinates.
The method according to claim 1,
Wherein the fingerprint recognition area is highlighted and displayed when a fingerprint input request due to the execution of a specific application is displayed.

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