Datasheet

E3ZM-B
9
Technical Descriptions
New Technology for Detecting Transparent Objects Exhibiting Birefringence
P-opaquing (Polarization-opaquing)
Conventional photoelectric sensors for detecting PET bottles
depend on refraction due to the bottle's shape or on the
attenuation of light intensity caused by surface reflection.
However, it is difficult to attain a sufficient level of excess gain
with these methods.
The E3ZM-B utilizes the birefringent (double refraction)
property of PET bottles to dramatically increase the level of
excess gain. The polarization component that is disturbed by
the PET bottles as they pass along the line is cut by a special
and unique OMRON polarization filter. This greatly lowers the
intensity of the light received to provide stable detection with
simple sensitivity adjustment.
“P-opaquing” is a word that was coined to refer to the process
of applying polarization in order to opaque transparent objects
that exhibit the property of birefringence.
The excess gain of the E3ZM-B is doubled for both light-ON
and dark-ON applications.
The excellent stability of the E3ZM-B prevents malfunctions
from occurring even if something causes the intensity of light
received to fluctuate by ±50%.
New Technology for Achieving Long-term Stability
AC
3
(AC cube: Auto Compensation Control for Contamination) (Not available on the E3ZM-B@T)
Conventional photoelectric sensors with built-in amplifiers
are not equipped with functions to compensate for changes
in the intensity of light received caused by dust and other
lens-soiling matter, ambient temperature, and changes that
occur in the LED over time. This makes it comparatively
difficult to achieve long-term, stable detection of objects that
exhibit little change in the intensity of light received, such as
transparent objects.
The AC
3
(AC cube) function provided on the E3ZM-B
periodically feeds the intensity of light received during light-
ON operation back to the light-emitting circuit, to keep the
intensity equal to the value set by teaching.
This allows the E3ZM-B to attain long-term, stable detection
while helping to cut down on maintenance requirements and
improve the equipment operating ratio.
Note: The AC
3
function cannot be used for dark-ON operation.
Patented
30%
E3ZM-B E39-RP1
Special
polarization filter
Polarization component
disturbed by birefringence
Conventional sensor Conventional reflector
Attenuation only from
the PET bottle shape,
refraction, and transmissivity
80%
0
Without
PET bottle
With
PET bottle
Minimum interrupted light level
Threshold
Light ON
excess gain = 2x
Incident level
while teaching
Dark ON
excess gain = 2x
Relative intensity
of light received
100%
50%
25%
Patented
No light-receiving compensation
Conventional sensor
Sensitivity adjustment
Time
Threshold
Intensity of light received
Intensity of light received is compensated every 30 s.
E3ZM-B
Teaching
Setting
Time
Intensity of light received
30 s
Restores
setting