I was just wondering if LCD monitors typically try to refresh
everything simultaneously. It might be easier if they did it top
to bottom since data comes in top to bottom, and
that requires no buffering.
bob@coolgroups.com wrote:
> I was just wondering if LCD monitors typically try to refresh
> everything simultaneously. It might be easier if they did it top
> to bottom since data comes in top to bottom, and
> that requires no buffering.
>
There is a description here, of how LCD elements are driven.
Page 14 shows a thin film transistor, controlling the charge
on the cell. It would suggest one line is loaded at a time.
If you had a 1280x1024 display, then 1280 wires would allow
setting the state of 1280 elements in one line. Then move
on to the next row. The cell holds the charge until the next
pass. For a constant cell light passing state, there is a
pure AC waveform across the cell - the voltage across it has
to alternate between +Vapplied and -Vapplied, (i.e. on
alternating scans), in order to prevent a net DC waveform
content from destroying the chemistry.
For a good review of some of the crazy things they do inside
LCD designs now, try this article. Some of the techniques used
are not "Photoshop-friendly", and monitors with "fake" high
contrast ratios, cannot be calibrated. Any monitor that
fiddles with the backlights, based on the image content, is
not a candidate for Photoshop. On the other hand, the info
on LED based displays looks interesting. LED illuminated displays
should be better for Photoshop, although claims elsewhere are that
they'll be more expensive and burn more power. (But a LED can
also be fiddled to get the "fake" high contrast, so what you'd
want is a claim of LED illumination, and a contrast ratio of no
more than 500:1.) I thought we'd see more of these LED based LCDs
by now. I guess price competition is what determines the technology,
as no manufacturer would want to do the necessary R&D if only
0.005% of the users will buy them. Everybody wants a $200 monitor :-)
LCD monitors 
Linear Mode
