From: Philippe Verdy (email@example.com)
Date: Thu May 03 2007 - 22:22:46 CST
Marnen Laibow-Koser wrote:
> Debbie Garside wrote:
> > IMHO the Optimus keyboard is way too over priced and because it uses
> > individual LCDs for each key it will remain over priced.
> LEDs, not LCDs.
> It is certainly overpriced right now, but the history of similar
> devices suggests that the price will come down in time. Right now
> it's really little more than proof of concept, but hopefully it will
> not always be so.
One factor of the high price is effectively the fact that there are many
individual small displays, and this complicates the construction, because
keys are mobile and if they must display the letters on top, then the
display must move, this requires many small connectors, and this could be
So instead of placing the display on the top of the key, why couldn't it be
behind the keyboard, in a single flat LCD panel with unidirectional
backlight, so that the letters are projected to a translucent area at the
top of the key?
It does not matter if the display is unfocused when the key is pressed; the
retro-projection just needs to be focused on the translucent area of the key
when it is released. Because of the retro-projection, the LCD area behind
the keyboard needs not be active on its whole area, just within the spot
areas where the backlight is going through, so there will remain space for
the mechanical parts of each key.
With such solution, you remove the complex connectics which are also a
problem for the mechanism, which must still remain robust.
Just look behind the keycaps of any keyboard (including on laptops where the
mechanism is quite different from desktop keyboard models), there is enough
space to fit a small hole for such projection system.
So the problem is now less a problem of mechanic due to connectors, but an
optical problem for focusing the projected images, and finding the correct
backlighting system (would this work with a simple diode, or should it be a
laser? If you need coloured key labels (for icons...) do you need that for
the whole keyboard or only for function keys, and where is color produced:
on the translucent area, in the background LCD used to produce the image, or
by colouring the backlight?
There are various solutions to explore, but such design would be very
robust. However, the final problem will be dust, hairs or tiny textile
fibres, that every keyboard accumulates over time between keycaps and the
background support, and that we already regularly have to clean every few
months (with more or less success). This dust would be a more important (and
frequent) problem for the optical system than with current mechanical
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