Abstract:
There is provided a touch sensing apparatus including a panel unit in which a plurality of electrodes intersecting with each other are disposed; and a control unit sensing changes in capacitance generated in regions in which respective electrodes, among the plurality of intersecting electrodes, intersect, wherein the panel unit includes a first region in which the plurality of electrodes are disposed with a first interval therebetween, and a second region in which the plurality of electrodes are disposed with a second interval therebetween, and the control unit senses a fingerprint touching the second region based on a change in capacitance generated therein.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of Korean Patent Application No. 10-2011-0123482 filed on Nov. 24, 2011, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a touch sensing apparatus having a fingerprint sensing function, and more particularly, to a touch sensing apparatus capable of providing an enhanced security function. 
         [0004]    2. Description of the Related Art 
         [0005]    Touch sensing apparatuses such as a touch screen, a touch pad, and the like, are apparatuses attached to display apparatuses and providing users with intuitive input methods, and have recently been applied to various electronic apparatuses such as cellular phones, personal digital assistants (PDAs), navigation devices, and the like. In particular, as demand for smart phones has recently increased, touch screens have increasingly been employed as touch sensing apparatuses capable of providing various input methods in a limited form factor. 
         [0006]    Touch screens applied to portable electronic apparatuses may be classified into resistive type touch screens and capacitive type touch screens according to a touch sensing method. Capacitive type touch screens can have advantageously long lifespans and various input methods and touch movements can be easily implemented therein, and thus, applications therefor have been increasing. In particular, as it is easier to implement a multi-touch interface in capacitive type touch screens rather than resistive type touch screens, capacitive type touch screens have a wide range of applications in electronic apparatuses such as smart phones. 
         [0007]    Touch screen apparatuses, as input apparatuses, have applications in the implementation of security functions in mobile apparatuses such as smart phones. For example, a password may be easily set and input through a touch screen apparatus, or a pattern input method, which may not be easily implemented using a general keypad, can be provided by the touch screen apparatus. However, password and pattern recognition functions may be exposed to third parties, thus neutralizing the security function. Additionally, even in the case that a fingerprint recognition sensor is additionally included in a smart phone, it is spatially inefficient in terms of smart phone characteristics which require the implementation of various functions in a limited form factor. 
       SUMMARY OF THE INVENTION 
       [0008]    To solve the above-described problem, the present invention implements a fingerprint recognition sensor in a region of a capacitive type touch sensing apparatus determining a touch using a change in capacitance by differentiating intervals between electrodes or densities of electrodes. Thus, since it is unnecessary to provide the fingerprint recognition sensor in separate hardware, an aspect of the present invention provides a touch sensing apparatus capable of providing an enhanced security function in a mobile apparatus having a limited form factor. 
         [0009]    According to an aspect of the present invention, there is provided a touch sensing apparatus including: a panel unit in which a plurality of electrodes intersecting with each other are disposed; and a control unit sensing changes in capacitance generated in regions in which respective electrodes, among the plurality of intersecting electrodes, intersect, wherein the panel unit includes a first region in which the plurality of electrodes are disposed with a first interval therebetween, and a second region in which the plurality of electrodes are disposed with a second interval therebetween, and the control unit senses a fingerprint touching the second region based on a change in capacitance generated therein. 
         [0010]    The panel unit may include a plurality of first electrodes extending in a first axial direction and electrically separating from each other; and a plurality of second electrodes extending in a second axial direction, intersecting with the first electrodes extending in the first axial direction, and electrically separated from each other. 
         [0011]    The control unit may sequentially apply a driving signal to the plurality of individual first electrodes, and sense the changes in capacitance generated from the second electrodes intersecting with the first electrodes to which the driving signal is applied. 
         [0012]    Intervals between the plurality of first electrodes in the second region of the panel unit may be smaller than intervals between the plurality of first electrodes in the first region thereof. 
         [0013]    Intervals between the plurality of second electrodes in the second region of the panel unit may be smaller than intervals between the plurality of second electrodes in the first region thereof. 
         [0014]    The control unit may compare the sensed fingerprint with fingerprint data stored in a predetermined memory, and determine whether to enter a security mode of the touch sensing apparatus according to a comparison result. 
         [0015]    The control unit may stop sensing the change in capacitance when the sensed fingerprint is not identical to the stored fingerprint data. 
         [0016]    According to another aspect of the present invention, there is provided a touch sensing apparatus including: a panel unit including a plurality of touch sensing pixels in which a plurality of electrodes intersect; and an arithmetic operation unit detecting a change in capacitance generated in the plurality of touch sensing pixels and determining at least one of a touch and a fingerprint pattern, wherein the panel unit includes a first region and a second region disposed in different locations, and the plurality of touch sensing pixels included in the first region and the plurality of touch sensing pixels included in the second region have different densities. 
         [0017]    The arithmetic operation unit may detect a change in mutual capacitance generated in the plurality of touch sensing pixels and determine at least one of the touch and the fingerprint pattern. 
         [0018]    Densities of the plurality of touch sensing pixels included in the first region may be smaller than densities of the plurality of touch sensing pixels included in the second region. 
         [0019]    The arithmetic operation unit may detect a change in capacitance generated in the plurality of touch sensing pixels included in the second region and determine the fingerprint pattern. 
         [0020]    The arithmetic operation unit may detect a change in capacitance generated in the plurality of touch sensing pixels included in the first region and the second region and determine the touch when the determined fingerprint pattern is identical to fingerprint data stored in a predetermined memory. 
         [0021]    The arithmetic operation unit may stop detecting the change in capacitance when the determined fingerprint pattern is not identical to fingerprint data stored in a predetermined memory. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0023]      FIG. 1  is a perspective view of the exterior of an electronic apparatus including a touch sensing apparatus according to an embodiment of the present invention; 
           [0024]      FIGS. 2 and 3  are plan views of touch sensing apparatuses according to embodiments of the present invention; 
           [0025]      FIG. 4  is a cross-sectional view of the touch sensing apparatus of  FIG. 2 ; 
           [0026]      FIG. 5  is a flowchart illustrating an operation of a touch sensing apparatus according to an embodiment of the present invention; and 
           [0027]      FIG. 6  is diagrams illustrating an operation of a touch sensing apparatus according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Embodiments of the present invention will be described in detail with reference to the accompanying drawings. These embodiments will be described in detail in order to allow those skilled in the art to practice the present invention. It should be appreciated that various embodiments of the present invention are different but are not necessarily exclusive. For example, specific shapes, configurations, and characteristics described in an embodiment of the present invention may be implemented in another embodiment without departing from the spirit and scope of the present invention. In addition, it should be understood that positions and arrangements of individual components in each embodiment may be changed without departing from the spirit and scope of the present invention. Therefore, a detailed description provided below should not be construed as being restrictive. In addition, the scope of the present invention is defined only by the accompanying claims and their equivalents if appropriate. Similar reference numerals will be used to describe the same or similar functions throughout the accompanying drawing. 
         [0029]    Hereinafter, 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 practice the present invention. 
         [0030]      FIG. 1  is a perspective view showing an electronic apparatus to which a touch sensing apparatus according to an embodiment of the present invention is applicable. Referring to  FIG. 1 , an electronic apparatus  100  of the present embodiment includes a display apparatus  110  for outputting an image, an input unit  120 , and an audio unit  130  for outputting audio, and may provide the touch sensing apparatus integrally formed with the display apparatus  110 . 
         [0031]    As shown in  FIG. 1 , in the case of a mobile apparatus, the touch sensing apparatus is integrally formed with the display apparatus  110 , and thus various input methods may be provided to users in a limited form factor. The touch sensing apparatus needs to have high light transmittance enough to transmit the image displayed by the display apparatus  110 . Thus, the touch sensing apparatus may be implemented by forming sensing electrodes formed of a transparent, electrically conductive material such as indium-tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), carbon nano tube (CNT), or graphene on a base substrate formed of a transparent film material such as polyethylene terephthalate (PET), polycarbonate (PC),polyethersulfone (PES),polyimide (PI), or the like. A wire pattern connected to the sensing electrodes formed of the transparent conductive material is disposed in a bezel region of the display apparatus  110 , and is visually shielded by the bezel region, and thus the wire pattern may be formed of a metal material such as silver (Ag), copper (Cu), or the like. 
         [0032]    In the case in which the touch sensing apparatus of the present embodiment may not be integrally formed with a display apparatus such as a touch pad of a notebook computer, the electronic apparatus  100  may be manufactured by simply patterning the sensing electrodes using metal on a circuit substrate. However, for convenience of description, the touch sensing apparatus and touch sensing method according to the embodiment of the present invention will now be described below on the assumption that the touch sensing apparatus is a touch screen. 
         [0033]      FIGS. 2 and 3  are plan views of touch sensing apparatuses according to embodiments of the present invention. Although rectangular or bar type electrodes are included in a panel unit of the touch sensing apparatus in  FIGS. 2 and 3 , this is merely one of the embodiments of the present invention, and the present invention is not necessarily limited thereto. 
         [0034]    Referring to  FIG. 2 , a touch sensing apparatus  200  of the present embodiment includes a transparent substrate  210  and a plurality of first and second electrodes  220  and  230  disposed on the transparent substrate  210 . A wire pattern electrically connected to the electrodes  220  and  230  may be disposed in a boundary of the transparent substrate  210  of the touch sensing apparatus  200 . A controller integrated circuit (IC) for sensing changes in capacitance in the electrodes  220  and  230  through the wire pattern may be mounted in a circuit substrate and connected to the transparent substrate  210  but is omitted in  FIGS. 2 and 3 . 
         [0035]    In  FIG. 2 , the first electrodes  220  extending in a first axial direction (a horizontal direction) may be electrically separated from each other and connected to sensing channels X 1  to Xn of the controller IC, respectively. The second electrodes  230  extending in a second axial direction (a vertical direction) intersecting with the first axial direction may be electrically separated from each other and connected to sensing channels Y 1  to Ym of the controller IC, respectively. The controller IC senses a change in capacitance by a touching object in each of the electrodes  220  and  230  and determines a touch. In particular, the controller IC may apply a predetermined driving signal to the first electrodes  220 , detect a change in mutual capacitance generated from the second electrodes  230  intersecting with the first electrodes  220  to which the driving signal is applied, and determine the touch. 
         [0036]    Intervals between the first electrodes  220  connected to the sensing channels X 1  to X 8  of the controller IC and intervals between the first electrodes  220  connected to the sensing channels X 8  to Xn of the controller IC may be different. As shown in  FIG. 2 , the intervals between the first electrodes  220  connected to the sensing channels X 8 ˜Xn may be smaller than the intervals between the first electrodes  220  connected to the sensing channels X 1  to X 8   n.  Likewise, intervals between the second electrodes  230  connected to the sensing channels Y 1  to Y 5  of the controller IC and intervals between the second electrodes  230  connected to the sensing channels Y 5  to Ym of the controller IC may be different. As shown in  FIG. 2 , the intervals between the second electrodes  230  connected to the sensing channels Y 5  to Ym may be smaller than the intervals between the second electrodes  230  connected to the sensing channels Y 1  to Y 5 . 
         [0037]    Intervals between the electrodes  220  and  230  connected some sensing channels are smaller, and thus, as shown in  FIG. 2 , the panel unit of the touch sensing apparatus  200  may be classified into a first region  240  and a second region  250 . For convenience of description, as shown in  FIG. 2 , the first region  240  is defined as a region having relatively great intervals between the electrodes  220  and  230 , and the second region  250  is defined as a region having relatively small intervals between the electrodes  220  and  230 . 
         [0038]    Likewise,  FIG. 3  is a plan view of a touch sensing apparatus  300  according to an embodiment of the present invention. Referring to  FIG. 3 , the touch sensing apparatus  300  includes a transparent substrate  310 , first electrodes  320  extending in a first axial direction (a horizontal direction) and electrically separated from each other, and second electrodes  330  extending in a second axial direction (a vertical direction) and electrically separated from each other. Intervals between the first and second electrodes  320  and  330  may be different in a certain region of the transparent substrate  310 , similar to the embodiment of  FIG. 2 , so that a first region  340  and a second region  350  may be divided on the touch sensing apparatus  300 . 
         [0039]    Meanwhile, in the touch sensing apparatus  300  of  FIG. 3 , unlike the touch sensing apparatus  200  of  FIG. 2 , widths of the first electrodes  320  may be greater than widths of the second electrodes  330 . Accordingly, the first electrodes  320  are disposed in a bottom surface of the transparent substrate relatively closer to a display apparatus, thereby obtaining an additional effect in a method of detecting mutual capacitance. That is, when a controller IC sequentially applies a driving signal to each of the first electrodes  320 , the first electrodes  320  to which the driving signal are is applied are connected to static voltage of a ground level GND, thereby preventing electric noise generated from the display apparatus from being transferred to the second electrodes  330 . 
         [0040]    Further, in detecting a change in mutual capacitance, self-capacitance generated between the second electrodes  330  and a touching object—a person&#39;s finger—may be minimized. The self-capacitance generated between the second electrodes  330  and the touching object is in proportional to an area in which the touching object and the second electrodes  330  overlap, and thus a change in self-capacitance maybe reduced by forming the second electrodes  330  having the small widths. The change in self-capacitance is reduced while the change in mutual capacitance is maintained, thereby relatively increasing sensitivity of the change in mutual capacitance to be detected. 
         [0041]    The first electrodes  320  are connected to driving channels D 1  to D 6 . The second electrodes  330  are connected to sensing channels S 1  to Sn. Throughout a valid sensing region of the touch sensing apparatus  300 , a method of sensing a touch is defined as the method of detecting the change in mutual capacitance, and thus a method of sensing a fingerprint in the second region  350  having relatively high densities of the electrodes  320  and  330  may be also defined as the method of detecting the change in mutual capacitance. 
         [0042]    In this regard, the first electrodes  320  having very small intervals therebetween are connected to the driving channel D 6 . A predetermined switching circuit unit may be included in the driving channel D 6 . A driving signal may be sequentially applied to the first electrodes  320  connected to the driving channel D 6  through the switching circuit unit, in order to implement a resolution capable of detecting a valley and a ridge of a fingerprint when the fingerprint is sensed in the second region  350 . 
         [0043]    Meanwhile, a general touch sensing operation may simultaneously apply a driving signal to the first electrodes  320  connected to the driving channel D 6 . Thus, the first electrodes  320  connected to the driving channel D 6  may be used for generating the change in mutual capacitance necessary for determining a touch like the first electrodes  320  connected to the other driving channels D 1  to D 5 . 
         [0044]    In the second electrodes  330  connected to the sensing channels S 1  to Sn, densities of the second electrodes  330  connected to the sensing channels S 5  to Sn included in the second region  350  of the touch sensing apparatus  300  are higher than densities of the second electrodes  330  connected to the other sensing channels S 1  to S 4 . In this regard, intervals between the second electrodes  330  connected to the sensing channels S 5  to Sn and intervals between the first electrodes  320  connected to the driving channel D 6  may be determined according to a resolution necessary for detecting a fingerprint. The resolution necessary for detecting the fingerprint may be absolutely calculated with respect to the area of the second region  350 . 
         [0045]    In a general touch determination mode, an arithmetic operation unit (not shown) may disregard a change in capacitance generated in the second electrodes  330  connected to the sensing channels S 6  to Sn-1. That is, the second electrodes  330  connected to the sensing channels S 6  to Sn-1 are additionally prepared to obtain a resolution required for sensing a fingerprint in the second region  250 , and accordingly may be disregarded in a general operation mode for determining a touch. 
         [0046]    Further, similar to sequentially applying the driving signal to the first electrodes  320  connected to the driving channel D 6  through the switching circuit unit, the second electrodes  330  connected to the sensing channels S 6  to Sn may also be connected to one sensing channel through the switching circuit unit. Accordingly, the second region  350  having high densities of the first and second electrodes  320  and  330  may solve problems of an extreme increase in the number of channels of the controller IC and an increase in a chip size. 
         [0047]      FIG. 4  is a cross-sectional view of the touch sensing apparatus  200  of  FIG. 2 . 
         [0048]    Referring to  4 , the touch sensing apparatus  200  may include the transparent substrate  210 , the first electrodes  220 , the second electrodes  230 , and a cover lens  260 . A display apparatus  270  may be attached to the bottom of the first electrodes  220 . The first electrodes  220  and the second electrodes  230  are separately disposed in a bottom surface and a top surface of the transparent substrate  210 , respectively. In this regard, on the assumption that a touch and a fingerprint are sensed from a change in mutual capacitance generated between the first and second electrodes  220  and  230 , the electrodes  220  to which a driving signal is applied may be disposed in the bottom surface of the transparent substrate  210  closer to the display apparatus  270 . That is, the driving signal may be applied to the first electrodes  220  in  FIG. 4 . 
         [0049]    The cover lens  260  may receive a touch through at least one surface, and in particular sense a fingerprint through the second region  250 . To implement a resolution required for recognizing the fingerprint in the second region  250 , densities of the first and second electrodes  220  and  230  may be higher in the second region  250  than in the first region  240 . To this end, intervals between the first and second electrodes  220  and  230  may be relatively small in the second region  250 . 
         [0050]      FIG. 5  is a flowchart illustrating an operation of the touch sensing apparatus  200  according to an embodiment of the present invention. As described in the embodiments of  FIGS. 2 through 4 , for convenience of description, the touch sensing apparatus  200  of the present embodiment is a touch screen. 
         [0051]    Referring to  FIG. 5 , the operation of the present embodiment is initiated with determining whether the touch screen is currently in a sleep mode (S 500 ). In a mobile apparatus having an environment in which a battery is frequently used, a power management of various electronic parts included in the mobile apparatus is very important, and thus the touch screen does not continuously operate in an active mode but may be switched between the sleep mode and an active mode periodically. 
         [0052]    Further, a user can temporarily stop the operation of the touch screen intentionally when an apparatus such as a smart phone, a tablet PC is not being used. In this case, so as to activate the operation of the touch screen and the whole smart apparatus in the sleep mode, a security release procedure such as the inputting of a password or a pattern may be necessary. A fingerprint recognition sensor is integrally formed with the touch screen in the present embodiment, thereby providing a safer and easier security function than the inputting of the password or the pattern. 
         [0053]    In the case in which it is determined that the touch screen or the mobile apparatus itself is currently in the sleep mode, when the user manipulates the mobile apparatus or applies a touch, a fingerprint input into the second region  250  is requested (S 510 ). The second region  250  is additionally defined in a certain region of the touch screen for fingerprint recognition as described above, and may be different form the first region  240  by having different intervals between the first and second electrodes  220  and  230  or different densities thereof. As a result of determination in S 500 , when it is determined that the touch screen or the mobile apparatus is not currently in the sleep mode, the touch applied to the touch screen is sensed (S 550 ), and the mobile apparatus may operate according to a user&#39;s manipulation. 
         [0054]    When a fingerprint is input into the second region  250  according to a fingerprint input request, a controller IC of the touch screen senses the fingerprint input into the second region  250  (S 520 ), and determines whether the input fingerprint is identical to fingerprint data stored in a predetermined memory (S 530 ). The memory in which the fingerprint data is stored may be a USIM card of the mobile apparatus, an internal or external memory, or the like. A plurality of users may register their fingerprints as authorized users according to an owner&#39;s will of the mobile apparatus. 
         [0055]    When it is determined that the fingerprint data stored in the memory is identical to the fingerprint input into the second region  250 , the controller IC releases the sleep mode of the touch screen and informs a main controller of the mobile apparatus that a user who is currently using the mobile apparatus is a registered and authorized user. Thus, the mobile apparatus may be switched to the active mode (S 540 ). Then, the user&#39;s touch applied to the touch screen is sensed (S 550 ), such that the user controls the operation of the mobile apparatus. 
         [0056]    Meanwhile, as a result of determination in S 530 , when it is determined that the fingerprint data stored in the memory is not identical to the fingerprint input into the second region  250 , the controller IC controls the display apparatus to output a fingerprint recognition authentication failure message (S 560 ). Further, the control IC recognizes an access of a currently unregistered user to the mobile apparatus without permission, and thus the mobile apparatus may be allowed to enter a security mode (S 570 ). For example, the security mode may be released when a registered user&#39;s fingerprint is input or a password and a pattern is input in addition to the fingerprint input. 
         [0057]      FIG. 6  is diagrams for explaining an operation of a touch sensing apparatus according to an embodiment of the present invention. 
         [0058]    Referring to  FIG. 6 , a fingerprint input request message is displayed on a screen of a mobile apparatus, and a fingerprint input is requested in a certain region of the screen corresponding to the second region  250  ( 600 ). The fingerprint input request may be made during a process of releasing a power saving mode or a sleep mode when the mobile apparatus enters the power saving mode due to a long idle time or a user intentionally allows the mobile apparatus to enter the power saving mode or the sleep mode. 
         [0059]    When the user inputs a fingerprint into the second region  250  according to the fingerprint input request, if the fingerprint input by the user is not identical to fingerprint data stored in a memory of the mobile apparatus, the mobile apparatus informs the user of a user authentication failure and operates in a security mode ( 610 ). In this regard, in consideration of an error that is likely to occur during a fingerprint recognition process, when the fingerprint recognition fails more than a predetermined number, the mobile apparatus may be set to operate in the security mode. As described above, when the mobile apparatus enters the security mode, the security mode may be released only when a registered user&#39;s fingerprint is input, or a password input, a pattern input, or the like in addition to the fingerprint input are confirmed. 
         [0060]    Meanwhile, when the fingerprint input by the user into the second region  250  according to the fingerprint input request is identical to the fingerprint data stored in the memory of the mobile apparatus, the mobile apparatus informs the user of a user fingerprint authentication success and is switched to an active mode ( 620 ). In this regard, so as to provide a further enhanced security function, a manipulation authority of the mobile apparatus may be differently limited with respect to users by identifying users according to the fingerprint sensed in the second region  250 , and differently setting an access authority for an application program of the mobile apparatus, data thereof, or the like according to the identified users. 
         [0061]    As set forth above, according to embodiments of the invention, a panel unit is formed to have small intervals between electrodes and high densities of electrodes in a partial region of a touch sensing apparatus, and a fingerprint is sensed based on a change in capacitance generated in that region having small intervals or high densities. Accordingly, a fingerprint recognition sensor can be integrally implemented in a touch sensing apparatus without additional hardware, whereby further enhanced security performance can be provided. 
         [0062]    While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.