Projection Type (Front Projection) - JVC DLA-G20 Sales Manual

Stacking system
3. DLA-M4000 multi-system (side by side)
Horizontal side-by-side placement of two DLA-M4000s is a
basic requirement for a DLA-M4000 multi-system. Two
DLA-M4000s are arranged horizontally and project images
directly on the white screen. What is most essential for
the multi system is the brightness on the screen and
difference in color tone. According to our research so far,
two horizontally placed DLA-M4000s can obtain the actual
use level as a multi system. In rear projection
configurations, screen characteristics are especially
important.
As shown in the photo, both the brightness and
tone reach the usage level. As a shading adjustment
function for dark sections (not provided with the DLA-
G10/G15/G20 ) has been added to the DLA-M4000,
brightness can be adjusted to less than 10 with Eab at
each point.
4. DLA-G15 multi system (2 units put side by side)
As with the DLA-M4000 multi-system, two horizontally
placed DLA-G15s are required. With this system, the
screen characteristics are also very important. In
particular, different viewing angles can produce variations
in illumination and color tone depending on the screen
characteristics. The DLA-G15 is affected by
manufacturing characteristics (optical characteristics,
especially D-ILA shading characteristics) because it is a
general projector. Check the characteristics before
shipping when selecting a projector for a multi-system.
<Reference for selection>
Compare R, G, and B shading adjustment data using the
PSA controller.
• Check that the dynamic shading adjustment data is
within 22% of unadjusted data.
• Make sure that each color has the same level.
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Reference: The performance of up to 3 horizontally
arranged units is ensured.

Projection type (front projection)

Front projection
Front projection systems project light directly onto a
screen. The reflected light appears as an image on the
screen. Typically, the projector is installed on a table or
suspended from the ceiling.
When external light is reflected on the screen, the
image contrast is lowered. As a result, it is common
practice to lower the lighting level during projection.
Thanks to the D-ILA multimedia projector's powerful light
output, however, projection is possible even in a relatively
Screen type
When it comes to determining the final picture quality of a
large-screen projection system, the quality of the screen
itself is often ignored. This is a mistake. Like the
speakers in an audio system, screen quality is essential in
determining the final result. Just as poor speakers will
result in poor sound, no matter how good the rest of the
audio system, so too will poor screen quality affect the
There are five basic types of front projection screen. General characteristics are shown below.
Standard Picture
Type Recurrence Visual field
gain (Gs) quality
The screen surface is white and there is almost no gain. As the angle of visibility is close to the
full diffusion of 180˚, this type is ideal for auditoriums and rooms with a theater-style layout since
White Reflectivity 1 Ultra wide the audience expands sideways as the distance from the screen increases. The benefit of a
white screen is more natural color reproduction if the room is dark or if the light output of the
projector is sufficient.
The screen surface is glossy pearl and the angle of visibility is around 30˚ for the left and right
(60˚ total). The picture quality is dynamic and beautiful. The gradation of black and color
Pearl Reflectivity 1.3 ~ 2.0 Wide reproduction are excellent and extremely high picture quality is obtained. Until recently, pearl
screens were the screen of choice when picture quality was a priority. Recently, however, a new
type of screen — beads screen — has been developed that offers comparable picture quality.
The screen surface is silver and the gain is extremely high, allowing pictures to be viewed in
relatively bright rooms. The field of view is limited, restricting the audience position. This type is
not suitable for large audiences.
Silver Reflectivity 3 ~ 4 Narrow
Hot spots are common and a curved screen is required. Picture quality is relatively low. This
type is suitable for special business applications (3D projection using a polarized light).
Using the characteristics of polarizing film, this reduces the effect of reflected external light. The
high contrast ratio can easily be maintained even in bright surroundings, making this type suitable
Polarized
Reflectivity 2 ~ 3 Middle for projection in situations where it is desirable to leave the lights on.
light
Care should be taken when using a polarized light screen because it is necessary to match the
polarized light projected from the projector with the characteristics of the screen.
Recurrence is the same as the lens effect of beads. The gain is high but the angle of visibility is
relatively narrow. Ghosts appear due to a stray light phenomenon. Focus is not sharp and
gradation is not smooth, resulting in soft picture quality. Recently, an excellent screen that
Beads Recurrence 2 ~ 3 Middle
eliminates these weak points has become available.
• The optimum screen differs depending on the situation. When selecting a screen, be sure to consider the advantages
and disadvantages of each screen type.
D-ILA Method Present Condition and Subject
bright environment. (Nevertheless, even with the D-ILA
projector, the less the external light reflection, the better
the image quality.) (Refer to the table on page 10.)
quality of the projected image. Although the D-ILA
multimedia projector's superior performance
characteristics enable it to achieve a high-quality picture
with any screen, choosing a high-quality screen with
characteristics suitable for the viewing environment will
assure optimum results. The information below will help
you select the most appropriate screen.
Characteristics
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