Seiko 9R65 User Manual

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Taste of a Mechanical Watch 
        +
High accuracy equivalent to a Quartz Watch
That is the concept of the Spring Drive.
Let’
s start from the drive method of a watch.
The method for driving a watch is divided into two types.
They are mechanical type and quartz type.
In a mechanical watch, the mainspring is wound and its unwinding 
power moves the hands.
Amazing mechanism created by high quality workmanship, 
and admiration goes to skilled craftsmen with passion.
You can feel the appreciation and personal touch of the craftsmen in 
the ticking sound.
On the other hand, with quartz watches, the quartz is oscillated by a 
battery and the hands are turned by a motor.
It is characterized by accuracy using state-of-the-art technology.
What is the Spring Drive like?
This is not a mechanical watch or a quartz watch.
In one word, this is a “mechanical watch having accuracy equivalent 
to a quartz watch.”
The  Spring  Drive  is  a  self-contained  drive  system  that  realizes 
accuracy equivalent to a quartz watch with only the power of the 
mainspring and has no battery, motor, or secondary battery.
Accuracy of monthly rate of ±15 seconds (daily rate of ±1 second)
 
equivalent to a quartz watch is achieved while using a mainspring.
The Spring Drive is Seiko’
s proprietary mechanism which is made 
available  only  by  SEIKO’s  unique  combination  of  skills  in  both 
mechanical and electronic micro-engineering.
Then,  how  could  it  be  possible  to  achieve  such  a  degree  of 
accuracy?
That is explained on the next page.
※ For Cal. 9R15, the average monthly rate is ±10 seconds 
  (equivalent to daily rate of ±0.5 second).
The power of the mainspring is regulated by electronic 
control. That is the essence of the Spring Drive.
What controls the accuracy of a mechanical watch is 
the  balance  spring,  a  part  of  the  speed-regulating  unit,  called  the 
balance.
This part influences the accuracy to some extent 
because  it  is  made  of  metal  which  expands  and  contracts  with 
changes in temperature.
The Spring Drive is 
completely different from a mechanical watch in this speed-regulating 
unit.
The Spring Drive is powered by a mainspring, 
but  adopts  an  electronic  speed-regulating  unit  comprising  a 
generator, IC circuit, and crystal oscillator.
In a little more detail, 
at the end of the train wheel that moves the hands, a series of speed 
increasing wheels with a rotor are provided.
The unwinding power of the mainspring rotates the rotor, generating 
electricity in the coil to drive the crystal oscillator and IC.
The  IC  controls  the  spinning  speed  of  the  rotor  by  applying  and 
releasing the electromagnetic brake, while comparing the accuracy 
of  the  electric  signals  generated  by  the  crystal  oscillator  and  the 
spinning speed of the rotor.
In addition, by making the energy transfer of the train wheel efficient 
and adopting an IC that drives with low power consumption and an 
amorphous core with low energy loss for the coil core part, power 
reserve  of  more  than  72  hours  far  exceeding  normal  mechanical 
watches is realized. 
An unprecedented drive system which offers quartz accuracy.
This is the Spring Drive.
Spring Drive Mechanism ①
Spring Drive Mechanism ②