90 +:0 | MAY 2017
WHAT ARE OPTICAL SWITCHES?
That’s where optical switches come in. These switches use light for
actuation instead of a mechanical connection, and promise even greater
longevity, robustness, and responsiveness.
However, what’s interesting is that these are still technically mechanical
switches by design, with very similar physical components like a key stem,
shaft, and spring. They can even be built to the same physical specifications
as regular switches and made to mimic the feel of familiar Cherry MX
switches (third-party keycaps will still be compatible).
. 5
Light Strike switches are
manufactured by a company
called A4tech, and feature a
horizontal infrared beam running
across the interior of the switch
shaft. The switch stem normally
blocks the light beam, but when
you push the key, the stem moves
down, eventually allowing the
beam to make a connection across
the shaft and actuate the key.LEARN(
Adomax’s Flaretech switches mount
all their key components on top of
the PCB, so the switch comprises just
a bunch of mechanical parts and can
be replaced easily. The PCB-mounted
sensor uses infrared photothermal
radiometry to detect actuation when
the switch descends on it. One benefit
of this design is the support for
analog input, and the ability to set
the actuation point almost anywhere
in the key travel.) ¤6
These resemble Cherry MX
RGB switches, complete with a
transparent housing for better
light dispersion. The switch design
is also very similar, and there’s
even a single metal contact leaf to
emulate the clickiness of Cherry
MX Blue switches. An infrared
sensor on the PCB senses the
position of the key stem and sends
an actuation signal once it reaches
a specific point.9^UJXTKTUYNHFQX\NYHMJX