on 3/25/01 9:30 AM, drchrisbarrett at drchrisbarrett@xxxxxxxxxxxxxxxxxxxx
wrote:
> Dear Tim,
>
> You wrote:
>
>
> "I am not sure it is that unlikely a structure as the surface layers
> need to
> include quite a few layers including a passivation layer, at least one
> metalization layer to bring in connections (possibly 2) at least one
> layer
> for the filters and possibly three seperate layers (1 for each color)
> and
> maybe even passivation layers between each of those."
>
> The metallisation layers are likely to be sub-micron, youre right about
> the "filling factor" for the sensing element itself. I've been
> calculating on the assumption that the sensors fill completely the chip
> chip, but I was trying to give some useful approximations. I think in an
> RGB chip, the filter layers will not be one on top of another, but will
> be side by side. They are likely to be the thickest layer, and could be
> several microns. However, thick layers are notoriously difficult to
> pattern so I think they would go for a thin layer of something with a
> high absorption coefficient.
> That said the undercutting that one gets when etching thick layers such
> as the filter could be used to approximate a hemispherical lens on top
> of each element, wich would help gather the low angle rays.
>
> "In a a non RGB sensor as
> is used in a dichroic beam splitter design the pixels are
> proportionately
> larger and don't need all the filter layers so the signals are larger by
> a
> factor of 3 and they don't have such deep wells. For analytic
> applications as
> your coleagues are probably using (?), the same thinner design
> applies,since
> they don't need on chip filters. "
>
> I did say at one point that I was ignoring the effect of small pixel
> sizes on noise levels but this would need to be considered.
>
> My colleagues don't use them for analytical applications but for a
> variety of imaging applications. The UK MoD requires us to retain
> experise and knowledge base in all aspects of miltary and commercially
> available devices, hence they know a lot about commercially available
> devices, even when they don't have an immediate use for them.
I have come across a Braun flash which I want to give to my daughter for
that occasional flash picture with an OM-2. Does anyone know anything about
this flash or perhaps even have an old manual from the 80's on this one. I
sure would appreciate any information.
Thanks
Bob Winters
Washington State
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|