Image sensor

Abstract

An image sensor includes a first unit pixel including a first sub-pixel and a second sub-pixel, a second unit pixel including a third sub-pixel and a fourth sub-pixel, a timing controller configured to apply a first effective integration time to the first sub-pixel and the fourth sub-pixel, such that a first sensing signal and a fourth sensing signal are generated from the first sub-pixel and the fourth sub-pixel, respectively, and to apply a second effective integration time shorter than the first effective integration time to the second sub-pixel and the third sub-pixel, such that a second sensing signal and a third sensing signal are generated from the second sub-pixel and the third sub-pixel, respectively, and an analog-to-digital converter configured to perform an averaging operation on the first sensing signal and the fourth sensing signal or on the second sensing signal and the third sensing signal.

What is claimed is: 
     
         1 . An image sensor, comprising:
 a plurality of unit color pixels each including a plurality of sub-pixels arranged in a matrix of rows and columns, each of the plurality of unit color pixels including:
 a first unit pixel including first to third sub-pixels included in a first column of the matrix; 
 a second unit pixel including fourth to sixth sub-pixels included in a second column of the matrix; and 
 a third unit pixel including seventh to ninth sub-pixels included in a third column of the matrix, wherein: 
   the first to third sub-pixels share a first charge detection node, the fourth to seventh sub-pixels share a second charge detection node, and the seventh to ninth sub-pixels share a third charge detection node, and   the first, fourth, and seventh sub-pixels generate a first set of sensing signals at a first time point, the second, fifth, and eighth sub-pixels generate a second set of sensing signals at a second time point, and the third, sixth, and ninth sub-pixels generate a third set of sensing signals at a third time point.   
     
     
         2 . The image sensor of  claim 1 , wherein:
 a first effective integration time is applied to the first, fourth, and seventh sub-pixels to generate the first set of sensing signals at the first time point,   a second effective integration time is applied to the second, fifth, and eighth sub-pixels to generate the second set of sensing signals at the second time point, and   a third effective integration time is applied to the third, sixth, and ninth sub-pixels to generate the third set of sensing signals at the third time point.   
     
     
         3 . The image sensor of  claim 1 , wherein the first, fourth, and seventh sub-pixels are included in different rows to each other, the second, fifth, and eighth sub-pixels are included in different rows to each other, and the third, sixth, and ninth sub-pixels are included in different rows to each other. 
     
     
         4 . The image sensor of  claim 3 , wherein:
 the first, sixth, and eighth sub-pixels are included in a first row of the matrix,   the second, fourth, and ninth sub-pixels are included in a second row of the matrix, and   the third, fifth, and seventh sub-pixels are included in a third row of the matrix.   
     
     
         5 . The image sensor of  claim 1 , further comprising a binning circuit configured to perform averaging operation for the first set of sensing signals, the second set of sensing signals, and the third set of sensing signals, respectively. 
     
     
         6 . The image sensor of  claim 1 , wherein the plurality of unit color pixels includes first to fourth unit color pixels arranged in 2 by 2 structure to constitute a first unit pixel group. 
     
     
         7 . The image sensor of  claim 6 , wherein:
 the plurality of unit color pixels further includes fifth to eighth unit color pixels arranged in 2 by 2 structure to constitute a second unit pixel group, and   the fifth to eighth unit color pixels correspond to the first to fourth unit color pixels, respectively.   
     
     
         8 . The image sensor of  claim 7 , further comprising a binning circuit configured to perform averaging operation for each pair of corresponding unit color pixels in the first and second unit pixel groups. 
     
     
         9 . The image sensor of  claim 8 , wherein the first unit pixel group is adjacent to the second unit pixel group in a row direction or a column direction. 
     
     
         10 . The image sensor of  claim 1 , wherein:
 the first to third sub-pixels share a first read-out circuit, connected to the first charge detection node, including a first reset transistor, a first drive transistor, and a first selection transistor,   the fourth to sixth sub-pixels share a second read-out circuit, connected to the second charge detection node, including a second reset transistor, a second drive transistor, and a second selection transistor, and   the seventh to ninth sub-pixels share a third read-out circuit, connected to the third charge detection node, including a third reset transistor, a third drive transistor, and a third selection transistor.   
     
     
         11 . The image sensor of  claim 10 , wherein:
 the first to third read-out circuits are connected to first to third column lines, respectively,   the first, fourth, and seventh sub-pixels transmit the first set of sensing signals through the first to third column lines, respectively, in response to the first to third selection transistors being turned on after the first time point,   the second, fifth, and eighth sub-pixels transmit the second set of sensing signals through the first to third column lines, respectively, in response to the first to third selection transistors being turned on after the second time point, and   the third, sixth, and ninth sub-pixels transmit the third set of sensing signals through the first to third column lines, respectively, in response to the first to third selection transistors being turned on after the third time point.   
     
     
         12 . The image sensor of  claim 11 , further comprising a binning circuit connected to the first to third column lines, wherein the binning circuit is configured to:
 perform an averaging operation for the first set of sensing signals transmitted from the first to third column lines in response to the first to third selection transistors being turned on after the first time point,   perform an averaging operation for the second set of sensing signals transmitted from the first to third column lines in response to the first to third selection transistors being turned on after the second time point, and   perform an averaging operation for the third set of sensing signals transmitted from the first to third column lines in response to the first to third selection transistors being turned on after the third time point.   
     
     
         13 . An image sensor, comprising:
 a first unit pixel including first to third sub-pixels sharing a first charge detection node;   a second unit pixel including fourth to sixth sub-pixels sharing a second charge detection node;   a third unit pixel including seventh to ninth sub-pixels sharing a third charge detection node; and   an analog-to-digital converter, wherein:   the first, fourth, and seventh sub-pixels are configured to have applied thereto a first effective integration time to generate a first set of sensing signals at a first time point, the second, fifth, and eighth sub-pixels are configured to have applied thereto a second effective integration time to generate a second set of sensing signals at a second time point, and the third, sixth, and ninth sub-pixels are configured to have applied thereto a third effective integration time to generate a third set of sensing signals at a third time point,   the first to third time points are different from each other, and   the analog-to-digital converter is configured to perform an averaging operation for the first set of sensing signals, the second set of sensing signals, and the third set of sensing signals, respectively.   
     
     
         14 . The image sensor of  claim 13 , wherein the first to third effective integration times are different from each other. 
     
     
         15 . The image sensor of  claim 14 , wherein:
 the first effective integration time is further applied to the fourth and seventh sub-pixels,   the second effective integration time is further applied to the fifth and eighth sub-pixels, and   the third effective integration time is further applied to the sixth and ninth sub-pixels.   
     
     
         16 . The image sensor of  claim 12 , wherein the first to third unit pixels constitute a unit color pixel corresponding to a single color. 
     
     
         17 . An image sensor, comprising:
 a row decoder configured to generate first and second transmission signals that transition to a high level at a first time point, and to generate third and fourth transmission signals that transition to a high level at a second time point;   a first unit pixel including first and third photoelectric conversion elements connected to a first charge detection node through first and third transmission transistors, respectively, the first and third transmission transistors operating in response to the first and third transmission signals, respectively;   a second unit pixel including second and fourth photoelectric conversion elements connected to a second charge detection node through second and fourth transmission transistors, respectively, the second and fourth transmission transistors operating in response to the second and fourth transmission signals, respectively; and   an analog-to-digital converter configured to:
 average a first set of sensing signals read out from the first and second charge detection nodes according to the transition at the first time point, and 
 average a second set of sensing signals read out from the second and third charge detection nodes according to the transition at the second time point. 
   
     
     
         18 . The image sensor of  claim 17 , wherein:
 the first and third photoelectric conversion elements integrate photoelectrons during a first effective integration time, and   the second and fourth photoelectric conversion elements integrate photoelectrons during a second effective integration time, which is shorter than the first effective integration time.   
     
     
         19 . The image sensor of  claim 17 , wherein the analog-to-digital converter is connected to the first charge detection node through a first read-out circuit and a first column line, and connected to the second charge detection node through a second read-out circuit and a second column line. 
     
     
         20 . The image sensor of  claim 17 , wherein the first to third unit pixels constitute a unit color pixel corresponding to a single color.