Sensor pixel array and separated array of storage and accumulation with parallel acquisition and readout wherein each pixel includes storage sites and readout nodes
View Patent ↗A demodulation image sensor, such as used in time of flight (TOF) cameras, performs the acquisition and readout of the pixels in parallel. This is used to avoid motion artifacts due to samplings performed separated in time.
1. A demodulation sensor, comprising:
a pixel array comprising pixels that each produce at least two samples for subframes; and
a storage array comprising storage elements, each of the storage elements receiving the at least two samples from a corresponding one of the pixels;
wherein the pixels each comprises storage sites and readout nodes in which charge carriers of the samples are integrated in the storage sites and then transferred to the readout nodes for readout to the storage array.
2. A demodulation sensor as claimed in claim 1 , wherein storage sites integrate charge carriers while the charge carriers are being readout from the readout nodes.
3. A demodulation sensor as claimed in claim 1 , wherein storage sites integrate charge carriers for a current integration time while the charge carriers are being readout from the readout nodes from a previous integration time.
4. A demodulation sensor as claimed in claim 1 , wherein the charge carriers are transferred to the readout nodes simultaneously for the entire pixel array.
5. A demodulation sensor as claimed in claim 4 , wherein readout of the pixel array to the storage array is performed row-wise.
6. A demodulation sensor as claimed in claim 1 , wherein the samples of the charge carriers are analog to digitally converted during readout of the pixel array to the storage array.
7. A demodulation sensor as claimed in claim 1 , wherein the storage array accumulates the subframe into sub-depth frames.
8. A demodulation sensor as claimed in claim 7 , wherein the storage array accumulates the sub-depth frames into full frames.
9. A demodulation sensor as claimed in claim 8 , further comprising performing depth calculations on the full frames.
10. A demodulation sensor as claimed in claim 8 , further comprising reading out the full frames off chip.
11. A demodulation sensor as claimed in claim 1 , wherein the sub-frame or the sub-depth-frame integration time might vary between different full frames.
12. A demodulation sensor as claimed in claim 1 , herein the sub-frame or the sub-depth-frame integration time might vary with the same full frame integration time.
13. A demodulation method, comprising:
producing at least two samples with a pixel array in storage sites;
transferring the samples to readout nodes within each of the pixels in the pixel array; and
reading out the samples from the readout nodes to a storage array.
14. A demodulation method as claimed in claim 13 , further comprising integrating charge carriers within storage sites while the charge carriers are being readout from the readout nodes.
15. A demodulation method as claimed in claim 13 , further comprising integrating charge carriers within storage sites for a current subframe integration time while the charge carriers are being readout from the readout nodes from a previous subframe integration time.
16. A demodulation method as claimed in claim 13 , further comprising transferring charge carriers to the readout nodes simultaneously for the entire pixel array.
17. A demodulation method as claimed in claim 16 , further comprising reading out the pixel array to the storage array row-wise.