HIGH DYNAMIC RANGE IMAGING SYSTEMS HAVING DIFFERENTIAL PHOTODIODE EXPOSURES

摘要

Image sensors may include an array of photodiodes arranged in groups of adjacent photodiodes that generate charge in response to same-colored light. The image sensor may generate high-dynamic-range (HDR) images. To establish an effective exposure ratio between sets of photodiodes on the array for generating HDR images, microlenses may be formed over some photodiodes in a checkerboard pattern and may have portions that extend over other photodiodes in the array. Control circuitry may control photodiodes in each group to perform pulsed integration in which charge transfer control signals are intermittently pulsed for those photodiodes. A substantially opaque element may be formed over photodiodes in each of the groups such that the corresponding photodiodes generate signals in response to crosstalk. In this way, different effective exposures may be established across the array, allowing for HDR images to be generated without motion artifacts and with super-pixel resolution.

主权项

1. An imaging system, comprising:
an array of photodiodes arranged in rows and columns, wherein the array includes a group of photodiodes and wherein the group of photodiodes comprises first, second, third, and fourth adjacent photodiodes in the array; at least one color filter element formed over the group of photodiodes, wherein the at least one color filter element is configured to pass light of a common color to each photodiode in the group of photodiodes; a first microlens that is optically aligned with the first photodiode and that has portions that extend over the second and third photodiodes; and a second microlens that is optically aligned with the fourth photodiode and that has portions that extend over the second and third photodiodes.