Motion detection device using temporal difference and spatial difference of pixel data

Abstract

There is provided an optical sensor including a pixel matrix and a readout circuit. The pixel matrix includes multiple pixels arranged in a matrix, and each of the multiple pixels outputs temporal difference pixel data. The readout circuit sequentially reads the pixel matrix using a readout block, and performs the hybrid difference calculation on the temporal difference pixel data of pixels within the readout block. Accordingly, the output of the readout circuit is the data accomplishing temporal difference and spatial difference.

What is claimed is: 
     
         1 . A motion detection device, comprising:
 a pixel region, comprising multiple pixels arranged in a matrix, each of the multiple pixels being configured to output bit 0 or bit 1;   a readout circuit, configured to read the pixel region, and calculate a difference of the bit 0 or the bit 1 respectively between each pixel and at least one adjacent pixel of the each pixel of the pixel region to generate spatial differences; and   a processor, configured to identify whether the motion detection device has a motion according to the spatial differences.   
     
     
         2 . The motion detection device as claimed in  claim 1 , wherein the bit 1 or the bit 0 is
 a difference value of charges generated by a photodiode of the multiple pixels between a current time and a reference time.   
     
     
         3 . The motion detection device as claimed in  claim 1 , wherein the bit 1 or the bit 0 is
 a difference value of charges generated by a photodiode of the multiple pixels between a current time and a previous time separated by a frame period.   
     
     
         4 . The motion detection device as claimed in  claim 1 , wherein the readout circuit is configured to
 read the pixel region using a readout block, and   calculate a difference of the bit 0 or the bit 1 between a center pixel and adjacent pixels of the center pixel in the readout block as the spatial differences.   
     
     
         5 . The motion detection device as claimed in  claim 4 , wherein the pixel region comprises at least 3×3 pixels. 
     
     
         6 . The motion detection device as claimed in  claim 4 , wherein the readout circuit is configured to
 compare the spatial differences of each readout block with a predetermined value,   count a number of the readout blocks having the spatial differences larger than the predetermined value, and   identify that the motion detection device has the motion when the number of the readout blocks of the pixel region is larger than a predetermined number.   
     
     
         7 . The motion detection device as claimed in  claim 4 , wherein the readout circuit is configured to
 calculate a difference value between the bit 1 or the bit 0 of the center pixel and the bit 1 or the bit 0 of each of the adjacent pixels in the readout block, and   calculate a summation of absolute values of the calculated difference values of the readout block as a hybrid difference.   
     
     
         8 . The motion detection device as claimed in  claim 1 , wherein the motion is a lift-up event of a navigation device or a motion event of a security system. 
     
     
         9 . A motion detection device, comprising:
 a first pixel region, configured to output a first image data;   at least one second pixel region, arranged at a side of the first pixel region and comprising multiple pixels arranged in a matrix, each of the multiple pixels being configured to output bit 1 or bit 0;   a readout circuit, configured to read the at least one second pixel region using a readout block, and calculate a spatial difference of the bit 1 or the bit 0 respectively between a center pixel and each of adjacent pixels of the center pixel in the readout block; and   a processor, configured to calculate displacement of the motion detection device according to the first image data, and identify whether the motion detection device has a motion according to the spatial difference.   
     
     
         10 . The motion detection device as claimed in  claim 9 , wherein the bit 1 or the bit 0 is
 a difference value of charges generated by a photodiode of the multiple pixels between a current time and a reference time; or   a difference value of charges generated by a photodiode of the multiple pixels between a current time and a previous time separated by a frame period.   
     
     
         11 . The motion detection device as claimed in  claim 9 , wherein the at least one second pixel region comprises at least 3×3 pixels. 
     
     
         12 . The motion detection device as claimed in  claim 9 , wherein the readout circuit is configured to
 compare spatial differences of each readout block with a predetermined value,   count, corresponding to each of the at least one second pixel region, a number of the readout blocks having the spatial differences larger than the predetermined value, and   identify that the motion detection device has the motion when the number of the readout blocks of one of the at least one second pixel region is larger than a predetermined number.   
     
     
         13 . The motion detection device as claimed in  claim 9 , wherein the readout circuit is configured to
 calculate a difference value between the bit 1 or bit 0 of the center pixel and the bit 1 or bit 0 of each of the adjacent pixels, and   calculate a summation of absolute values of the calculated difference values of the readout block as a hybrid difference.   
     
     
         14 . The motion detection device as claimed in  claim 9 , wherein the motion detection device comprises 4 second image regions respectively arranged at 4 sides of the first pixel region. 
     
     
         15 . The motion detection device as claimed in  claim 9 , wherein the at least one second pixel region and the first pixel region are respectively different regions of a same pixel matrix. 
     
     
         16 . The motion detection device as claimed in  claim 9 , wherein the motion is a lift-up event of a navigation device or a motion event of a security system. 
     
     
         17 . A motion detection device, comprising:
 a pixel matrix, comprising multiple pixels arranged in a matrix, and each of the multiple pixels being configured to output bit 1 or bit 0; and   a readout circuit, configured to sequentially read the pixel matrix using a readout block, and calculate a spatial difference of the bit 1 or bit 0 respectively between a center pixel and adjacent pixels of the center pixel of the readout block to determine a brightness variation within the readout block.   
     
     
         18 . The motion detection device as claimed in  claim 17 , wherein the bit 1 or bit 0 is
 a difference value of charges generated by a photodiode of the multiple pixels between a current time and a reference time; or   a difference value of charges generated by a photodiode of the multiple pixels between a current time and a previous time separated by a frame period.   
     
     
         19 . The motion detection device as claimed in  claim 17 , further comprising a comparator configured to compare spatial differences of each readout block calculated by the readout circuit with a predetermined value. 
     
     
         20 . The motion detection device as claimed in  claim 19 , further comprising a counter configured to
 count a number of the readout blocks in the pixel matrix having the spatial differences larger than the predetermined value, and   generate a trigger signal when the number of the readout blocks is larger than a predetermined number.