MQ-W
SERIES
Triple Beam Trigonometric
Area Reflective Photoelectric Sensors
Very accurate detection by triple beam triangulation sensing method in a compact package.
Environmental resistance
Immersion protected construction
(equivalent to IEC IP67)
High speed detection: Max. 2 ms
Light-ON/Dark-ON output is wire
selectable.
Operating voltage of 12 to 24 V DC
Adjuster and Indicators
Distance adjustment dial
Adjustment
indicator LED
(Comply with EMC directive MQ-W-EM type only)
* Original
Sensor
MQ-W3 type
MW-W20 type
Distance adjustment dial
Operation
Indicator LED
Adjustment
indicator LED
FEATURES
Accurate detection regardless of
color, material, or shape of objects
Area reflective type sensor can detect
white or black object at the same dis-
tance. In case of diffuse reflective type,
it is difficult to detect objects of various
color with the same sensitivity setting.
MQ-W area reflective type sensor is
useful for such a case.
No-miss operation regardless of
back-grounds
Area reflective type sensor does not
detect objects beyond the set range.
Resistant to lens surface soiling
Area reflective type sensor detects the
distance by the angle, not the intensity
of received light. Even if the lens sur-
face is soiled by dust or any powdery
material, there is a little variation of
sensing range.
MQ-W70 type
Operation
Indicator LED
SENSING RANGES
Sensing range (m
ft.)
0.03
.098
MQ-W3 types
MQ-W20 types
MQ-W70 types
0.2
.656
0.7
2.297
PRODUCT TYPE
Detection method
Range
Rated operating voltage Control output
NPN
0.03 m
.098 ft.
PNP
Triple beam area
reflective type
0.2 m
.656 ft.
PNP
NPN
PNP
Light source
Infrared LED
Red LED
Infrared LED
Red LED
Infrared LED
Red LED
Infrared LED
Red LED
Infrared LED
Part number
MQ-W3A-DC12-24V
MQ-W3AR-DC12-24V
MQ-W3C-DC12-24V
MQ-W3CR-DC12-24V
MQ-W20A-DC12-24V
*
1
CE types
MQ-W3A-DC12-24VEM
MQ-W3AR-DC12-24VEM
MQ-W3C-DC12-24VEM
MQ-W3CR-DC12-24VEM
MQ-W20A-DC12-24VEM
12 to 24 V DC
NPN
MQ-W20AR-DC12-24V MQ-W20AR-DC12-24VEM
MQ-W20C-DC12-24V
MQ-W20C-DC12-24VEM
MQ-W20CR-DC12-24V MQ-W20CR-DC12-24VEM
MQ-W70A-DC12-24V
MQ-W70C-DC12-24V
MQ-W70A-DC12-24VEM
MQ-W70C-DC12-24VEM
0.7 m
2.297 ft.
*
1
These suffix EM types conform to CE. These types have the grounding connection inside of housing
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03/2003
MQ-W
SPECIFICATIONS
1) Ratings
Operating side
Load side
Rated operating voltage
Rated current consumption
Output current capacity
12 to 24 V DC
30 mA or less (excluding load)
100 mA or less
2) Performance
Detection principle
Detection method
Type
Part number
Sensing range
Detectable distance
Standard target
Detectable target
Hysteresis
Operating voltage range
Response time (freq.)
Initial insulation resistance
Initial breakdown voltage
Vibration resistance
Shock resistance
Protective construction
Usable ambient
light level
Incandescent lamp
Sunlight
10% or less the set range
MQ-W3A-DC12-24V
MQ-W3AR-DC12-24V
MQ-W3C-DC12-24V
MQ-W3CR-DC12-24V
0.03 m
.098 ft.
0.02 to 0.04 m
.066 to .131 ft.
White drawing paper
1i1 cm
.394i.394 inch
Triple beam triangulation sensing method
Area reflective type
Amplifier selfcontained DC type
MQ-W20A-DC12-24V
MQ-W20AR-DC12-24V
MQ-W20C-DC12-24V
MQ-W20CR-DC12-24V
0.2 m
.656 ft.
0.04 to 0.2 m
.131 to .656 ft.
White drawing paper
2i2 cm
.787i.787 inch
Opaque, translucent
20% or less of the set range
9.6 to 30 V DC ripple (P-P) included
2 ms or less (250 times per second or less)
Min. 20 MΩ between a lead wire and external housing (at 500 V DC)
Between a lead wire and external housing: 500 Vrms for 1 min
10 to 55 Hz (1 cycle/min), double amplitude 1.5 mm
.059 inch
(2 h each on 3 axes)
980 m/s
2
{approx. 100 G} (6 times each on 3 axes)
Diecast case immersion protected (equivalent to IEC IP67)
10,000 lux or less
30,000 lux or less
–25 to 55°C
–13 to +131°F
(non-icing condition)
Max. 85% RH (non-condensing condition)
–25 to 55°C
–13 to +131°F
Operation indicator: Red LED ON with light entry
Adjustment indicator: Red LED ON with sufficient volume of lights
Infrared LED/Red LED (R is added to the suffix of W3(20)A(C) in the part No.)
MQ-W70A-DC12-24V
MQ-W70C-DC12-24V
0.7 m
2.297 ft.
0.2 to 0.7 m
.656 to 2.297 ft.
White drawing paper
7.5i7.5 cm
2.953i2.953 inch
Ambient temperature
Ambient humidity
Storage temperature
Indicator
Light source
Note: Unless otherwise specified, the measurement conditions comprise rated operating voltage, power supply by battery, 20°C
68°F
ambient
temperature, standard target and 200 lux or less illuminance on the receiver surface.
3) Output circuit diagram
NPN Output type
PNP Output type
03/2003
181
MQ-W
DATA
1. Operating range characteristics
MQ-W3 types
Operating
distance
(mm)
(ft.)
MQ-W20 types
Operating
distance (mm)
(ft.)
MQ-W70 types
Operating
distance (mm)
(ft.)
40
.131
For 40 mm
.131 ft.
Moving direction
Standard target
(white drawing paper
10×10 mm
.394×.394 inch)
For 30 mm
.098 ft.
For 20 mm
.066 ft.
200 For 200 mm
.656 ft.
.656
150 For 150 mm
.492 ft.
.492
Moving direction
Standard target
(white drawing paper 20×
100
20 mm
.787×.787 inch)
.328
For 100 mm
.328 ft.
50
.164
For 50 mm
.164 ft.
30
.098
20
.066
600
1.969
400
1.312
200
.656
For 700 mm
2.297 ft.
For 500 mm
1.641 ft.
Moving direction
Standard target
(white drawing paper 75×
75 mm
2.953×2.953 inch)
For 300 mm
.984 ft.
10
10
.394
5 0 5
.394
.197
.197
Operating range (mm)
(inch)
10
10
.394
5 0 5
.394
.197
.197
Operating range (mm)
(inch)
10
10
.394
5 0 5
.394
.197
.197
Operating range (mm)
(inch)
2. Projector beam diameter characteristics
Light beam diameter is determined as the region where the amount of light is decreased to 1/e
2
(e]2.72) when the largest amount of light is
assumed as 1.
MQ-W3 types
MQ-W20 types
MQ-W70 types
2.5 dia. 2.3 dia. 4.0 dia. (mm
.098
.091
.157
inch)
6.7 dia. 6.9 dia. 7.4 dia. 8.3 dia. (mm
.264
.272
.291
.327
inch)
23.0 dia. 33.0 dia. 39.0 dia. (mm
.906
1.299
1.535
inch)
0
0
20
.066
30
.098
40 (mm
ft.)
.131
50
.164
100
.328
150
.492
200 (mm
ft.)
.656
0
300
.989
500
1.641
700 (mm
ft.)
2.287
3 Detectable target characteristics
MQ-W3 types
MQ-W20 types
MQ-W70 types
700
2.297
Distance range (mm
ft.)
Distance range (mm
ft.)
600
1.969
500
1.641
400
1.312
300
.984
200
.656
Distance setting 40 mm
.131 ft.
0
100
1000
0.155
1.55
Target size (mm
2
inch
2
)
100
.328
0
1,000
1.55
10,000
15.5
Distance setting 200 mm
.656 ft.
Distance setting 400 mm
1.312 ft.
Distance setting 700 mm
2.297 ft.
Standard target
(white drawing paper 75×75 mm
2.953×2.953 inch)
Distance range (mm
ft.)
40
.131
Standard target
(white drawing paper 10×10 mm
.394×.394 inch)
Distance setting 40 mm
.131 ft.
30
.098
Distance setting 30 mm
.098 ft.
200
.656
Distance setting 200 mm
.656 ft.
Standard target
(white drawing paper 20×20 mm
.787×.787 inch)
Distance setting 100 mm
.328 ft.
100
.328
20
.066
Distance setting 20 mm
.066 ft.
0
100
10
0.155
0.015
Target size (mm
2
inch
2
)
Target size (mm
2
inch
2
)
4. Material characteristics
Comparision between MQ-W20A and former product
Condition: Target (40i60 mm
1.575i2.362 inch),
target assumed as natural shape
For the former product (diffuse reflective type),
depending upon the object material, the operating
range varied greatly, but for the triple beam type
there a little variation.
White drawing
paper
Corrugated
carton
Veneer panel
Black rubber
MQ-W3 types
Condition: Target (40i60 mm
1.575i2.362
inch),
natural shape
Glossy target Semi-glossy target Non-glossy target
White
drawing
paper
Black
drawing
paper
Veneer panel
Corrugated
paper
Black rubber
Copper clad
printed circuit
board
White acrylic
Blue acrylic
Mirror
MQ-W20 types
Condition: Target (40i60 mm
1.575i2.362
inch),
natural shape
Glossy target Semi-glossy target Non-glossy target
White
drawing
paper
Black
drawing
paper
Veneer panel
Corrugated
paper
Black rubber
Copper clad
printed circuit
board
White acrylic
Blue acrylic
Mirror
Former pruduct
Triple beam type (MQ-W20A)
×
Black frosted
×
finish
Copper clad
printed circuit
board
Aluminum
panel
Mirror
100
200
300
400
500
600
.328 .656 .984 1.132 1.641 1.969
Distance range (mm
ft.)
×
: Impossible
10
.033
20
.066
30
.098
40
.131
Distance range (mm
ft.)
50
100
150
.164
.328
.492
Distance range (mm
ft.)
200
.656
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03/2003
MQ-W
OPERATING PRINCIPLES
Detection principle of new triple beam area reflective series
$
Optical triangulation sensing method
The light beam projected by the LED,
passing through the condensing lens of
the light projector, is applied to the sur-
face of the target to be detected. One
part of the diffused reflected light rays
passes through the light receiver lens
producing a spot on the position sensi-
tive device. When the detectable target
is at a position A that is at a compara-
tively near distance as shown in Fig. 1,
a spot is produced at (a). When the tar-
get is at a position B that is far, a spot
is produced at (b). Accordingly, if any
spot position on the position sensitive
device is detected, the distance to the
target can be determined. This is the
principle of optical triangulation range
measurement.
Fig. 1 Optical triangulation range
measurement method
Other examples of this method are
the automatic focusing and camera
range measurement systems.
$
Triple beam type range sensing principle
The MQ photoelectric sensor area
reflective type has adapted this optical
triangulation range measurement prin-
ciple, but in order to improve the relia-
bility of the detection of the sensor, a
more elaborate method has been
devised. First, light receivers are posi-
tioned symmetrically on either side of
the axis of the light projector, compos-
ing a triple beam arrangement. As
shown in Fig. 2, when the moving
detectable target is at the edge of the
projected light beam, the spot reflected
from the target is at a location different
from the point where the spot is pro-
duced when the beam is completely
intercepted, generating a range mea-
surement difference of +
∆
X, but with
the triple beam composition, the sym-
metrically arranged position sensitive
device (2) has a spot produced con-
versely at a –
∆
X difference position,
and by means of averaging both range
measurement signals, the correct range
measurement can be made. This
results in significantly improved
repeatability and background suppres-
sion.
Fig. 2 Triple beam range measure-
ment method
By averaging the range measure-
ment signals of the 2 light receiving
systems, the range measurement
difference is cancelled.
$
Optical system of the triple beam photoelectric sensor
In the MQ photoelectric sensor area
reflective type, it is necessary to give
special consideration to the lens. In
order to improve the precision, an
aspherical lens, having limited spherical
and coma aberration, is used.
In addition, as shown in Fig. 4, a photo
diode having 2 output terminals is used.
By comparing the output currents from
the 2 PSDs, there is no relationship to
the level of the incident light. Thus, the
ratio of reflection from the detectable
target exerts no influence and the
range measurement and detection can
be interpreted accuracy.
Fig. 3 Light beam trace of the lens
(a) is a spherical lens, and (b) is the
aspherical lens. Because there is no
aberration in (b), range measure-
ment precision is high.
Fig. 4 PSD (position sensitive
device) construction
By making a calculation of the ratio
of I
1
and I
2
, the light spot position
can be detected.
$
Operating principle of area reflective method
The operation of the MQ photoelectric
sensor area reflective type is explained
in Fig. 5. After the output from the 2
PSD elements is added, the I/V value is
converted and the logarithm deter-
mined. By subtraction, the distance sig-
nal in (I
1
/I
2
) is obtained. This can be
optionally set, and with the distance
adjustment control, comparison with the
produced value can be made to detect
whether the target is or is not within the
distance range.
Fig. 5 Signal processing circuit block diagram
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03/2003
Microchip MCU
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