Agilent Technologies 5DX - Laser Theory of Operation

7-8 Surface Map Subsystem
Surface Map Subsystem Components 5DX Series 3
Laser Theory of Operation
To develop a Surface Map of a panel reference point, the Laser measures the panel
surface by finding the linear displacement (actual location) of the small point of
projected laser light. The laser spot is imaged by a miniature lens built into the
sensor. The lens focuses the laser spot onto a position sensitive detector that
indicates the linear displacement as the panel is moved up and down in the Z-Axis
(positions Z
1
, Z
2
and Z
3
), as shown in Figure 7-4.
Figure 7-4: Laser Theory of Operation
z
1
z
2
z
3
LASER
I / O INTERFACE TO THE
(MX1A) AMPLIFIER UNIT
LENS
AND SYSTEM CONTROLLER
Z
Z
DETECTOR ARRAY
LENS
z
1
z
2
z
3
z
1
z
2
z
3
DETECTOR
ARRAY
(View of Laser Spot at Different Z-Height Locations)
DETECTOR