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Lead Contents

Displacement / Measurement Sensors

These Sensors can be used to measure distances and heights. A wide variety of models is available, including Laser Sensors, LED Sensors, Ultrasonic Sensors, Contact Sensors, Eddy Current Sensors, and more.

Overview Features
Principles Classifications
Engineering Data Further Information

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Primary Contents

Principle of measurement of the optical displacement sensor

Light from the light source is condensed by the lens and directed onto the object.
Light reflected from the object is condensed onto a one-dimensional position sensing device (PSD)* by the receiving lens. If the position of the object (the distance to the measuring device) changes, the image formation positions on the PSD will differ, and if the balance of the two PSD outputs changes, the image formation positions on the PSD will differ and the balance of the two PSD outputs changes.
If the two outputs are A and B, calculate A/(A + B) and use appropriate values for the span coefficient "k" and the offset "C".

can be obtained.

The value measured is not the illuminance (brightness), but the two output displacements A and B, and thus even if the received light intensity changes because the distance to the object changes, the result is not affected and linear output proportional to the distance difference and position shift is obtained.

Optical system of the Displacement Sensor

Regular reflection model

Light from the object is directly received by regular reflection, and stable measurement is possible of metal and other objects with a glossy surface.

Diffuse reflection model

A light beam is projected perpendicularly onto the surface of the object, and the diffuse light that is reflected back is received for a wide measurement area.