TM
USING Deuce VIDEO SCALERS TO
MATCH THE SWEET SPOT OF CRT
PROJECTORS IN HOME THEATERS
MARKET: Home Theater
DOC. NUMBER: T-14
Despite advances in LCD / DMD type technologies, CRT
projectors remain the preferred technology for home the-
ater video displays due to their ability to produce a smooth,
natural image. A major problem with home theater instal-
lations is that the large screen sizes utilized accentuate
the weakness of the image quality of standard definition
TV signals (SDTV). Projecting any SDTV signal (NTSC,
PAL or SECAM) will result in the display of dark horizontal
scan lines since these are interlaced signals. To remove
these scan lines and present a good quality image, the
SDTV signal must be changed to a high resolution, pro-
gressive scan image.
Every CRT projector has a “sweet spot”: this is the
resolution at which the projector provides the brightest and
sharpest image possible. It is important to realize that the
sweet spot resolution is not necessarily the highest reso-
lution that the projector is capable of displaying.
This TECHnique will describe how Deuce
®
Intelligent
Video Scalers allow the user to match the sweet spot of
any CRT projector to provide the optimum image in a home
theater installation.
CRT) and the screen size. It is important to understand
that the sweet spot of any given projector is different for
various screen sizes. For example, a certain projector’s
sweet spot could be 800 x 600 for a 60 inch screen. For
this same projector, the sweet spot for a 100 inch screen
could be 1024 x 768.
Home theater installers attempt to optimize the screen
dimensions for the size of the theater room and the capa-
bilities of the specified projector (CRT size). Then, once
the screen and projector are installed, they can determine
the projector’s sweet spot for that particular set-up.
Standard TV signals (SDTV) vary in detail around the
world, but all the current standards — NTSC, PAL or SECAM
— have main characteristics that need to be changed in
order to match the sweet spot of any projector. Specifi-
cally, SDTV signals require de-interlacing and an increase
in refresh rate and resolution.
So, what is the best method to convert these various
SDTV signals to a suitable signal for the CRT projector?
Video scaling. It’s the superior method to convert SDTV
signals to match the sweet spot of any CRT projector.
®
uses sophisticated processing algorithms to ma-
nipulate the image, thereby changing the resolution, re-
fresh rate and aspect ratio to exactly match the native
resolution of any given display. In addition, Deuce
®
pro-
vides advanced motion compensation to eliminate the dis-
tortions that result from the de-interlacing process.
Different Deuce models provide for a variety of output
formats and resolutions. (Refer to the comparison chart
for specifics.) Plus, Deuce
®
allows for the output of either 4:3
ratio images or full 16:9 ratio capability. Most home the-
aters are designed to project both the standard 4:3 and the
16:9 ratios.
CRT projectors have a wide range of input signal com-
patibility. However, the best quality image — the sharp-
est and brightest image possible — is achieved when the
source signal matches the “sweet spot” resolution of the
projector.
The sweet spot of a given projector is determined by a
combination of the projector’s CRT size (7,8, or 9 inch
Select the Deuce model that is best for you by comparing
the native resolution of your intended display device with
the output resolutions offered by the various Deuce
models. Also, keep in mind whether you will ever want to
output to a widescreen display device. All models except
for Deuce SDQ output to both 4:3 and16:9 ratios.
Each Deuce model is designed to offer certain performance
advantages. Deuce MC offers the most control over
Deuce is a registered trademark of Communications Specialties, Inc.
© 2000, Communications Specialties, Inc.