LiDAR device

A light detection and ranging (LiDAR) device for measuring a distance using a laser, comprising:

• a laser emitting unit configured to emit laser;
• a nodding mirror configured to change a flight path of the emitted laser by nodding within a preset angle range, wherein the nodding mirror comprises a reflective surface configured to change the flight path of the emitted laser;
• a rotating polygonal mirror configured to change the flight path of the emitted laser by rotating about an axis, wherein the rotating polygonal mirror comprises a plurality of reflective surfaces configured to change the flight path of the emitted laser;
• and
• a detecting unit configured to detect a reflected laser from an object,
• wherein the LiDAR device is configured to output the emitted laser reflected by the rotating polygonal mirror through an irradiation path as an irradiated laser and receive the reflected laser through a reception path,
• wherein the irradiation path is set towards the object sequentially through the nodding mirror and the rotating polygonal mirror, and the reception path is set towards the detecting unit through only the rotating polygonal mirror among the nodding mirror and the rotating polygonal mirror,
• wherein the nodding mirror is disposed outside the reception path so as to increase an amount of the reflected laser detected by the detecting unit,
• wherein the LiDAR device has a first field of view defined in a horizontal direction of the irradiated laser and a second field of view defined in a vertical direction of the irradiated laser,
• wherein the laser emitting unit, the nodding mirror, and the rotating polygonal mirror are configured such that:
• (i) the laser emitted from the laser emitting unit is reflected from the rotating polygonal mirror after being reflected from the nodding mirror,
• (ii) a size of the reflective surface of the nodding mirror is smaller than a size of each of the plurality of reflective surfaces of the rotating polygonal mirror,
• (iii) the horizontal direction of the irradiated laser is changed by the rotating polygonal mirror,
• (iv) the vertical direction of the irradiated laser is changed by the nodding mirror,
• (v) an extent of the preset angle range of the nodding mirror is smaller than a first angle calculated by a relationship of (360 degrees/a number of the plurality of reflective surfaces of the rotating polygonal mirror) such that the second field of view is smaller than the first field of view, and
• (vi) while the rotating polygonal mirror rotates by the first angle, the nodding mirror reciprocates within the preset angle range at least twice.