http://patft.uspto.gov/netacgi/nph-P...&RS=PN/7138663
or
http://tinyurl.com/2xextp

This has been posted on DPReview.

Interesting comments:
"According to the second embodiment, as in the case of the first
embodiment, since the red, blue, and green light passes through the same
opening, the photon utilization efficiency of the light receiving
element can be increased. In addition, the red, blue, and green light is
in the same spatial position, so that false color does not appear."

So, although photosite size is probably small, this is (at least
partially) offset by not losing light through rgb filters. Patent was
applied for in 2003.

Canon also proposed a more conventional "foveon" type sensor in about
2000, but it hasn't eventuated in a (Canon) camera yet.