Patent ID: 8407904

Claim:
A rotary laser beam emitter comprising: a base unit including a reference reflector having a reference reflective face parallel to a reference plane; a rotary element supported on the base unit and rotatable around a rotary axis; and a beam emitting unit contained in the rotary element and comprising a light source for emitting a laser beam along an optical axis orthogonal to the rotary axis and an optical emission system for receiving the laser beam from the light source and emitting the laser beam in a direction parallel to the reference plane, wherein, when the rotary element is inclined relative to the rotary axis, causing the laser beam emitted from the light source to be inclined relative to the reference plane, the optical emission system is configured to have the inclined laser beam reflected by the reference reflective face in a direction inclined to an optical axis of the inclined laser beam so as to neutralize the inclination of the laser beam.