Laser scanner
A laser scanner includes a light source, a scanning mirror, and a first photodetector. The scanning mirror includes: a first reflective surface reflects the laser light from the light source; and a second reflective surface that reflects, toward the photodetector, the laser light reflected from the target object. The first reflective surface and at least part of the second reflective surface are disposed at mutually different angles. When a first optical axis passing through the target object and the first reflective surface is parallel with a second optical axis passing through the target object and the second reflective surface, a third optical axis passing through the first reflective surface and the light source and a fourth optical axis passing through the second reflective surface and the photodetector are at a predetermined angle relative to one another.
1. A laser scanner for scanning laser light toward a target object, the laser scanner comprising:
a light source that emits laser light;
a scanning mirror that scans the laser light from the light source toward the target object by oscillating about a predetermined axis, and reflects the laser light reflected from the target object, the scanning mirror having a plate shape, and having a first surface and a second surface parallel with the first surface; and
a photodetector that receives, via the scanning mirror, the laser light reflected from the target object,
wherein the scanning mirror includes:
a first reflective surface that scans the laser light from the light source by reflecting the laser light from the light source;
a second reflective surface that reflects, toward the photodetector, the laser light reflected from the target object; and
an inner wall defining an opening through which the laser light from the light source passes, the laser light passing through from a first surface side of the scanning mirror to an opposing second surface side of the scanning mirror,
wherein the first reflective surface and at least part of the second reflective surface are disposed at mutually different angles,
wherein when (i) a first optical axis passing through the target object and the first reflective surface is parallel with (ii) a second optical axis passing through the target object and the second reflective surface, (iii) a third optical axis passing through the first reflective surface and the light source and (iv) a fourth optical axis passing through the second reflective surface and the photodetector are at a predetermined angle relative to one another,
wherein the first reflective surface is formed on the inner wall defining the opening, reflects the laser light entering the opening from the light source, and scans the reflected laser light out of the opening toward the target object, and
the second reflective surface is formed on the second surface of the scanning mirror and reflects, toward the photodetector, the laser light reflected from the target object.
2. The laser scanner according to claim 1 , wherein
the first optical axis and the second optical axis are coincident.
3. The laser scanner according to claim 1 , wherein
in a plan view of the scanning mirror, a region defined by the first reflective surface is included within a region defined by the second reflective surface.
4. The laser scanner according to claim 1 , wherein
the first reflective surface is disposed along the predetermined axis.
5. The laser scanner according to claim 1 , wherein
the opening is a notch extending from an edge of the scanning mirror, in a direction substantially perpendicular to a thickness direction of the scanning mirror, and
the first reflective surface is formed on the inner wall defining the notch, at a base of the notch.
6. The laser scanner according to claim 1 , wherein
the first reflective surface is substantially perpendicular to the second reflective surface.
7. The laser scanner according to claim 1 , wherein
the opening is an aperture formed through the thickness of the scanning mirror, and
the first reflective surface is formed on the inner wall defining the aperture.
8. The laser scanner according to claim 7 , wherein
the first reflective surface is oblique to the second reflective surface.
9. The laser scanner according to claim 7 , wherein
the aperture has an area on the first surface side of the scanning mirror that is greater than an area of the aperture on the second surface side of the scanning mirror.
10. The laser scanner according to claim 1 , wherein
the scanning mirror includes, on the first surface side, a low-reflection surface having a lower reflectivity than the first reflective surface and the second reflective surface.
11. The laser scanner according to claim 1 , wherein
the opening has a width that is greater than or equal to a diameter of the laser light from the light source.
12. A laser scanner for scanning laser light toward a target object, the laser scanner comprising:
a light source that emits laser light;
a scanning mirror that scans the laser light from the light source toward the target object by oscillating about a predetermined axis, and reflects the laser light reflected from the target object; and
a photodetector that receives, via the scanning mirror, the laser light reflected from the target object,
wherein the scanning mirror includes:
a first reflective surface that scans the laser light from the light source by reflecting the laser light from the light source;
a second reflective surface that reflects and condenses, toward the photodetector, the laser light reflected from the target object;
a reflective component that reflects the laser light reflected from the target object; and
a lens component that is stacked on the reflective component, and transmits and condenses the laser light,
wherein the first reflective surface and at least part of the second reflective surface are disposed at mutually different angles,
wherein when (i) a first optical axis passing through the target object and the first reflective surface is parallel with (ii) a second optical axis passing through the target object and the second reflective surface, (iii) a third optical axis passing through the first reflective surface and the light source and (iv) a fourth optical axis passing through the second reflective surface and the photodetector are at a predetermined angle relative to one another, and
wherein the second reflective surface is an interface between the reflective component and the lens component.
13. The laser scanner according to claim 12 , wherein
the first reflective surface is disposed along an optical axis of the second reflective surface, and
the first reflective surface is oblique to a plane perpendicular to the optical axis of the second reflective surface.
14. The laser scanner according to claim 12 , wherein
the second reflective surface surrounds the first reflective surface.
15. The laser scanner according to claim 12 , wherein
the scanning mirror has a substantially planar surface opposing the second reflective surface, the substantially planar surface being perpendicular to an optical axis of the second reflective surface, and
the optical axis of the second reflective surface intersects the predetermined axis.
16. The laser scanner according to claim 12 , wherein
the scanning mirror includes a protrusion that protrudes outward from the second reflective surface, and
the first reflective surface is at least part of a surface formed by the protrusion.
17. The laser scanner according to claim 1 , wherein
the center of mass of the scanning mirror is disposed along the predetermined axis.