In the autocollimation concept, which uses only one optical lens, the beam of light emitted by the sensor and the light beam reflected by the reflector lie on a single optical axis. The emitted light passes through a semi-transparent mirror before exiting the optical unit. After being reflected by the reflector, the light beam is diverted to the receiver with the aid of the same mirror. The advantage is that, unlike with the dual lens concept, there is no blind zone in front of the sensor.
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