Overview and advantages
TAIYO YUDEN's optical displacement sensors realize simple low cost compatibility between highly-precise detection and long-range detection in the displacement of an object being measured by an optical detecting method.
Features (benchmarking with other types)
||Optical displacement type
||Strain gauge type
||Electromagnetic equilibrium type
(on the precision stage)
(on the Load cell)
|| 1/20,000 - 1/100,000
|| 1/2,000 - 1/20,000
|| 1/100,000 - 1/2,000,000
*A strain gauge with an external amplifier is more expensive than an optical displacement sensor.
The ultra-high accuracy optical sensor has the same level of drive range as our conventional type (high-precision grade). However, when an electrical signal (Lissajous signal after it has passed the LPF) is evaluated after the device is moved 1.0 mm on the precision stage, the ultra-high precise optical displacement sensor has a precision of ±1.5 nm while our conventional type has a precision of ±100 nm. With respect to responsiveness, we made use of its strengths to design an optical displacement sensor that has higher responsiveness than other types.
Principle of ultra-high precision grade (reflection type)
Am optical displacement sensor has a structure such that two optical devices are sandwiched between a light-emitting device and a light-receiving element facing each other. The structure of the sensor is simple. One of the optical devices is fixed such that it can move together with a movable pin. When the pin shifts and undergoes displacement, this optical device is also displaced. This sensor has been designed such that a small amount of displacement of the optical device will cause a large change in the amount of incoming light to the photosensitive surface of the pin. This variation of light and shade is then converted to distance.
Compared to other displacement measuring methods, the advantage of this method is the capability of detecting linear displacement directly based on the graduations on the optical device itself.