Imaging device and drive method therefor

Abstract

An imaging device includes: a photoelectric converter that includes first and second electrodes and a photoelectric conversion layer therebetween and that generates signal charge; a capacitor having first and second terminals, the first terminal being connected to the first electrode; a first voltage supply circuit that selectively supplies at least two different voltages to the second electrode; and a second voltage supply circuit that selectively supplies at least two different voltages to the second terminal. In a predetermined period in each frame, when the first voltage supply circuit supplies a first voltage to the second electrode, the second voltage supply circuit supplies a second voltage to the second terminal, and when the first voltage supply circuit supplies a third voltage higher than the first voltage to the second electrode, the second voltage supply circuit supplies a fourth voltage lower than the second voltage to the second terminal.

What is claimed is: 
     
         1 . An imaging device comprising:
 a photoelectric converter that includes a first electrode, a second electrode, and a photoelectric conversion layer between the first electrode and the second electrode and that generates signal charge through photoelectric conversion;   a capacitor having a first terminal and a second terminal, the first terminal being connected to the first electrode;   a first voltage supply circuit that selectively supplies at least two different voltages to the second electrode; and   a second voltage supply circuit that selectively supplies at least two different voltages to the second terminal,   wherein in a predetermined period in each of frames, the first voltage supply circuit supplies one of voltages including a first voltage and a third voltage to the second electrode, the third voltage being higher than the first voltage;   in the predetermined period, when the first voltage supply circuit supplies the first voltage to the second electrode, the second voltage supply circuit supplies a second voltage to the second terminal; and   in the predetermined period, when the first voltage supply circuit supplies the third voltage to the second electrode, the second voltage supply circuit supplies a fourth voltage to the second terminal, the fourth voltage being lower than the second voltage.   
     
     
         2 . The imaging device according to  claim 1 ,
 wherein the voltages further includes a fifth voltage that is higher than the first voltage and that is lower than the third voltage; and   in the predetermined period, when the first voltage supply circuit supplies the fifth voltage to the second electrode, the second voltage supply circuit supplies a sixth voltage to the second terminal, the sixth voltage being lower than the second voltage and being higher than the fourth voltage.   
     
     
         3 . The imaging device according to  claim 1 ,
 wherein the predetermined period includes a period for reading a signal corresponding to a potential at the first electrode.   
     
     
         4 . The imaging device according to  claim 1 ,
 wherein the predetermined period includes a period for resetting a potential at the first electrode.   
     
     
         5 . The imaging device according to  claim 1 , further comprising:
 a first transistor having a gate connected to the first electrode,   wherein the predetermined period includes a period in which the first transistor outputs a signal corresponding to a potential at the first electrode.   
     
     
         6 . The imaging device according to  claim 5 , further comprising:
 a second transistor having a source or a drain connected to one of a source and a drain of the first transistor,   wherein the predetermined period includes a period in which the second transistor turns on.   
     
     
         7 . The imaging device according to  claim 1 , further comprising:
 a charge accumulator that is connected to the first electrode to accumulate the signal charge,   wherein in an accumulation period in which the signal charge is accumulated in the charge accumulator, the first voltage supply circuit alternately supplies the first voltage and the third voltage to the second electrode.   
     
     
         8 . The imaging device according to  claim 1 , further comprising:
 a charge accumulator that is connected to the first electrode to accumulate the signal charge,   wherein in a period in which the first voltage supply circuit supplies the third voltage to the second electrode, the period being included in an accumulation period for accumulating the signal charge in the charge accumulator, the second voltage supply circuit supplies the fourth voltage to the second terminal.   
     
     
         9 . The imaging device according to  claim 1 , further comprising:
 a charge accumulator that is connected to the first electrode to accumulate the signal charge,   wherein in a period in which the first voltage supply circuit supplies the first voltage to the second electrode, the period being included in an accumulation period for accumulating the signal charge in the charge accumulator, the second voltage supply circuit supplies the second voltage to the second terminal.   
     
     
         10 . The imaging device according to  claim 1 ,
 wherein the signal charge is a hole; and   when the first voltage is supplied to the second electrode, the photoelectric converter has no sensitivity to incident light.   
     
     
         11 . The imaging device according to  claim 1 ,
 wherein the signal charge is an electron; and   when the third voltage is supplied to the second electrode, the photoelectric converter has no sensitivity to incident light.   
     
     
         12 . The imaging device according to  claim 1 , further comprising:
 pixels arranged in a matrix having rows and columns,   wherein each of the pixels includes the photoelectric converter and the capacitor; and   the second voltage supply circuit selectively supplies, for each row included in the rows, the at least two different voltages to the second terminal.   
     
     
         13 . The imaging device according to  claim 12 ,
 wherein the pixels includes an effective pixel that outputs a signal corresponding to an amount of incident light and an ineffective pixel that outputs an optical black level; and   in a period for reading a signal of the effective pixel in each of the frames, the first voltage supply circuit supplies one of the voltages including the first voltage and the third voltage to the second electrode.   
     
     
         14 . A drive method for an imaging device including: a photoelectric converter that includes a first electrode, a second electrode, and a photoelectric conversion layer between the first electrode and the second electrode and that generates signal charge through photoelectric conversion; and a capacitor having a first terminal and a second terminal, the first terminal being connected to the first electrode, the drive method comprising:
 supplying one of voltages including a first voltage and a third voltage to the second electrode in a predetermined period in each of frames, the third voltage being higher than the first voltage;   supplying a second voltage to the second terminal when the first voltage is supplied to the second electrode in the predetermined period; and   supplying a fourth voltage to the second terminal when the third voltage is supplied to the second electrode in the predetermined period, the fourth voltage being lower than the second voltage.