Microlens alignment procedures in CMOS image sensor design
US7564629B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 2005 |
| Grant date | Jul 21, 2009 |
| Priority date | — |
| Expiry date | Jan 22, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/18
Abstract
A method for aligning a microlens array in a sensor die to resolve non-symmetric brightness distribution and color balance of the image captured by the sensor die. The method includes performing a pre-simulation to simulate a microlens array alignment in a silicon die and to determine a shrink-factor and de-centering values, calculating the error in a real product's alignment in process and image offset, performing a post simulation based on offset calculation on the real product and re-design of the microlens alignment, and repeating the steps of calculating the error and performing the post-simulation until a satisfactory brightness distribution is obtained. The sensor die has sensor pixels, each pixel comprising a photodiode and a microlens for directing incoming light rays to the photodiode, wherein optical axis of the microlens is shifted with respect to optical axis of the photodiode by a preset amount determined by at least one iteration of alignment process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.