The below are short excerpts from 'extremetech.com'. interesting site:
It seems to explain why some have observed excess blurring
during moving images. Also mentions contrast.
_____________________________________
Speed
LCD displays have an inherent lag between the time that a cell is switched, and the time that the
change is visible. This is a result of the fact that the liquid crystals must actually move within the cell,
and this movement takes time. This puts LCDs at a distinct disadvantage compared with CRTs (and DLPs) when
displaying fast-moving images, such as scrolling data or movies.
___________________________________________________
DLP:
One advantage of these panels is that they have extremely fast response times. It is possible to
have individual pixels turn on or off many times during the projection of just one image frame. This
makes it possible to create a full-color image with one panel, using a field-sequential procedure.
First, green light shines on the panel, and the mechanical mirrors are adjusted to display the
green pixel data of the image. Then the mirrors are adjusted again for the red and blue pixel data
of the image. (Some projectors get extra brightness by using a fourth, white field to add more
light to the white and lighter shades of colors in the image.) All this happens faster than the
human eye can see, and the separate fields are combined in the brain where they are perceived
as a single, full-color image.
DLP panels have high resolution and have proven to be extremely reliable. They also have roughly
twice the contrast of polysilicon LCD projectors, making them more effective in bright room settings.
Disadvantages
There are few problems with DLP, but they are more expensive than polysilicon panels.
Field-sequential images can appear to break up into different colors if you look from one spot on
the screen to another, especially if the image has small white objects on a black background. In
projector applications, the motor used to spin the color wheel can be a noisy distraction, but
there are new, solid-state color filter systems coming on the market that are silent, which would
eliminate this problem.
____________________________________________
LCOS:
Panels are of moderate cost with relatively fast response times. It is
possible that the prices for these panels could be reduced greatly, especially if demands permits
production in large volumes.
Disadvantages
One of the weaknesses of LCOS displays is that they do not have the high contrast seen in DLP
images. Some are designed for field-sequential illumination--as used with single-panel DLP
applications--but others either rely on combining the image of three separate panels, or use color
filters and triple the number of pixels for a given resolution.
------------------
Jim Story
Live long and Prosper
It seems to explain why some have observed excess blurring
during moving images. Also mentions contrast.
_____________________________________
Speed
LCD displays have an inherent lag between the time that a cell is switched, and the time that the
change is visible. This is a result of the fact that the liquid crystals must actually move within the cell,
and this movement takes time. This puts LCDs at a distinct disadvantage compared with CRTs (and DLPs) when
displaying fast-moving images, such as scrolling data or movies.
___________________________________________________
DLP:
One advantage of these panels is that they have extremely fast response times. It is possible to
have individual pixels turn on or off many times during the projection of just one image frame. This
makes it possible to create a full-color image with one panel, using a field-sequential procedure.
First, green light shines on the panel, and the mechanical mirrors are adjusted to display the
green pixel data of the image. Then the mirrors are adjusted again for the red and blue pixel data
of the image. (Some projectors get extra brightness by using a fourth, white field to add more
light to the white and lighter shades of colors in the image.) All this happens faster than the
human eye can see, and the separate fields are combined in the brain where they are perceived
as a single, full-color image.
DLP panels have high resolution and have proven to be extremely reliable. They also have roughly
twice the contrast of polysilicon LCD projectors, making them more effective in bright room settings.
Disadvantages
There are few problems with DLP, but they are more expensive than polysilicon panels.
Field-sequential images can appear to break up into different colors if you look from one spot on
the screen to another, especially if the image has small white objects on a black background. In
projector applications, the motor used to spin the color wheel can be a noisy distraction, but
there are new, solid-state color filter systems coming on the market that are silent, which would
eliminate this problem.
____________________________________________
LCOS:
Panels are of moderate cost with relatively fast response times. It is
possible that the prices for these panels could be reduced greatly, especially if demands permits
production in large volumes.
Disadvantages
One of the weaknesses of LCOS displays is that they do not have the high contrast seen in DLP
images. Some are designed for field-sequential illumination--as used with single-panel DLP
applications--but others either rely on combining the image of three separate panels, or use color
filters and triple the number of pixels for a given resolution.
------------------
Jim Story
Live long and Prosper
