Ferroelectric LCD Monitors

Hi

Does anyone know of any Ferroelectric LCD based monitors or
microdisplays currently in the market? FLC is different from LCD. It
can only have two states - on or off. LCD has analog response. This
means that you don't have to do a digital to analog conversion to drive
an FLC display. I was wondering if any display manufacturer has tried
to make pixel drivers for an FLC based display given this difference.

Thanks in advance,
Sean

<seankhn@yahoo.com> wrote in message
news:1163606696.171946.247040@m7g2000cwm.googlegroups.com...
> Hi
>
> Does anyone know of any Ferroelectric LCD based monitors or
> microdisplays currently in the market? FLC is different from LCD. It
> can only have two states - on or off. LCD has analog response. This
> means that you don't have to do a digital to analog conversion to drive
> an FLC display. I was wondering if any display manufacturer has tried
> to make pixel drivers for an FLC based display given this difference.

It's been tried - Fujitsu attempted a line of FLC monitor panels (and
monitors) back, as I recall, around the early-to-mid 1990s. One
problem (among several) was that very bistability - driving something like
that at high resolutions is a real headache, and has basically no real
advantage over conventional LCs. "Not having to do a digital to
analog conversion" in the drivers is by no means an advantage per
se. The monitors in question were all monochrome types with limited
gray-scale capability.

There's still at least one company - Displaytech, here in Colorado -
doing FLC-based microdisplays, but having the display built on top
of a CMOS chip does change the economics of what you can do
in the drivers.

Bob M.

Bob Myers wrote:
> <seankhn@yahoo.com> wrote in message
> news:1163606696.171946.247040@m7g2000cwm.googlegroups.com...
> > Hi
> >
> > Does anyone know of any Ferroelectric LCD based monitors or
> > microdisplays currently in the market? FLC is different from LCD. It
> > can only have two states - on or off. LCD has analog response. This
> > means that you don't have to do a digital to analog conversion to drive
> > an FLC display. I was wondering if any display manufacturer has tried
> > to make pixel drivers for an FLC based display given this difference.
>
> It's been tried - Fujitsu attempted a line of FLC monitor panels (and
> monitors) back, as I recall, around the early-to-mid 1990s. One
> problem (among several) was that very bistability - driving something like
> that at high resolutions is a real headache, and has basically no real
> advantage over conventional LCs. "Not having to do a digital to
> analog conversion" in the drivers is by no means an advantage per
> se. The monitors in question were all monochrome types with limited
> gray-scale capability.
>
> There's still at least one company - Displaytech, here in Colorado -
> doing FLC-based microdisplays, but having the display built on top
> of a CMOS chip does change the economics of what you can do
> in the drivers.
>
> Bob M.

Thanks for the reply Bob, I assume the difficulty with driving such
monitors has to do with DC balancing? From what i have read FLC
materials, unless driven equally in the reverse direction, would
eventually deteriorate and cause poor picture quality. Does DisplayTech
use any special technique to get around it?

Sean

<seankhn@yahoo.com> wrote in message
news:1163656975.073339.75630@b28g2000cwb.googlegroups.com...

> Thanks for the reply Bob, I assume the difficulty with driving such
> monitors has to do with DC balancing? From what i have read FLC
> materials, unless driven equally in the reverse direction, would
> eventually deteriorate and cause poor picture quality. Does DisplayTech
> use any special technique to get around it?

DC balancing is a problem for conventional LCs. The main
problem with coming up with a drive scheme for FLCs is the
very thing you mentioned originally - they're either on or off,
with no inherent "gray scale" capability. To get any number of
gray levels, you need to use either temporal (PWM) or
spatial (dithering) modulation - neither of which is a particularly
fun thing, and there's no real advantage in either over a
conventionally-driven LC. So why bother?

Bob M.