Asymmetric angular response pixels for single sensor stereo

1. Depth sensing imaging pixels comprising:

first and second adjacent photosensitive elements having an asymmetrical angular response to incident light;

a single microlens positioned above the first and second adjacent photosensitive elements;

a first color filter of a first color interposed between the single microlens and the first photosensitive elements;

a second color filter of a second color that is different than the first color interposed between the single microlens and the second photosensitive element;

a first light pipe disposed between the first photosensitive element and the single microlens for directing the incident light toward the first photosensitive element; and

a second light pipe disposed between the second photosensitive element and the single microlens for directing the incident light toward the second photosensitive element, wherein:

the first light pipe is configured to receive the incident light at a relatively high signal response when the incident light forms a positive angle with respect to a vertical plane passing between the first and second adjacent photosensitive elements; and

the second light pipe is configured to receive the incident light at a relatively high signal response when the incident light forms a negative angle with respect to a vertical plane passing between the first and second adjacent photosensitive elements.

2. The imaging pixels of claim 1 wherein the single microlens has a length that is substantially twice the length of either the first or second photosensitive element in a horizontal direction, the single microlens has a width that is substantially the same as a width of either the first or second photosensitive element in a vertical direction, and the horizontal and vertical directions are horizontal and vertical directions of a planar image array.

3. The imaging pixels of claim 2 wherein the single microlens has a radius of curvature in the horizontal direction that is the different from its radius of curvature in the vertical direction.

4. The imaging pixels of claim 1 wherein the color filter has a length that is substantially twice the length of either the first or second photosensitive element in a horizontal direction, the color filter has a width that is substantially the same as a width of either the first or second photosensitive element in the vertical direction, and the horizontal and vertical directions are horizontal and vertical directions of a planar image array.

5. The imaging pixels of claim 1 wherein

the first and second light pipes include material of a refractive index greater than a refractive index of material external of the first and second light pipes.

6. An imaging array comprising:

multiple pixel pairs of left and right pixels, wherein each pixel pair comprises depth sensing pixels having asymmetrical angular responses to incident light;

multiple color filter elements disposed on top of the multiple pixel pairs, wherein each color filter element comprises a single color and spans completely across the left and right pixels in each pixel pair;

microlenses that each span one pixel pair, wherein the microlenses are formed over the multiple color filter elements, wherein each microlens of the microlenses has a width and a length, and wherein the length of each microlens is longer than the width of that microlens; and

image processing circuitry configured to obtain an image depth signal by using subtraction to determine a difference between an output signal from a first one of the left pixels and an output signal from a first one of the right pixels.

7. The imaging array of claim 6 wherein the multiple pixel pairs are configured to provide one of the following:

(a) two separate images, one image derived from left pixels and the other image derived from right pixels, and

(b) a single image upon summing respective left and right pixels in each of the multiple pixel pairs.

8. The imaging array of claim 6 , wherein each microlens covers 2×1 pixels, defining two pixels in a row and one pixel in a column.

9. The imaging array of claim 8 wherein each microlens in a row is shifted by one pixel relative to each microlens in a neighboring row.

10. The imaging array of claim 9 wherein

two separate patterns are formed, in which left and right image arrays are formed from neighboring four rows.

11. The imaging array of claim 6 including

multiple light pipes disposed between the multiple pixel pairs and multiple color filters,

wherein each light pipe is configured to direct the incident light toward one of either a left pixel or a right pixel.

12. The imaging pixels of claim 1 wherein the first and second photosensitive elements are configured to detect distance.

13. The imaging array of claim 6 , further comprising:

additional pixels having symmetrical angular responses to the incident light.

14. The imaging array of claim 6 , wherein the first one of the left pixels and the first one of the right pixels are positioned in the same row of pixels.

15. The imaging array of claim 6 , wherein the first one of the left pixels and the first one of the right pixels form a first pixel pair of the multiple pixel pairs.

16. An imaging array comprising:

a pixel pair that includes a left pixel and a right pixel, wherein the left pixel and the right pixel are depth sensing pixels having asymmetrical angular responses to incident light;

a color filter element disposed on top of the pixel pair, wherein the color filter element comprises a single color and spans completely across the left and right pixels in the pixel pair;

a microlens that spans the pixel pair, wherein the microlens is formed over the color filter element; and

image processing circuitry configured to:

obtain an image depth signal by using subtraction to determine a difference between an output signal from the left pixel of the pixel pair and an output signal from the right pixel of the pixel pair; and

determine a distance to an imaged object based on the image depth signal.

17. The imaging array of claim 16 , wherein the microlens has a length and a width and wherein the length is substantially twice the width.

18. The imaging array of claim 6 , wherein the length of each microlens is twice as long as the width of that microlens.

19. The imaging array defined in claim 6 , wherein the image processing circuitry is configured to form a first image based on output signals from each left pixel of the multiple pixel pairs and wherein the image processing circuitry is configured to form a second image that is separate from the first image based on output signals from each right pixel of the multiple pixel pairs.