DEVICES FOR INTEGRATED MULTI-APERTURE IMAGING
DEVICES FOR INTEGRATED MULTI-APERTURE IMAGING Student: Keith Fife Adviser: Abbas El Gamal Date: Wednesday, May 28, 2008 Time: 3:00 PM (Refreshments served at 2:30 PM) Location: CISX 101 Auditorium Abstract: There has been significant development of image sensors over the last decade with work on CCDs and CMOS-based devices. Several issues have been addressed such as sensitivity, resolution, capture rate, dynamic range, dark current, crosstalk, power consumption, manufacturability and cost. One consistent limitation in conventional image sensors has been that the sensing area is constrained to a regular array of photosites used to recover an intensity distribution in the focal plane of the imaging system. Although this is the most direct method of image capture, there are both practical and fundamental issues that limit the scalability or performance of these systems. This research explores an alternative, multi-aperture approach to imaging, whereby the integrated image sensor is partitioned into an array of apertures, each with its own local subarray of pixels and image-forming optics. A virtual image is focused a certain distance above the sensor such that the apertures capture overlapping views of the scene. The subimages are post-processed to obtain both a high resolution 2D image and a depth map. A key feature of this design is in the use of submicron pixels to obtain accurate depth measurements derived from the localization of features within adjacent subarrays. Other benefits include the ability to (i) image objects at close proximity to the sensor without the need for objective optics, (ii) achieve excellent color separation through a per-aperture color filter array, (iii) relax the requirements on the camera objective optics, and (iv) increase the tolerance to defective pixels. The multi-aperture architecture is also highly scalable, making it possible to increase pixel counts well beyond current levels. Fabricated pixel sizes down to 0.5um pitch will be presented along with a prototype multi-aperture image sensor, which comprises a 166x76 array of 16x16, 0.7um pixel, FT-CCD subarrays with local readout circuit and per-column 10-bit ADCs fabricated in a 0.11um CMOS process modified for buried channel charge transfer.
CIS-X is the annex to the Center for Integrated Systems (CIS) building. The Auditorium is on the first floor to the left of the elevators. It is located at 330 Serra Mall. CIS is located at 420 Via Palou Mall. The google map shows the address for CIS since it does not properly locate CIS-X.