Operation Of The Galvo System??Not An Official Name?Any Ideas - Kodak DirectView CR 800 System Theory Manual

Operation of the GALVO System??not an official name?any ideas?

The main purpose of the GALVO system is to rotate a mirror to cause the beam of the LASER to scan across the PHOSPHOR PLATE (fast scan), do a quick retrace,
and scan another line until the entire plate has been scanned.
In its simplest form, the operation of the GALVO system is a feedback system in which the desired position of the GALVO ??SHAFT, MIRROR ?? is compared to its
actual position in the rotation??motion??, and corrections are made to keep the GALVO, hence the beam of the LASER, focused on the exact spot of the STORAGE
PHOSPHOR PLATE at the expected time.
Simple block diagram of the Digitizer BD, inputs to the GALVO
the GALVO and the deflected beam of the LASER on a
target (PLATE)
9–40
A3 DIGITIZER BD The DIGITIZER BD is a key player in that it controls the
operation of the GALVO BD to sweep the beam of the
LASER as well as the PMT/DAS BD to collect the
image data off the scanned PHOSPHOR PLATE.
GALVO The GALVO consists of a motor that rotates a SHAFT
with a MIRROR at the end that deflects the beam of the
LASER onto the PHOSPHOR PLATE.
A4 GALVO BD The GALVO BD contains an extremely accurate
feedback circuit for controlling the position of the
MIRROR ?OR SHAFT?, hence the beam of the
LASER. Inputs to the GALVO BD which define the
desired position of the MIRROR include:
• Clock signal from the DIGITIZER BD which starts,
continues, and stops a 13 bit counter that keeps
track of the ????.
• Current PLATE size from the DIGITIZER BD (per
the barcode on the PLATE).
• Offset (start) and amplitude (how far) values for the
particular PLATE size, which were set up in
calibration.
Input from position sensors determine exactly where in
the sweep the GALVO SHAFT is, the actual position.
The actual position is compared to the desired position
and any error is corrected for to ensure a smooth sweep
of the beam.
Output of the GALVO BD are line start signals to the
DIGITIZER BD to say that a line is complete and it is
able to start another.
12/12/94 – 1234563