1-6
D4K25 Service Manual
020-100880-01 Rev. 1 (06-2012)
Section 1: Introduction
1.6
Lamp
The Xenon arc lamp resides in the rear left hand side of the projector. Replacing a lamp requires the low-
security key for unlocking the lamp door. The lamp is mounted so that its rear (cathode) end is free to move via
an automatic adjustment mechanism, but its front (anode) end is stable. The front end of the lamp rests in a
supporting “cradle” or yoke, which can be located approximately 1" forward or back to accommodate longer
(2.0kW and 3.0kW CDXL) vs. shorter (3.0kW CDXL-30SD) lamps. An anode clamp secured to the end of the
lamp protruding beyond this yoke conducts current from the igniter. Good contact between this clamping collar
and the anode end of the lamp is essential for lamp ignition and performance, thus the materials and design
resist deformation caused by the high voltages. With the simple yoke support at the front, the rear of the bulb is
free to move up-and-down (Y-axis adjustment), side-to-side (X-axis adjustment) and forward-or-backward (Z-
axis adjustment) within the necessary ranges for optimized lamp position. These motorized movements are
controlled at the TPC using the LampLOC
™
Do Auto
feature in the
Advanced Setup>LampLOC Setup
window. Generally, the
Do Auto
positioning is adequate for all installations. Alternatively, individual arrow
buttons in this same menu can be used to move the lamp in one direction (and along one axis).
1.6.1 LampLOC
™
Module
The electro-mechanical LampLOC
™
module or lamp adjuster adjusts the lamp along three axes to optimize the
lamp position relative to the reflector. With the lamp “aimed” properly, the greatest amount of light will be
collected by the reflectors and used in the optical system. All adjustments are motorized using three stepper
motors on the LampLOC
™
module controlled by the nearby Integrated Motor Control Board (IMCB) under
command of TPC software. Feedback from the Light Sensor Module indicates where the light output is
maximized, terminating the lamp movement. In case of an electronics failure, the motors can be controlled
manually with thumbwheels (service technician required, as the rear panel of the projection head must be
removed).
1.6.2 Lamp Reflectors
A pair of glass reflectors-elliptical (rear) and spherical (front)-work together to efficiently collect the lamp light
output and direct it to the optics in the projector. Each reflector mounts to a single common cast and machined
mounting plate using four stainless steel spring clips that minimize stress points. Reflector shapes and coatings
are optimized for maximum brightness. A spun aluminum shield in the same basic shape as the rear reflector is
mounted coaxially with it, essentially covering the outside surface of the reflector and providing a consistent
gap for air flow. High temperature black paint on the inside of the shield absorbs the IR and UV light passed
through by the reflector. Holes in the reflector mount allow cooling air to pass through to the inside of the front
reflector and on to the lamp anode.
