Method for position detection and sensing device applying the same method

Abstract

A method for position detection is adapted to a sensing device. The sensing device includes a plurality of sensing blocks arranged in a 2D array, with each block having a plurality of sensing points arranged in a 2D array. The method includes conducting a block-scan to determine if a touched block exists, and conducting a point-scan to obtain a touched point if the touched block exists. In order to obtain a touched point, the sensing device applying the method conducts a block-scan within the sensing area and then a point-scan within the touched block instead of point-scanning the whole sensing area. Accordingly, the sensing device could obtain the touched point faster than before.

What is claimed is: 
     
         1 . A method for position detection adapted to a sensing device having a plurality of sensing blocks arranged in a 2-D array, with each sensing block having a plurality of sensing points arranged in a 2-D array, comprising:
 conducting a block-scan to determine whether a touched block exists;   conducting a point-scan within the touched block to obtain a plurality of first touched points;   defining a plurality of extended areas by extending horizontally and vertically in the positive and negative directions from each first touched point as a center point by a preset distance, wherein the preset distance is calculated by dividing a predetermined movement speed by a measurement sampling rate;   obtaining an expansion area with borders of the expansion area are respectively defined by extending a right border of a right-most extended area of the overlapped extended areas, extending a left border of a left-most extended area of the overlapped extended areas, extending a top border of a top-most extended area of the overlapped extended areas and extending a bottom border of a bottom-most extended area of the overlapped extended areas;   designating the expansion area and any non-overlapping extended area as the first area; and   activating and detecting the sensing points within the first area to obtain a second touched point which occurs after the plurality of first touched points.   
     
     
         2 . The method of  claim 1 , wherein the predetermined movement ranges from 50 cm/s to 90 cm/s. 
     
     
         3 . The method of  claim 1 , wherein conducting the block-scan to determine whether the touched block exists comprises:
 activating and detecting each of the sensing blocks in sequence such that all of the sensing points within the scanned sensing block are activated simultaneously and then detected simultaneously to obtain a block capacitance; and   designating the sensing block as a touched block when the corresponding block capacitance is greater than a first threshold value.   
     
     
         4 . The method of  claim 1 , wherein conducting the block-scan to determine whether the touched block exists comprises:
 activating all of the sensing blocks simultaneously to activate all of the sensing points within each sensing block;   detecting all of the sensing points within the activated sensing blocks simultaneously to obtain a block capacitance; and   designating the sensing block as the touched block when the corresponding block capacitance is greater than a first threshold value.   
     
     
         5 . The method of  claim 4 , wherein if any touched sensing block is identified, the touched sensing block is point-scanned to obtain the plurality of first touched points by:
 activating and detecting each of the sensing points in sequence within the touched sensing block to obtain a corresponding point capacitance; and   designating that the sensing point as the first touched point when the corresponding point capacitance is greater than a second threshold value.   
     
     
         6 . The method of  claim 5 , wherein the first threshold value is defined by adding a block capacitance differential to a block background signal value, while the second threshold value is defined by adding a point capacitance differential to a point background signal value. 
     
     
         7 . A sensing device, comprising:
 a first sensing layer and a second sensing layer arranged in a stacked manner to define a sensing area, which including a plurality of sensing blocks arranged in a 2-D array, with each sensing block having a plurality of sensing points arranged in a 2-D array; and   a controller for:
 conducting a block-scan to determine whether a touched block exists; 
 conducting a point-scan within the touched block to obtain a plurality of first touched points; 
 defining a plurality of extended areas by extending horizontally and vertically in the positive and negative directions from each first touched point as a center point by a preset distance, wherein the preset distance is calculated by dividing a predetermined movement speed by a measurement sampling rate; 
 obtaining an expansion area with borders of the expansion area are respectively defined by extending a right border of a right-most extended area of the overlapped extended areas, extending a left border of a left-most extended area of the overlapped extended areas, extending a top border of a top-most extended area of the overlapped extended areas and extending a bottom border of a bottom-most extended area of the overlapped extended areas; 
 designating the expansion area and any non-overlapping extended area as the first area; and 
 activating and detecting the sensing points within the first area to obtain a second touched point which occurs after the plurality of first touched points. 
   
     
     
         8 . The sensing device of  claim 7 , wherein the predetermined movement ranges from 50 cm/s to 90 cm/s. 
     
     
         9 . The sensing device of  claim 7 , wherein the controller comprises:
 a plurality of activators with each activator corresponding to at least one sensing block for activating the sensing points therewithin;   a plurality of detectors with each detector corresponding to at least one sensing block for detecting the capacitance of each activated sensing point within the sensing block; and   a processor for activating the activators and detectors for the block-scan, wherein the processor:
 activating and detecting each of the sensing blocks in sequence so that the sensing points are activated simultaneously and then detected simultaneously to obtain a block capacitance; and 
 designating the sensing block as the touched block if the corresponding block capacitance is greater than a first threshold value. 
   
     
     
         10 . The sensing device of  claim 7 , wherein the controller comprises:
 a plurality of activators with each activator corresponding to at least one sensing block for activating the sensing points therewithin;   a plurality of detectors with each detector corresponding to at least one sensing block for detecting the capacitance of each activated sensing point within the sensing block; and   a processor for activating the activators and detectors for the block-scan, wherein the processor:
 activating the activators simultaneously to activate the sensing points within each of the sensing blocks; 
 activating the detectors simultaneously to detect the sensing points simultaneously within activated sensing blocks to obtain corresponding block capacitances; and 
 designating the sensing block as the touched block if the corresponding block capacitance is greater than a first threshold value. 
   
     
     
         11 . The sensing device of  claim 10 , wherein when the touched block has been identified, the touched block is point-scanned to obtain a touched point, and wherein the point-scan includes:
 activating and detecting each of the sensing points in sequence within the touched block to obtain a corresponding point capacitance; and   designating that the sensing point as the first touched point when the corresponding point capacitance is greater than a second threshold value.   
     
     
         12 . The sensing device of  claim 10 , wherein the first threshold value is defined by adding a block capacitance differential to a block background signal value, while the second threshold value is defined by adding a point capacitance differential to a point background signal value. 
     
     
         13 . The sensing device of  claim 10 , wherein the activator and detector both corresponding to the same sensing block are grouped within a single integrated circuit. 
     
     
         14 . The sensing device of  claim 10 , wherein the sensing points within each of the sensing blocks are not adjacent to one another along the detection direction. 
     
     
         15 . A method for position detection adapted to a sensing device having a plurality of sensing blocks arranged in a 2-D array, with each sensing block having a plurality of sensing points arranged in a 2-D array, comprising:
 conducting a block-scan to determine whether a touched block exists;   conducting a point-scan within the touched block to obtain a first touched point;   obtaining a first area surrounding the first touched point and at least one other sensing point of the plurality of sensing points, the first area being defined based on a preset distance away from the touched point independent of a boundary of the touched block including the first touched point, wherein the preset distance is calculated by dividing a predetermined movement speed by a measurement sampling rate; and   activating and detecting the sensing points within the first area to obtain a second touched point which occurs after the first touched point.   
     
     
         16 . The method of  claim 15 , wherein the predetermined movement ranges from 50 cm/s to 90 cm/s. 
     
     
         17 . The method of  claim 15 , wherein conducting the block-scan to determine whether the touched block exists comprises:
 activating and detecting each of the sensing blocks in sequence such that all of the sensing points within the scanned sensing block are activated simultaneously and then detected simultaneously to obtain a block capacitance; and   designating the sensing block as a touched block when the corresponding block capacitance is greater than a first threshold value.   
     
     
         18 . The method of  claim 15 , wherein conducting the block-scan to determine whether the touched block exists comprises:
 activating all of the sensing blocks simultaneously to activate all of the sensing points within each sensing block;   detecting all of the sensing points within the activated sensing blocks simultaneously to obtain a block capacitance; and   designating the sensing block as the touched block when the corresponding block capacitance is greater than a first threshold value.   
     
     
         19 . The method of  claim 18 , wherein if any touched sensing block is identified, the touched sensing block is point-scanned to obtain the first touched point by:
 activating and detecting each of the sensing points in sequence within the touched sensing block to obtain a corresponding point capacitance; and   designating that the sensing point as the first touched point when the corresponding point capacitance is greater than a second threshold value.   
     
     
         20 . The method of  claim 19 , wherein the first threshold value is defined by adding a block capacitance differential to a block background signal value, while the second threshold value is defined by adding a point capacitance differential to a point background signal value. 
     
     
         21 . The method of  claim 15 , wherein after the second touched point has been obtained, further comprising:
 obtaining a position vector based on the first touched point and the second touched point;   obtaining a second area based on the second touched point and the position vector, and wherein the second area includes a plurality of sensing points, with a length of the second area and a width of the second area being directly proportional to the magnitude of the position vector, and wherein the second touched point being located at the center of the second area; and   activating and detecting the sensing points within the second area.