Photodetector and computed tomography apparatus

Abstract

A photodetector according to an embodiment includes: a photodetector element unit including a first cell array including a plurality of first cells arranged in an array and a second sell array including a plurality of second cells arranged in an array, each of the first and second cells including a photoelectric conversion element, the second cell array being arranged to be adjacent to the first cell array; a first pulse height analyzer unit analyzing a pulse height of an electrical signal outputted from the first cell array; a second pulse height analyzer unit analyzing a pulse height of an electrical signal outputted from the second cell array; and a signal processing unit determining non-uniformity of a distribution of photons entering the first and second cell arrays using an output signal of the first pulse height analyzer unit and an output signal of the second pulse height analyzer unit.

1 .- 13 . (canceled) 
     
     
         14 . A photodetector comprising:
 a first array in which a plurality of first photoelectric conversion elements are arranged in an array;   a second array in which a plurality of second photoelectric conversion elements are arranged in an array, the second array being arranged to be adjacent to the first array;   a first electrode electrically connected to the first array and a first analyzer analyzing a pulse height of an electrical signal outputted from the first array; and   a second electrode electrically connected to the second array and a second analyzer analyzing a pulse height of an electrical signal outputted from the second array.   
     
     
         15 . The photodetector according to  claim 14 , further comprising a signal processing unit that determines a distribution of photons entering the first array and the second array using an output signal of the first analyzer and an output signal of the second analyzer. 
     
     
         16 . The photodetector according to  claim 14 , further comprising a signal processing unit that receives an output signal of the first analyzer and an output signal of the second analyzer and determines a distribution of photons entering the first array and the second array. 
     
     
         17 . The photodetector according to  claim 14 , wherein the second array is arranged to surround the first array. 
     
     
         18 . The photodetector according to  claim 14 , wherein the second array is divided into a plurality of arrays. 
     
     
         19 . The photodetector according to  claim 14 , wherein the first and second photoelectric conversion elements are avalanche photodiodes. 
     
     
         20 . The photodetector according to  claim 19 , wherein the avalanche photodiodes are connected in parallel with each other. 
     
     
         21 . A computed tomography apparatus comprising:
 a radiation generating emitting radiation;   a display displaying an image;   a photodetector comprising;   a first array in which a plurality of first photoelectric conversion elements are arranged in an array;   a second array in which a plurality of second photoelectric conversion elements are arranged in an array, the second array being arranged to be adjacent to the first array;   a first electrode electrically connected to the first array and a first analyzer analyzing a pulse height of an electrical signal outputted from the first array; and   a second electrode electrically connected to the second array and a second analyzer analyzing a pulse height of an electrical signal outputted from the second array.   
     
     
         22 . The apparatus according to  claim 21 , further comprising a signal processing unit that determines a distribution of photons entering the first array and the second array using an output signal of the first analyzer and an output signal of the second analyzer. 
     
     
         23 . The apparatus according to  claim 21 , further comprising a signal processing unit that receives an output signal of the first analyzer and an output signal of the second analyzer and determines a distribution of photons entering the first array and the second array.