Optical apparatus, and on-vehicle system and moving apparatus including the same
An optical apparatus includes a deflection unit configured to deflect illumination light from a light source to scan an object and deflect reflected light from the object, and a light guide unit configured to guide the illumination light from the light source to the deflection unit and guide the reflected light from the deflection unit to a light-receiving element, wherein the light guide unit includes a first surface on which the illumination light from the light source is incident and a second surface including a transmissive region through which the illumination light from the first surface is transmitted and a reflective region that reflects the reflected light from the deflection unit, wherein the first and the second surfaces are non-parallel to each other, and wherein the illumination light from the first surface is incident on the transmissive region without passing through other surfaces.
1. An optical apparatus comprising:
deflector configured to deflect illumination light from a light source to scan an object and deflect reflected light from the object; and
a light guide configured to guide the illumination light from the light source to the deflector and guide the reflected light from the deflector to a first sensor,
wherein the light guide includes a first surface on which the illumination light from the light source is incident and a second surface including a transmissive region through which the illumination light from the first surface is transmitted and a reflective region that reflects the reflected light from the deflector,
wherein the first and the second surfaces are non-parallel to each other, and
wherein the illumination light from the first surface is incident on the transmissive region without passing through other surfaces, and the illumination light from the transmissive region is incident on the deflector without passing through other surfaces.
2. The optical apparatus according to claim 1 , wherein, when light traveling in a direction opposite to a traveling direction of the reflected light reflected by the reflective region is incident on the transmissive region, the light refracted by the transmissive region is not incident on a passage region for the illumination light on the first surface.
3. The optical apparatus according to claim 1 , wherein the traveling direction of the illumination light incident on the first surface and the traveling direction of the reflected light reflected by the reflective region are parallel to each other.
4. The optical apparatus according to claim 3 , wherein, in a cross-section perpendicular to the first and the second surfaces, the following conditional expression is satisfied:
t s /h 1 >sin(90°−θ 2 −2θ 3 )/(cos θ 1 *sin 2θ 3 )
where t s denotes a minimum optical path length of the illumination light from the first surface to the transmissive region, h 1 denotes the diameter of the illumination light incident on the first surface, θ 1 [°] denotes an incident angle of the illumination light with respect to the first surface, θ 2 [°] denotes an refraction angle of the illumination light with respect to the first surface, and θ 3 [°] denotes the incident angle of the illumination light with respect to the transmissive region.
5. The optical apparatus according to claim 1 , wherein the traveling direction of the illumination light incident on the first surface and the traveling direction of the reflected light reflected by the reflective region are perpendicular to each other.
6. The optical apparatus according to claim 5 , wherein, in a cross-section perpendicular to the first and the second surfaces, the following conditional expression is satisfied:
t 1 /h 1 >sin(90°+θ 2 −2θ 3 )/(cos θ 1 *sin 2θ 3 )
where t 1 denotes a maximum optical path length of the illumination light from the first surface to the transmissive region, h 1 denotes the diameter of the illumination light incident on the first surface, θ 1 [°] denotes the incident angle of the illumination light with respect to the first surface, θ 2 [°] denotes the refraction angle of the illumination light with respect to the first surface, and θ 3 [°] denotes the incident angle of the illumination light with respect to the transmissive region.
7. The optical apparatus according to claim 1 , wherein, in a cross-section perpendicular to the first and the second surfaces, the diameter of the illumination light emitted from the transmissive region is larger than the diameter of the illumination light incident on the first surface.
8. The optical apparatus according to claim 1 , wherein a part of the illumination light from the first surface is reflected by the transmissive region, and the light guide has a third surface on which the part of the illumination light reflected by the transmissive region is incident.
9. The optical apparatus according to claim 8 , wherein the first surface reflects the light reflected by the transmissive region, to guide the light to the third surface.
10. The optical apparatus according to claim 1 , further comprising a second sensor for light source configured to receive the light reflected by the transmissive region.
11. The optical apparatus according to claim 1 , wherein, in a cross-section perpendicular to the first and the second surfaces, the following conditional expression is satisfied:
−10<θ B −θ 1 <10
where θ 1 [°] denotes the incident angle of the illumination light with respect to the first surface, and θ B [°] denotes Brewster's angle on the first surface.
12. The optical apparatus according to claim 1 , wherein a shape of the transmissive region is an ellipse.
13. The optical apparatus according to claim 1 , wherein the light guide includes a single optical element.
14. The optical apparatus according to claim 13 , wherein the refraction index of the material of the optical element with respect to a 905 nm wavelength is 1.70 or higher.
15. The optical apparatus according to claim 1 , further comprising an optical system configured to enlarge the diameter of the illumination light from the deflector and reduce the diameter of the reflected light from the object.
16. The optical apparatus according to claim 1 , further comprising a control unit configured to acquire distance information of the object based on an output of the first sensor.
17. An on-vehicle system comprising the optical apparatus according to claim 1 , wherein a possibility of a collision between a vehicle and the object is determined based on the distance information of the object obtained by the optical apparatus.
18. A moving body comprising the optical apparatus according to claim 1 , wherein the moving body is movable while holding the optical apparatus.
19. An optical apparatus comprising:
a deflector configured to deflect illumination light from a light source to scan an object and deflect reflected light from the object; and
a light guide configured to guide the illumination light from the light source to the deflector and guide the reflected light from the deflector to a first sensor,
wherein the light guide includes a first surface on which the illumination light from the light source is incident and a second surface including a transmissive region through which the illumination light from the first surface is transmitted and a reflective region that reflects the reflected light from the deflector,
wherein the first and the second surfaces are non-parallel to each other,
wherein the illumination light from the first surface is incident on the transmissive region without passing through other surfaces,
wherein the traveling direction of the illumination light incident on the first surface and the traveling direction of the reflected light reflected by the reflective region are parallel to each other, and
wherein, in a cross-section perpendicular to the first and the second surfaces, the following conditional expression is satisfied:
t s /h 1>sin(90°−θ 2 −2θ 3 )/(cos θ 1 *sin 2θ 3 )
where t s denotes a minimum optical path length of the illumination light from the first surface to the transmissive region, h1 denotes the diameter of the illumination light incident on the first surface, θ 1 [°] denotes an incident angle of the illumination light with respect to the first surface, θ 2 [°] denotes an refraction angle of the illumination light with respect to the first surface, and θ 3 [°] denotes the incident angle of the illumination light with respect to the transmissive region.
20. An optical apparatus comprising:
a deflector configured to deflect illumination light from a light source to scan an object and deflect reflected light from the object; and
a light guide configured to guide the illumination light from the light source to the deflector and guide the reflected light from the deflector to a first sensor,
wherein the light guide includes a first surface on which the illumination light from the light source is incident and a second surface including a transmissive region through which the illumination light from the first surface is transmitted and a reflective region that reflects the reflected light from the deflector,
wherein the first and the second surfaces are non-parallel to each other,
wherein the illumination light from the first surface is incident on the transmissive region without passing through other surfaces,
wherein the traveling direction of the illumination light incident on the first surface and the traveling direction of the reflected light reflected by the reflective region are perpendicular to each other, and
wherein, in a cross-section perpendicular to the first and the second surfaces, the following conditional expression is satisfied:
t 1 /h 1 >sin(90°+θ 2 −2θ 3 )/(cos θ 1 *sin 2θ 3 )
where t 1 denotes a maximum optical path length of the illumination light from the first surface to the transmissive region, h 1 denotes the diameter of the illumination light incident on the first surface, θ 1 [°] denotes the incident angle of the illumination light with respect to the first surface, θ 2 [°] denotes the refraction angle of the illumination light with respect to the first surface, and θ 3 [°] denotes the incident angle of the illumination light with respect to the transmissive region.