Optical apparatus

1. An optical apparatus comprising:

a lighting unit that emits illumination rays;

an imaging unit that includes a wavelength selecting unit including a plurality of wavelength selection regions through which the illumination rays reflected by a surface of an object or the illumination rays transmitted through the surface pass, and a sensor configured to receive the illumination rays passing through the wavelength selecting unit;

a processor; and

a positioning unit, wherein

the lighting unit includes:

a light emitting unit from which the illumination rays are emitted; and

an imaging optical element that makes the illumination rays emitted from the light emitting unit parallel,

the imaging unit includes a first imaging optical element through which the illumination rays reflected by the surface or the illumination rays transmitted through the surface pass,

the illumination rays passing through the first imaging optical element are incident on the wavelength selecting unit,

the positioning unit determines whether or not the illumination rays and an optical axis of the first imaging optical element are in a directly-facing relationship, by moving the light emitting unit,

in the directly-facing relationship,

when rays are incident along one of the illumination rays and the optical axis of the first imaging optical element and reflected by the surface, a dominant, specular component of reflected rays is in a specular direction along the other of the illumination rays and the optical axis of the first imaging optical element, and

when rays are incident along one of the illumination rays and the optical axis of the first imaging optical element and transmits the object, a dominant component of transmitting rays is along the other of the illumination rays and the optical axis of the first imaging optical element,

the plurality of wavelength selection regions includes a first wavelength selection region and a second wavelength selection region,

the first wavelength selection region converts a first ray passing through the first wavelength selection region among the illumination rays into a first selected ray whose dominant wavelength is a first wavelength,

the second wavelength selection region converts a second ray passing through the second wavelength selection region among the illumination rays into a second selected ray whose dominant wavelength is a second wavelength different from the first wavelength,

the sensor is able to acquire color phase information indicating color phases of the first selected ray and the second selected ray, and

the processor is configured to estimate a ray direction of the first ray and a ray direction of the second ray based on the color phase information and a relative position of the wavelength selecting unit in the imaging unit.

2. The optical apparatus according to claim 1 , wherein the wavelength selecting unit is arranged on a focal plane of the first imaging optical element.

3. The optical apparatus according to claim 1 , wherein the lighting unit includes:

a light emitting unit from which the illumination rays are emitted;

a second imaging optical element that makes the illumination rays emitted from the light emitting unit parallel; and

the positioning unit, and

the positioning unit is able to incline ray directions of the parallel rays with respect to an optical axis of the second imaging optical element.

4. The optical apparatus according to claim 1 , wherein

the imaging unit includes the positioning unit, and

the positioning unit determines a position of the wavelength selecting unit.

5. The optical apparatus according to claim 1 , wherein the processor is configured to acquire information on ray directions of scattered light scattered on the surface by using the color phase information.

6. The optical apparatus according to claim 1 , wherein the wavelength selection regions are rotation symmetry.

7. The optical apparatus according to claim 1 , wherein

the plurality of wavelength selection regions are lined up in a row, and

the sensor includes a line sensor.

8. The optical apparatus according to claim 1 , further comprising:

a beam splitter that causes the ray directions of the illumination rays just before being reflected by the surface to be along a direction from the imaging unit toward a point where the illumination ray is reflected by the surface.

9. The optical apparatus according to claim 1 , further comprising:

a beam splitter, wherein

the lighting unit includes a light emitting unit that is arranged on a focal plane of the first imaging optical element along a ray path broken by the beam splitter.

10. The optical apparatus according to claim 9 , wherein

the positioning unit includes a movable unit that includes the light emitting unit and the wavelength selection regions, and

the movable unit is movable along the optical axis of the first imaging optical element in a state where a relative position between the light emitting unit and the wavelength selection regions is maintained.

11. The optical apparatus according to claim 10 , wherein

the first imaging optical element includes a zoom lens, and

the movable unit moves along the optical axis in accordance with a movement of a focal plane of the zoom lens accompanied with a change in a zooming magnification of the zoom lens.

12. The optical apparatus according to claim 10 , wherein the positioning unit includes:

a parallel link mechanism that includes a plurality of robot arms connected to the movable unit and moves the movable unit;

a driving unit that drives the parallel link mechanism; and

the control device that controls the driving unit, and the movable unit includes the sensor.