Service manual

LUMISCAN ACR-2000 SERVICE MANUAL - SECTION 8.0 REPLACEMENT PARTS
8 - 6
4. Connect the interlock cable to the interlock switch.
5. Reinstall the Galvo PCA.
Refer to Section 5 “Final High Voltage Adjustment and Reference LED Adjustment” to set the high
voltage and Blue LED.
Occasionally after replacing the laser module the spot size is adversely affected resulting in poor image
resolution. The fiber optic tip not being inserted correctly into the connector on the lens barrel
assembly often causes this. If there is a resolution problem it is always best to confirm that the
connection between the fiber optic cable tip is keyed correctly. If you are confident that the fiber optic
tip is placed correctly in the connector and resolution is still poor then it may be necessary to re-focus
the beam.
FOCUSING THE LASER
Focusing the laser beam is never done as part of a standard PM. The beam spot is set at the factory
and will not change without a preceding event such as changing the laser itself. Gain, laser power and
cleanliness could all effect resolution quality. Never re-focus the laser without consulting a member of
the Lumisys Technical Support Staff.
An oscilloscope, a very dim light environment, a non shedding cloth (preferably an opaque photographic
shroud) to drape over the machine and a red Lumisys QA pattern are required for this procedure.
1. Remove the main enclosure, place a cheater key in the interlock, dim the lights and cover the
reader with the opaque cloth.
2. Connect channel one of the scope to SIG (TP1) and sync off SOS (TP8).
3. From the tools directory Run ddt option 20.
4. On the lens barrel assembly the two set screws that are nearest the fiber cable end of the assembly
secure the F/C connector in the barrel assembly preventing it from moving.
5. Loosen these two set screws with a 1/16” hex-head wrench such that they are still putting a small
pressure on the F/C connector. This pressure will help with control during the minute changes you will be
making during the focusing procedure. Furthermore if the set screws are too loose focus will probably
be effected when you retighten them.
6. Place the red Lumisys QA test pattern in the reader such that a block set of three line pair patterns are
in the beam path. Notice that there are three distinct, side by side traces representing the three different
line pair densities with three different amplitudes. The tightest line pair pattern will have the smallest
amplitude.