Pearl CM-127 User manual

Instruction Manual
for the
CM-127
CM-127TV
Centering Microscopes

1
Thank you for purchasing one of our CM-127 Centering microscopes.
To get full and long lasting performance, and to enjoy all the functions of this equipment, use the
microscope as described in this manual.
Features of the Centering Microscope
The Centering microscope is used to evaluate optical lenses and plate materials. To evaluate
eccentricity, manually rotate the object to measure to allow you to evaluate the amount of eccentricity
by the amount of tilt in the transmitted light beam. It can find the center of compound lenses, and
measure the amount of deviation and direction from the center with great precision, after multiple
lenses are attached firmly on their holders. It can be used for checking optional lenses and plates on
production lines.
This microscope employs high brightness LEDs as its light source. They consume about 1/15
th
the
power as an ordinary tungsten filament lamp.
Table of Contents
Features of the Centering Microscope .......................................................... 1
1. Configuration and Name of Each Part ........................................................... 2
2. Assembling and Preparation before Use........................................................ 5
3. How to Use.................................................................................................... 6
4. Lens Adapter ............................................................................................... 14
5. How to Adjust the Light Level....................................................................... 15
6. Reasons Why Lenses with Smaller Focal Distances Cannot Be Measured . 16
7. Measure to Take If the Fine Adjustment Handle Resistance is Too Loose....１7
8. Specifications .............................................................................................. 18

2
1. Configuration and Name of Each Part
1-1. Configuration
1) Main housing
CM-127
6) BNC coaxial cable (TV)
5) 12-pin camera cable (TV) 7) Camera adaptor (TV)
CM-127TV
2) AC adapter
3) Extension cord
4) Lens adapter

3
1) Main housing CM-127 / CM-127TV
2) AC adapter AC adapter
3) Extension cord With an ON/OFF switch
4) Lens adapter
5) Camera cable 12 pin, round connector (CM-127TV)
6) Coaxial cable BNC coaxial cable (CM-127TV)
7) Camera adapter (CM-127TV)
8) Monitor 9 inch, black and white
9) Power cable
10) Instruction manual
10) Instruction manual
9) Power cable (TV)
8) Monitor (TV)

4
1-2. Name of each part
Stand
Objective lens
Lens holder
Fine adjustment
handle
Arm
Collimating lens
adjustment ring
Lock knob
Base
Eyepiece
Mirror barrel clamp
Light source
Stage fine
adjustment knob
Stage
CM-127TV
CCD camera
Relay lens

5
2. Assembling and Preparation before Use
Connect each cable.
(1) CM-127
(2) CM-127TV
Connect to a wall
outlet
VIDEO 1
CAMERA
VIDEO IN
Connect to a wall outlet
BNC coaxial cable
Camera cable
Insert the AC adapter
jack into the light
source
Plug the AC adapter into the
extension cord with a switch.
Plug into a wall
outlet.
Turn the light source on/off
using the switch on the
extension cord.

6
3. How to Use
(1) Turn on the extension cord switch to turn on the light source.
(2) Turn on the power to the camera adapter and TV monitor to make the system ready for
capturing CCD camera images. (CM-127TV only)
(3) Install a lens in the lens holder and adjust its position so that it will be in the beam of light from
the microscope’s light source.
Extension cord
Turn on the switch
AC adapter
Lens to measure
Turn on the power switches

7
(4) Look through the eyepiece of the microscope and adjust the eyepiece until you can see the
eyepiece scale clearly. (CM-127 only)
(5) Turn the collimating lens adjustment ring left and right to find the middle of the range. Leave the
ring in that position.
* If the focal distance of the lens you want to measure is less than 100 mm, turning this ring to the
right may improve the accuracy.
* If the focal distance of the lens you want to measure is longer, turn this ring to the left.
Collimating lens
adjustment ring
Negative direction
Positive
direction

8
(6) Loosen the lock knob and then turn the fine adjustment handle to the approximate position for
the microscope’s objective lens, based on the lens you want to measure.
(7) While looking through the eyepiece (or the TV monitor in the case of the CM-127TV), turn the
fine adjustment handle to move the microscope up.
Move the microscope down
Fine adjustment handle
Lock knob
Move the microscope up.

9
(8) When you can see the crosshairs, tighten the lock knob to fix the position of the microscope.
*1: If you cannot see the crosshair image even after moving the microscope all the way up, lower
the microscope and loosen the barrel. Then raise the barrel.
After you can see the crosshairs, secure the barrel and then adjust the focus again by turning
the fine adjustment handle.
*2: If you cannot see the crosshair image after following the procedures in *1 above, turn the
collimating adjustment ring left or right. Then start again at step (6) above.
Note: Turning the fine adjustment handle while the lock knob is tightened will damage the main
housing.
Lift the barrel up
Loosen the barrel
clamp

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(9) Adjust the stage fine adjustment knob and slide the lens so that the crosshairs will be in the
center of the view.
(10) When the crosshairs are at the center of the view, rotate the lens you want to measure.
Stage fine adjustment knob

11
X axis feed amount
(11) When you rotate the lens, the crosshairs will also turn accordingly. Now, read the X axis feed
amount on the scale.
This feed amount is the total feed amount. Eccentricity is expressed as 1/2 of the total feed
amount.
Eccentricity amount (θ) = Total feed amount / 2
Ex.: If the total feed amount is 12 ticks on the scale, the eccentricity is 6.
(12) Measure distance “A” between the lens you want to measure and the objective lens.
Total feed amount

12
Table 1
Read the value for distance “A” that corresponds to one tick by referring to table 1.
Ex.: When the total feed amount in the crosshair image is 12 ticks (the eccentricity is 6) and the
distance “A” between the target lens and the objective lens is 50 mm
The amount of eccentricity (θ) = 41 (seconds) x 6 (ticks)
= 246 (seconds)
= 4 (minutes) and 6 (seconds)
Distance “A”
between the lens you
want to measure and
the objective lens
Value of one tick in
the eyepiece
(minutes and
second)
10 mm 3 min. and 26 sec.
20 mm 1 min. and 43 sec.
30 mm 1 min. and 9 sec.
40 mm 52 sec.
50 mm 41 sec.
60 mm 34 sec.
70 mm 30 sec.
80 mm 26 sec.
90 mm 23 sec.
100 mm 20 sec.

13
When you want to use the measured amounts of eccentricity for other calculations, if you measure a
lens with a shorter focal distance the measurement error will be larger. Therefore, please note the
following points about measurements.
The distance between the target lens and the objective lens should be the precise distance between
the main point in the target lens and the focal position of the microscope objective lens.
If the main point in the target lens is not known, use the center of the target lens thickness. (However,
in this case the error will be larger.)
If the main point is already known as a specified value, calculate the distance using this value.
Focal point distance between
the microscope objective lens
and the main point of the lens
you want to measure.

14
4. Lens Adapter
This system is not capable of measuring most concave lenses (because the focal distance for
concave lenses is a negative value.) However, if you use the lens adapter that is available as an
accessory, you can measure some concave lenses.
How to install the lens adapter
1) Secure the center and lower stages and then remove the upper stage. (Screw in type)
2) Install the lens adapter on the upper stage. (Screw in type).
3) Secure the center and lower stages and then reinstall the upper stage with the lens adapter
installed in it.
Lens adapter
Screw in
Upper stage
Lower stage
Intermediate
stage

15
5. How to Adjust the Light Level
If the lamp is too bright, adjust the light level as you like by inserting a slotted screwdriver into the
light adjusting hole.
Light level adjusting hole
Precision slotted screwdriver
(Available commercially)
Light source

16
6. Reasons Why Lenses with Smaller Focal
Distances Cannot Be Measured
With the transmission type Centering measurement, focal distance “f” is a key factor for
measurement.
Finding the amount of eccentricity is effectively reading the θangle of deviation. If the angle is
identical between two lenses, the lens with a longer focal distance have a wider angle, which means
that its eccentricity can be read easily. (Obtain the resolution.)
If θis 1 minute
The minimum division in the eyepiece is 0.01 mm and lenses with a smaller feed amount than this
length cannot be measured in this device.
Therefore, a lens with a shorter focal distance will have a smaller feed amount and it cannot be
measured.
Width(feed amount)
Width(feed amount)

17
7. Measure to take if the Fine Adjustment Handle
Resistance is Too Loose
After a long use of this system, the fine adjustment handle may become loose and then the
microscope may descend on its own.
This is because the rack in the microscope has become worn.
In this case, take the following steps. However, if you cannot solve the problem after following the
steps below, please contact our sales desk.
1) Loosen the set screws inside the fine adjustment handle.
2) Turn the fine adjustment handle clockwise. Stop turning at an appropriate position. Be careful
because by turning it too much the handle will become too stiff.
3) Tighten the set screw securely.
4) Do this the same for both the left and right handles.
Stopper screw
Fine adjustment
handle
Turn clockwise

18
8. Specifications
Model name CM-127 CM-127TV
Application (object to measure) Convex lenses, concave lenses, doublet lenses, etc.
Objective lens 10x
Eyepiece lens 10x (with a diopter adjustment)
CCD camera 1/2-inch black and white
Monitor 9-inch black and white
Lens holder sizes φ10 to φ50
Focal distance of lenses to measure
30 to 300 mm
Minimum readable resolution 20 sec. (When the distance between the test lens and objective lens
is 100 mm)
Light source High-brightness green LED (6V, 180 mW)
Power supply
AC adapter 100 V to 240 VAC, 50/60 Hz
Monitor 100V to 240 VAC, 15W
CCD camera
adapter 100V to 240 VAC, 25W
Size & Weight L220 x W170 x H370, 4 kg L220 x W170 x H430, 13 kg
Accessories AC adapter, extension cord, lens
adapter, instruction manual
Monitor, power supply for
camera, camera cable, BNC
cable, AC adapter extension
cord, instruction manual

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2015-01-29