Image sensors and sensing methods to obtain time-of-flight and phase detection information
Indirect time-of-flight (i-ToF) image sensor pixels, i-ToF image sensors including such pixels, stereo cameras including such image sensors, and sensing methods to obtain i-ToF detection and phase detection information using such image sensors and stereo cameras. An i-ToF image sensor pixel may comprise a plurality of sub-pixels, each sub-pixel including a photodiode, a single microlens covering the plurality of sub-pixels and a read-out circuit for extracting i-ToF phase signals of each sub-pixel individually.
1. A system, comprising:
a light source;
an image sensor including a plurality of image sensor pixels, each image sensor pixel comprising a plurality of sub-pixels, each sub-pixel including a photodiode;
a microlens covering the plurality of sub-pixels, wherein the plurality of image sensor pixels are indirect time-of-flight (i-ToF) image sensor pixels that are configured to receive light which is emitted from the light source and reflected from a scene to generate i-ToF phase signals; and
a read-out circuit (ROC) for extracting the i-ToF phase signals of each sub-pixel individually, wherein each i-ToF image sensor pixel includes a switch, wherein in one state the switch is closed so that the sub-pixels together form one pixel and the ROC reads out the one pixel for generating an i-ToF depth map, and wherein in another state the switch is opened so that the ROC reads out the sub-pixels individually for generating a stereo depth map.
2. The system of claim 1 , wherein the light source is in the near infrared (NIR) region.
3. The system of claim 1 , wherein the i-ToF phase signals represent stereo image data as captured by a stereo camera having a vertical or a horizontal baseline.
4. The system of claim 1 , wherein the system includes an application processor, and wherein the application processor is configured to generate a fused depth map by using stereo depth map data and ToF depth map data.
5. The system of claim 1 , wherein the extracting of the i-ToF phase signals of each sub-pixel individually includes extracting of fewer than all i-ToF signals generated by the plurality of the sub-pixels.
6. The system of claim 5 , wherein the extracted i-ToF phase signals are used to calculate a relative ToF depth map.
7. The system of claim 5 , wherein the extracted i-ToF phase signals are used to calculate a 1-shot depth map.
8. The system of claim 6 , wherein the relative TOF depth map is used to generate a high fps depth map stream having a fps≥35.
9. The system of claim 7 , wherein the 1-shot depth map is used to generate a high fps depth map stream having a fps≥35.
10. The system of claim 1 , wherein the system is integrated into a smartphone.