Patent Publication Number: US-11393257-B2

Title: Information processor, information processing method, program, and wearable device

Description:
CROSS REFERENCE TO PRIOR APPLICATION 
     This application is a National Stage Patent Application of PCT International Patent Application No. PCT/JP2018/044586 (filed on Dec. 4, 2018) under 35 U.S.C. § 371, which claims priority to Japanese Patent Application No. 2018-024619 (filed on Feb. 15, 2018), which are all hereby incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to an information processor, an information processing method, a program, and a wearable device. 
     BACKGROUND ART 
     Conventionally, a technology for authenticating a user of a device has been proposed. For example, Patent Document 1 below describes a wristband type authentication device. 
     CITATION LIST 
     Patent Document 
     Patent Document 1: Japanese Patent Application Laid-Open No. 2002-312324 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In such a field, display for performing effective authentication is desired. 
     An object of the present disclosure is to provide an information processor, an information processing method, a program, and a wearable device that enable display for performing effective authentication. 
     Solutions to Problem 
     The present disclosure is, for example, 
     an information processor including: 
     a sensor unit that recognizes an operating tool that comes into contact with a display unit; and 
     a control unit that shows a guidance display for guiding an operation of the operating tool on the display unit. 
     The present disclosure is, for example, 
     an information processing method including: 
     a sensor unit recognizing an operating tool that comes into contact with a display unit; and 
     a control unit showing a guidance display for guiding an operation of the operating tool on the display unit. 
     The present disclosure is, for example, 
     a program that causes a computer to execute an information processing method including: 
     a sensor unit recognizing an operating tool that comes into contact with a display unit; and 
     a control unit showing a guidance display for guiding an operation of the operating tool on the display unit. 
     The present disclosure is, for example, 
     a wearable device including: 
     a display unit; 
     a sensor unit that recognizes an operating tool that comes into contact with the display unit; and 
     a control unit that shows a guidance display for guiding an operation of the operating tool on the display unit. 
     Effects of the Invention 
     According to at least one embodiment of the present disclosure, display for performing effective authentication can be performed. Note that the effects described herein are not necessarily limited, and any of the effects described in the present disclosure may be exerted. Additionally, the contents of the present disclosure should not be interpreted as being limited by the exemplified effects. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram showing an example of the appearance of a general smartphone. 
         FIG. 2  is a diagram showing an example of the appearance of a wristband type electronic device according to an embodiment. 
         FIG. 3  is a diagram showing an example of the internal structure of the wristband type electronic device according to the embodiment. 
         FIG. 4  is a diagram showing an example of the circuit configuration of the wristband type electronic device according to the embodiment. 
         FIG. 5A  is a diagram showing an example of display shown at the time of one-touch authentication,  FIG. 5B  is a diagram showing an example of display shown at the time of slide authentication, and  FIG. 5C  is a diagram showing an example of display shown at the time of multi-slide authentication. 
         FIG. 6  is a flowchart showing the flow of authentication processing according to a first embodiment. 
         FIG. 7  is a flowchart showing the flow of authentication processing according to a second embodiment. 
         FIG. 8  is a diagram for describing an example of a guidance display according to a third embodiment. 
         FIG. 9  is a diagram for describing an example of a guidance display according to a fourth embodiment. 
         FIG. 10  is a flowchart showing the flow of processing of showing a guidance display according to a fifth embodiment. 
         FIG. 11A  and  FIG. 11B  are diagrams for describing examples of a guidance display according to the fifth embodiment. 
         FIG. 12A  to  FIG. 12E  are diagrams for describing an example of a guidance display according to a sixth embodiment. 
         FIG. 13A  and  FIG. 13B  are diagrams for describing processing performed when showing a guidance display according to the sixth embodiment. 
         FIG. 14  is a diagram for describing a modification. 
         FIG. 15  is a diagram for describing a modification. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments and the like of the present disclosure will be described with reference to the drawings. Note that the description will be given in the following order. 
     &lt;General technology&gt; 
     &lt;1. First Embodiment&gt; 
     &lt;2. Second Embodiment&gt; 
     &lt;3. Third Embodiment&gt; 
     &lt;4. Fourth Embodiment&gt; 
     &lt;5. Fifth Embodiment&gt; 
     &lt;6. Sixth Embodiment&gt; 
     &lt;7. Modification&gt; 
     The embodiments and the like described below are preferable specific examples of the present disclosure, and the contents of the present disclosure are not limited to these embodiments and the like. 
     General Technology 
     First, a general technology will be described with reference to  FIG. 1  to facilitate understanding of the present disclosure.  FIG. 1  shows the appearance of a smartphone (smartphone  1 ), which is an example of a mobile device. The smartphone  1  has, for example, a housing  2 , a display  3 , and a fingerprint sensor unit  4 . The display  3  is provided on one main surface of the housing  2 , and the fingerprint sensor unit  4  is provided below the display  3  in the housing  2 . 
     In a case of such a configuration, since the fingerprint sensor unit  4  is provided in an area different from the display  3 , the device cannot be designed to be compact as a whole. Additionally, the fingerprint sensor unit  4  applied to the smartphone  1  is often of a capacitance type configured to detect a change in capacitance due to unevenness of a fingerprint. Such a fingerprint sensor unit  4  is susceptible to environmental humidity, and has a problem that it can hardly detect a wet finger in particular. 
     Additionally, in the general fingerprint authentication system shown in  FIG. 1 , in a case where a display prompting fingerprint authentication is shown on the display  3 , for example, since the position of the display is apart from the position of the fingerprint sensor unit  4 , when performing fingerprint authentication, it is necessary to move the finger and the line-of-sight out of the display  3 . Hence, there is a problem that an intuitive user interface (UI) cannot be provided. In view of such problems, embodiments of the present disclosure will be described in detail. 
     1. First Embodiment 
     [Wristband Type Electronic Device] 
     (Appearance Example of Wristband Type Electronic Device) 
     Next, a first embodiment will be described. The first embodiment is an example in which the present disclosure is applied to an example of an information processor, more specifically, to a wristband type electronic device that is an example of a wearable device.  FIG. 2  shows an example of the appearance of a wristband type electronic device (wristband type electronic device  10 ) according to the first embodiment. 
     As shown in  FIG. 2 , the wristband type electronic device  10  is used like a watch, for example. More specifically, the wristband type electronic device  10  has a band portion  11  that is wound around a wrist  5  of the user, and a main body portion  12 . The main body portion  12  has a display  13 . 
     (Internal Structure Example of Wristband Type Electronic Device) 
       FIG. 3  is a partial cross-sectional view for describing an example of the internal structure of the main body portion  12  of the wristband type electronic device  10 . The main body portion  12  of the wristband type electronic device  10  has the aforementioned display  13 , a light guide plate  14 , a light emitting unit  15 , a touch sensor unit  16  as an example of a contact detector, an image sensor  17  as an example of a sensor unit, and a lens unit  18 , for example. 
     Generally, as shown in  FIG. 3 , a contact operation with a fingertip F, which is an example of an operating tool, is performed on the display  13 , and presence or absence of contact is detected by the touch sensor unit  16 . The main body portion  12  of the wristband type electronic device  10  has a structure in which the light guide plate  14 , the display  13 , the lens unit  18 , and the image sensor  17  are sequentially stacked when viewed from the operation side. Note that contact with the display  13  may include not only direct contact with the display  13 , but also indirect contact through another member (e.g., light guide plate  14 ). Additionally, contact with the display  13  may include not only the fingertip F coming into contact with the display  13 , but also the fingertip F approaching the display  13 , for example. 
     Hereinafter, each configuration will be described. The display  13  includes a liquid crystal display (LCD), an organic light emitting diode (OLED), and the like. The light guide plate  14  is a light transmissive member that guides light from the light emitting unit  15  to an area AR where the fingertip F comes into contact, for example. The light guide plate  14  is not limited to a transparent one, and may be any type as long as it transmits light to the extent that an image of a fingerprint of the fingertip F can be captured by the image sensor  17 . 
     The light emitting unit  15  includes a light emitting diode (LED) and the like, and is provided at least partially around the light guide plate  14 . Note that the area AR is an area including a position corresponding to the image sensor  17 , specifically, an area including at least a position corresponding to a range of imaging by the image sensor  17 . The light emitting unit  15  provides light required for imaging by lighting up when capturing an image of a fingerprint, for example. 
     The touch sensor unit  16  is a sensor that detects contact of the fingertip F with the display  13 . As the touch sensor unit  16 , a capacitive touch sensor is applied, for example. Other types of touch sensors, such as a resistive film type, may be applied instead. Note that while the touch sensor unit  16  is locally provided near a part below the area AR in  FIG. 3 , the touch sensor unit  16  may be provided over substantially an entire surface below the display  13 . 
     The image sensor  17  includes a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like. The image sensor  17  photoelectrically converts subject light incident through the lens unit  18  into a charge amount to generate an image of the fingerprint of the fingertip F. Various types of processing at the subsequent stage are performed on an image signal obtained through the image sensor  17 . The lens unit  18  includes a lens (microlens) provided for each pixel of the image sensor  17 . 
     (Circuit Configuration Example of Wristband Type Electronic Device) 
       FIG. 4  is a block diagram showing an example of the circuit configuration and the like of the wristband type electronic device  10 . The wristband type electronic device  10  has, in addition to the display  13 , the touch sensor unit  16 , the image sensor  17 , and the like described above, a control unit  21 , a wireless communication unit  22 , an antenna  23  connected to the wireless communication unit  22 , a near field communication (NFC) communication unit  24 , an antenna  25  connected to the NFC communication unit  24 , a global positioning system (GPS) unit  26 , an antenna  27  connected to a position sensor unit  26 , a memory unit  28 , a vibrator  29 , a motion sensor  30 , a speech processing unit  31 , a microphone  32 , and a speaker  33 , for example. 
     The control unit  21  includes a central processing unit (CPU), for example, and controls each unit of the wristband type electronic device  10 . As a specific example, the control unit  21  controls information displayed on the display  13 , and controls the display  13  to show a guidance display described later. Additionally, the control unit  21  performs various types of image processing on a fingerprint image of the fingertip F captured by the image sensor  17 , and performs fingerprint authentication based on an image (fingerprint image) of the fingerprint that is one type of biological information. 
     The wireless communication unit  22  performs short-range wireless communication with another terminal on the basis of the Bluetooth (registered trademark) standard, for example. The wireless communication unit  22  performs modulation/demodulation processing, error correction processing, and the like in accordance with the Bluetooth (registered trademark) standard, for example. 
     The NFC communication unit  24  performs wireless communication with a nearby reader/writer on the basis of the NFC standard. Note that although illustration is omitted, power is supplied to each unit of the wristband type electronic device  10  from a battery such as a lithium ion secondary battery. The battery may be wirelessly charged according to the NFC standard. 
     The position sensor unit  26  is a positioning unit that performs positioning of the current position using a system called global navigation satellite system (GNSS), for example. Data obtained by the wireless communication unit  22 , the NFC communication unit  24 , and the position sensor unit  26  is supplied to the control unit  21 . Then, the control unit  21  executes control based on the supplied data. 
     The memory unit  28  is a generic term for a read only memory (ROM) in which a program executed by the control unit  21  is stored, a random access memory (RAM) used as a work memory when the control unit  21  executes the program, a nonvolatile memory for data storage, and the like. Note that the memory unit  28  stores the user&#39;s fingerprint information for fingerprint authentication. The fingerprint information is initially registered when the wristband type electronic device  10  is used for the first time, for example. 
     The vibrator  29  is a member that vibrates the main body portion  12  of the wristband type electronic device  10 , for example. Vibration of the main body portion  12  by the vibrator  29  notifies the user of an incoming call, reception of an e-mail, and the like. 
     The motion sensor  30  detects a movement of the user wearing the wristband type electronic device  10 . As the motion sensor  30 , an acceleration sensor, a gyro sensor, an electronic compass, a barometric pressure sensor, or the like is used. Note that the wristband type electronic device  10  may incorporate a sensor other than the motion sensor  30 . For example, a biosensor that detects biological information other than the fingerprint such as blood pressure, pulse, sweat glands (position of sweat glands or degree of sweating from sweat glands), body temperature, or the like of a user wearing the wristband type electronic device  10  may be incorporated. Alternatively, a pressure sensor or the like for detecting whether or not the user has worn the wristband type electronic device  10  may be provided on the back side (side facing the wrist) of the band portion  11  or the main body portion  12 . 
     The microphone  32  and the speaker  33  are connected to the speech processing unit  31 , and the speech processing unit  31  performs call processing with a party on the other end connected by wireless communication performed by the wireless communication unit  22 . Additionally, the speech processing unit  31  can also perform processing for a speech input operation. 
     Since the display  13 , the touch sensor unit  16 , and the like have already been described, overlapping description will be omitted. 
     [Display Example when Performing Fingerprint Authentication] 
     Next, display examples when performing fingerprint authentication will be described. Control for showing these display examples on the display  13  is performed by the control unit  21 , for example. 
       FIG. 5A  shows a first example of a display shown when performing fingerprint authentication. As shown in  FIG. 5A  a display AA imitating a fingerprint is displayed on the display  13 , for example. With this display, it is possible to indicate that the position where the display AA is shown is the position where the fingertip F is brought into contact, and it is possible to prompt the user to perform fingerprint authentication. The image sensor  17  is located below at least a part of the position where the display AA is shown. Note that  FIG. 5  shows the position of the image sensor  17  for easy understanding. 
     The user brings the fingertip F into contact with a position corresponding to the display AA. When the contact with the fingertip F is detected by the touch sensor unit  16 , the control unit  21  performs control for capturing an image of the fingerprint. According to such control, a fingerprint image, which is information on the fingertip F, is obtained through the image sensor  17 . After subjecting the obtained fingerprint image to appropriate image processing, the control unit  21  performs match processing between the fingerprint image and the user&#39;s fingerprint image stored in the memory unit  28  to perform authentication. For example, authentication is performed by comparing the degree of coincidence of feature points between fingerprint images. Other known methods can be applied as the authentication method, as a matter of course. Alternatively, authentication based on any biological information or a combination thereof may be performed. Note that the display exemplified in  FIG. 5A  is an example in which authentication is performed by a single contact, and is not a display accompanied by a guidance display. 
     With such a configuration, the part where the fingerprint authentication is performed can be integrated with the display. Hence, the wristband type electronic device  10  can be downsized. Additionally, by showing the display for performing fingerprint authentication above the device for performing fingerprint authentication (image sensor  17  in present embodiment), it becomes easy for the user to recognize where to place the fingertip F, and an intuitive UI can be implemented. Additionally, authentication can be performed irrespective of the humidity of the fingertip F, and the accuracy of authentication can be ensured. 
       FIG. 5B  shows a second example of a display shown when performing fingerprint authentication. The second example is an example of a guidance display for guiding the operation of the fingertip F together with the position where the fingertip F is brought into contact. The guidance display in the present embodiment is a display indicating the moving direction of the fingertip F. 
     For example, as shown in  FIG. 5B , as an example of the guidance display, a display CC of three downward-pointing arrows is shown together with a display BB imitating a fingerprint. With this display, it is possible to prompt the user to move the fingertip F downward. 
     In response to an operation of moving the fingertip F downward, an image of the fingerprint is captured. With this operation, it is possible to obtain more feature points of the fingerprint. By comparing the feature points of the captured fingerprint image with the feature points of the fingerprint image stored in the memory unit  28 , more accurate fingerprint authentication can be performed. 
       FIG. 5C  shows a third example of a display shown when performing fingerprint authentication. The display shown on the left side of  FIG. 5C  is similar to the display shown in  FIG. 5B . The display shown in the center of  FIG. 5C  includes, as an example of the guidance display, a display DD of three rightward-pointing arrows together with the display BB imitating a fingerprint. The display shown on the right side of  FIG. 5C  includes, as an example of the guidance display, a display EE of three leftward-pointing arrows together with the display BB imitating a fingerprint. 
     The three displays shown in  FIG. 5C  are displayed consecutively, for example. For example, based on the display on the left side of  FIG. 5C , the fingertip F is slid and an image of the fingerprint is captured. Then, when the touch sensor unit  16  detects that the fingertip F is separated from the display  13 , the control unit  21  shows the display shown in the center of  FIG. 5C  on the display  13 . According to the display, the fingertip F is slid rightward and an image of the fingerprint is captured. When the touch sensor unit  16  detects that the fingertip F is separated from the display  13 , the control unit  21  shows the display shown on the right side of  FIG. 5C  on the display  13 . According to the display, the fingertip F is slid leftward and an image of the fingerprint is captured. 
     With such processing, it is possible to obtain more feature points of the fingerprint than feature points of the fingerprint obtained on the basis of the display shown in  FIG. 5B , for example. By comparing the feature points of the captured fingerprint image with the feature points of the fingerprint image stored in the memory unit  28 , more accurate fingerprint authentication can be performed. 
     Note that in the following description, authentication performed in response to an operation of bringing the fingertip F into contact with the display  13  once as shown in  FIG. 5A  is referred to as one-touch authentication as appropriate. Additionally, authentication performed in response to an operation of bringing the fingertip F into contact with the display  13  once and then sliding the fingertip F once as shown in  FIG. 5B  is referred to as slide authentication as appropriate. Additionally, authentication performed in response to an operation of sliding the fingertip F multiple times on the display  13  as shown in  FIG. 5C  is referred to as multi-slide authentication as appropriate. 
     Authentication Processing in First Embodiment 
     (Authentication Processing Flow) 
     Next, authentication processing in the first embodiment will be described with reference to a flowchart shown in  FIG. 6 . The authentication processing in the first embodiment is authentication processing performed when the wristband type electronic device  10  is worn on the wrist  5  and used. Note that the authentication processing described below may be performed after passage of a predetermined time after the wristband type electronic device  10  is worn, or the like. 
     Before the authentication is successfully performed by the authentication processing, the wristband type electronic device  10  is in a locked state. The locked state may be a state in which use of all the functions of the wristband type electronic device  10  is prohibited, or a state in which use of only a function that does not require authentication (e.g., display of time) is permitted. If the authentication is successful, the locked state is released, and use of all the functions of the wristband type electronic device  10  is permitted. Hereinafter, a specific processing flow will be described. Note that the following processing is performed under the control of the control unit  21  unless otherwise specified. 
     In step ST 101 , one-touch authentication is performed. That is, a shape imitating a fingerprint is displayed on the display  13 , and when the user brings the fingertip F into contact with the display, fingerprint authentication is performed. Then, the processing proceeds to step ST 102 . 
     In step ST 102 , it is determined whether or not the authentication has been successful. For example, the control unit  21  compares the captured fingerprint image with the fingerprint image stored in the memory unit  28 , and if the feature points match by a threshold value or more, determines that the authentication has been successful, and if not, determines that the authentication has failed. If the control unit  21  determines that the authentication has been successful, the processing proceeds to step ST 110 . 
     In Step ST 110 , since the authentication has been successful, the control unit  21  releases the locked state of the wristband type electronic device  10 . Thereafter, all the functions of the wristband type electronic device  10  become available. 
     In the determination processing of step ST 102 , if the control unit  21  determines that the authentication has failed, the processing proceeds to step ST 103 . In step ST 103 , it is determined whether or not the number of authentication failures is equal to or greater than a threshold value (e.g., three times). If the number of authentication failures is less than three, the processing returns to step ST 101 , and one-touch authentication is performed again. If the number of authentication failures is three or more, the processing proceeds to step ST 104 . 
     In step ST 104 , slide authentication is performed. That is, a shape imitating a fingerprint including a guidance display is displayed on the display  13 , and when the user brings the fingertip F into contact with the display and slides the fingertip F once, fingerprint authentication is performed. Here, since the one-touch authentication has failed multiple times, slide authentication is performed to more accurately authenticate the person to be authenticated. Then, the processing proceeds to step ST 105 . 
     In step ST 105 , it is determined whether or not the authentication has been successful. For example, the control unit  21  compares the captured fingerprint image with the fingerprint image stored in the memory unit  28 , and if the feature points match by a threshold value or more, determines that the authentication has been successful, and if not, determines that the authentication has failed. If the control unit  21  determines that the authentication has been successful, the processing proceeds to step ST 110 . 
     In Step ST 110 , since the authentication has been successful, the control unit  21  releases the locked state of the wristband type electronic device  10 . Thereafter, all the functions of the wristband type electronic device  10  become available. 
     In the determination processing of step ST 105 , if the control unit  21  determines that the authentication has failed, the processing proceeds to step ST 106 . In step ST 106 , it is determined whether or not the number of authentication failures is equal to or greater than a threshold value (e.g., three times). If the number of authentication failures is less than three, the processing returns to step ST 104 , and slide authentication is performed again. If the number of authentication failures is three or more, the processing proceeds to step ST 107 . 
     In step ST 107 , multi-slide authentication is performed. That is, a shape imitating a fingerprint including a guidance display is displayed on the display  13 , and when the user brings the fingertip F into contact with the display and slides the fingertip F multiple times, fingerprint authentication is performed. Here, since slide authentication has failed multiple times, multi-slide authentication is performed to more accurately authenticate the person to be authenticated. Then, the processing proceeds to step ST 108 . 
     In step ST 108 , it is determined whether or not the authentication has been successful. For example, the control unit  21  compares the captured fingerprint image with the fingerprint image stored in the memory unit  28 , and if the feature points match by a threshold value or more, determines that the authentication has been successful, and if not, determines that the authentication has failed. If the control unit  21  determines that the authentication has been successful, the processing proceeds to step ST 110 . 
     In Step ST 110 , since the authentication has been successful, the control unit  21  releases the locked state of the wristband type electronic device  10 . Thereafter, all the functions of the wristband type electronic device  10  become available. 
     In the determination processing of step ST 108 , if the control unit  21  determines that the authentication has failed, the processing proceeds to step ST 109 . In step ST 109 , since the authentication in all of one-touch authentication, slide authentication, and multi-slide authentication has failed, it is determined that the person to be authenticated is not the genuine user of the wristband type electronic device  10 . Hence, the control unit  21  maintains the locked state of the wristband type electronic device  10 . 
     (Modification of Authentication Processing) 
     In the above-described all of authentication processing, one-touch authentication, slide authentication, and multi-slide authentication are performed in accordance with the success or failure of authentication. However, the present invention is not limited to this. For example, the authentication processing may be processing of performing authentication based on slide authentication without first performing one-touch authentication, and performing multi-slide authentication in a case where the authentication based on slide authentication fails multiple times. 
     2. Second Embodiment 
     Next, a second embodiment will be described. The second embodiment is generally an example in which different guidance displays are displayed according to security levels. Note that items described in the first embodiment (e.g., appearance, configuration, and the like of wristband type electronic device  10 ) can be applied to the second embodiment unless otherwise specified. Note that a wristband type electronic device  10  according to the second embodiment has a payment function that enables payment by bringing the wristband type electronic device  10  closer to a reader. 
     Authentication Processing in Second Embodiment 
     Authentication processing in the second embodiment will be described with reference to a flowchart shown in  FIG. 7 . The authentication processing in the second embodiment is generally authentication processing in which processing from step ST 201  to step ST 204  in the processing shown in  FIG. 7  is performed when the wristband type electronic device  10  is worn, and the processing from step ST 205  to step ST 209  is performed in response to a request from an application that executes a payment function. Note that while the following describes that the authentication processing performed when the wristband type electronic device  10  is worn and the authentication processing performed in response to a request from the application are performed consecutively, the two types of processing do not need to be performed consecutively. 
     In step ST 201 , the worn state of the wristband type electronic device  10  is detected. For example, the worn state of the wristband type electronic device  10  is detected on the basis of a detection result by a pressure sensor provided in a band portion  11  of the wristband type electronic device  10 . Then, if the wristband type electronic device  10  is worn, the processing proceeds to step ST 202 . 
     In step ST 202 , it is determined whether or not wear authentication, which is authentication performed when the wristband type electronic device  10  is worn, has been completed. For example, a control unit  21  refers to a flag stored in a memory unit  28  and indicating whether or not wear authentication has been completed, and determines whether or not wear authentication has been completed. If wear authentication has not been completed, the processing proceeds to step ST 203 . 
     In step ST 203 , wear authentication is performed by authentication based on one-touch authentication, for example. Then, the processing proceeds to step ST 204 . 
     In step ST 204 , it is determined whether or not the wear authentication has been successful. If the wear authentication has failed, the processing returns to step ST 201 , and wear authentication according to the worn state is performed. If the wear authentication has been successful, the control unit  21  updates the flag to indicate that the wear authentication has been completed, for example. Then, the processing proceeds to step ST 205 . 
     In step ST 205 , the user makes a payment with so-called electronic money using the wristband type electronic device  10 . In step ST 205 , in order to make such a payment, an application that makes the payment requests the wristband type electronic device  10  to perform fingerprint authentication and send the result of the fingerprint authentication. Then, the processing proceeds to step ST 206 . 
     In step ST 206 , the control unit  21  determines the security level. In the present embodiment, the control unit  21  determines the security level according to the payment amount. For example, if the payment amount is small (e.g., 10,000 yen or less), it is determined that the required security level is “low”. Instead, if the payment amount is a predetermined amount (e.g., 10,000 to 100,000 yen or less), it is determined that the required security level is “intermediate”. Instead, if the payment amount is large (e.g., more than 100,000 yen), it is determined that the required security level is “high”. 
     If the security level is “low”, the processing proceeds to step ST 207 . In step ST 207 , since the security level is “low”, the control unit  21  determines that only completion of wear authentication is necessary, and re-authentication is not necessary. Here, since wear authentication has already been completed in step ST 202 , the application returns to the control unit  201  that wear authentication has already been completed and re-authentication is unnecessary. Note that although illustration is omitted, payment using the wristband type electronic device  10  is possible thereafter. 
     If the result of the determination processing in step ST 206  is that the security level is “intermediate”, the processing proceeds to step ST 208 . In step ST 208 , since the security level is “intermediate”, slide authentication that enables more accurate authentication is performed. That is, a display including the guidance display shown in  FIG. 5B  is shown, for example, and slide authentication is performed. The result of slide authentication is returned to the application. If the result of slide authentication is “success”, processing of a function displayed on a display  13  is performed. For example, if the result of slide authentication is “success”, payment by the application is performed. Instead, if the result of slide authentication is “failure”, the payment by the application is not permitted. 
     If the result of the determination processing in step ST 206  is that the security level is “high”, the processing proceeds to step ST 209 . In step ST 209 , since the security level is “high”, multi-slide authentication that enables more accurate authentication is performed. That is, a display including the guidance display shown in  FIG. 5C  is shown, for example, and multi-slide authentication is performed. The result of multi-slide authentication is returned to the application. If the result of multi-slide authentication is “success”, the payment by the application is performed, and if the result of multi-slide authentication is “failure”, the payment by the application is not permitted. 
     By performing such processing, if wear authentication has been completed, it is permitted to make a purchase at a low price (e.g., tea for about 100 yen), and it is not necessary to perform authentication for every purchase at a low price. Hence, it is possible to achieve both a certain level of security and user convenience. Additionally, when making a purchase at a relatively high price, highly accurate authentication is performed. Hence, payment by impersonation or the like can be prevented. 
     Modification of Second Embodiment 
     In a case where the security level is “intermediate”, multi-slide authentication may be performed. Then, in a case where the security level is “high”, one-touch authentication and multi-slide authentication may be performed. The kind of guidance display to be shown and the way of authentication to be performed according to a security level can be changed as appropriate. 
     While security levels set assuming face-to-face payment have been described in the above description, the present invention is not limited to this. For example, as shown in Table 1 below, in addition to face-to-face payments, it is also possible to set security levels according to the amount of non-face-to-face payments and functions in Internet banking, and shown guidance displays according to the security levels. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 NON-FACE-TO- 
                   
               
               
                   
                 FACE-TO-FACE 
                 FACE INTERNET 
                 INTERNET 
               
               
                   
                 PAYMENT 
                 PAYMENT 
                 BANKING 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 LOW SECURITY 
                 10,000 YEN 
                   
                   
               
               
                 LEVEL 
                 OR LESS 
               
               
                 INTERMEDIATE 
                 10,000 TO 
                 10,000 YEN 
                 LOGIN (TO CHECK 
               
               
                 SECURITY LEVEL 
                 100,000 YEN 
                 OR LESS 
                 BALANCE OR 
               
               
                   
                   
                   
                 OTHER ITEM) 
               
               
                 HIGH SECURITY 
                 100,000 YEN 
                 10,000 YEN 
                 REMITTANCE 
               
               
                 LEVEL 
                 OR MORE 
                 OR MORE 
               
               
                   
               
            
           
         
       
     
     Additionally, the security level may be set in accordance with entry control, data access authority, and the like, as well as payment. 
     3. Third Embodiment 
     Next, a third embodiment will be described. The third embodiment is an example in which an operation of a fingertip F is guided by erasing a predetermined display displayed on a display  13  along the moving direction of the fingertip F. Note that the items described in the above embodiment can be applied to the present embodiment unless otherwise specified. 
     For example, as shown in  FIG. 8A , characters (including numbers) “Y19,800” are displayed on the display  13  as an example of a predetermined display. For example, an image sensor  17  is located below the character “Y”. 
     The user first brings the fingertip F into contact with the position of “Y”, and then slides the fingertip F along the character string. This operation of the fingertip F is called a swipe. As shown in  FIGS. 8B and 8C , the characters disappear along with the sliding operation of the fingertip F. When the fingertip F is slid, the fingertip F passes above the image sensor  17 . Hence, a fingerprint image of the fingertip F can be acquired. Slide authentication is performed on the basis of the acquired fingerprint image, and if the fingerprint authentication is established, as shown in  FIG. 8D , “Thank you!” is displayed and payment is performed, for example. Note that in a case where the fingerprint authentication fails, the characters “Y19,800” may be displayed again. 
     By such processing, the user can confirm the amount of payment, and perform an operation of approving the amount of payment by acting as if he/she has actively signed. 
     Note that the image sensor  17  only needs to be located below at least a part of the path along which the fingertip F slides. Additionally, when displaying the characters “Y19,800” to facilitate understanding of the moving direction of the fingertip F by the user, after sequentially erasing the character string from left to right and erasing all the characters, the characters “Y19,800” may be displayed again. Additionally, this display mode may be repeated. Moreover, when a touch sensor unit  16  detects contact of the fingertip F with the position of “Y”, the display density of the adjacent character (“1” in this example) can be reduced, for example. The guidance display that show the characters as if they are fading out allows the user to perceive the direction in which to move the fingertip F. That is, erasing the display may include not only erasing but also changing the density of the display. 
     4. Fourth Embodiment 
     Next, a fourth embodiment will be described. Note that the items described in the above embodiment can be applied to the present embodiment unless otherwise specified. 
     As shown in  FIG. 9A , a rectangular frame portion  40  is displayed on the display  13 . An image sensor  17  is located below the frame portion  40 . Characters A, B . . . , displayed in rectangular frames in  FIGS. 9A and 9B  indicate icons corresponding to applications. A predetermined icon is displayed in the frame portion  40  in accordance with an operation of sliding a fingertip F of the user. For example, in  FIG. 9B , an icon corresponding to application B is displayed in the frame portion  40 . 
     The user performs fingerprint authentication by bringing the fingertip F into contact with the frame portion  40 . If the authentication is established, it is possible to log in to the application B. With such processing, it is possible to simultaneously select and log in to the application B. Note that a guidance display such as, for example, an arrow pointing upward or downward may be displayed in the frame portion  40 , and the user may be prompted to perform slide authentication or multi-slide authentication in accordance with the display. 
     5. Fifth Embodiment 
     Next, a fifth embodiment will be described. Note that the items described in the above embodiment can be applied to the present embodiment unless otherwise specified. The fifth embodiment is generally an example in which a different guidance display is displayed according to a detection result of a motion sensor  30 , which is an example of a posture detector. 
       FIG. 10  is a flowchart showing the flow of processing in the fifth embodiment. In step ST 501 , a predetermined application requests fingerprint authentication. Then, the processing proceeds to step ST 502 . 
     In step ST 502 , a control unit  21  detects the posture of a wristband type electronic device  10  on the basis of sensor information supplied from the motion sensor  30 . Then, the processing proceeds to step ST 503 . 
     In step ST 503 , the control unit  21  determines from the posture of the wristband type electronic device  10  whether or not the hand wearing the wristband type electronic device  10  is down. If the control unit  21  determines that the hand wearing the wristband type electronic device  10  is down, the processing proceeds to step ST 504 . In step ST 504 , the control unit  21  performs control to display a graphical user interface (GUI) for vertical finger authentication on a display  13 . Then, the processing proceeds to step ST 506 . 
     In the determination processing of step ST 503 , if the control unit  21  determines that the hand wearing the wristband type electronic device  10  is not down, the processing proceeds to step ST 505 . In step ST 505 , the control unit  21  performs control to display a GUI for horizontal finger authentication on the display  13 . Then, the processing proceeds to step ST 506 . 
     In step ST 506 , fingerprint authentication using the above-described GUI is performed. Then, it is determined whether or not the fingerprint authentication has been completed. If the fingerprint authentication has been completed, processing according to the authentication result is performed, and then the processing is ended. If the fingerprint authentication has not been completed, the processing returns to step ST 503 , and the processing after step ST 503  is repeated. 
     Note that in the above-described processing, the case where fingerprint authentication is performed is not limited to a request from an application, and may include other cases (e.g., re-authentication after passage of predetermined time from when wristband type electronic device  10  is worn). 
       FIG. 11A  shows an example of a GUI for vertical finger authentication, and  FIG. 11B  shows an example of a GUI for horizontal finger authentication. 
     In the case of the GUI for vertical finger authentication shown in  FIG. 11A , a shape imitating a fingerprint is displayed in a direction substantially orthogonal to the extending direction of the user&#39;s wrist  5 , and a guidance display for guiding the fingertip F to slide in this direction (three arrows in illustrated example) is shown, for example. 
     In the case of the GUI for horizontal finger authentication shown in  FIG. 11B , a shape imitating a fingerprint is displayed in a direction along the extending direction of the user&#39;s wrist  5 , and a guidance display for guiding the fingertip F to slide in this direction (three arrows in illustrated example) is shown, for example. 
     As described above, it is also possible to display different guidance displays according to the detection result of the motion sensor  30 . By performing such processing, it is possible to display a guidance display with excellent operability even when, for example, the user has his/her arm down while holding a bag, and the like. 
     6. Sixth Embodiment 
     Next, a sixth embodiment will be described. Note that the items described in the above embodiment can be applied to the present embodiment unless otherwise specified. The sixth embodiment is generally an example in which guidance display is performed by changing the position of a display shown on a display  13 . 
     For example, as shown in  FIG. 12A , the display  13  shows a linear display  60  including multiple rectangular dots and extending in the horizontal direction. Additionally, an imaging range of an image sensor  17  is indicated by a dotted rectangle. The imaging range overlaps with a position where at least some of the dots included in the display  60  are shown. 
     As shown in  FIG. 12B , the user brings a fingertip F into contact with the position corresponding to the imaging range of the image sensor  17 . At this time, to facilitate understanding of the part to bring the fingertip F into contact by the user, the dots at the position overlapping the imaging range of the image sensor  17  may be colored or blinked. 
     When a touch sensor unit  16  detects the contact of the fingertip F with the display  13 , a control unit  21  performs control to change the display of the linear display  60 . Specifically, the control unit  21  changes the display position of the dots included in the display  60 , thereby controlling the display content to move the display  60  downward as a whole, as shown in  FIGS. 12C and 12D . By performing such display processing, it is possible to prompt the user to slide the fingertip F downward. Slide authentication can be performed by the user sliding the fingertip F downward. The control unit  21  may instead control the display content to move the display  60  upward or to the right or left as a whole, as a matter of course. 
     When the touch sensor unit  16  detects a slide of the fingertip F by a predetermined amount or more, the control unit  21  performs control to erase the display  60  as shown in  FIG. 12E , for example. With this operation, the user understands that the operation for fingerprint authentication has been completed, and can take the fingertip F off the display  13 . 
     As described above, it is also possible to perform guidance display by changing the display position shown on the display  13 . 
     Incidentally, as shown in  FIG. 13A , if dots are displayed in the imaging range of the image sensor  17  at the time of capturing an image of a fingerprint, the accuracy of fingerprint detection may be affected. For example, in a case where the display  13  includes OLEDs and dots are displayed by light emission of the OLED, mixing of the OLED light when capturing an image of the fingerprint may affect the accuracy of fingerprint detection. Hence, all dots are displayed until the user brings the fingertip F into contact with the display  13 . Then, when the touch sensor unit  16  detects that the contact of the fingertip F with the display  13 , the dots located within the imaging range may be erased as shown in  FIG. 13B . 
     Alternatively, instead of erasing the dots located within the imaging range, a filter such as a band pass filter (BPF) is inserted in the incident direction of light incident on the image sensor  17 . Then, by displaying the dots using light having a wavelength that does not pass through the filter, deterioration in the accuracy of fingerprint authentication due to the display of dots can be prevented. 
     7. Modification 
     While multiple embodiments of the present disclosure have been specifically described above, the contents of the present disclosure are not limited to the above-described embodiments, and various modifications based on the technical idea of the present disclosure are possible. Hereinafter, modifications will be described. 
     The internal structure of the wristband type electronic device  10  described above can be appropriately changed. For example, as shown in  FIG. 14 , a structure omitting the light guide plate  14  and the light emitting unit  15  may be employed. In this case, a self-luminous display such as an OLED is used as the display  13 . Light for imaging may be provided by irradiating the part that comes into contact with the fingertip F with light from the display  13 . With this configuration, the light guide plate  14  becomes unnecessary, and the thickness of the device can be reduced. Additionally, the touch sensor unit  16  may be provided on the other main surface side (e.g., upper surface side) of the display  13  in the embodiment. 
     The shape and the like of the wristband type electronic device  10  can also be appropriately changed. For example, as shown in  FIG. 15 , a device in which the band portion  11  and the main body portion  12  are integrally formed may be used. Additionally, the wearable device is not limited to a wristband type electronic device, but may be a smartphone or a portable audio player. Additionally, the present disclosure can be applied to electronic devices such as a personal computer and robot devices. Additionally, the present disclosure can be applied to authentication performed when using an on-vehicle device and authentication performed by an automatic teller machine (ATM) in a bank. 
     The above-described wristband type electronic device  10  may have a function of notifying the other party using fingerprint authentication of a message. For example, multiple messages are displayed on the display  13 . When the user slides a predetermined message from among the multiple messages, the authentication described in the embodiment is performed. When the authentication is established, the other party is notified of the message through the wireless communication unit  22 . As the message, a message to a family member such as “I&#39;m coming home” can be set, for example. The message may be a message to a boss, a friend, or the like, and the content of the message can be set as appropriate. 
     In the above-described finger authentication for sending a message, the destination of the message may be specified in accordance with the type of the authenticated finger (thumb, forefinger . . . , little finger). For example, the user sets the association between the type of finger and the destination, such as father for thumb, mother for forefinger, and sister for little finger. Then, when the user wants to send a message “I&#39;m coming home” to the mother, the user slides the forefinger with the message. If the authentication is established, the mother is notified of the message “I&#39;m coming home”. Even in such a case, guidance display can be performed. For example, multiple messages may be shown on the display, or a message to return home may be automatically displayed at a certain time (e.g., in the evening). Multiple destinations may be displayed on the left side of the display, and authentication may be performed when a predetermined destination is touched with a finger. Then, if the authentication is established, multiple messages may be displayed on the right side of the display as a guidance display. The finger contacting the display to specify the destination may then be guided to directly slide to the desired message. 
     While the above-described embodiments use a fingertip of a person as an example of an operating tool, the present invention is not limited to this. For example, the operating tool may be a pen-shaped device. Then, authentication may be performed by recognizing a specific shape formed at the pen tip. 
     While the embodiments described above use the moving direction of the fingertip F as an example of the operation of the operating tool (fingertip F) to be guided, the present invention is not limited this. For example, the number of times of contact with the fingertip F or the type of finger (thumb, index finger, or another finger) may be used, or a combination of these may be used. Then, a guidance display indicating the number of times of contact or the type of finger may be displayed. For example, as the required security level increases, the number of times of contact with the fingertip F may be guided to increase, so that the authentication may be performed multiple times by multiple contacts of the fingertip F. 
     In the above-described embodiments, guidance of the operating tool by voice or the like may be performed. Note, however, that when the user brings the fingertip F into contact, the user&#39;s line-of-sight is focused on the contact point. Hence, a configuration in which the user can recognize the guidance of the operating tool with the same perception (vision) is preferable. 
     multiple image sensors  17  may be provided, and multiple positions where fingerprint authentication can be performed may be provided on the display  13 . 
     The present disclosure can also be implemented by an apparatus, a method, a program, a system, and the like. For example, a program that performs the function described in the above-described embodiment can be provided in a downloadable state, and a device that does not have the function described in the embodiment can download and install the program to control the device in the manner described in the embodiment. The present disclosure can also be implemented by a server that distributes such a program. Additionally, the items described in each of the embodiments and modifications can be appropriately combined. 
     The present disclosure can also adopt the following configurations. 
     (1) 
     An information processor including: 
     a sensor unit that recognizes an operating tool that comes into contact with a display unit; and 
     a control unit that shows a guidance display for guiding an operation of the operating tool on the display unit. 
     (2) 
     The information processor according to (1), in which 
     the control unit performs authentication on the basis of biological information on the operating tool obtained by the sensor unit. 
     (3) 
     The information processor according to (2), in which 
     the biological information is authentication based on at least a fingerprint, a sweat gland, a pulse, a blood pressure, a body temperature, or a combination thereof. 
     (4) 
     The information processor according to (2), in which 
     the control unit performs processing of a function displayed on the display unit on the basis of authentication based on the biological information. 
     (5) 
     The information processor according to any one of (1) to (4), in which 
     the guidance display is a display indicating at least one of a moving direction of the operating tool, the number of times of contact of the operating tool, or a type of the operating tool. 
     (6) 
     The information processor according to any one of (1) to (5), in which 
     the control unit shows a different guidance display on the display unit according to a security level. 
     (7) 
     The information processor according to any one of (1) to (5), in which 
     the control unit guides an operation of the operating tool by erasing, along a moving direction of the operating tool, a predetermined display shown on the display unit. 
     (8) 
     The information processor according to any one of (1) to (5), in which 
     the control unit shows the guidance display at a position corresponding to the sensor unit on the display unit. 
     (9) 
     The information processor according to any one of (1) to (5) further including a posture detector, in which 
     the control unit shows a different guidance display according to a detection result by the posture detector. 
     (10) 
     The information processor according to any one of (1) to (5), in which 
     the control unit performs the guidance display by changing a position of a display shown on the display unit. 
     (11) 
     The information processor according to any one of (1) to (10), in which 
     the control unit shows, on the display unit, a display that does not include the guidance display and indicates a contact position of the operating tool. 
     (12) 
     The information processor according to any one of (1) to (11), in which 
     the information processor has a structure in which the display unit, the sensor unit, and a contact detector that detects contact of the operating tool with the display unit are stacked on top of one another. 
     (13) 
     The information processor according to (12) further including: 
     a light emitting unit; and 
     a light guiding unit that guides light from the light emitting unit to a position where the operating tool comes into contact with the display unit. 
     (14) 
     The information processor according to (12), in which 
     the display unit is a self-luminous display, and has a configuration in which a position where the operating tool comes into contact with the display unit is irradiated with light from the display unit. 
     (15) 
     The information processor according to (14), in which 
     the control unit erases a display shown at a position corresponding to the sensor unit when contact of the operating tool is detected by the contact detector. 
     (16) 
     The information processor according to any one of (1) to (15), in which 
     the operating tool is a fingertip, and the sensor unit is an image sensor. 
     (17) 
     An information processing method including: 
     a sensor unit recognizing an operating tool that comes into contact with a display unit; and 
     a control unit showing a guidance display for guiding an operation of the operating tool on the display unit. 
     (18) 
     A program that causes a computer to execute an information processing method including 
     a sensor unit recognizing an operating tool that comes into contact with a display unit, and 
     a control unit showing a guidance display for guiding an operation of the operating tool on the display unit. 
     (19) 
     A wearable device including: 
     a display unit; 
     a sensor unit that recognizes an operating tool that comes into contact with the display unit; and 
     a control unit that shows a guidance display for guiding an operation of the operating tool on the display unit. 
     REFERENCE SIGNS LIST 
     
         
           10  Wristband type electronic device 
           13  Display 
           14  Light guide plate 
         Light emitting unit 
           16  Touch sensor unit 
           17  Image sensor 
           21  Control unit 
           30  Motion sensor