Systems and methods for correcting for warpage of a sensor array in an array camera module by introducing warpage into a focal plane of a lens stack array
View Patent ↗Systems and methods in accordance with embodiments of the invention provide an array camera module in which warpage is designed into the projection plane of images from a lens stack array to correct for warpage in a sensor of the array camera module. The resulting array camera modules has back focal lengths for each of the lens stacks in the lens stack array that are substantially consistent when placed over a sensor.
1. An array camera comprising:
an array camera module including:
a sensor including an array of pixels that is subdivided into a plurality of sub-arrays of pixels, where each of the plurality of sub-arrays forms a focal plane; and
a lens stack array comprising a plurality of lens stacks wherein each of the plurality of lens stacks includes an aperture and forms an image on a focal plane formed by one of the plurality of sub-array of pixels on the sensor;
wherein the surface of the sensor on which images are formed by the lens stack array includes a warpage;
wherein a projection plane of images formed by the lens stack array incorporates a warpage that at least partially corrects the warpage in the sensor.
2. The array camera of claim 1 wherein the warpage of the sensor has a curvature of a bow that is convex.
3. The array camera of 2 wherein the warpage of the focal plane of the lens stack array has a curvature of a bow that is convex.
4. The array camera of 1 wherein the curvature of the warpage of the focal of the lens stack array is substantially equal to the curvature of the warpage of the sensor.
5. The array camera of claim 1 wherein the warpage of the lens stack array corrects the warpage of the sensor to provide back focal lengths for each of the plurality lens stacks in the lens stack array that are substantially consistent.
6. A method for manufacturing an array camera module comprising:
manufacturing a sensor including an array of pixels that is subdivided into a plurality of sub-arrays of pixels wherein each of the plurality of sub-arrays forms a focal plane;
measuring a warpage of the sensor to generate warpage information;
generating a design for a lens stack array comprising a plurality of lens stacks wherein each of the plurality of lens stacks is associated with a focal plane formed by one of the plurality of sub-array of pixels in the sensor and wherein the lens stack array is configured to have a projection plane of images formed by the lens stack array that has a warpage that corrects the warpage in the sensor based upon the warpage information for the sensor;
manufacturing the lens stack array in accordance with the generated design; and
placing the lens stack array over the sensor to form an array camera module.
7. The method of claim 6 further comprising:
aligning the lens stacks in the lens stack array with focal planes formed by the plurality of sub-arrays in the sensor.
8. The method of claim 6 wherein the warpage of the lens stack array corrects the warpage of the sensor to provide back focal lengths for each of the plurality of lens stacks in the lens stack array that are substantially consistent.
9. The method of claim 6 wherein the warpage of the sensor has a curvature of a bow that convex.
10. The method of 9 wherein the warpage of the projection plane of lens stack array has a curvature of a bow that is convex.
11. The method of 9 wherein the curvature of the warpage of the projection plane of the lens stack array is substantially equal to the curvature of the warpage of the sensor.
12. The method of claim 6 wherein the flatness requirements for the sensor are relaxed during the manufacturing and packaging of the sensor.
13. A method for mass manufacturing an array camera module comprising:
manufacturing a first plurality of sensors wherein each of the plurality of sensors includes an array of pixels that is subdivided into a plurality of sub-arrays of pixels wherein each of the plurality of sub-arrays forms a focal plane;
measuring a warpage of each of the first plurality of sensors to generate warpage information;
generating a design for a lens stack array comprising a plurality of lens stacks wherein each of the plurality of lens stacks is associated with a focal plane formed by one of the plurality of sub-array of pixels in the sensor and wherein the lens stack array is configured to have a projection plane of images formed by the lens stack array that has a warpage that corrects the warpage in the sensor based upon the warpage information for the first plurality of sensor;
manufacturing a second plurality of sensors in accordance with a process used to manufacture the first plurality of sensors;
manufacturing a plurality of lens stack arrays in accordance with the generated design; and
placing a one of the lens stack arrays over one of the second plurality of sensors to form array camera modules.
14. The method of claim 13 further comprising:
aligning the lens stacks in each of the plurality of lens stack arrays with focal planes formed by the plurality of sub-arrays in each of the second plurality of sensors.
15. The method of claim 13 wherein the warpage in the lens stack array design corrects the warpage of the first plurality of sensors to provide back focal lengths for each of the plurality of lens stacks in the lens stack array that are substantially consistent when placed over the second plurality of sensors.
16. The method of claim 13 wherein the warpage of the first and second plurality of sensors has a curvature of a bow that convex.
17. The method of 16 wherein the warpage of the projection planes of the plurality of lens stack arrays have a curvature of a bow that is convex.
18. The method of 16 wherein the curvature of the warpage of the projection planes of the plurality of lens stack arrays is substantially equal to a curvature of bow of the warpage of the plurality of sensors.