Wednesday, April 27, 2011

Vertical Transfer Gates Proposed by Omnivision, KETRI

Aiming to improve fill factor in small pixels, both KETRI and Omnivision applied for patents on vertical transfer gate structures, US20110084322 and US20110089311 respectively. The structures look quite similar:

Omnivision's Gate

Meanwhile, applications from Apple Imaging Group continue to trickle in. A large 91-page US20110090351 talks about temporal noise filtering with motion artifact reduction. The algorithm itself is quite straightforward but assumes that one has pixels motion vectors ready:

The Apple application also talks about other ISP stages, such as shading correction, defect pixel correction, demosaicing, etc.


  1. It is remarkable that these two patents were filed less than 2 weeks apart in 2009. Even more remarkable is that I know of other activity in this area which probably predates this (not by me) by just a bit that I expect has been also filed. If the technology goes anywhere, first-to-invent will be fun to ascertain.
    Is it an idea whose time has come and was apparent to many people, or were there some leaks along the way?

  2. See also US 2010/0025738, US 2009/0303371

  3. '371 from Sony is a 135 page document that seems to cover a lot of interesting ground. The main thrust is multiple layer photodiodes (e.g. Foveon) and using VTGs of different depths to reach different "color" layers. But they cover shared VTG pixels, pixels with combination horizontal and vertical transfers, etc.

    Thanks Anon for finding this. Quite interesting, especially as I was working with two-layer photodiodes and thinking about similar ways for readout. But, alas, this predates my work (as does other work) even tho it is a bit different. I will present a paper on the two layer work at 2011 IISW. Wish I could have referenced '371 in the final paper. Nice patent.

  4. Here are some more relevant documents having vertical transfer gates: US 2005/0167704, US 2007/0052056, US 2007/0184614, US 4760273.

    Eric, you may be interested in US 2007/0131987 and US 2008/0265352 both of which deal with vertical transfer gates in Foveon type sensors.


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