Low profile lidar scanner with polygon mirror

An optical scanner configured to direct light in accordance with a scan pattern to scan a field of regard, the optical scanner comprising:

• a rotatable polygon mirror having a block having a first wall, a second wall, and a plurality of reflective surfaces extending between the first and second walls, the reflective surfaces being angularly offset from one another along a periphery of the block;
• a polygon mirror axle extending into the block through at least one of the first and second walls, about which the block rotates;
• a second mirror pivotable along an axis orthogonal to the polygon mirror axle within an available range, wherein the second mirror includes a pivot mirror block having a reflective surface facing the polygon mirror, the center of gravity of the pivot mirror block being displaced closer to the reflective surface than to a wall of the second mirror opposite the second surface, and the pivot mirror block of the second mirror includes a layer with a honeycomb structure;
• a first motor configured to impart rotation to the polygon mirror axle;
• and
• a second motor configured to impart oscillating motion to the second mirror within an operational range smaller than the available range;
• wherein the second motor modifies the operational range of the second mirror in response to a drive signal.

A lidar system comprising:

• a light source configured to emit light;
• a scanner configured to direct the emitted light to scan a field of regard of the lidar system in accordance with a scan pattern, the scanner including:
• a rotatable polygon mirror having a block having a first wall, a second wall, and a plurality of reflective surfaces extending between the first and second walls, the reflective surfaces being angularly offset from one another along a periphery of the block,
• a polygon mirror axle extending into the block through at least one of the first and second walls, about which the block rotates, and
• a second mirror pivotable along an axis orthogonal to the polygon mirror axle, wherein the second mirror includes a pivot mirror block having a reflective surface facing the polygon mirror, the center of gravity of the pivot mirror block being displaced closer to the reflective surface than to a wall of the second mirror opposite the second surface, and the pivot mirror block of the second mirror includes a layer with a honeycomb structure;
• a receiver configured to detect at least a portion of the emitted light scattered by one or more remote targets;
• and
• a controller configured to control motion of at least the second mirror to modify the scan pattern.

A lidar system comprising:

• a light source configured to emit light;
• a scanner configured to direct the emitted light to scan a field of regard of the lidar system in accordance with a scan pattern, the scanner including:
• a rotatable polygon mirror having a block having a first wall, a second wall, and a plurality of reflective surfaces extending between the first and second walls, the reflective surfaces being angularly offset from one another along a periphery of the block,
• a polygon mirror axle extending into the block through at least one of the first and second walls, about which the block rotates, and
• a second mirror pivotable along an axis orthogonal to the polygon mirror axle;
• a receiver configured to detect at least a portion of the emitted light scattered by one or more remote targets;
• a controller configured to control motion of at least the second mirror to modify the scan pattern;
• and
• a housing at least partially enclosing one or more of the light source, the scanner, the receiver, and the controller, wherein at least a portion of the second mirror extends above the rotatable polygon mirror, and only a region extending from a lower edge of the second mirror to a top of the housing projects prominently from a surface of a body of a vehicle on which the lidar system is deployed.