Test For 3-Axis Scan Systems With F-Theta Objective - Scanlab RTC 5 PC Interface Board Installation And Operation Manual

Procedure:
(1) Adjust the correct mechanical distance between
the scan system and the z = 0 working plane and
– if applicable – the correct distance between the
varioSCAN and the scan system
(2) Load the desired 3D correction table via
load_correction_file and assign it via
select_cor_table.
(3) Use the command get_head_para
the assigned coefficients A, B and C.
For the varioSCAN FC (also with an intelliWELD
steps (4) to (7) don't need to be performed. In this
case, proceed directly to step (8).
(4) Use the command goto_xyz
spot to the reference point
(5) Place a test object at the reference point.
(6) Use the command load_z_table(0, 0, 0) to set
the Z axis to the neutral (middle) position.
(7) Now adjust the laser focus
– with a varioSCAN or a varioSCAN
adjusting the focusing ring
– with a varioSCAN
FLEX
optic's position via the command move_to.
(8) Move the focus to an arbitrary point (x|y|z)
within the required image space using the
(3)
command goto_xyz .
(9) Use the command get_z_distance
focus length value l (in bits) set by the RTC
(4)
this point .
(10)Optimize the laser focus at this new location.
Therefore, use the command
load_z_table(A=z , 0, 0) to vary the Z output
out
value z until the quality of the laser focus
out
meets your requirements
(1) See the corresponding 3-axis scan system's or the varioSCAN's
user manual.
(2) The reference point's coordinate values (in mm) are provided in
the "Readme.txt" file that accompanies your 3D correction file
or in the 3-axis scan system's or the varioSCAN's user manual.
If you are using an F-Theta objective, the reference point is
generally the origin (0|0|0)
the z = 0 working plane for which a middle focus length value
is required for a sharp laser focus. The laser beam shall be
focused to the reference point when the Z axis is set to the
neutral position (Z output value z
(3) If you are using a scan system with an F-Theta objective, it is
sufficient to select various points (0|0|z) on the Z coordinate
axis. The maximum possible working volume is specified in the
corresponding user manual.
®
RTC 5 PC Interface Board
Rev. 1.9 e
8 Advanced Functions for Scan Head and Laser Control
(1)
.
to read out
®
FC),
to move the laser
(2)
.
by manually
de
by adjusting the focusing
to query the
®
5 for
(5)
.
. The reference point is a point in
= 0).
out
(11)Repeat steps (8) through
tions (x|y|z) as possible
values (l|z ) for each new point. If possible,
out
seek to thereby cover the entire working space
required by your application.
(12)Fit your set of (l|z ) values to a function of
out
the type z = A + Bl +Cl
out
(13)Use the resulting coefficients A, B and C to adjust
the 3D correction table via load_z_table(A, B, C).
(14)Values loaded via load_z_table
written by a subsequent
command (load_correction_file
coefficients A, B and C to the default values of the
(7)
loaded correction table
load_correction_file, you should therefore also
call load_z_table(A, B, C) again.
Test for 3-Axis Scan Systems with F-Theta
Objective
• With the adjusted 3D correction table, mark two
identical large squares using 3D vector
commands (see page 172). Mark one of the
squares with the work piece in Z-position
z = z , the other one with z = z
min
• These two squares should match exactly. If this is
not the case, your correction file is not perfectly
suited to your objective. To solve this problem,
measure the size (x and y) of both squares and
report these values to SCANLAB. You will then
receive a new 3D correction file.
(4) The focus length value l can be positive or negative.
(5) The optimal z output value can be positive or negative.
out
When seeking the optimal laser focus, you can calculate a
starting value in accordance with A + Bl +Cl
previously read focus length value l and the previously read or
used values A, B and C.
(6) Note that larger z control values lead to shorter working
distances and that the focus will thereby shift toward the scan
system. The test object might have to be tracked accordingly.
(7) Each 3D correction table calculated by SCANLAB contains
values for the coefficients A, B and C (also see the respective
"Readme.txt" file or get_table_para).
(10) for as many loca-
(6)
and write down the
2
.
will be over-
load_correction_file
sets the three
). After each
.
max
2
by using the
175