Fiber sensor

By guiding the light source with an optical fiber connected to an amplifier, it is possible to detect an object even in a narrow space.

Compared to other methods, it has the following features.

● The detection unit can be small, and it can detect even in a narrow space due to the flexibility of the optical fiber, and it is easy to detect minute objects.
● Since the detection unit is an optical fiber, high reliability can be obtained even in adverse environments such as temperature, humidity, vibration, shock, water, and electrical noise.
● Since the detection beam can be guided to the detection position by optical fiber, the mounting location of the amplifier unit can be freely selected.

As shown in the figure, the optical fiber used in the optical fiber type consists of a central core and a clad with a different refractive index. When light is incident on the core, the light is repeatedly totally reflected at the boundary surface of the clad.

The light emitted from the end face through the optical fiber is radiated to the detection object with a spread of about 60 ° on the plastic fiber.

The detection method of the optical fiber type photoelectric sensor is roughly divided into the transmission type and the reflection type. The transmissive type has two configurations: light projection and light reception.
The reflection type is combined into one in appearance, but when looking at the cross section, it can be divided into parallel type, coaxial type, and split type.