Solid-state imaging device, X-ray imaging system, and solid-state imaging device driving method
A solid-state imaging device includes a photodetecting unit including MN pixels arrayed two-dimensionally in M rows and N columns, an output unit outputting a digital value generated on the basis of the amount of charge input from the pixels, and a control unit. The control unit divides the MN pixels in the photodetecting unit into unit regions each including pixels in Q rows and R columns, divides the unit regions arrayed two-dimensionally in (M/Q) rows and (N/R) columns into binning regions each including unit regions in K rows and one column, and repeatedly outputs the digital value according to the sum of amounts of the charges output from KQR pixels included in each binning region from the output unit K times in a column order for each row sequentially for the binning regions arrayed two-dimensionally in (M/KQ) rows and (N/R) columns.
1. A solid-state imaging device comprising:
a photodetecting unit including MN pixels P 1,1 to P M,N , each including a photodiode generating a charge of an amount according to an incident light intensity and a readout switch connected to the photodiode, arrayed two-dimensionally in M rows and N columns;
a row selection line L V,m applying an m-th row selection control signal for instructing an opening and closing operation to the readout switch of each of N pixels P m,1 to P m,N in an m-th row in the photodetecting unit;
a readout line L O,n being connected to the readout switch of each of M pixels P 1,n to N M,n in an n-th column in the photodetecting unit, and reading the charge generated in the photodiode of any of the M pixels P 1,n to P M,n via the readout switch of the pixel;
an output unit being connected to each of the readout lines L O,1 to L O,N and outputting a digital value generated on the basis of the amount of the charge input via the readout line L O,n ; and
a control unit controlling an opening and closing operation of the readout switch of each of MN pixels P 1,1 to P M,N in the photodetecting unit via the row selection lines L V,1 to L V,M and controlling a digital value output operation in the output unit, wherein
the control unit
divides the pixels P 1,1 to P M,N arrayed two-dimensionally in M rows and N columns in the photodetecting unit into unit regions each including pixels in Q rows and R columns, divides the unit regions arrayed two-dimensionally in (M/Q) rows and (N/R) columns into binning regions each including unit regions in K rows and one column,
closes the readout switches of the pixels included in the binning region in the row for each row sequentially for the binning regions arrayed two-dimensionally in (M/KQ) rows and (N/R) columns in the photodetecting unit, inputs the charges generated in the photodiodes of the pixels to the output unit, and repeatedly outputs the digital value according to the sum of amounts of the charges output from the KQR pixels included in each binning region from the output unit K times sequentially for each column (where M and N are each an integer of 2 or more, m is an integer of 1 or more and M or less, n is an integer of 1 or more and N or less, Q and R are each an integer of 1 or more, and K is an integer of 2 or more).
2. The solid-state imaging device according to claim 1 , wherein the output unit includes a storage unit storing the digital value according to the sum of amounts of the charges output from the pixels included in each binning region, and
the control unit repeatedly reads and outputs the digital value stored in the storage unit from the storage unit K times sequentially for each column.
3. The solid-state imaging device according to claim 2 , wherein the output unit includes, as the storage unit, K FIFO memories storing the digital value according to the sum of amounts of the charges output from the pixels included in each binning region sequentially for each column, and
the control unit causes the digital values to be sequentially output from the K FIFO memories so that the digital value according to the sum of amounts of the charges output from the pixels included in each binning region is repeatedly output K times sequentially for each column.
4. The solid-state imaging device according to claim 2 , wherein the output unit includes, as the storage unit, a FIFO memory storing the digital value according to the sum of amounts of the charges output from the pixels included in each binning region sequentially for each column, and
the control unit causes the digital value to be output from the FIFO memory and causes the digital value to be stored in the FIFO memory so that the digital value according to the sum of amounts of the charges output from the pixels included in each binning region is repeatedly output K times sequentially for each column.
5. The solid-state imaging device according to claim 1 , comprising a plurality of blocks each including the photodetecting unit and the output unit connected to each other by the readout line L O,n , wherein
the photodetecting units in the respective blocks are arranged in parallel in the row direction.
6. An X-ray imaging system comprising:
the solid-state imaging device according to claim 1 , and an X-ray generating device, wherein
X-rays output from the X-ray generating device and transmitted through an imaging object are imaged by the solid-state imaging device.
7. The X-ray imaging system according to claim 6 , wherein the solid-state imaging device moves in the column direction in the photodetecting unit in the imaging period.
8. A method for driving a solid-state imaging device including:
a photodetecting unit including MN pixels P 1,1 to P M,N , each including a photodiode generating a charge of an amount according to an incident light intensity and a readout switch connected to the photodiode, arrayed two-dimensionally in M rows and N columns;
a row selection line L V,m applying an m-th row selection control signal for instructing an opening and closing operation to the readout switch of each of N pixels P m,1 to P m,N in an m-th row in the photodetecting unit;
a readout line L O,n being connected to the readout switch of each of M pixels P 1,n to P M,n in an n-th column in the photodetecting unit, and reading the charge generated in the photodiode of any of the M pixels P 1,n to P M,n via the readout switch of the pixel; and
an output unit being connected to each of the readout lines L O,1 to L O,N and outputting a digital value generated on the basis of the amount of the charge input via the readout line L O,n ,
the solid-state imaging device driving method comprising:
dividing the pixels P 1,1 to P M,N arrayed two-dimensionally in M rows and N columns in the photodetecting unit into unit regions each including pixels in Q rows and R columns, dividing the unit regions arrayed two-dimensionally in (M/Q) rows and (N/R) columns into binning regions each including unit regions in K rows and one column,
closing the readout switches of the pixels included in the binning region in the row for each row sequentially for the binning regions arrayed two-dimensionally in (M/KQ) rows and (N/R) columns in the photodetecting unit, inputting the charges generated in the photodiodes of the pixels to the output unit, and repeatedly outputting the digital value according to the sum of amounts of the charges output from the KQR pixels included in each binning region from the output unit K times sequentially for each column (where M and N are each an integer of 2 or more, in is an integer of 1 or more and M or less, n is an integer of 1 or more and N or less, Q and R are each an integer of 1 or more, and K is an integer of 2 or more).
9. The solid-state imaging device driving method according to claim 8 , wherein in the output unit, a storage unit storing the digital value according to the sum of amounts of the charges output from the pixels included in each binning region is used, and
the digital value stored in the storage unit is repeatedly read and output from the storage unit K times sequentially for each column.
10. The solid-state imaging device driving method according to claim 9 , wherein in the output unit, as the storage unit, K FIFO memories storing the digital value according to the sum of amounts of the charges output from the pixels included in each binning region sequentially for each column are used, and
the digital values are sequentially output from the K FIFO memories so that the digital value according to the sum of amounts of the charges output from the pixels included in each binning region is repeatedly output K times sequentially for each column.
11. The solid-state imaging device driving method according to claim 9 , wherein in the output unit, as the storage unit, a FIFO memory storing the digital value according to the sum of amounts of the charges output from the pixels included in each binning region sequentially for each column is used, and
the digital value is output from the FIFO memory and the digital value is stored in the FIFO memory so that the digital value according to the sum of amounts of the charges output from the pixels included in each binning region is repeatedly output K times sequentially for each column.