Patent Publication Number: US-2016224775-A1

Title: Electronic apparatus having fingerprint sensor operating in vector mode

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 104103171 filed in Taiwan, R.O.C. on 2015 Jan. 29, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The instant disclosure relates to an electronic apparatus, and particularly relates to an electronic apparatus having a fingerprint sensor operating in a vector mode. 
     2. Related Art 
     Biometric is a user identification technology based on the uniqueness of fingerprints, facial outlooks, voices, irises, or even DNA molecules of human bodies. To review the developments of identification technologies, password identification was once the commonest one. However, the customer had to bear the risk from forgetting password or personal information leakage. Afterwards, while the developments of smart cards solved the problems for memorizing passwords, the customer still had to worry about the consequences caused by the missing of the smart card once the smart card was missing. Biometric utilizes the physiological features of human bodies as the recognition passwords. Because the expressed physiological features for most people are different from each other, and because the physiological features are parts of the human bodies, the physiological features can be provided as the recognition passwords conveniently. In addition, since the biometric mainly utilizes the physiological features of human bodies as the recognition passwords, the developments of biometric devices head to those devices adapted to recognize biological features which have high recognition accuracies and which are easy to be used. 
     As compared to a conventional optical recognition device, a capacitive fingerprint recognition chip is small and has the ability for identifying living things. Therefore, the capacitive fingerprint recognition chip would not be cheated by a fake finger easily. In addition, because the application of the capacitive fingerprint chips is no more restricted in governments&#39; recognition systems, the application of fingerprint recognition in consumer electronics grows gradually in the last decade; consumer electronics including flash disks, portable hard drives, laptops, and mobile phones may have fingerprint recognition chips to protect user information. After Apple launched its iPhone 5S installed with fingerprint recognition chip in September of 2013, other mobile phone companies began to launch their devices installed with fingerprint recognition functions. Accordingly, applications of fingerprint recognition in consumer electronics became popular again. In addition, because of the rapid eruption of electrical commerce and mobile payment, fingerprint recognition chips may possibly be the standard equipments of mobile devices. 
     A conventional fingerprint sensor for mobile device is disposed at the front or the rear of a mobile device. For example, in iOS, the homepage key functions are totally replaced by fingerprint sensors in every generations after Apple&#39;s iPhone 5S. Conversely, for mobile devices with Android system, for example, the HTC One Max has the fingerprint sensor at the rear, while Samsung&#39;s mobile phone has the fingerprint sensor at the front to replace the homepage key. The fingerprint sensor can provide unlock, encryption, or one-touch function; for example, the fingerprint sensor may be provided as the capturing key when the mobile device is adapted to take a picture. 
     When the mobile device having fingerprint sensor is adapted to execute the encryption or the unlock function, a user&#39;s finger is put on the fingerprint sensor or slides over the fingerprint sensor along a direction, so that the fingerprint sensor can obtain a fingerprint image and compare the fingerprint image with the user fingerprint information stored in the mobile device to determine if the user is a correct user. Such implementation utilizes the unique biometric technology so that the user can be recognized correctly as compared to the conventional password approach; however, it has some risks. For example, when the user is sleeping or in an unconscious situation, an invader may use the finger of the user to execute an encryption function or an unlock function. 
       FIG. 1  illustrates a schematic view of a conventional electronic apparatus  200 . As shown in  FIG. 1 , the electronic apparatus  200  has a display  230  for displaying information, such as icons  231 , screen images, or texts. For the electronic apparatus  200  with Android OS, the return key and the function key are still executed by the touch control function. Commonly, the touch control area  260  of the return key and the touch control area  240  of the function key are respectively located at two sides of the touch control area  250  of the homepage key; however, the positions of the touch control areas may be different for different mobile devices. In addition, in order to allow the electronic apparatus  200  to perform the return key function or the function key function, the touch control sensing wires below the touch control screen of the electronic apparatus  200  have to be extended to the non-display area. Moreover, inks are applied on the protecting sheet of the electronic apparatus  200  to form patterns of the return key and the function keys, and then LEDs  280  and light guiding films  270  are integrated with the protecting sheet. Accordingly, the structure of the conventional electronic apparatus  200  is complicated, and the cost thereof cannot be reduced easily. 
     SUMMARY 
     One object of the instant disclosure is to provide an electronic apparatus having a fingerprint sensor operating in a vector mode. Therefore, the key configuration of the electronic apparatus can be simplified and the fingerprint recognition function can be performed. 
     To achieve these and other objects, the instant disclosure provides an electronic apparatus. One embodiment of the electronic apparatus includes a fingerprint sensor and an operation unit. The fingerprint sensor senses a plurality of fingerprint images of a finger at different time instants. In a vector mode, the operation unit determines one or multiple moving directions of the finger according to the fingerprint images to generate a motion vector signal. The electronic apparatus executes a specific function according to the motion vector signal. The specific function is selected from a group consisting of a return key function, a function key function, and an unlocking function. 
     According to the electronic apparatus of embodiments of the instant disclosure, the key configuration of the electronic apparatus can be simplified. In addition, the fingerprint sensor can be adapted to achieve the fingerprint recognition function, the homepage key function, the return key function, and the gesture determination function. Moreover, the security of the electronic apparatus can be improved by the combination of the gesture determination function and the fingerprint recognition function. 
     Detailed description of the characteristics and the advantages of the instant disclosure are shown in the following embodiments. The technical content and the implementation of the instant disclosure should be readily apparent to any person skilled in the art from the detailed description, and the purposes and the advantages of the instant disclosure should be readily understood by any person skilled in the art with reference to content, claims and drawings in the instant disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the detailed description given herein accompanying by the following figures, which are illustration only, and thus not limitative of the disclosure, wherein: 
         FIG. 1  illustrates a schematic view of a conventional electronic apparatus; 
         FIG. 2  illustrates a block diagram of a fingerprint sensing recognition module of one embodiment of the instant disclosure; 
         FIG. 3  illustrates a partial schematic view of an electronic apparatus of one embodiment of the instant disclosure; 
         FIG. 4  illustrates a block diagram of the electronic apparatus of one embodiment of the instant disclosure; 
         FIG. 5  illustrates a control procedure flowchart of the electronic apparatus in an unlocked mode of one embodiment of the instant disclosure; and 
         FIG. 6  illustrates a control procedure flowchart of the electronic apparatus in a locked mode of one embodiment of the instant disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     An embodiment of the instant disclosure provides an electronic apparatus having a fingerprint sensor operating in a vector mode. By the image capturing function of the fingerprint sensor and the determine function of the algorithms of the electronic apparatus, a command representing the return key or the function key is generated accordingly when a user&#39;s finger is slid over the fingerprint sensor leftward or rightward. The definitions of the commands may be set by the preference of the apparatus manufacturer. In addition, before or after the fingerprint sensor obtains the fingerprint image of the finger, the user may use his/her finger to write numbers, texts, or to perform a vector command as passwords. Accordingly, the passwords and the fingerprint information are integrated as a safe and secret biometric lock. 
     An embodiment of the instant disclosure also provides an operating method for the electronic apparatus. The operating method may be installed to the electronic apparatus by firmware or software approaches. The fingerprint sensor may be assembled on a mobile device. The mobile device may be a mobile phone, a tablet, or so. In the following description, the mobile phone is taken as an illustrative example, but embodiments are not limited thereto. 
       FIG. 2  illustrates a block diagram of a fingerprint sensing recognition module  150  of one embodiment of the instant disclosure. The fingerprint sensing recognition module  150  comprises a fingerprint sensor  10  and an operation unit  20 . The operation unit  20  is electrically connected to the fingerprint sensor  10  and outputs encrypted data ED and a motion vector signal MVS. Because the differences between  FIG. 2  and  FIG. 4  are small, in the following description,  FIG. 4  is provided as the illustrative reference for understanding the disclosure. That is, in  FIG. 4 , the electronic apparatus  100  further comprises a display  30  and a storage  40 ; while in  FIG. 2 , the fingerprint sensing recognition module  150  does not comprise a display and a storage.  FIG. 3  illustrates a partial schematic view of an electronic apparatus  100  of one embodiment of the instant disclosure.  FIG. 4  illustrates a block diagram of the electronic apparatus  100  of one embodiment of the instant disclosure. As shown in  FIG. 3  and  FIG. 4 , the electronic apparatus  100  comprises a fingerprint sensor  10  and an operation unit  20 . In addition, the electronic apparatus  100  may further comprise a display  30  and a storage  40 . 
     The fingerprint sensor  10  is provided to sense a plurality of fingerprint images FIM of a finger F at different time instants. 
     The operation unit  20  may be integrated with the fingerprint sensor  10  in a same chip by hardwarization techniques or may be existed in the electronic apparatus  100  in a format of software or hardware. In a vector mode, the operation unit  20  determines one or multiple moving directions of the finger F according to the fingerprint images FIM to generate the motion vector signal MVS, so that the electronic apparatus  100  executes a specific function according to the motion vector signal MVS. The specific function is selected from a group consisting of a return key function, a function key function, and an unlocking function. The motion vector signal MVS may represent a text, a number, or a vector unit. It is understood that, in the determination of the motion vector, a fingerprint image to be computed by the operation unit may be a whole fingerprint image or a partial fingerprint image. In other words, for a slide-type fingerprint sensor which captures large and elongate shaped images, parts of the fingerprint image or the fingerprint image with fewer pixels would be provided for the comparison. Conversely, for a fingerprint sensor which captures rectangular, round, or polygonal shaped images, a certain region at the middle of the image, for example, an image with pixels of 32*32, may be chosen for the computation to reduce the computation loading or for the concern of energy saving. 
     The display  30  is electrically connected to the operation unit  20  for displaying information. The information comprises, but not limited to, pictures, texts, or so. The display  30  may have the touch control function. 
     The storage  40  is electrically connected to the operation unit  20 . In a login mode (or called a fingerprint register mode), the operation unit  20  processes one or more of the fingerprint images FIM as fingerprint feature data and stores the fingerprint feature data in the storage  40  for subsequent comparisons. 
     The operation unit  20  comprises an image temporal storing region  22 , an image encryption processing unit  23 , a fingerprint recognition algorithm unit  24 , an image comparison unit  25 , and a motion vector processing unit  26 . The fingerprint image FIM output by the fingerprint sensor  10  is stored in the image temporal storing region  22 . It is noticed that, the image encryption processing unit  23  may have two parts, one is a processing part, and the other is an encryption part. The processing part processes one or more of the fingerprint images FIM. The image processing procedure may be a fingerprint image recombination procedure for enhancing the sharpness of the fingerprint images FIM. Alternatively, the image processing procedure may be a compression or a simplification procedure of the fingerprint image information for improving the quality or the image transmission speed of the fingerprint images FIM. Therefore, the computation of the subsequent algorithms can be facilitated. On the other hand, the encryption part is provided for executing an encryption procedure. The encrypted fingerprint image is then sent to other units of the operation unit  20 , and fingerprint feature points are stored in the storage  40  via algorithm programs. To enter a recognition mode, the fingerprint recognition algorithm unit  24  processes and compares the fingerprint image FIM with the information stored in the storage  40  to obtain a result showing the recognition is passed or failed. To enter the vector mode, the image comparison unit  25  compares the fingerprint images FIM with each other to generate the motion vector signal MVS having one or multiple motion vectors; then, the motion vector processing unit  26  can combine one or multiple motion vectors into a text, a graph, or a simple motion vector MV 1 , MV 2 , MV 3 . The motion vector includes linear displacements with any orientation, displacements having angles, or displacements having pressures. 
     When the motion vector MV 1  is generated, the operation unit  20  obtains the vector command of the motion vector MV 1  and sends the vector command to the system of the electronic apparatus  100 , so that the electronic apparatus  100  executes the return key function to exit an executing program of the electronic apparatus  100  or to return to the last page. When the motion vector MV 2  is generated, the operation unit  20  obtains the vector command of the motion vector MV 2 , so that the electronic apparatus  100  executes the function key function to allow the executing program of the electronic apparatus  100  to show available menus. When the motion vector MV 3  is generated, because the motion vector MV 3  is an unlock gesture preset by the user, the operation unit  20  sends the vector command of the motion vector MV 3  to the system of the electronic apparatus  100  to allow the executing program of the electronic apparatus  100  to be unlocked. 
     In another embodiment, when the electronic apparatus  100  is in a locked mode, the operation unit  20  executes a first unlock determine procedure according to the motion vector signal MVS. The motion vector signal MVS may comprise one or multiple vectors. The operation unit  20  executes a second unlock determine procedure according to the fingerprint images FIM. When both the first unlock determine procedure and the second unlock procedure are passed, the operation unit  20  allows the electronic apparatus  100  to exit the locked mode. In other words, when both the fingerprint recognition and the gesture recognition are passed, the electronic apparatus  100  can exit the locked mode. In one embodiment, the priority and the necessity of the first unlock determine procedure and the second unlock determine procedure for exiting the locked mode are determined by an application program having registered fingerprint information. It is noticed that, the locked mode may be a sleep locked mode of the electronic apparatus or may be a file access locked mode for accessing certain files in the electronic apparatus. In other words, in the sleep locked mode, the user slides the screen of the electronic apparatus to unlock the electronic apparatus and allows the electronic apparatus to enter into a power on mode or a normal mode; conversely, in the file access locked mode, the user unlocks the electronic apparatus to obtain the access authority of the file in the electronic apparatus  100 . Alternatively, the locked mode may be any mode which requests for the fingerprint recognition results for user checking. 
     In practice, when the electronic apparatus  100  is in an unlocked mode, the operation unit  20  generates the motion vector signal MVS according to the fingerprint images FIM received within a predetermined time. Alternatively, when the electronic apparatus  100  enters into the vector mode of an unlocked mode, the operation unit  20  allows the electronic apparatus  100  to execute a specific function according to the motion vector signal MVS. In a further option, when the electronic apparatus  100  is in a non homepage and unlocked mode, the operation unit  20  executes a homepage key function according to a first fingerprint image of the fingerprint images FIM, so that the electronic apparatus  100  is switched back to a homepage mode. 
       FIG. 5  illustrates a control procedure flowchart of the electronic apparatus in an unlocked mode of one embodiment of the instant disclosure. As shown in  FIG. 5 , the control procedure of the electronic apparatus in the unlocked mode comprises following steps. In the step S 1 , capturing a fingerprint image. In the step S 2 , determining if the motion vector is generated, if no, entering into the step S 3 , i.e., executing a system pressing command, for example, a home command; if yes, entering into the step S 4  and then executing the specific function command.  FIG. 6  illustrates a control procedure flowchart of the electronic apparatus in a locked mode of one embodiment of the instant disclosure. As shown in  FIG. 6 , the steps S 1 , S 2 , and S 4  are the same as those shown in  FIG. 5 . After the step S 4 , the step S 6  is executed, i.e., illustrating a union of the vectors. On the other hand, after the step S 1 , the step S 7  is executed, i.e., executing a recognition algorithm And then, after the step S 7 , the step S 8  is executed, i.e., extracting feature points of the fingerprint images. Next, in the step S 9 , the results of the steps S 6  and S 8  are combined. Next, the step S 10  is executed, i.e., determining if the motion vector and the feature points are met with the preset motion vector and the preset feature points, if no, back to the step S 1 ; if yes, executing the unlock step (the step S 11 ). 
     In other words, the operation unit is provided for recognizing the fingerprint image or for comparing the fingerprint feature points. The operation unit may be the central processing unit (CPU) of the mobile phone or an external computation processor. The fingerprint sensor captures fingerprint images at different time instants. The vector of each of the fingerprint images is determined according to an image determination algorithm. Then, the moving direction of the finger is determined according to the result of the vector determination. Next, the result of the moving direction of the finger is provided to replace the return key command and the function key command which are originally executed by the touch control function of the mobile phone. For example, if the operation unit obtains a leftward vector result, the vector result is provided as a return key command and the return key function is executed accordingly; if the operation unit obtains a rightward vector result, the vector result is provided as a function key command and the function key function is executed accordingly. Such vector action mode may be in any vector format depended on the setting of the device manufacturer or the setting of the user. However, it is noticed that, the vector representing the return key function should be opposite with or have obvious differences from and the vector representing the function key function, so that the operation unit can recognize the vectors easily and the user can perform the vectors conveniently. 
     In another embodiment, the finger may move continuously on the fingerprint sensor, and the operation unit compares the images obtained at different time instants from each other to obtain a continuous vector unit by the image recognition algorithm. The result of the vector unit may form any text, number, or graph illustrated by the user. The text, number, or graph may be combined with the fingerprint image obtained by the fingerprint sensor or combined with the feature points computed by the fingerprint computation procedure. The combination is then further computed by algorithms to form a much safer and secret biometric lock. The biometric lock may comprise: (a) the text, number, or graph formed by the fingerprint image vector; (b) the fingerprint image or the feature points computed by the fingerprint computation procedure; and (c) the order of the data showing in item (a) and item (b). 
     When the mobile device is encrypted, unlocked, or performs actions request the fingerprint recognition command, the fingerprint image is sent to the image temporal storing region after the fingerprint image is read by the fingerprint sensor. If the image temporal storing region only obtains a preset number of images in a preset time, meaning that the user is performing fingerprint recognition. Conversely, if the image temporal storing region obtains images having a greater number than the preset number in a preset time or if the displacement of the vector changes obviously, the image comparison unit performs the speed determination, and then the motion vector processing unit performs the motion vector determination to obtain a motion vector output. Accordingly, the system of the mobile phone can obtain information which can form numbers, texts, or gesture commands. 
     In fingerprint registration software, the user can set if an intersection determination of numbers, texts, or gestures is added, and the finger of the user is pressed on or moved on the fingerprint sensor to complete the registration of the fingerprint or to complete the setting of numbers, texts, or gestures. When the user has to apply the encryption or the unlocking function, or when the fingerprint determination mechanism applied by the user needs to be checked, the finger of the user needs to illustrate images of the preset number, text, or gesture on the fingerprint sensor before or after the finger of the user presses on or slides over the fingerprint sensor to obtain the fingerprint information. Therefore, the images illustrated by the user can be combined with the fingerprint information of the user for the software to execute the intersection determination. 
     In the case of the mobile phone is in a non homepage, the display returns to the homepage when the fingerprint sensor is pressed. Upon the mobile phone executing an application program, when a user tends to return to the last page or to manipulate the mobile phone, the finger of the user slides over the fingerprint sensor, and then the system determines the action of the user satisfies the direction of the motion vector of the return key, so that the display performs responds the user&#39;s request. Conversely, when the user tends to use the function key, the finger of the user slides over the fingerprint sensor, so that the system determines the action of the user meets the direction of the motion vector of the function key. 
     According to the electronic apparatus of embodiments of the instant disclosure, the key configuration of the electronic apparatus can be simplified. In addition, the fingerprint sensor can be adapted to achieve the fingerprint recognition function, the homepage key function, the return key function, and the gesture determination function. Moreover, the security of the electronic apparatus can be improved by the combination of the gesture determination function and the fingerprint recognition function. 
     While the instant disclosure has been described by the way of example and in terms of the preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.