Ever since CITIZEN began making watches, the challenge of achieving greater precision has been a key mission.
After creating a purer, more refined individual second by rethinking the crystal oscillator, the next challenge we faced was how to keep marking those seconds precisely, reliably and beautifully with light as the sole power source.
You cannot make a watch accurate to ±1 second per year without insisting on precision in every element that goes into it.
We succeeded in making this watch because we are a manufacture d’horlogerie and developed all the components from scratch.
LIGA TECHNOLOGYThe quest for more precise
Using precision manufactured components is a prerequisite for telling the precise time. To achieve precision manufacturing, we adopted the LIGA process for components like gears and springs normally made by pressing and machining. This process eliminated even the smallest eccentricity from the gears, creating components of unprecedented precision.
BACKLASH SUPPRESSION MECHANISMNo play for the gear —
or the second hand
The second hand visibly twitches when a watch experiences gear backlash. For normal quartz watches, this phenomenon is within tolerance, but it is something that we, in our quest for the purest, most refined individual second, could not overlook. We developed and installed a special gear, made with the LIGA process, that pushes against the direction of rotation of the gears to prevent backlash. As a result, the second hand keeps telling the precise time, lining up perfectly with the minute tracks, second by second. Thanks to our first-of-a-kind system that can rotate the second hand both forwards and backwards, the watch can quickly display the correct time when it wakes up from power saving mode.
TEMPERATURE CORRECTION FUNCTIONMonitoring the temperature
once per minute
The integrated circuit, the “brain” of the watch, includes many CITIZEN proprietary technologies. One of these is a temperature correction function that monitors the temperature in the watch movement once per minute and adjusts its frequency accordingly. There are tiny individual differences between crystal oscillators. That is why CITIZEN tests the thermal characteristics of every crystal oscillator it uses. Not only did we double the number of points we temperature test in the manufacturing process, but we also improved the testing methodology for a tenfold jump in measurement precision.
THREE PROTECTIVE FUNCTIONSTelling the precise time
Systems that correct, monitor and protect the second hand from external shocks like bumps and magnetism have an important role to play when it comes to marking the individual seconds with perfect purity. The watch includes a shock counteraction function (which locks the rotor to keep the hands in place and release them instantly); an automatic hand correction function (which regularly checks the position of the hands and automatically resets them in the event of deviation); and an antimagnetic function which can resist magnetic fields of 4,800A/m.
MOTORA second hand that moves
with force and beauty
We wanted this watch to express each individual second beautifully. To do this, for the first time on an Eco-Drive watch we used a brass second hand matched with a specially developed powerful high-holding-torque motor. Despite the brass second hand having roughly twice the unbalanced weight and moment of inertia of an aluminium hand, it rotates with confident elegance, coming to a precise stop every second.
powered by nothing but light
Our mission was to keep telling the time with accuracy of ±1 second per year. We achieved this by using light-powered Eco-Drive, a core CITIZEN technology with over 40 years of history. We reduced electricity consumption to power the whole movement—the power-hungry AT cut crystal oscillator, the temperature correction function, the heavy brass second hand—with only light. A single full charge keeps the watch running for eight months.