Barco OverView D Series, Руководство пользователя

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3. Design and functions
Barco - OverView D series - Doc-3353-2 - user's manual - Revision 04 - April 2005
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In Hot Standby both lamps are on. In case of a lamp failure, the light output of the other lamp is immedi-
ately switched to illuminate the optics, and there is no noticeable effect on the displayed information: no
loss of information, no impact on quality. Switching time is about half a second.
In
Cold Standby mode the second lamp is only switched on in case a failure occurs with the active lamp.
Since the second lamp needs about one minute to reach a stable operating temperature, at the beginning
the display will have reduced brightness. The contents of information, however, is available nearly without
any interrupt.
Auto Switch mode is a special version of the cold standby mode: the lamps are active in turns during a se-
lectable cycle time. Alternatingly the light path is illuminated by Lamp top or lamp bottom. Since the lamp is
switched on some minutes in advance, the takeover of the other lamp is nearly not noticeable. The cycle
time can be set between 12 hours and 500 hours.
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Color wheel
The color wheel consists of four segments, one for red, green, blue and white. For XGA and SXGA resolution,
it spins at triple speed (178 Hz), for SXGA+ resolution it spins at double speed.
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DMD
A Digital Micromirror Device (DMD™) is an array of tiny, tiltable mirrors, each of which corresponds to an in-
dividual pixel. The mirrors are orientated by applying an electrical signal and can take up alternatively two
positions: 12° (+10°) and -12° (.10°). If they are in the +10° position light is reflected to the screen,
otherwise it is reflected away. The tilting angle as well as the dimenesion of the DMD chips and the number
of active mirrors depends on resolution.
DMD is a trademark of Texas Instruments Incorporated.
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Electronics
The electronics comprises graphics and video signal processing electronics as well as the functionality to
control the projection engine.
The electronics converts the image signals of the graphic card into control signals for the DMD’s. The image is
electronically mirrored in the process and the reversal of the image following the deflection mirror is thus
compensated.
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Data cable
The digital display information is transmitted via a cable directly from the controller to the DMD control elec-
tronics.
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Lens system
The projection lens system has been especially developed for O
VER
V
IEW
D. It projects the image resulting of
the DMDs via the deflection mirrors onto the rear of the screen module.
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Fan
A fan in the housing ensures that the unit is sufficiently cooled. A second fan positioned beneath the lamp
lift optimizes the air circulation.
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Deflection mirror
Due to folding up the optical path by a mirror the installation depth of the O
VER
V
IEW
D projection unit is ex-
ceptionally small.