Single image sensor for capturing mixed structured-light images and regular images
An integrated image sensor for capturing a mixed structured-light image and regular image using an integrated image sensor are disclosed. The integrated image sensor comprises a pixel array, one or more output circuits, one or more analog-to-digital converters, and one or more timing and control circuits. The timing and control circuits are arranged to perform a set of actions including capturing a regular image and a structured-light image. According to the present invention, the structured-light image captured before or after the regular image is used to derive depth or shape information for the regular image. An endoscope based on the above integrated image sensor is also disclosed. The endoscope may comprises a capsule housing adapted to be swallowed, where the components of integrated image sensor, a structured light source and a non-structured light source are enclosed and sealed in the capsule housing.
1. An integrated image sensor, comprising:
a pixel array being responsive to light energy received by the pixel array to produce pixel signals having a voltage level depending on the light energy received by the pixel array;
one or more output circuits coupled to the pixel array to access the pixel signals produced by the pixel array;
one or more analog-to-digital converters having a first dynamic range and a second dynamic range, wherein the first dynamic range is lower than the second dynamic range;
one or more timing and control circuits coupled to the pixel array, said one or more output circuits, said one or more analog-to-digital converters or a combination thereof, wherein said one or more timing and control circuits are arranged to:
capture, by the pixel array, a structured-light image formed on a common image plane during a first frame period by applying first reset signals to the pixel array to reset rows of pixels of the pixel array, exposing the rows of pixels of the pixel array to structured light to cause first analog signals from the rows of pixels, and converting the first analog signals from the rows of pixels of the pixel array into first digital outputs for the structured-light image using one or more analog-to-digital converters at the first dynamic range; and
capture, by the pixel array, a regular image formed on the common image plane during a second frame period longer than the first frame period by applying second reset signals to the pixel array to reset the rows of pixels of the pixel array, exposing the rows of pixels to non-structured light to cause second analog signals from the rows of pixels, and converting the second analog signals from the rows of pixels into second digital outputs for the regular image using said one or more analog-to-digital converters at the second dynamic range; and
wherein the structured-light image is captured before or after the regular image to derive depth or shape information for the regular image.
2. The integrated image sensor of claim 1 , wherein said one or more analog-to-digital converters correspond to a configurable analog-to-digital converter to provide both the first dynamic range and the second dynamic range.
3. The integrated image sensor of claim 1 , wherein said one or more analog-to-digital converters correspond to two analog-to-digital converters with two different resolutions to provide both the first dynamic range and the second dynamic range.
4. The integrated image sensor of claim 1 , wherein said one or more timing and control circuits are further arranged to cause the structured-light image to be captured at lower spatial resolution than the regular image.