KR20120003764A - Touch sensor and method for recognizing a touch - Google Patents

Abstract

PURPOSE: A touch sensor and a touch recognizing method are provided to maximize the usage of a mobile terminal by providing an intuitive user interface when various additional functions are used. CONSTITUTION: A top electrode(310) and a bottom electrode(320) are comprised of stick or planar conductors. The top electrode is installed in an inner side of a case(101,102) and is diced by a separator. A piezoelectric element(330) is installed between the top electrode and the bottom electrode. The control unit determines a touch input based on the comparison result by comparing a first voltage with a second voltage. A support unit(340) prevents vibration from the bottom electrode through the piezoelectric element. The separator mechanically and electrically isolates sensing areas by dicing the top electrode and the piezoelectric element.

Description

TOUCH SENSOR AND METHOD FOR RECOGNIZING A TOUCH}

The present invention relates to a touch sensor and a touch recognition method, and more particularly, to a touch sensor mounted on a case of a mobile terminal and a touch recognition method of such a touch sensor.

Recently, mobile terminals capable of inputting various commands through touch buttons or touch pads have been increasing. Therefore, there is a need for a touch sensor that is more convenient and highly usable.

The present invention, by mounting a touch sensor on the metal case of the mobile terminal, overcomes the problem that the existing capacitive touch sensor can not be used in the metal case to meet the market demand for a beautiful design, to solve the conflicting technical problem At the same time to solve the problem is to provide a convenience of operation by improving the degree of freedom of the user input by allowing the touch sensor to be installed freely in the desired position of the side or rear of the mobile terminal.

The body sensor for solving the technical problem, the first electrode is mounted on the side or rear of the mobile terminal having a terminal body made of a metal material, the first electrode mounted on the inner surface of the terminal body; A second electrode opposed to the first electrode; And a voltage mounted between the first electrode and the second electrode, and when a voltage is applied, vibration corresponding to the applied voltage is induced, and outputs a first voltage corresponding to the induced vibration, and generates the induced voltage by an external touch. And a piezoelectric element for outputting a second voltage corresponding to the generated vibration when the change occurs.

In a preferred embodiment, the piezoelectric body is characterized in that to maintain some or all of the vibration induced by the applied voltage even after the applied voltage is removed.

In addition, in the preferred embodiment, the touch sensor is opposed to the inner surface of the terminal body, characterized in that it further comprises a support for preventing the vibration generated from the second electrode.

In addition, in a preferred embodiment, the touch sensor further comprises a separator for separating each of the first electrode and the piezoelectric material into at least two regions, each of the separated regions operating independently of other separated regions It is characterized by.

In a further preferred embodiment, each of the separated regions is characterized in that they are mechanically and electrically isolated from other separated regions.

Also in a preferred embodiment, the separated regions are characterized by forming a one-dimensional or two-dimensional array.

In addition, in a preferred embodiment, the piezoelectric body is characterized by consisting of PTZ (PbZr _x Ti _{1- x} ).

On the other hand, the touch recognition method for solving the technical problem is a touch recognition method of the touch sensor mounted on the side or the rear of the mobile terminal having a terminal body made of a metal material, the step of applying a voltage; Oscillating a vibration corresponding to the applied voltage and outputting a first voltage corresponding to the induced vibration; Generating a change in the induced vibration by an external touch; And outputting a second voltage corresponding to the vibration of the change, wherein the touch sensor is mounted on an inner surface of the terminal body.

According to one embodiment of the present invention, the touch sensor can be installed in the metal case of the mobile terminal, thereby providing aesthetic effects and convenience of use at the same time. When using the function, there is an advantage that can maximize the utilization of the mobile terminal by providing an intuitive user interface (UI).

1 is a block diagram of a mobile terminal according to an embodiment of the present invention.
2A is a front perspective view of an example of a mobile terminal or a mobile terminal according to an embodiment of the present invention.
FIG. 2B is a rear perspective view of the portable terminal shown in FIG. 2A.
3 is a conceptual diagram illustrating a structure of a mobile terminal equipped with a touch sensor according to an embodiment of the present invention.
4 is a cross-sectional view of a case and a touch sensor according to an exemplary embodiment of the present invention.
5A through 5D are diagrams illustrating operating principles of a touch sensor according to an exemplary embodiment of the present invention.
6A to 6C are conceptual views illustrating a touch sensor mounted on the side of the mobile terminal 100 according to an embodiment of the present invention.
7A and 7B show waveform diagrams of voltages output from the sensing area of the touch sensor 210.
8 is a flowchart of a touch recognition process according to an embodiment of the present invention.

Hereinafter, a mobile terminal according to the present invention will be described in more detail with reference to the accompanying drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

General description of the mobile terminal

The mobile terminal described herein may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), navigation, and the like. However, it will be readily apparent to those skilled in the art that the configuration according to the embodiments described herein may also be applied to fixed terminals such as digital TVs, desktop computers, etc., except when applicable only to mobile terminals.

1 is a block diagram of a mobile terminal according to an embodiment of the present invention.

The mobile terminal 100 includes a wireless communication unit 110, an A / V input unit 120, a user input unit 130, a sensing unit 140, an output unit 150, a memory 160, and an interface. The unit 170, the controller 180, and the power supply unit 190 may be included. The components shown in FIG. 1 are not essential, so that a mobile terminal having more or fewer components may be implemented. Hereinafter, the components will be described in order.

The wireless communication unit 110 may include one or more modules that enable wireless communication between the mobile terminal 100 and the wireless communication system or between the mobile terminal 100 and a network in which the mobile terminal 100 is located. For example, the wireless communication unit 110 may include a broadcast receiving module 111, a mobile communication module 112, a wireless Internet module 113, a short range communication module 114, and a location information module 115 .

The broadcast receiving module 111 receives a broadcast signal and / or broadcast related information from an external broadcast management server through a broadcast channel.

The broadcast channel may include a satellite channel and a terrestrial channel. The broadcast management server may mean a server that generates and transmits a broadcast signal and / or broadcast related information or a server that receives a previously generated broadcast signal and / or broadcast related information and transmits the same to a terminal. The broadcast signal may include not only a TV broadcast signal, a radio broadcast signal, and a data broadcast signal, but also a broadcast signal having a data broadcast signal combined with a TV broadcast signal or a radio broadcast signal.

The broadcast related information may mean information related to a broadcast channel, a broadcast program, or a broadcast service provider. The broadcast related information may also be provided through a mobile communication network. In this case, it may be received by the mobile communication module 112.

The broadcast related information may exist in various forms. For example, it may exist in the form of Electronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB) or Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld (DVB-H).

The broadcast receiving module 111 may include, for example, Digital Multimedia Broadcasting-Terrestrial (DMB-T), Digital Multimedia Broadcasting-Satellite (DMB-S), Media Forward Link Only (MediaFLO), and Digital Video Broadcast (DVB-H). Digital broadcast signals can be received using digital broadcasting systems such as Handheld and Integrated Services Digital Broadcast-Terrestrial (ISDB-T). Of course, the broadcast receiving module 111 may be configured to be suitable for not only the above-described digital broadcasting system but also other broadcasting systems.

The broadcast signal and / or broadcast related information received through the broadcast receiving module 111 may be stored in the memory 160.

The mobile communication module 112 transmits and receives a wireless signal with at least one of a base station, an external terminal, and a server on a mobile communication network. The wireless signal may include various types of data according to transmission and reception of a voice call signal, a video call call signal, or a text / multimedia message.

The wireless internet module 113 refers to a module for wireless internet access and may be embedded or external to the mobile terminal 100. Wireless Internet technologies may include Wireless LAN (Wi-Fi), Wireless Broadband (Wibro), World Interoperability for Microwave Access (Wimax), High Speed Downlink Packet Access (HSDPA), and the like.

The short range communication module 114 refers to a module for short range communication. As a short range communication technology, Bluetooth, Radio Frequency Identification (RFID), Infrared Data Association (IrDA), Ultra Wideband (UWB), ZigBee, and the like may be used.

The location information module 115 is a module for obtaining a location of a mobile terminal, and a representative example thereof is a GPS (Global Position System) module.

Referring to FIG. 1, the A / V input unit 120 is for inputting an audio signal or a video signal, and may include a camera 121 and a microphone 122. The camera 121 processes image frames such as still images or moving images obtained by the image sensor in the video call mode or the photographing mode. The processed image frame may be displayed on the display unit 151.

The image frame processed by the camera 121 may be stored in the memory 160 or transmitted to the outside through the wireless communication unit 110. Two or more cameras 121 may be provided according to the use environment.

The microphone 122 receives an external sound signal by a microphone in a call mode, a recording mode, a voice recognition mode, etc., and processes the external sound signal into electrical voice data. The processed voice data can be converted into a form that can be transmitted to the mobile communication base station through the mobile communication module 112 when the voice data is in the call mode, and output. The microphone 122 may implement various noise removing algorithms for removing noise generated in the process of receiving an external sound signal.

The user input unit 130 generates input data for the user to control the operation of the terminal. The user input unit 130 may include a key pad dome switch, a touch pad (static pressure / capacitance), a jog wheel, a jog switch, and the like.

The sensing unit 140 detects a current state of the mobile terminal 100 such as an open / closed state of the mobile terminal 100, a location of the mobile terminal 100, presence or absence of a user contact, orientation of the mobile terminal, acceleration / deceleration of the mobile terminal, and the like. To generate a sensing signal for controlling the operation of the mobile terminal 100. For example, when the mobile terminal 100 is in the form of a slide phone, it may sense whether the slide phone is opened or closed. In addition, whether the power supply unit 190 is supplied with power, whether the interface unit 170 is coupled to the external device may be sensed. On the other hand, the sensing unit 140 may include a proximity sensor (not shown).

The output unit 150 is used to generate an output related to sight, hearing, or tactile sense, and includes a display unit 151, an audio output module 152, an alarm unit 153, and a haptic module 154. Can be.

The display unit 151 displays (outputs) information processed by the mobile terminal 100. For example, when the mobile terminal is in a call mode, the mobile terminal displays a user interface (UI) or a graphic user interface (GUI) related to the call. When the mobile terminal 100 is in a video call mode or a photographing mode, the mobile terminal 100 displays photographed and / or received images, a UI, and a GUI.

The display unit 151 includes a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), and a flexible display (flexible). and at least one of a 3D display.

Some of these displays can be configured to be transparent or light transmissive so that they can be seen from the outside. This may be referred to as a transparent display. A representative example of the transparent display is TOLED (Transparant OLED). The rear structure of the display unit 151 may also be configured as a light transmissive structure. With this structure, the user can see the object located behind the terminal body through the area occupied by the display unit 151 of the terminal body.

According to an implementation form of the mobile terminal 100, two or more display units 151 may exist. For example, in the mobile terminal 100, a plurality of display portions may be spaced apart from one another, or may be disposed integrally with one another, and may be disposed on different surfaces, respectively.

When the display unit 151 and a sensor for detecting a touch operation (hereinafter, referred to as a touch sensor) form a mutual layer structure (hereinafter referred to as a touch screen), the display unit 151 may be configured in addition to an output device. Can also be used as an input device. The touch sensor may have, for example, a form of a touch film, a touch sheet, a touch pad, or the like.

The touch sensor may be configured to convert a change in pressure applied to a specific portion of the display unit 151 or capacitance generated in a specific portion of the display unit 151 into an electrical input signal. The touch sensor may be configured to detect not only the position and area of the touch but also the pressure at the touch.

If there is a touch input to the touch sensor, the corresponding signal (s) is sent to the touch controller. The touch controller processes the signal (s) and then transmits the corresponding data to the controller 180. As a result, the controller 180 can know which area of the display unit 151 is touched.

Referring to FIG. 1, a proximity sensor (not shown) may be disposed in an inner region of the mobile terminal covered by the touch screen or near the touch screen. The proximity sensor refers to a sensor that detects the presence or absence of an object approaching a predetermined detection surface or an object present in the vicinity without using a mechanical contact by using an electromagnetic force or infrared rays. Proximity sensors have a longer life and higher utilization than touch sensors.

Examples of the proximity sensor include a transmission photoelectric sensor, a direct reflection photoelectric sensor, a mirror reflection photoelectric sensor, a high frequency oscillation proximity sensor, a capacitive proximity sensor, a magnetic proximity sensor, and an infrared proximity sensor. When the touch screen is capacitive, the touch screen is configured to detect the proximity of the pointer by the change of the electric field according to the proximity of the pointer. In this case, the touch screen (touch sensor) may be classified as a proximity sensor.

Hereinafter, for convenience of explanation, the act of allowing the pointer to be recognized without being in contact with the touch screen so that the pointer is located on the touch screen is referred to as a "proximity touch", and the touch The act of actually touching the pointer on the screen is called "contact touch." The position where the proximity touch is performed by the pointer on the touch screen refers to a position where the pointer is perpendicular to the touch screen when the pointer is in proximity proximity.

The proximity sensor detects a proximity touch and a proximity touch pattern (for example, a proximity touch distance, a proximity touch direction, a proximity touch speed, a proximity touch time, a proximity touch position, and a proximity touch movement state). Information corresponding to the sensed proximity touch operation and proximity touch pattern may be output on the touch screen.

The sound output module 152 may output audio data received from the wireless communication unit 110 or stored in the memory 160 in a call signal reception, a call mode or a recording mode, a voice recognition mode, a broadcast reception mode, and the like. The sound output module 152 may also output a sound signal related to a function (eg, a call signal reception sound, a message reception sound, etc.) performed in the mobile terminal 100. The sound output module 152 may include a receiver, a speaker, a buzzer, and the like.

The alarm unit 153 outputs a signal for notifying occurrence of an event of the mobile terminal 100. Examples of events occurring in the mobile terminal include call signal reception, message reception, key signal input, and touch input. The alarm unit 153 may output a signal for notifying occurrence of an event in a form other than a video signal or an audio signal, for example, vibration. The video signal or the audio signal may be output through the display unit 151 or the audio output module 152, so that they 151 and 152 may be classified as part of the alarm unit 153.

The haptic module 154 generates various tactile effects that the user can feel. Vibration is a representative example of the haptic effect generated by the haptic module 154. The intensity and pattern of vibration generated by the haptic module 154 can be controlled. For example, different vibrations may be synthesized and output or may be sequentially output.

In addition to vibration, the haptic module 154 may be configured to provide a pin array that vertically moves with respect to the contact skin surface, a jetting force or suction force of air through an injection or inlet port, grazing to the skin surface, contact of an electrode, electrostatic force, and the like. Various tactile effects can be generated, such as effects by the endothermic and the reproduction of a sense of cold using the elements capable of endotherm or heat generation.

The haptic module 154 may not only deliver the haptic effect through direct contact, but also may implement the user to feel the haptic effect through a muscle sense such as a finger or an arm. Two or more haptic modules 154 may be provided according to a configuration aspect of the mobile terminal 100.

The memory 160 may store a program for the operation of the controller 180 and may temporarily store input / output data (for example, a phone book, a message, a still image, a video, etc.). The memory 160 may store data regarding vibration and sound of various patterns output when a touch input on the touch screen is performed.

The memory 160 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), RAM (Random Access Memory, RAM), Static Random Access Memory (SRAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Programmable Read-Only Memory (PROM), Magnetic Memory, Magnetic It may include a storage medium of at least one type of disk, optical disk. The mobile terminal 100 may operate in connection with a web storage that performs a storage function of the memory 160 on the Internet.

The interface unit 170 serves as a path with all external devices connected to the mobile terminal 100. The interface unit 170 receives data from an external device, receives power, transfers the power to each component inside the mobile terminal 100, or transmits data inside the mobile terminal 100 to an external device. For example, a wired / wireless headset port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device having an identification module, an audio I / O port, A video input / output (I / O) port, an earphone port, and the like may be included in the interface unit 170.

The identification module is a chip that stores various types of information for authenticating the usage rights of the mobile terminal 100, and includes a user identification module (UIM), a subscriber identify module (SIM), and a universal user authentication module ( Universal Subscriber Identity Module (USIM), and the like. Devices with identification modules (hereinafter referred to as "identification devices") can be manufactured in a smart card format. Accordingly, the identification device can be connected to the terminal 100 through the port.

The interface unit may be a passage through which power from the cradle is supplied to the mobile terminal 100 when the mobile terminal 100 is connected to an external cradle, or various command signals input from the cradle by a user may be transferred. It may be a passage that is delivered to the terminal. Various command signals or power input from the cradle may be operated as signals for recognizing that the mobile terminal is correctly mounted on the cradle.

The controller 180 typically controls the overall operation of the mobile terminal. For example, perform related control and processing for voice calls, data communications, video calls, and the like. The controller 180 may include a multimedia module 181 for playing multimedia. The multimedia module 181 may be implemented in the controller 180 or may be implemented separately from the controller 180.

The controller 180 may perform a pattern recognition process for recognizing a writing input or a drawing input performed on the touch screen as text and an image, respectively.

The power supply unit 190 receives an external power source and an internal power source under the control of the controller 180 to supply power for operation of each component.

Various embodiments described herein may be implemented in a recording medium readable by a computer or similar device using, for example, software, hardware or a combination thereof.

According to a hardware implementation, the embodiments described herein include application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and the like. It may be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and electrical units for performing other functions. The described embodiments may be implemented by the controller 180 itself.

According to the software implementation, embodiments such as the procedures and functions described herein may be implemented as separate software modules. Each of the software modules may perform one or more functions and operations described herein. Software code can be implemented in a software application written in a suitable programming language. The software code may be stored in the memory 160 and executed by the controller 180.

2A is a front perspective view of an example of a mobile terminal or a mobile terminal according to an embodiment of the present invention.

The disclosed portable terminal 100 has a terminal body in the form of a bar. However, the present invention is not limited thereto and may be applied to various structures such as a slide type, a folder type, a swing type, a swivel type, and two or more bodies are coupled to be relatively movable.

The body includes a casing (casing, housing, cover, etc.) that forms an exterior. In this embodiment, the case may be divided into a front case 101 and a rear case 102. Various electronic components are built in the space formed between the front case 101 and the rear case 102. At least one intermediate case may be further disposed between the front case 101 and the rear case 102.

The cases may be formed by injecting synthetic resin or may be formed of a metal material, for example, a metal material such as stainless steel (STS) or titanium (Ti).

The display unit 151, the audio output unit 152, the camera 121, the user input units 130/131 and 132, the microphone 122, and the interface 170 may be disposed in the terminal body, mainly the front case 101. have.

The display unit 151 occupies most of the main surface of the front case 101. The sound output unit 152 and the camera 121 are disposed in regions adjacent to one end of both ends of the display unit 151, and the user input unit 131 and the microphone 122 are disposed in regions adjacent to the other end. The user input unit 132 and the interface unit 170 may be disposed on side surfaces of the front case 101 and the rear case 102.

The user input unit 130 is manipulated to receive a command for controlling the operation of the portable terminal 100 and may include a plurality of operation units 131 and 132. The manipulation units 131 and 132 may also be collectively referred to as manipulating portions, and may be employed in any manner as long as the user operates the tactile manner with a tactile feeling.

Content input by the first or second manipulation units 131 and 132 may be variously set. For example, the first operation unit 131 receives commands such as start, end, scroll, and the like, and the second operation unit 132 controls the size of the sound output from the sound output unit 152 or the size of the sound output from the display unit 151 To the touch recognition mode of the touch screen.

FIG. 2B is a rear perspective view of the portable terminal shown in FIG. 2A.

Referring to FIG. 2B, a camera 121 ′ may be additionally mounted on the rear of the terminal body, that is, the rear case 102. The camera 121 'may have a photographing direction substantially opposite to the camera 121 (see FIG. 2A), and may be a camera having different pixels from the camera 121.

For example, the camera 121 has a low pixel so that the user's face is photographed and transmitted to the counterpart in case of a video call, and the camera 121 'photographs a general subject and does not transmit it immediately. It is desirable to have a high pixel because there are many. The cameras 121 and 121 'may be installed in the terminal body so as to be rotatable or pop-upable.

A flash 123 and a mirror 124 are further disposed adjacent to the camera 121 '. The flash 123 shines light toward the subject when the subject is photographed by the camera 121 '. The mirror 124 allows the user to see his / her own face or the like when photographing (self-photographing) the user using the camera 121 '.

The sound output unit 152 'may be further disposed on the rear surface of the terminal body. The sound output unit 152 ′ may implement a stereo function together with the sound output unit 152 (see FIG. 2A), and may be used to implement a speakerphone mode during a call.

The antenna for receiving a broadcast signal may be additionally disposed on the side of the terminal body. An antenna that forms part of the broadcast receiving module 111 (refer to FIG. 1) may be installed to be pulled out of the terminal body.

A power supply unit 190 for supplying power to the portable terminal 100 is mounted on the terminal body. The power supply unit 190 may be embedded in the terminal body or may be directly detachable from the outside of the terminal body.

The rear case 102 may be further equipped with a touch pad 135 for sensing a touch. Like the display unit 151, the touch pad 135 may also be configured to have a light transmission type. In this case, if the display unit 151 is configured to output visual information from both sides, the visual information may be recognized through the touch pad 135. The information output on both surfaces may be controlled by the touch pad 135. Alternatively, a display may be additionally mounted on the touch pad 135, and a touch screen may be disposed on the rear case 102 as well.

The touch pad 135 operates in association with the display unit 151 of the front case 101. The touch pad 135 may be disposed in parallel to the rear of the display unit 151. The touch pad 135 may have the same or smaller size as the display unit 151.

Various types of time information can be displayed on the display unit 151. [ These pieces of information can be displayed in the form of letters, numbers, symbols, graphics, or icons. At least one of the letters, numbers, symbols, graphics, or icons may be displayed in a predetermined arrangement for inputting such information, thereby being implemented as a keypad. Such a keypad may be called a so-called " soft key ".

Hereinafter, embodiments related to a control method that can be implemented in a terminal configured as described above will be described with reference to the accompanying drawings. Embodiments described later may be used alone or in combination with each other. In addition, embodiments described below may be used in combination with the above-described user interface (UI).

Structure of Mobile Terminal with Touch Sensor

3 is a conceptual diagram illustrating a structure of a mobile terminal equipped with a touch sensor according to an embodiment of the present invention.

The touch sensor may be mounted on the side (including upper, lower, left and right sides) or the rear side of the mobile terminal 100. In addition, the touch sensor may be mounted on an inner surface of a case made of a metal material.

The touch sensor may be mounted on any one of an inner surface of the case 101, an inner surface of the case 102, or a region including both a portion of the inner surface of the case 101 and a portion of the inner surface of the case 102. In addition, when the touch sensor further includes an intermediate case, the touch sensor may include an area including both an inner surface of the intermediate case, a part of the inner surface of the case 101 and a part of the inner surface of the intermediate case, a part of the inner surface of the intermediate case, and the case. It can be mounted on any one of the region including all of a portion of the inner surface of the 102, and the region including all of a portion of the inner surface of the case 101, a portion of the inner surface of the intermediate case and a portion of the inner surface of the case 102. have.

The touch sensor may include one independent sensing area, but may also include two or more independent sensing areas. In particular, when the touch sensor includes two or more sensing regions, the sensing regions may form a one-dimensional or two-dimensional array.

Referring to FIG. 3, the touch sensor 210 is mounted on an area including both a part of the inner surface of the case 101 and a part of the inner surface of the case 102 made of a metal material on the left side of the mobile terminal 100. It can be seen that. The touch sensor 210 includes four sensing regions A, B, C, and D and forms a one-dimensional array.

4 is a cross-sectional view of a case and a touch sensor according to an exemplary embodiment of the present invention.

The touch sensor 210 includes an upper electrode 310, a lower electrode 320, and a piezoelectric body 330. In addition, the touch sensor 210 may further include a support 340 and at least one separator 350.

The upper electrode 310 and the lower electrode 320 are rod-shaped or plate-shaped conductors, and the upper electrode 310 is mounted on the inner surface of the case 101 or 102, and the lower electrode 320 is the upper electrode 310. Against) Also, the upper electrode 310 and the lower electrode 320 become opposite poles. In one embodiment, the upper electrode 310 becomes an anode and the lower electrode 320 becomes a cathode. In addition, when the touch sensor 210 includes two or more sensing regions, the upper electrode 310 may be diced by the separator 350.

The piezoelectric element 330 is mounted between the upper electrode 310 and the lower electrode 320, and when a voltage is applied, vibration corresponding to the applied voltage is induced and outputs a first voltage corresponding to the induced vibration. In addition, when an external touch is applied to the piezoelectric body 330 through the cases 101 and 102, the induced vibration is changed, and a second voltage corresponding to the changed vibration is output. The controller 180 may compare the first voltage and the second voltage and determine whether a touch is input based on the comparison result.

The piezoelectric element 330 may be used as an actuator because a piezoelectric element 330 generates a displacement proportional to the voltage when the voltage is applied. On the contrary, when a force is applied from the outside and the displacement is induced in the piezoelectric element 330, a charge may be generated on the surface of the piezoelectric element 330 in proportion to the induced displacement, and thus may be used as a sensor. A representative material of the piezoelectric material 330 is PZT (PbZr _x Ti _{1- x} ), and various other materials may be used as the piezoelectric material 330.

When the touch sensor 210 includes two or more sensing regions, the piezoelectric body 330 may be diced by the separator 350, similarly to the upper electrode 310.

Support 340 is opposed to the case (101, 102, etc.), and prevents the vibration transmitted from the lower electrode 320 through the piezoelectric body (330).

The separator 350 dicing the upper electrode 310 and the piezoelectric body 330 when the touch sensor 210 includes two or more sensing regions to mechanically and electrically isolate the sensing regions.

5A through 5D are diagrams illustrating operating principles of a touch sensor according to an exemplary embodiment of the present invention.

Referring to FIG. 5A, since the voltage is not applied to the touch sensor 210 when the touch sensor 210 is inactivated, vibration is maintained. Referring to FIG. 5B, when _a voltage Va is applied to the touch sensor 210, _a deformation 410 occurs in the piezoelectric body 330, and vibrations are induced in the cases 101 and 102. Referring to FIG. 5C, when the voltage V _a applied to the touch sensor 210 is removed while vibration is induced in the case 101, 102, or 103, damping exists in the deformation 420. Slight vibrations persist.

Referring to FIG. 5D, a displacement occurs in the piezoelectric body 330 due to the vibration, and the generated displacement induces charge, and the induced charge is detected as a voltage V _s . On the other hand, when an external touch is applied to the cases 101 and 102 (for example, when a finger touches), a change in the amplitude of vibration occurs. In the state where the external touch is not applied, the amplitude of vibration is relatively high, and thus the induced voltage of the piezoelectric body 330 is high. On the other hand, in the state in which the external touch is applied, since the amplitude of the vibration is relatively small, the induced voltage of the piezoelectric body 330 is low. By using the operation principle, the mobile terminal 100 may detect whether an external touch is generated, that is, whether a touch is input.

6A to 6C are conceptual views illustrating a touch sensor mounted on the side of the mobile terminal 100 according to an embodiment of the present invention. 7A and 7B show waveform diagrams of voltages output from the sensing region of the touch sensor 210.

Referring to FIG. 6A, FIG. 6A illustrates a state in which an external touch is not applied to the cases 101 and 102, for example, a state in which a thumb is not in contact with a portion corresponding to the touch sensor 210. Referring to FIG. 7A, when the touch sensor 210 includes two or more (eg, four) sensing regions as shown in FIG. 6A, the voltage output from each sensing region is the same waveform 510. May appear.

On the other hand, since the voltage output from each sensing region may be different according to the characteristics of the touch sensor 210 and the contact state of the cases 101, 102, etc., the output from each sensing region without an external touch is applied. The voltage applied to the piezoelectric body 330 may be calibrated to have the same voltage.

Referring to FIG. 6B, FIG. 6B illustrates a state in which an external touch is applied to a portion of the cases 101 and 102 corresponding to the sensing area A. FIG. Referring to FIG. 7B, when an external touch is applied to a portion corresponding to the sensing area A as shown in FIG. 6B, the voltage output from the sensing area A is relatively reduced by an attenuation so that the waveform 520 is reduced. Appears. On the other hand, the voltage output from the sensing areas B, C, and D to which the external touch is not applied to the corresponding portion has no attenuation, thereby maintaining the original waveform 510.

Referring to FIG. 6C, FIG. 6C illustrates a state in which a drag occurs from a portion corresponding to the sensing area A to a portion corresponding to the sensing area C among the cases 101 and 102. In this case, the voltage output from the sensing region A returns to the original waveform 510, and the voltage output from the sensing region C decreases as a relatively large value due to the damping, and thus appears as a waveform 520.

8 is a flowchart of a touch recognition process according to an embodiment of the present invention.

In a state in which the touch sensor 210 is inactive, the controller 180 monitors whether the touch sensor 210 receives an activation request (S110).

In operation 110, when receiving the activation request of the touch sensor 210, the controller 180 applies a voltage to the piezoelectric body 330 (S120). When a voltage is applied, vibration corresponding to the voltage applied to the piezoelectric body 330 is induced (S130).

If vibration is induced in the piezoelectric body 330, the controller 180 removes the voltage and measures the first voltage output from the piezoelectric body 330 (S140).

When an external touch is generated through the cases 101 and 102 (S150), a change occurs in the induced vibration of the piezoelectric body 330 (S160).

If a change occurs in the vibration of the piezoelectric body 330, the controller 180 measures the second voltage output from the piezoelectric body 330 (S170).

The controller 180 may determine whether a touch is input by comparing the first voltage and the second voltage. In addition, when the touch sensor 210 includes two or more sensing regions, it may be determined whether drag input is performed by determining whether the touch is continuously input.

In the above, preferred embodiments of the present invention have been described with reference to the accompanying drawings.

Here, the terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings, but should be construed as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all of the technical idea of the present invention, which can be replaced at the time of the present application It should be understood that there may be various equivalents and variations.

100: mobile terminal 101: upper case
102: lower case 210: touch sensor
310: upper electrode 320: lower electrode
330: piezoelectric 340: support
350: separator

Claims (8)

In the touch sensor mounted on the side or the rear of the mobile terminal having a terminal body made of a metal material,
A first electrode mounted on an inner surface of the terminal body;
A second electrode opposed to the first electrode; And
Mounted between the first electrode and the second electrode, and when a voltage is applied, vibration corresponding to the applied voltage is induced and outputs a first voltage corresponding to the induced vibration, and is induced by an external touch. And a piezoelectric element for outputting a second voltage corresponding to the vibration generated when the change occurs in the vibration. The method of claim 1, wherein the piezoelectric body,
And retaining some or all of the vibration induced by the applied voltage even after the applied voltage is removed. The method of claim 1,
The touch sensor, which faces the inner surface of the terminal body, further comprises a support for preventing vibration generated from the second electrode. The method of claim 1,
Further comprising a separator for separating each of the first electrode and the piezoelectric material into at least two regions,
Each of the separated regions,
Touch sensor, characterized in that it operates independently from other separated areas. The method of claim 3, wherein each of the separated regions,
Touch sensor, characterized in that it is mechanically and electrically isolated from other separated areas. The method of claim 3, wherein the separated regions,
Touch sensor, characterized in that to form a one-dimensional or two-dimensional array. The method of claim 1, wherein the piezoelectric body,
Touch sensor, characterized in that consisting of PTZ (PbZr _x Ti _{1 -x} ). In the touch recognition method of the touch sensor mounted on the side or the rear of the mobile terminal having a terminal body made of a metal material,
Applying a voltage;
Oscillating a vibration corresponding to the applied voltage and outputting a first voltage corresponding to the induced vibration;
Generating a change in the induced vibration by an external touch; And
Outputting a second voltage corresponding to the oscillated vibration;
The touch sensor,
Touch recognition method, characterized in that mounted on the inner surface of the terminal body.

Images