F-Theta Lens - RAYLASE MINISCAN II Manual

Chapter 4
4.2
The F-Theta lens is specially designed for use with two-axis deflection units. It focuses the
laser beam at optimum quality on any position in the marking field. At the same time, it pro-
vides partial optical compensation for the barrel-shaped distortion that is unavoidable when
using a two-axis deflection unit. The remaining distortion (see below) must be compensated
by the deflection unit drive.
Fig. 3
Field distortion
with and without

F-Theta lens

Distortion caused by two-mirror
deflection.
Fig. 4
Example: F-
Theta lens for
Nd:YAG
1 Lens element incl. lens
2 Protection window
Assembly instructions
o Before assembly, check the lens and the protection window for dirt, scratches or cracks.
-
-
o Screw the lens into the beam output on the deflection unit until it is positioned securely.
16 RAYLASE 2-Axis Subsystems for Laser Beam Deflection
For deflection units fitted with an F-Theta lens only
F-Theta lens
If the optics is dirty, it must be cleaned ( page 22, Instructions for cleaning lenses and
protective glasses).
An element with a scratched or cracked lens and/or protection window must be
replaced. If necessary, the protection window can be replaced separately.
Distortion caused by F-Theta
lens.
3 Clamp ring
4 Protective cap
Functional description
Distortion caused by two-
mirror deflection and F-Theta
lens.
MN072 / v1.0.0