Imaging device and imaging system

Abstract

An object of the present invention is to prevent a sensitivity difference between pixels. There are disposed plural unit cells each including plural photodiodes, plural transfer MOSFETs arranged corresponding to the plural photodiodes, respectively, and a common MOSFET which amplifies and outputs signals read from the plural photodiodes. Each pair within the unit cell, composed of the photodiode and the transfer MOSFET provided corresponding to the photodiode, has translational symmetry with respect to one another. Within the unit cell, there are included a reset MOSFET and selecting MOSFET.

What is claimed is: 
     
         1 . An imaging device having disposed therein a plurality of unit cells, an each unit cell comprising:
 a plurality of photoelectric conversion regions;   a transfer means arranged corresponding to the plurality of photoelectric conversion regions, respectively; and   common amplification means which amplifies signals transferred from the plurality of photoelectric conversion regions,   wherein each pair within the unit cell, composed of the photoelectric conversion region and the transfer means provided corresponding to the photoelectric conversion region, arranged translational symmetry with respect to one another.   
     
     
         2 . The imaging device according to  claim 1 , wherein reset means which resets an input of the amplification means is included in the unit cell. 
     
     
         3 . The imaging device according to  claim 1 , wherein selection means which switches between selection and non-selection of the output of the amplification means is included in the unit cell. 
     
     
         4 . The imaging device according to  claim 1 , further comprising floating diffusion regions provided corresponding to each of the photoelectric conversion regions, wherein the floating diffusion regions are connected by conductive materials. 
     
     
         5 . The imaging device according to  claim 1 , wherein the amplification means, having a plurality of unit elements connected in parallel to each other, is constructed as one unit of amplification means. 
     
     
         6 . The imaging device according to  claim 2 , wherein the reset means, having a plurality of unit elements connected in parallel to each other, is constructed as one unit of reset means. 
     
     
         7 . The imaging device according to  claim 3 , wherein the selection switch means, having a plurality of unit elements connected in parallel to each other, is constructed as one unit of selection switch means. 
     
     
         8 . The imaging device according to  claim 5 , wherein the unit element is an insulating gate type transistor. 
     
     
         9 . The imaging device according to  claim 1 , further comprising a color filter having combined therein plural kinds of filters having. spectral transmission factors different from each other with′ respect to incident light, wherein the period at which the unit cell is disposed coincides with the period at which the color filter is disposed. 
     
     
         10 . The imaging device according to  claim 9 , wherein the color filter has bayer arrangement. 
     
     
         11 . An imaging device having disposed therein a plurality of unit cells, an each unit cell comprising:
 a plurality of photoelectric conversion regions;   a plurality of floating diffusion regions provided corresponding to the plurality of photoelectric conversion regions, respectively;   a MOS transistor for transferring signal charges of the. photoelectric conversion region to the floating diffusion region; and   common amplification means which amplifies signals transferred from the plurality of photoelectric conversion regions,   wherein each of the photoelectric conversion regions is disposed at a first pitch; each of the MOS transistor gate electrodes is disposed at a second pitch; each of the floating diffusion regions is disposed at a third pitch; and the first, second and third pitches are equal to each other.   
     
     
         12 . An imaging system comprising:
 the imaging device according to  claim 1 ;   an optical system which focuses light on the imaging device; and   a signal processing circuit which processes an output signal from the imaging device.