|
Home
> DLP vs LCD
DLP vs LCD Projector Technology
Projectors can be broadly catogorised
into two technologies, DLP (Digital Light Processing) or LCD (Liquid
Crystal Display). This refers to the internal mechanisms that the
projector uses to compose the image.
LCD
and DLP each have unique advantages over one another, which is why
its important to understand what each of the technologies has to
offer.
DLP
Projector Technology
Digital
Light Processing™ is the world's only all-digital display
solution. DLP™ technology uses an optical semiconductor, known
as the Digital Micromirror Device, or DMD chip to recreate source
material.

Advantages
of DLP
- Less
'chicken wire' (or 'screen door') effect because pixels are much
closer together. This doesn't make so much difference with data,
but it produces smoother images for video. A comparrison of an
LCD and DLP projection to illustrate the 'screen door' or 'chicken
wire effect on LCD projections.
- Higher
contrast achievable.
- DLP
projectors are generally more poratable as fewer components are
required.
- It
has been claimed that DLP projectors last longer than LCD projectors.

Disadvantages of DLP
- Less
colour saturation (more of a problem with data than video)
- The
'rainbow' effect, appearing as a momentary flash of rainbow-like
striping typically trailing the bright objects when looking from
one side of the screen to the other, or when looking away from
the projected image to an offscreen object. Only some people see
this effect, or you can create it for yourself by moving your
eyes very quickly across the screen. There are two types of DLP
projector - the old ones had four segments on the colour wheel,
the new ones have six and spin faster, which means less rainbow
effect and more saturated colour.
- The
'halo' effect (or 'light leakage'). It may bother some people
using their projector for home cinema. Basically it's a grey band
around the outside of the image, caused by stray light being bounced
off the edges of the tiny mirrors on the DLP chip. It can be a
distraction, but can be overcome by having a black border a few
inches wide around the screen, so the halo falls on to the border.
However the halo effect is less evident in the newer DLP chips
such as the DDR chip
- Generally,
DLP is a better technology for home theatre than LCD . Some of
the more home theatre-oriented projectors have virtually no halo
effect.
LCD Projector Technology
LCD (liquid crystal display) projectors contain three separate LCD
glass panels, one for red, green, and blue components of the image
signal being transfered to the projector. As the light passes through
the LCD panels, individual pixels can be opened to allow light to
pass or closed to block the light. This activity modulates the light
and produces the image that is projected onto the screen.

Advantages of LCD
- LCD
is generally more 'light efficient' than DLP (ie. the same wattage
lamp in both an LCD and DLP would produce a brighter image through
the LCD).
- LCD
tends to produce more saturated colours. However, the colours
being more saturated makes people perceive the projector to be
brighter overall, even though the DLP white may be brighter.
- Hence,
with a data signal, if you put a 1000 lumen LCD next to a 1200
lumen DLP and showed a colour image people would probably prefer
the LCD for brightness.
- LCD
tends to produce a sharper image (ie. more precisely focused).
This can actually be a bit of a disadvantage for video, where
it makes the pixellation more obvious.
Disadvantages
of LCD
-
Chicken wire effect causing the image to look more pixellated.
- Generally
more bulky, as there are more internal components.
- 'Dead
Pixels' - Pixels can become permanently on or permanently off,
while this is barely noticeable with one dead pixel, if the projector
develops multiple dead pixels it can be a irritation.
- LCD
panels can fail, and are very expensive to replace. DLP chips
can also fail but as there are fewer parts in a DLP projector
this is relatively rare.
Conclusion
DLP projector technology is generally preferred for home cinema
and portablity. However there has recently been developments within
the LCD projector home cinema catagory, some models are now claiming
contast rations of up to 10,000:1!
LCD projectors are generally better where colour reproduction is
critical, although DLP projectors are working towards a much better
colour accuracy.
There are some great LCD and DLP machines availble on the market,
and the technology for both is always improving. If you are still
unsure please contact us.
Our staff are on hand to advise you, offering an unbias opinion
on the projectors that would be suitable for the application you
have in mind.
|