A rotatable polygon mirror including a plurality of reflecting surfaces includes first and second surfaces connecting to the reflecting surfaces provided on opposite ends, first and second protrusion portions with an annular shape, provided on the first and second surfaces and protruding inversely to each other in the rotational axis direction, about a rotational axis of the rotatable polygon mirror. A height of a top surface portion of the first protrusion portion from the first surface is higher than that of a top surface portion of the second protrusion portion from the second surface with respect to the rotational axis direction. In a case that the rotatable polygon mirrors are stacked in the rotational axis direction, a wall of an inner peripheral side of the first protrusion portion and a wall of an outer peripheral side of the second protrusion portion are engaged with each other.

A rotatable polygon mirror including a plurality of reflecting surfaces includes first and second surfaces connecting to the reflecting surfaces provided on opposite ends, first and second protrusion portions with an annular shape, provided on the first and second surfaces and protruding inversely to each other in the rotational axis direction, about a rotational axis of the rotatable polygon mirror. A height of a top surface portion of the first protrusion portion from the first surface is higher than that of a top surface portion of the second protrusion portion from the second surface with respect to the rotational axis direction. In a case that the rotatable polygon mirrors are stacked in the rotational axis direction, a wall of an inner peripheral side of the first protrusion portion and a wall of an outer peripheral side of the second protrusion portion are engaged with each other.

An apparatus including a focused light beam receptor apparatus configured to be positioned proximate a first end of a vehicle, a focused light beam generator; and wherein the focused light beam receptor apparatus includes a focused light beam receiving surface for receiving a focused light beam from the focused light beam generator to provide alignment of the focused light beam receptor relative to a centerline of the vehicle. A method of aligning a focused light beam receptor, focused light beam generator and a movable alignment stand relative to a centerline of a vehicle is also provided.

An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.

An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.

A light deflector 2 includes: a mirror section 9 that reflects light; a movable frame 8 provided in such a manner as to surround the mirror section 9; a pair of torsion bars 13a and 13b having one end of each torsion bar connected to the mirror section 9 and the other end thereof connected to the movable frame 8 on a Y-axis; and semi-annular piezoelectric actuators 10a and 10b that are provided on the movable frame 8 and rotate the torsion bars 13a and 13b around the Y-axis in a reciprocating manner. The torsion bars 13a and 13b each have a constricted shape in which the transverse width at both end parts is the largest and the transverse width gradually decreases toward the central part thereof in a length direction.

An optical element includes a plate portion including a reflecting surface on an upper surface in a direction of a vertically extending central axis, a shaft that extends in a direction of a first axis intersecting with the central axis and is fixed to a lower surface of the plate portion, a magnet below the shaft in the direction of the central axis, and a holder below the plate portion to hold the magnet, the holder including a magnet accommodating portion in which the magnet is accommodated, the magnet accommodating portion including a magnet pressing portion that covers at least a portion of a lower surface of the accommodated magnet.

A light detection and ranging (lidar) device includes: a lower base; an upper base; a laser emitting unit for emitting a laser in a form of a point light source; a nodding mirror for transforming the laser in the form of the point light source to a line beam pattern which is perpendicular to the lower base, wherein the nodding mirror reflects the laser emitted from the laser emitting unit; a polygonal mirror for transforming the line beam pattern to a plane beam pattern and receiving a laser reflected from an object; and a sensor unit for receiving the laser reflected from the object via the polygonal mirror.

A light detection and ranging (lidar) device includes: a lower base; an upper base; a laser emitting unit for emitting a laser in a form of a point light source; a nodding mirror for transforming the laser in the form of the point light source to a line beam pattern which is perpendicular to the lower base, wherein the nodding mirror reflects the laser emitted from the laser emitting unit; a polygonal mirror for transforming the line beam pattern to a plane beam pattern and receiving a laser reflected from an object; and a sensor unit for receiving the laser reflected from the object via the polygonal mirror.

The present disclosure describes a system and method for LiDAR scanning. The system includes a light source configured to generate one or more light beams; and a beam steering apparatus optically coupled to the light source. The beam steering apparatus includes a first rotatable mirror and a second rotatable mirror. The first rotatable mirror and the second rotatable mirror, when moving with respect to each other, are configured to: steer the one or more light beams both vertically and horizontally to illuminate an object within a field-of-view; redirect one or more returning light pulses generated based on the illumination of the object; and a receiving optical system configured to receive the redirected returning light pulses.