Patent Publication Number: US-11397493-B2

Title: Method for touch sensing enhancement implemented in single chip, single chip capable of achieving touch sensing enhancement, and computing apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a technology for touch sensing enhancement, and in particular to a method for touch sensing enhancement implemented in a single chip, a single chip capable of achieving touch sensing enhancement, and a computing apparatus. 
     2. Description of the Related Art 
     For computing devices, such as smart phones, tablet computers or other information processing devices, touch screens have become indispensable components of the computing devices for user interactions. A user can give input or control the computing device through single-touch or multi-touch gestures by touching the touch screen with one or more fingers or a special stylus. 
     Demand for better touch performance for touch screens continues to increase. The touch performance can be affected by a variety of factors such as the size of sensor pitch, the stability of the common ground, the length of the sensing time, the magnitude of the environmental noise, and the circuit structure of analog front end and so on. 
     In addition, the touch screens have their own intrinsic limitations so that it is challenging to improve their touch performance. For example, a capacitive touch screen typically has its touch resolution much less than the display resolution of the touch screen. The position of a touch may not be obtained accurately. For multi-touch functions, if two fingers contacting the touch screen are too close to be distinguished, an incorrect touch event may be determined, causing undesirable user experience. 
     BRIEF SUMMARY OF THE INVENTION 
     An objective of the present disclosure is to provide a technology for touch sensing enhancement, in which output touch data can be generated based on touch sensing data and fingerprint sensing data. With the contribution of the fingerprint sensing data, touch sensing enhancement can be achieved. 
     To achieve at least the above objective, the present disclosure provides a method for touch sensing enhancement implemented in a single chip, wherein the single chip is used to be coupled to a display panel with a touch sensor and a fingerprint sensor. The method comprises obtaining touch sensing data by a touch sensing module disposed within the single chip and coupled to the touch sensor; obtaining fingerprint sensing data by a fingerprint sensing module disposed within the single chip and coupled to the fingerprint sensor; and generating output touch data based on the touch sensing data and the fingerprint sensing data. 
     In an embodiment, the fingerprint sensing data is obtained when the display panel does not show any request for a fingerprint. 
     In an embodiment, the fingerprint sensing data is obtained and used internally in the single chip for touch sensing enhancement, after user identification recognition is completed (i.e., a user has been authenticated) or which even can be irrelevant to user identification recognition. 
     In an embodiment, the method further comprises requesting the fingerprint sensing data from the fingerprint sensing module when the touch sensing data indicates a touch event. 
     In an embodiment, the method further comprises determining that the touch sensing data indicates the touch event when the touch sensing data exceeds a threshold value. 
     In an embodiment, the step of obtaining the fingerprint sensing data comprises converting the fingerprint sensing data from a first domain corresponding to a fingerprint sensing resolution to a second domain corresponding to a touch sensing resolution. 
     In an embodiment, the step of obtaining the fingerprint sensing data comprises controlling the fingerprint sensor to have a fingerprint sensing resolution equal to a touch sensing resolution. 
     In an embodiment, the output touch data includes a position indicating a touch point. 
     In an embodiment, the position indicating the touch point is determined based on the touch sensing data and the fingerprint sensing data. 
     In an embodiment, the touch sensing data includes a first position detected by the touch sensor, the fingerprint sensing data includes a second position detected by the fingerprint sensor, and the position indicating the touch point is determined according to the first position and the second position. 
     In an embodiment, the position indicating the touch point is a weighted averaged position of the first position and the second position. 
     In an embodiment, the output touch data includes a plurality of positions indicating a plurality of touch points correspondingly. 
     In an embodiment, the step of generating output touch data based on the touch sensing data and the fingerprint sensing data includes determining a plurality of fingerprint data regions in the fingerprint sensing data according to the fingerprint sensing data; determining a plurality of touch data regions in the touch sensing data according to the fingerprint data regions; and determining the output touch data at least based on at least one of the touch data regions. 
     In an embodiment, the step of determining the output touch data includes: determining a corresponding position for each one of the touch data regions based on the one of the touch data regions, wherein the output touch data includes the corresponding position for each one of the touch data regions. 
     To achieve at least the above objective, the present disclosure provides a single chip capable of achieving touch sensing enhancement, wherein the single chip is used to be coupled to a display panel with a touch sensor and a fingerprint sensor. The single chip comprises a touch sensing circuit, a fingerprint sensing module, and a control unit. The touch sensing circuit is utilized for being coupled to the touch sensor and obtaining touch sensing data. The fingerprint sensing module is employed for being coupled to the touch sensor and obtaining fingerprint sensing data. The control unit, coupled to the touch sensing circuit and the fingerprint sensing module, is utilized for generating output touch data based on the touch sensing data and the fingerprint sensing data. 
     To achieve at least the above objective, the present disclosure further provides a computing apparatus comprising a display panel with a touch sensor and a fingerprint sensor, a processing unit, and a single chip capable of achieving touch sensing enhancement. The single chip capable of achieving touch sensing enhancement is coupled between the display panel and the processing unit. The single chip comprises a touch sensing circuit, a fingerprint sensing module, and a control unit. The touch sensing circuit, coupled to the touch sensor, is utilized for obtaining touch sensing data. The fingerprint sensing module, coupled to the fingerprint sensor, is utilized for obtaining fingerprint sensing data. The control unit, coupled to the touch sensing circuit and the fingerprint sensing module, is utilized for generating output touch data based on the touch sensing data and the fingerprint sensing data. 
     In some embodiments of the single chip or computing apparatus, the fingerprint sensing data is obtained when a display panel does not show any request for a fingerprint. 
     In some embodiments of the single chip or computing apparatus, the fingerprint sensing data is obtained and used internally in the single chip for touch sensing enhancement, after user identification recognition is completed (i.e., a user has been authenticated) or which even can be irrelevant to user identification recognition. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to request the fingerprint sensing data from the fingerprint sensing module when the touch sensing data indicates a touch event. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to determine that the touch sensing data indicates the touch event when the touch sensing data exceeds a threshold value. 
     In some embodiments of the single chip or computing apparatus, the fingerprint sensing data is converted from a first domain corresponding to a fingerprint sensing resolution to a second domain corresponding to a touch sensing resolution. 
     In some embodiments of the single chip or computing apparatus, the fingerprint sensor is controlled to have a fingerprint sensing resolution equal to a touch sensing resolution. 
     In some embodiments of the single chip or computing apparatus, the output touch data includes a position indicating a touch point. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to determine the position based on the touch sensing data and the fingerprint sensing data. 
     In some embodiments of the single chip or computing apparatus, the touch sensing data includes a first position detected by the touch sensor, the fingerprint sensing data includes a second position detected by the fingerprint sensor, and the position indicating the touch point is determined according to the first position and the second position. 
     In some embodiments of the single chip or computing apparatus, the position indicating the touch point is a weighted averaged position of the first position and the second position. 
     In some embodiments of the single chip or computing apparatus, the output touch data includes a plurality of positions indicating a plurality of touch points correspondingly. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to determine a plurality of touch data regions in the touch sensing data according to the fingerprint sensing data, and determines the output touch data at least based on the touch data regions. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to determine a position at least based on a corresponding one of the touch data regions, wherein the output touch data includes the position. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to determine a plurality of fingerprint data regions in the fingerprint sensing data according to the fingerprint sensing data; the control unit is configured to determine a plurality of touch data regions in the touch sensing data according to the fingerprint data regions; and the control unit is configured to determine the output touch data based on the touch data regions. 
     In some embodiments of the single chip or computing apparatus, the control unit is configured to determine a corresponding position for each one of the touch data regions at least based on the one of the touch data regions, wherein the output touch data includes the corresponding position for each one of the touch data regions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a single chip capable of achieving touch sensing enhancement according to an embodiment of the invention, employed in a computing device. 
         FIG. 2  is a block diagram illustrating a single chip capable of achieving touch sensing enhancement according to another embodiment of the invention. 
         FIG. 3  is a schematic diagram illustrating an example of touch sensing data. 
         FIG. 4  is a schematic diagram illustrating an example of fingerprint sensing data. 
         FIG. 5  is a flowchart illustrating a method for touch sensing enhancement implemented in a single chip according to an embodiment of the invention. 
         FIG. 6A  is a schematic diagram illustrating an example of a fingerprint sensing resolution greater than a touch sensing resolution. 
         FIG. 6B  is a schematic diagram illustrating an example of association between a touch data node and a plurality of fingerprint data nodes in accordance with the example of  FIG. 6A . 
         FIG. 7  is a schematic diagram illustrating an example of determination of a representative point based on the touch sensing data and the fingerprint sensing data. 
         FIG. 8  is a schematic diagram illustrating conversion of the coordinates between the touch sensing data and the fingerprint sensing data. 
         FIG. 9  is a flowchart illustrating an embodiment of step S 30  of the method based on  FIG. 5 . 
         FIG. 10  is a schematic diagram illustrating an example of variation of touch sensing data. 
         FIG. 11  is a schematic diagram illustrating an example of variation of fingerprint sensing data. 
         FIG. 12  is a schematic diagram illustrating an example of determination of fingerprint data regions in the fingerprint sensing data. 
         FIG. 13  is a schematic diagram illustrating an example of determination of touch data regions (on the right) in the touch sensing data based on the fingerprint data regions (on the left) determined as shown in  FIG. 12 . 
         FIG. 14  is a schematic diagram illustrating another example of determination of touch data regions. 
         FIG. 15  is a block diagram illustrating a single chip capable of achieving touch sensing enhancement according to another embodiment of the invention, employed in a computing device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     To facilitate understanding of the object, characteristics and effects of this present disclosure, embodiments together with the attached drawings for the detailed description of the present disclosure are provided. 
     The following provides various embodiments for the technology for touch sensing enhancement, in which output touch data is capable of being generated based on touch sensing data and fingerprint sensing data. The touch sensing can be enhanced with the contribution of the fingerprint sensing data. 
     For the sake of illustration, in the following embodiments of a single chip capable of achieving touch sensing enhancement and a computing apparatus employing the single chip are introduced firstly. Then, provided are embodiments of a method for touch sensing enhancement implemented in the single chip. 
     Referring to  FIG. 1 , a single chip  10  capable of achieving touch sensing enhancement is illustrated, which can be employed in a computing device  1 , according to an embodiment of the invention in block diagram form. As shown in  FIG. 1 , the computing device  1  includes a processing unit  5 , a display panel  9 , and a single chip  10 . The single chip  10  capable of achieving touch sensing enhancement can be utilized for being coupled between the display panel  9  and the processing unit  5 . As will be exemplified later, the single chip  10  can be configured to perform a method for touch sensing enhancement illustrated in  FIG. 5 , in which the single chip  10  is capable of generating output touch data based on touch sensing data and fingerprint sensing data, thus enhancing the touch sensing with the contribution of the fingerprint sensing data. 
     Based on the structure of computing device  1  illustrated in  FIG. 1 , any electronic device such as a smart phone, tablet computer or any other information processing device can be realized, wherein the computing device  1  may further include, but not limited to, additional components such as memory, circuits for wireless or wired communication, image capturing or so on, whenever appropriate. 
     The processing unit  5  is capable of being configured to control the display panel  9  to provide specific functionality. For example, the processing unit  5  executes an application program under an operating system to control the display panel  9  through the single chip  10  so that the computing device  1  can interact with a user through the display panel  9 . 
     The display panel  9  includes a display module  91 , such as a liquid crystal display (LCD) module, organic light emitting diode (OLED) module, or so on, and is provided with a touch sensor  93  and a fingerprint sensor  95 . The display panel  9 , for example, can be implemented by an in-cell type or on-cell type touch display panel integrated with fingerprint sensing, wherein the display panel  9 , the touch sensor  93 , and the fingerprint sensor  95  are integrated in a layered manner or any appropriate manner. The touch sensor  93  may be implemented by using a capacitive touch sensor  93  in a form of touch sensing array. The fingerprint sensor  95 , for example, can be implemented by an optical fingerprint sensor, capacitive fingerprint sensor, ultrasonic fingerprint sensor, or any device for sensing fingerprint signals. In some embodiments, the fingerprint sensor  95  may be implemented to detect at least one portion of the viewable area of image displaying by the display panel  91 . In a preferred embodiment, the fingerprint sensor  95  is a full-screen fingerprint sensor, which can cover a same area substantially for image displaying of the display module  91  and for touch sensing of the touch sensor  93 . Certainly, the implementation of the invention is not limited to the above examples. 
     The single chip  10  capable of achieving touch sensing enhancement can be utilized to be coupled to the display panel  9  with the touch sensor  93  and the fingerprint sensor  95 . In  FIG. 1 , the single chip  10  can include a touch sensing circuit  110 , a fingerprint sensing module  12 , and a control unit  112 . In an embodiment, the control unit  112  and the touch sensing circuit  110  may be implemented or viewed as a touch sensing module  11 . From the viewpoint of the processing unit  5 , the single chip  10  may serve as a “bridge” between the display panel  9  and the processing unit  5 . The processing unit  5  may be configured to control the single chip  10  so as to obtain output touch data and/or output fingerprint data. It is noted although a single chip is illustrated in the embodiment, in other implementations, multiple chips can be implemented according to design requirements. For example, in some embodiments, the touch sensing module and the fingerprint sensing module can be implemented as different chips. 
     The touch sensing circuit  110  can be utilized for being coupled to the touch sensor  93  and obtaining touch sensing data. For example, the touch sensing circuit  110  may include a touch analog front end (AFE) circuit for converting analog touch signals received from the touch sensor  93  into corresponding digital touch data, such as a set of raw touch data associated with and distributed over an area on the screen of the display panel  9  where at least one touch is detected. The touch sensing data can be further obtained based on the digital touch data, for example, by the control unit  112 . 
     The fingerprint sensing module  12  can be utilized for being coupled to the fingerprint sensor  95  and obtaining fingerprint sensing data. For example, the fingerprint sensing module  12  may be implemented for converting fingerprint signals received from the fingerprint sensor  95  into corresponding digital fingerprint data, such as a set of raw fingerprint data associated with and distributed over an area on the screen of the display panel  9  where a fingerprint (or a portion of a fingerprint) is detected. The fingerprint sensing data can be further obtained based on the digital fingerprint data, for example, by the fingerprint sensing module  12  or the control unit  112 . 
     The control unit  112  can be coupled to the touch sensing circuit  110  and the fingerprint sensing module  12 . In an example, the control unit  112  can obtain the touch sensing data based on the digital touch data outputted by the touch sensing circuit  110 . 
     Referring to  FIG. 2 , another embodiment of a single chip capable of achieving touch sensing enhancement is illustrated in block diagram form. As shown in  FIG. 2 , a single chip  10 A, as an embodiment based on the single chip  10  in  FIG. 1 , includes a touch sensing module  11  and a fingerprint sensing module  12 A. The fingerprint sensing module  12 A may include a fingerprint sensing circuit  120  and a control unit  122  for fingerprint sensing. 
     For example, the fingerprint sensing circuit  120  may include a fingerprint analog front end (AFE) circuit for converting fingerprint signals received from the fingerprint sensor  95  into corresponding digital fingerprint data, such as a set of raw fingerprint data associated with and distributed over an area where a fingerprint (or a portion of a fingerprint) is detected. The fingerprint sensing data can be further obtained based on the digital fingerprint data, for example, by the control unit  122 . 
     The control unit  122 , coupled to the fingerprint sensing circuit  120  and the touch sensing module  11 , can be utilized for fingerprint sensing, for example, to generate fingerprint sensing data based on the digital fingerprint data. 
     In the above examples, the touch sensing circuit  110  or fingerprint sensing circuit  120  may include an analog front end circuit implemented by circuit components such as a low-noise amplifier, an analog-to-digital converter. In the above examples, the control unit  112  or  122  may be complemented by using a processor, microcontroller, or programmable circuit such as field-programmable gate array (FPGA) or application specific integrated circuit (ASIC). In an example, the control units  112  and  122  can be implemented by using a single control unit. Certainly, the implementation of the invention is not limited to the above examples. 
     Referring to  FIG. 3 , an example of touch sensing data is illustrated in schematic form. As shown in  FIG. 3 , the display panel  9  has a screen area  300  within which a plurality of small blocks are illustrated schematically to indicate an array of touch sensing elements of the touch sensor  93  corresponding to the touch sensing resolution (e.g., 18×36). When a touch is detected on the screen area  300 , an area  310  (e.g., 5×5) within the screen area  300  can be determined and represented by using the touch sensing data that may include a plurality of touch sensing values associated with positions in the area  310 . As shown in  FIG. 3 , a block  320  illustrates an enlarged version of the area  310 , indicating the touch sensing values associated with positions in the area  310 . In addition, in  FIG. 3  or other relevant Figures, the sensing values within the block  320  (or other block) are shown for the sake of illustration only; the greater the sensing value (e.g., touch sensing or fingerprint sensing value) is, the greater the detected magnitude (e.g., touch or fingerprint) is. Certainly, the implementation of the invention is not limited to the examples. 
     The area  310  (e.g., 5×5) within the screen area  300  of  FIG. 3  can also be associated with the fingerprint sensing data, as indicated by a block  410  in  FIG. 4 , for example. As shown in  FIG. 4 , the block  410  illustrates the fingerprint sensing data that may include a plurality of fingerprint sensing values which are associated with positions in the area  310  of  FIG. 3 , for example, in different resolution. In the example of  FIGS. 3 and 4 , with respect to the area  310 , the touch sensing data of A1 by A2 (e.g., 5×5) is associated with the fingerprint sensing data of B1 by B2 (e.g., 15×15), wherein A1 and A2 indicate the same or different numbers; B1 and B2 indicate the same or different numbers. The fingerprint sensing resolution may be greater than or equal to the touch sensing resolution. In addition, for the sake of illustration only, some fingerprint sensing values with relatively greater values are shown with an imaginary boundary in bold within the block  410  to indicate that the fingerprint sensing values within the imaginary boundary may correspond to a touch point. Certainly, the implementation of the invention is not limited to the examples. 
     Referring to  FIG. 5 , a method for touch sensing enhancement is illustrated according to an embodiment in flowchart form. The method for touch sensing enhancement is implemented in a single chip, such as the single chip  10  or  10 A exemplified above, which is used to be coupled to a display panel  9  with a touch sensor  93  and a fingerprint sensor  95 . As shown in  FIG. 5 , the method includes the following steps. 
     As indicated by step S 10 , touch sensing data is obtained by a touch sensing module  11  disposed within the single chip  10  and coupled to the touch sensor  93 . The touch sensing data is illustrated in  FIG. 3 , for example. 
     As indicated by step S 20 , fingerprint sensing data is obtained by a fingerprint sensing module  12  disposed within the single chip  10  and coupled to the fingerprint sensor  95 . The fingerprint sensing data is illustrated in  FIG. 4 , for example. 
     As indicated by step S 30 , output touch data is generated based on the touch sensing data and the fingerprint sensing data. The step S 30  can be performed by the control unit  112 , for example. 
     As such, touch sensing enhancement can be achieved with the contribution of the fingerprint sensing data. For example, if the output touch data includes a position, such as coordinates, indicating a touch point, the coordinates can be obtained more accurately with the contribution of the fingerprint sensing data as in step S 30 . In another example for multi-touch operations, if the output touch data includes a plurality of positions, such as coordinates, indicating a plurality of touch points correspondingly, the touch points can be distinguished more accurately with the contribution of the fingerprint sensing data as in step S 30 . 
     In an embodiment, the fingerprint sensing data is obtained in step S 20  when the display panel  9  does not show any request for a user to input a fingerprint. For example, step S 20  is performed because the touch sensing enhancement is required in the single chip  10  or  10 A internally and hence the processing unit  5  does not control the display panel  9  to show any request message for a user to input a fingerprint. 
     In an embodiment, the obtaining of the fingerprint sensing data is performed after user identification recognition is completed (i.e., a user has been authenticated) or which even can be irrelevant to user identification recognition. In other words, the fingerprint sensing data can be used to contribute to generating touch data and may enhance the accuracy of the touch data. For example, the fingerprint sensing data obtained in step S 20  can be used in step S 30  for touch sensing enhancement implemented in the single chip  10  or  10 A internally while the processing unit  5  does not require the single chip  10  or  10 A to provide output fingerprint data for user identification recognition. This may occur after the computing device  1  has been unlocked such that a user is authorized to operate the computing device  1 . 
     In some embodiments of the method of  FIG. 5 , step S 20  is performed only when at least one criterion is satisfied. In one of the embodiments, the method further includes requesting the fingerprint sensing data from the fingerprint sensing module  12  when the touch sensing data indicates a touch event. For example, the control unit  112  can send a request to the fingerprint sensing module  12  for the fingerprint sensing data when the touch sensing data indicates a touch event. Conversely, when the touch sensing data does not indicate a touch event, the control unit  112  cannot send the request to the fingerprint sensing module  12 . In this manner, the fingerprint sensing data can be utilized to enhance the generation of output touch data, more efficiently and effectively. In some embodiments, the method further includes determining that the touch sensing data indicates the touch event when the touch sensing data exceeds a threshold value. For example, it is supposed that the touch sensing data indicates a plurality of touch sensing values associated with positions in an area where a touch is detected (e.g., area  310  of  FIG. 3 ), the touch sensing data can be represented by an average of the touch sensing values and the control unit  112  can determine that the touch sensing data indicates the touch event when the average of the touch sensing values exceeds a corresponding threshold value. In another example, the control unit  112  can determine that the touch sensing data indicates a touch event when one or more of the touch sensing values exceeds a threshold value. 
     In some embodiments, the fingerprint sensing resolution is greater than the touch sensing resolution. The fingerprint sensing resolution can be adjusted to match the touch sensing resolution, by hardware (for example, by adjusting the operation of the fingerprint sensor) or by software (for example, by processing the fingerprint sensing data). For example, in the example of  FIGS. 3 and 4 , with respect to the area  310 , the touch sensing data of A1 by A2 (e.g., 5×5) is associated with the fingerprint sensing data of B1 by B2 (e.g., 15×15). Referring to  FIG. 6A , in an example, the fingerprint sensing resolution of 1080×2160, indicated by a block  600 , is greater than the touch sensing resolution of 18×36, indicated by a block  300 . Any one of the positions of touch sensing in the block  300  may be associated with at most 60×60 corresponding positions of fingerprint sensing in the block  600 . In order to reduce the complexity of association between a touch sensing position and fingerprint sensing positions, a grouping technique may be employed. Referring to  FIG. 6B , an example of association between a touch data node (e.g., indicated by a block  301 ) and a plurality of fingerprint data nodes (e.g., indicated by 3×3 blocks  610 ) is illustrated in accordance with the example of  FIG. 6A . In  FIG. 6B , each fingerprint data node, indicated by block  610 , is associated with a plurality of fingerprint sensing elements (e.g., 20×20). In other words, a plurality of fingerprint sensing elements (e.g., 20×20) or positions can be grouped as a fingerprint data node associated with a touch data node (or touch sensing element) or position. In this manner, simplification of signal or data processing and fast processing speed can be achieved. 
     In one of the embodiments, the step S 20  of obtaining the fingerprint sensing data includes converting the fingerprint sensing data from a first domain corresponding to a fingerprint sensing resolution to a second domain corresponding to a touch sensing resolution (e.g., block  300  of 18×36). Taken the above examples in  FIGS. 6A and 6B , an example of the first domain corresponding to a fingerprint sensing resolution is shown in the block  600  of resolution of 1080×2160 in  FIG. 6A , and the second domain is a fingerprint sensing resolution of 54×108 corresponding to the touch sensing resolution as shown in the block  300  of 18×36 by downscaling the resolution of the block  600  in terms of 20×20 fingerprint sensing elements as a fingerprint data node, indicated by the block  610  in  FIG. 6B . In this manner, simplification of signal or data processing can be achieved while the accuracy can be enhanced with the contribution of the fingerprint sensing data in a relative higher resolution, even though being downscaled. 
     In an embodiment, the step of obtaining the fingerprint sensing data includes controlling the fingerprint sensor  95  to have a fingerprint sensing resolution equal to a touch sensing resolution. For example, the fingerprint sensor  95  is supposed to have adjustable resolution function and the control unit  112  may send a control signal to the fingerprint sensing module  12  to control the fingerprint sensor  95  to have a fingerprint sensing resolution equal to a touch sensing resolution. 
     In another embodiment, the fingerprint sensor  95  can have a lower fingerprint sensing resolution. For example, the fingerprint sensing elements can be divided into a plurality of groups (e.g., N×M elements for a group, where N and M may be equal or different numbers), and each group is connected to a corresponding analog front end circuit in the fingerprint sensing module  12  or  12 A so as to lower the fingerprint sensing resolution, and thus faster processing or power saving can be achieved. 
     In an embodiment of step S 20 , the fingerprint sensing module  12  or the fingerprint sensing circuit  120  may include a plurality of analog front end circuits, each of which can be configured to be coupled to a plurality of fingerprint sensing elements of the fingerprint sensor  95  so as to obtain a fingerprint signal. 
     In the following, embodiments of the method for touch sensing enhancement implemented in a single chip  10  are provided for enhancing accuracy of determining one or more touch points. 
     In a scenario of a computing device  1  such as a smart phone being not held by human&#39;s hand, the signal-to-noise ratio (SNR) may reduce due to no common ground for the smart phone in contrast to the situation of the smart phone being held. In particular, if the display panel  9  is a capacitive touch display panel  9  and the single chip  10  is configured to generate a position of a touch point, the coordinates of the touch point derived from signals from the touch sensor  93  (or detected by the touch sensor  93 ) may be sensitive to or affected by noise, leading to inaccuracy or jitter of the touch point. Accordingly, in the following embodiments, the position of the touch point is generated based on the touch sensing data and the fingerprint sensing data so as to enhance the accuracy of the position with the contribution of the fingerprint sensing data. 
     In some embodiments, the output touch data includes a position indicating a touch point. In one of the embodiments, the position indicating the touch point is determined based on the touch sensing data and the fingerprint sensing data. 
     In another one of the embodiments, the touch sensing data includes a first position detected by, or derived from signals from, the touch sensor  93 , the fingerprint sensing data includes a second position detected by, or derived from signals from, the fingerprint sensor  95 , and the position indicating the touch point is determined according to the first position and the second position. Alternatively, in one of the embodiments, in step S 30  of the method of  FIG. 5 , a first position detected by, or derived from signals from, the touch sensor  93  is determined based on the touch sensing data, a second position detected by, or derived from signals from, the fingerprint sensor  95  is determined based on the fingerprint sensing data, and the position indicating the touch point is determined according to the first position and the second position. Examples regarding implementation of the embodiments are provided below. 
     For example, the first position, second position can be determined by way of calculation of a representative point, such as a centroid or center of mass of a set of data. For the sake of illustrating the calculation of a centroid of a data set, referring to  FIG. 7 , it is supposed an image  701  as a data set is on an area  700  with a coordinates system of Index_X and Index_Y as illustrated. The coordinates of a centroid (or center of mass) of the image  701 , denoted by P=(X,Y), can be defined by the following equation (1):
 
 P =( X,Y )=(Numerator_ X /Denominator,Numerator_ Y /Denominator),  Eq. (1)
 
wherein D(x,y) represents a gray level value associated with the coordinates (x,y) of one of the pixels of the image  701 ,
 
     Denominator=ΣD(x,y), i.e., a summation of D(x,y) for all pixels of the image  701 ; 
     Numerator_X=Index_X*D(x,y); and 
     Numerator_Y=Index_Y*D(x,y). 
     Regarding the image  701  in  FIG. 7 , for example, it is determined that: 
     
         
         Denominator=D(2,2)+D(3,2)+D(4,2)+ . . . +D(5,5); 
         Numerator_X=2*D(2,2)+3*D(3,2)+4*D(4,2)+ . . . +5*D(5,5); and 
         Numerator_Y=2*D(2,2)+2*D(3,2)+2*D(4,2)+ . . . +5*D(5,5). 
       
    
     With respect to the touch sensing data derived from signals detected by the touch sensor  93 , the touch sensing values (e.g., indicated by the block  320  of  FIG. 3 ) can be viewed as an image and the coordinates of a representative point of the touch sensing values can be determined by the equation (1) in a similar manner. Hence, the coordinates of the representative point of the touch sensing values obtained by using equation (1), denoted by Pt=(Xt, Yt), can be treated as a first position detected by the touch sensor  93 . 
     With respect to the fingerprint sensing data derived from signals detected by the fingerprint sensor  95 , the fingerprint sensing values (e.g., indicated by the block  410  of  FIG. 4 ) can be viewed as an image and the coordinates of a representative point of the fingerprint sensing values can be determined by the equation (1) in a similar manner. Hence, the coordinates of the representative point of the fingerprint sensing values obtained by using equation (1), denoted by Pf=(Xf, Yf), can be treated as a second position detected by the fingerprint sensor  95 . 
     Accordingly, the position indicating a touch point, indicated by P=(X, Y), can be determined according to the first position (e.g., Pt=(Xt, Yt)) and the second position (e.g., Pf=(Xf, Yf)). 
     In some embodiments, the position indicating the touch point is a weighted averaged position of the first position and the second position. For example, the position indicating the touch point (e.g., P=(X, Y)) can be determined according to the following equation (2):
 
 P =( X,Y )=((1− w )* Xt+w*Xf ,(1− w )* Yt+w*Yf ),  Eq. (2)
 
where w is a positive real value and 0&lt;w≤1, provided that the fingerprint sensing resolution is equal to the touch sensing resolution. For example, if w is taken as 0.5, the position indicating the touch point can be determined based on the coordinates of (0.5*(Xt+Xf), 0.5*(Yt+Yf)) in accordance with the equation (2).
 
     In addition, if the fingerprint sensing resolution is greater than the touch sensing resolution, the coordinates of the representative point of the fingerprint sensing values obtained by using equation (1), denoted by Pf=(Xf, Yf), or the second position, is required to be downscaled to the touch sensing domain. 
     Referring to  FIG. 8 , conversion of the coordinates between the touch sensing data and the fingerprint sensing data is illustrated in schematic form according to an embodiment. As shown in  FIG. 8 , blocks T indicating 3 touch data nodes are illustrated under the touch sensing resolution. Blocks F 1  indicating 6 fingerprint data nodes are illustrated under a first fingerprint sensing resolution which is two times greater than the touch sensing resolution in value; and blocks F 2  indicating 8 fingerprint data nodes are illustrated under a second fingerprint sensing resolution which is three times greater than the touch sensing resolution in value. In accordance with relationships of the resolutions shown in  FIG. 8  in the X-axis direction, x-coordinate in a fingerprint sensing domain, denoted by Xf, can be converted to or downscaled to x-coordinate in a touch sensing domain, denoted by Xfd, by the following equation (3):
 
 Xfd =( Xf+ 0.5)/ SL− 0.5,  Eq. (3)
 
where SL denotes a ratio of the fingerprint sensing resolution to the touch sensing resolution in value. Further, the relationship for conversion or downscaling of y-coordinate in a fingerprint sensing domain to y-coordinate in a touch sensing domain can be derived in a similar manner. For brevity sake, the details will not be repeated. Certainly, the implementation of the invention is not limited to the above examples.
 
     Thus, if the fingerprint sensing resolution is greater than the touch sensing resolution, the position indicating the touch point (e.g., P=(X, Y)) can be determined according to the first position (e.g., Pt=(Xt, Yt)) and the second position (e.g., Pf=(Xf, Yf)) which is downscaled to the touch sensing domain. 
     As such, in the above embodiments, the position of a touch point can be generated based on the touch sensing data and the fingerprint sensing data. The position of the touch point can be generated accurately with the contribution of the fingerprint sensing data. In a scenario of practical application for a computing device  1 , such as smart phone, based on  FIG. 1 , a touch point by the user can be precisely determined based on the touch sensing data and the fingerprint sensing data, even though the signal-to-noise ratio (SNR) of touch sensing may reduce in a situation that the user does not hold the smart phone or the touch sensor  93  may be sensitive to noise. 
     For implementation of the above embodiments related to the method of  FIG. 5  in the single chip  10  based on  FIG. 1  or  FIG. 2 , the position indicating the touch point can be determined by the touch sensing module  11 , such as the control unit  112 , for example. The first position and second position can be determined by the touch sensing module  11  and fingerprint sensing module  12 , respectively, for example. Alternatively, the first position, second position, position indicating the touch point can be determined by the touch sensing module  11 , such as the control unit  112 , for example. 
     In some scenarios, the user may perform multi-touch operations on the display panel  9  of the computing device  1 . The following provides embodiments based on the method of  FIG. 5  to enhance the touch sensing for multi-touch operations. 
     In some embodiments, the output touch data may include a plurality of positions indicating a plurality of touch points correspondingly. Examples regarding implementation of the embodiments are provided below, wherein the fingerprint sensing resolution is greater than the touch sensing resolution. 
     In an embodiment based on the method of  FIG. 5 , the step S 30  can be implemented by a process including steps S 310 -S 330 , as shown in  FIG. 9 . 
     As indicated in step S 310 , a plurality of fingerprint data regions in the fingerprint sensing data are determined according to the fingerprint sensing data. 
     As indicated in step S 320 , a plurality of touch data regions in the touch sensing data are determined according to the fingerprint data regions. 
     As indicated in step S 330 , the output touch data is determined at least based on at least one of the touch data regions. 
     As such, the process as shown in  FIG. 9  can be employed in a scenario of practical application for a computing device  1 , such as smart phone, based on  FIG. 1 , multi-touch points by the user can be determined accurately based on the touch sensing data and the fingerprint sensing data, even though the multi-touch points may not be distinguished by using the touch sensing data. 
     For the sake of illustration, it is supposed that two fingers of the user touches the display panel  9 , and the single chip  10  produces internally the touch sensing data as indicated in  FIG. 10  and the fingerprint sensing data as indicated in  FIG. 11 , for example, wherein the touch sensing data and fingerprint sensing data correspond to a same area on the screen area of the display panel  9 . In  FIG. 10 , the touch sensing values of the touch sensing data, indicated by a block  910 , do not indicate any data “valley” (e.g., a local minimum value occurs between two peak values) that can be used for data segmentation. As one can observe in  FIG. 10 , a curve  915  shows the touch sensing values taken along a middle column indicated by an arrow  911  and varies smoothly and maintains relative high values in the middle section of the curve  915 . In this situation, the touch sensing data may not indicate the valley significantly due to touch sensing resolution, and hence one region for obtaining coordinates of one touch position may be obtained if data segmentation is performed on the touch sensing data only. As such, the touch sensing data seems to indicate the characteristic of a single touch and thus the computing device  1  may determine an incorrect touch event, not corresponding to the one that the user would expect. 
     By contrast, referring to  FIG. 11 , the fingerprint sensing values of the fingerprint sensing data, indicated by a block  920 , indicate a data “valley” apparently that can be used for data segmentation. As one can observe in  FIG. 11 , a curve  925  shows the fingerprint sensing values taken along a middle column indicated by an arrow  921  and includes a data “valley,” for example, a point  926 , indicating a fingerprint sensing value of 429, between two peak values in the middle section of the curve  925 . Hence, the fingerprint sensing data shows the characteristic of multi-touch more accurately. In the above scenario, fingerprint sensing data indicates the valley(s) more significantly due to the fingerprint sensing resolution higher than the touch sensing resolution, and two or more corresponding regions can be derived when data segmentation is performed on the fingerprint sensing data, resulting in two or more touch positions and/or corresponding touch information. 
     By implementing step S 30  using the process in  FIG. 9 , the method of  FIG. 5  can be further employed to facilitate the data segmentation of the touch sensing data, with the contribution of the fingerprint sensing data. In an example of step S 310 , a boundary row, indicated by an arrow  922 , passing through the data valley (e.g., the point  926 ) can be determined and divides the fingerprint sensing data into two fingerprint data regions (e.g., an upper portion and a lower portion of the block  920 ). In an example of step S 320 , the touch sensing data (indicated by the block  910 ) can also be divided into two corresponding touch data regions (e.g., an upper portion and a lower portion of the block  910 ) by utilizing a boundary row, indicated by an arrow  912 , that can be derived from the boundary row, indicated by the arrow  922 . In step S 330 , the output touch data can then be determined at least based on at least one of the touch data regions; that is, at least based on one or more of the touch data regions, at least based on at least one of the touch data regions and at least one of the fingerprint data regions, or at least based on the touch data regions and fingerprint data regions. In this manner, the single chip  10  that implements the method based on  FIGS. 5 and 9  can provide the output touch data associated with multi-touch operations more accurately. 
     In other words, one or more touch points (or touch positions) can be identified in various cases, even though the touch sensing data may merely indicate a single touch data region and a single touch point while the fingerprint sensing data may indicate a number of touch data regions. Thus, the synergy of using the touch sensing data and the fingerprint sensing data can facilitate more accurate results of determination of touch events. 
     In some embodiments, step S 330  may include the step of determining a position at least based on one of the touch data regions, or at least based on one of the touch data regions and a corresponding one of the fingerprint data regions, wherein the output touch data includes the position. For example, for one or more of the touch data regions determined in step S 320  (e.g., the upper portion and lower portion of the block  910  with respect to the boundary row indicated by an arrow  912  shown in  FIG. 10 ), a position indicating a touch point in a corresponding one of the touch data regions can be determined based on the corresponding one of the touch data regions, or at least based on the corresponding one of the touch data regions and a corresponding one of the fingerprint data regions. For example, a respective position for each of the touch data regions can be determined, based on a corresponding one of the touch data regions, wherein the output touch data includes the respective position for each of the touch data regions. In the example shown in  FIG. 11 , two touch data regions including respective touch points can be determined accordingly. For implementation of the determination of the positions of the touch points, the above examples of determination of a representative point based on the equation (1), and/or (3) (as exemplified in  FIG. 7 or 8 ) can be employed for each of the touch data regions. As such, the touch points of the user&#39;s multi-touch operation can be determined accurately and then multi-touch events can be determined more accurately. In some embodiments, the step S 30  or S 330  may be implemented additional or alternatively to provide the output touch data including one or more multi-touch parameters, such as distance between two touch points, size of the touch data region, and so on. For example, if any two touch points are determined (e.g., in the example shown in  FIGS. 10 and 11 ), a distance (such as Euclidean distance, city block distance, or chessboard distance) between the positions of the two touch points can then be determined. In another example, when one of the touch data regions is determined, an area or size of that touch region can also be determined. Certainly, the implementation of the invention is not limited to the examples. 
     The following provides examples of data segmentation that may be employed in step S 310  or S 320 . For example, a watershed algorithm for image segmentation may be employed to divide the fingerprint sensing data into a number of fingerprint data regions in accordance with the relations between any valley and peak found in the fingerprint sensing data. For example, a criterion, described in pseudo code shown in TABLE 1, may be taken in using an implementation of the watershed algorithm for step S 310  or S 320 . 
                         TABLE 1               Criterion in pseudo code   Comments                  IF ( valley / min(peak0, peak1) &lt;   If a valley divided by a minimum       threshold),   of peaks such as peak0 and peak1                             THEN   is less than a threshold, the peaks           Label(peak0, peak1, 2);   are to be labeled by function           ELSE   Label( ) as in two regions; or else           Label(peak0, peak1, 1);   the peaks are to be labeled by                         function Label( ) as in a same           region.                        
In the above example in TABLE 1, “peak0” and “peak1” indicate two local maximum values and “valley” is a local minimum value corresponding to a position located adjacent to those of the two local maximum values. If the threshold is set to 90% and the fingerprint sensing data exemplified in  FIG. 11  is taken, then valley=429, peak0=482, peak1=481, valley/min(peak0, peak1)=429/481=89.2%&lt;90%, leading to the criterion satisfied. In this case, it is determined that the fingerprint sensing data have the two peaks and can be labeled as having two regions, as illustrated in  FIG. 12 . In  FIG. 12 , the block  920  including a plurality of fingerprint data nodes is illustrated with a first portion  931  of the fingerprint data nodes labeled as 0 and a second portion  932  of the fingerprint data nodes labeled as 1. For implementation of the labeling, the function Label( ) may be configured to find one or more boundaries for partitioning of the fingerprint sensing data (e.g., the boundary row indicated by the arrow  922 ), and partition the fingerprint sensing data into the fingerprint data regions by assigning corresponding label values (e.g., 0, 1 and so on) to the fingerprint data nodes in the fingerprint sensing data, for example. Referring to  FIG. 12 , each fingerprint data node is then associated with at least a position (e.g., coordinates Index_X and Index_Y), a fingerprint sensing value, and a label. Certainly, the implementation of the invention is not limited to the examples.
 
     In an embodiment of step S 320 , touch data regions in the touch sensing data can be determined based on the fingerprint data regions and the association between the touch data node and fingerprint data nodes. For example, referring to  FIGS. 10 and 11 , one touch data node of the touch sensing data indicated by the block  910  is associated with 3×3 fingerprint data nodes of the fingerprint sensing data indicated by the block  920 . In this way, as illustrated in  FIG. 13 , each group of 3×3 fingerprint data nodes (e.g., those indicated by a block  941 ) is associated with one of touch data nodes and the one of touch data nodes (e.g., one indicated by a block  942 ) can be assigned a label according to the labels that the associated group of fingerprint data nodes have (e.g., 0). 
     In an embodiment, a representative label can be obtained by taking a specific position, such as a center, corner, and so on, of each group of fingerprint data nodes and assigned to the associated touch data node. This approach is efficient. To be more precise, in another embodiment, a representative label can be determined for each group of fingerprint data nodes by counting which label exists the most of the times. For example, the label 0 occurs in the group of fingerprint data nodes (e.g., those indicated by a block  941 ) for 9 times so that the representative label is the label 0 and the touch data node (e.g., one indicated by a block  942 ) can be assigned the label 0. In another example, the touch data node (e.g., one indicated by a block  944 ) can be assigned a label 0 because the label 0 occurs in the group of fingerprint data nodes (e.g., those indicated by a block  943 ) for 6 times and the label 1 occurs for 3 times. In another embodiment, if two labels occur the same times in the group of fingerprint data nodes, the associated touch data node can be assigned a representative label that is taken from the label of a center of the group of fingerprint data nodes. Certainly, the implementation of the invention is not limited to the above examples. 
     The above embodiments for determining the representative label for being assigned to the associated touch sensing node can be utilized when the number of fingerprint sensing regions is two, three or above. Referring to  FIG. 14 , it is supposed that the fingerprint sensing data, indicated by a block  920 , in an example, is partitioned into three or more fingerprint data regions, which may be in arbitrary form. In an example, for the sake of illustration, it is supposed that three labels 0, 1, and 2 occur in a group of fingerprint data nodes (e.g., those indicated by a block  951 ). In this situation, a representative label can be obtained for each group of fingerprint data nodes by counting which label exists the most of the times. In an example, if the labels 0, 1, and 2 occur in the group of fingerprint data nodes (e.g., those indicated by the block  951 ) for the same number of times, the associated touch data node (e.g., one indicated by a block  952 ) can be assigned a representative label (e.g., 1) that is taken from the label of a center of the group of fingerprint data nodes (e.g., those indicated by the block  951 ). Certainly, the implementation of the invention is not limited to the above examples. 
     Further, the single chip capable of achieving touch sensing enhancement as exemplified above can be integrated with a display driving module. Referring to  FIG. 15 , a single chip  10 B capable of achieving touch sensing enhancement is illustrated according to another embodiment of the invention in block diagram form. As shown in  FIG. 15 , the single chip  10 B can be based on  FIG. 1 or 2  and further includes a display driving module  19 , which is coupled to the touch sensing module  11  and the fingerprint sensing module  12  internally in the single chip  10 B; and the display driving module  19  is utilized for being coupled to the display module  91  of the display panel  9  for driving the display module  91  to display images. In an embodiment for the display panel  9  with a fingerprint sensor  95  which is an optical fingerprint scanner, for example, when a touch event is detected by the touch sensing module  11 , the touch sensing module  11  can inform the display driving module  19  of an area that the touch event occurs. In some implementations, the display driving module  19  may drive the display module  91  to emit light or an image pattern for exposure of the area. In the meantime, the touch sensing module  11  can inform the fingerprint sensing module  12  for activating the fingerprint sensing elements (e.g., optical sensing elements) corresponding to the area for fingerprint detection so as to obtain fingerprint sensing data. The fingerprint sensing data can be utilized internally in the single chip  10 B in accordance with the method based on  FIG. 5  as exemplified in one of the above embodiments. For the fingerprint sensor being other type such as capacitive fingerprint sensor, ultrasonic fingerprint sensor, the single chip  10 B may be implemented to operate in a manner wherever appropriate. Certainly, the implementation of the invention is not limited to the above examples. It is also noted that different implementations may be made to integrate or separate the different modules as one or more circuits. For example, the display driving module and the touch sensing module can be integrated as a circuit, and the fingerprint sensing module can be implemented as another circuit which can be further totally or partially separated from or integrated with the circuit of the display driving module and the touch sensing module. 
     While the present disclosure has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the present disclosure set forth in the claims.