88242361-04-01 Vol 1 DEK TQ TECHNICAL REFERENCE (1) - 第125页
8 SQUEEGEE MODULE 8.1 OVERVIEW TECHNICAL REFERENCE MANUAL DEK TQ 04/2021 125 8.1.2 Paste Roll Height Monitor (PRHM) 8.1.2.1 Laser Safety C AU T I ON R AD I A T IO N. RI S K OF I NJ U RY T O T H E E Y E S D U E T O L A S …
8 SQUEEGEE MODULE
8.1 OVERVIEW
124 TECHNICAL REFERENCE MANUAL DEK TQ 04/2021
The pressure being applied during the print stroke is measured by a load cell (located in the spring
beam assembly of the squeegee mechanism) and if necessary, a correction to the pressure is
made by the software. The electronics for monitoring the squeegee pressure (load cell) is on the
conditioning board which is detailed in 7.1.1
"Conditioning Board" [}115].
8.1.1 Sensor Locations
1
3
2
5
4
View on Rear of Squeegee Mechanism
1 Rear Squeegee Home Sensor 4 Paste Roll Height Monitor Sensor
2 Load Cell 5 Front Squeegee Home Sensor
3 Spring Beam Assembly
8 SQUEEGEE MODULE
8.1 OVERVIEW
TECHNICAL REFERENCE MANUAL DEK TQ 04/2021 125
8.1.2 Paste Roll Height Monitor (PRHM)
8.1.2.1 Laser Safety
CAUTION
RADIATION. RISK OF INJURY TO THE EYES DUE TO LASER LIGHT BEING
PRESENT IN THE VICINITY OF THE LABEL. DO NOT LOOK AT THE LIGHT
SOURCE OR REFLECTIONS FROM A SURFACE.
CAUTION
EQUIPMENT SERVICING. THE LASER DOES NOT CONTAIN USER
SERVICEABLE PARTS. OPENING THE UNIT COULD CAUSE MIS-ALIGNMENT
OF THE LASER, THIS MAY MAKE THE EQUIPMENT DANGEROUS TO
OPERATE.
CAUTION
LASER CONTROLS AND ADJUSTMENTS. USE OF CONTROLS OR
ADJUSTMENTS OR PERFORMANCE OF PROCEDURES OTHER THAN THOSE
SPECIFIED HEREIN MAY RESULT IN HAZARDOUS RADIATION EXPOSURE.
This module uses a Class 1 laser light source which in normal use does not represent a significant
risk of eye injury. When switched ON, the user should not stare directly into the laser light or at re-
flections from the light targeted surfaces for long periods.
Laser
1
IEC 60825-1:2014
Laser
1
IEC 60825-1:2014
8 SQUEEGEE MODULE
8.1 OVERVIEW
126 TECHNICAL REFERENCE MANUAL DEK TQ 04/2021
8.1.2.2 Purpose
The PRHM monitors the amount of paste on the stencil during the rearward print stroke. This is
achieved by using a laser beam to measure the top of the paste roll. As the software knows the dis-
tance to the stencil, it can calculate the height of the paste roll.
The system can:
●
Suspend print if too much paste is detected
●
Suspend print if too little paste is detected
●
Warn when a user defined lower limit is reached
If, combined with an automatic paste dispenser it can also add paste, independent of pre-defined
paste management settings (see Note below)
NOTE
If a PRHM is fitted and enabled and a paste dispenser is fitted and enabled the dispense rate para-
meters are ignored. PRHM determines when paste is dispensed by the height set in the minimum
paste warning parameter.
8.1.2.3 PRHM Assembly
The PRHM assembly consists of a laser photoelectric sensor mounted on the squeegee mechan-
ism. The laser is angled allowing the sensor to project the laser beam between the squeegees to
the paste roll.
Laser
1
IEC 60825-1:2014
3
4
1
2
View on Right Hand Side of Squeegee Mechanism
1 Laser Photoelectric Sensor 3 Laser Emitter
2 Paste Roll 4 Laser Receiver