| US 7,352,454 B2 | ||
| Methods and devices for improved charge management for three-dimensional and color sensing | ||
| Cyrus Bamji, Fremont, Calif. (US); and Hakan Yalcin, Fremont, Calif. (US) | ||
| Assigned to Canesta, Inc., Sunnyvale, Calif. (US) | ||
| Filed on Feb. 06, 2006, as Appl. No. 11/349,017. | ||
| Application 11/028290 is a division of application No. 10/464299, filed on Jun. 17, 2003, granted, now 6,906,793, filed on Jun. 14, 2005. | ||
| Application 11/349017 is a continuation in part of application No. 11/028290, filed on Dec. 30, 2004. | ||
| Application 10/464299 is a continuation in part of application No. 10/020339, filed on Dec. 11, 2001, granted, now 6,580,496. | ||
| Claims priority of provisional application 60/650915, filed on Feb. 08, 2005. | ||
| Claims priority of provisional application 60/254873, filed on Dec. 11, 2000. | ||
| Claims priority of provisional application 60/247158, filed on Nov. 09, 2000. | ||
| Claims priority of provisional application 60/400002, filed on Jul. 29, 2002. | ||
| Claims priority of provisional application 60/396422, filed on Jul. 15, 2002. | ||
| Claims priority of provisional application 60/393408, filed on Jul. 01, 2002. | ||
| Prior Publication US 2006/0128087 A1, Jun. 15, 2006 | ||
| Int. Cl. G01B 11/26 (2006.01); G01C 1/00 (2006.01); G01C 3/08 (2006.01) | ||
| U.S. Cl. 356—141.1 [356/5.01; 356/4.01; 257/414] | 23 Claims |
| 1. A CMOS-implementable semiconductor photodetector useable in a system that illuminates a target with optical energy having
a modulated periodic waveform that includes a high frequency component, generated in response to signal provided by a clock
generator, and that detects a fraction of said optical energy reflected by said target with at least one said semiconductor
photodetector, said photodetector comprising:
a semiconductor substrate having a surface upon which said incoming optical energy can impinge onto an optical energy sensitive
region, said surface defining an x-direction and a y-direction;
at least a first elongate-shaped polysilicon gate disposed on said surface parallel to said y-direction, said first gate coupleable
to a first bias clock signal, synchronously generated by said clock generator, that is high during a first bias regime to
detect and collect charge generated by at least a fraction of said incoming optical energy;
a first source region formed in said substrate adjacent a distal end of said first gate;
at least a second elongate-shaped polysilicon gate disposed on said surface parallel to said first elongate-shaped gate and
spaced-apart in said x-direction a distance substantially shorter than a length of either said gate, said second gate coupleable
to a second bias clock signal synchronously generated by said clock generator;
a second source region formed in said substrate adjacent a distal end of said second gate;
wherein responsive to said first bias clock signal and said second bias clock signal, photoelectic charge generated in said
substrate is moved in said x direction to become trapped beneath an elongate-shaped gate and is then moved in said y-direction
to an adjacent source region for collection, charge movement in said y-direction being slower than charge movement in said
x-direction, wherein modulation contrast of said photodetector is enhanced.
|