Weekly Patent Review

Sanyo application US20090032854 adds CCD-like electron multiplier to a CMOS pixel. Incidentally, Sanyo also presented a paper on this pixel at ISSCC last week. The idea is very nice and allows to minimize the pixel noise at low illumination level. However, the higher voltage and large pixel size limits it to the applications where cost is not the primary consideration.

IBM application US20090035886 proposes to use pre-doped poly for transfer gate to avoid possibility of wrong doping type in its parts after all the complex doping procedures of 4T pixel. Looks like quite weak patent application to me.

Samsung application US20090032852 presenta yet another variation of the idea of expanding floating diffusion dynamic range by making it low capacitance for small signals and higher capacitance for large signals.