Imaging apparatus comprising 3D stacked global shutter

1. An imaging apparatus, comprising:

a pixel array, comprising a plurality of pixels arranged in rows and columns, wherein at least one of the pixels comprises:

a first capacitor configured to store a reset signal, and

a second capacitor configured to store a pixel signal, and

a plurality of column circuits, wherein at least one of the column circuits reads the reset signal from the first capacitor, reads the pixel signal from the second capacitor, and generates difference between the reset signal and the pixel signal,

wherein the pixel is configured to store the pixel signal to the second capacitor after the reset signal is stored to the first capacitor,

wherein the pixel further comprises an output transistor, which is connected between a source follower transistor and the ground, and controlled by a bias control signal; and when ‘reset’ and ‘signal’ signals are read out and stored to the first and second capacitors, the output transistor is in turned off state to ensure the storage of the signals, and after that, the output transistor grounds an output of source follower transistor to reduce the inference when the ‘reset’ and ‘signal’ signals are read out, and to ensure auto-zeroing,

wherein the pixel further comprises an output source follower transistor and a row selection transistor, said output source follower transistor is connected to an output of the first capacitor and the second capacitor and said row selection transistor,

wherein the pixel further comprises a reset storage switch and a signal storage switch, the reset storage switch being between the signal storgae switch and the first capacitor, and the signal storage switch being connected between the output of the source follower transistor and the second capacitor, and

wherein both the first capacitor and the second capacitor are connected to ground; and the imaging apparatus is physically configured that turning the signal storage switch off will disconnect both the first capacitor and the second capacitor from the source follower transistor, and turning the reset storage switch on will connect both the first capacitor and the second capacitor to the output source follower transistor.

2. The imaging apparatus according to claim 1 , wherein the pixel comprises a first spacing layer, a first wafer, a second spacing layer and a second wafer sequentially, and wherein the first spacing layer comprises a plurality of filters.

3. The imaging apparatus according to claim 2 , wherein the pixel comprises a plurality of micro lens located on the first spacing layer.

4. The imaging apparatus according to claim 3 , wherein the first wafer includes a plurality of photodiodes, and the second wafer comprises at least part of circuit of the pixel.

5. The imaging apparatus according to claim 4 , wherein the second wafer comprises the first capacitor and the second capacitor.

6. The imaging apparatus according to claim 4 , wherein the second spacing layer comprises a pixel inner-connection structure that electrically connects the at least one of the photodiodes located in the first wafer with the at least part of circuit of the pixel located in the second wafer.

7. The imaging apparatus according to claim 4 , wherein the first spacing layer comprises a plurality of filters, at least one of which is located between the micro lens and the photodiode.