Spectrometry device and image forming apparatus

1. A spectrometry device comprising:

a spectroscope that includes a light receiving optical system including a light receiver and on which light from a measurement target is incident;

a distance detector that detects a distance between the measurement target and the spectroscope; and

a first optical path adjusting unit that adjusts an optical path of the light incident on the light receiving optical system from the measurement target according to the distance detected by the distance detector,

wherein the light receiving optical system includes a first reflecting mirror that reflects the light incident on the light receiving optical system toward the light receiver, and

the first optical path adjusting unit adjusts the optical path by changing an angle between a surface of the first reflecting mirror and a direction from the first reflecting mirror toward the light receiver such that the angle becomes smaller as the distance increases.

2. The spectrometry device according to claim 1 ,

wherein the spectroscope includes an illumination optical system that irradiates the measurement target with illumination light, and

the first optical path adjusting unit adjusts the optical path of the light incident on the light receiving optical system so that the light that is reflected toward the light receiving optical system from a region in the measurement target irradiated with the illumination light is incident on the light receiver.

3. The spectrometry device according to claim 1 ,

wherein the light receiving optical system includes a first reflecting mirror that reflects the light incident on the light receiving optical system toward the light receiver, and

the first optical path adjusting unit moves the first reflecting mirror in a predetermined direction.

4. The spectrometry device according to claim 1 ,

wherein the first optical path adjusting unit moves the light receiver.

5. The spectrometry device according to claim 4 ,

wherein the first optical path adjusting unit parallelly moves the light receiver.

6. The spectrometry device according to claim 4 ,

wherein the light receiving optical system includes an aperture that passes part of light from the measurement target, and

the first optical path adjusting unit pivots the light receiver around the aperture.

7. The spectrometry device according to claim 4 ,

wherein the light receiving optical system includes a spectroscopy element on which the light incident on the light receiving optical system is incident, and

the first optical path adjusting unit moves the spectroscopy element.

8. The spectrometry device according to claim 1 ,

wherein the first optical path adjusting unit rotates the light receiver.

9. The spectrometry device according to claim 8 ,

wherein the light receiving optical system includes a spectroscopy element on which the light from the measurement target is incident, and

the first optical path adjusting unit pivots the spectroscopy element.

10. An image forming apparatus comprising:

the spectrometry device according to claim 1 ; and

an image forming unit that forms an image on an image formation target.

11. A spectrometry device comprising:

a spectroscope that includes an illumination optical system including a light source and irradiating a measurement target with illumination light and a light receiving optical system including a light receiver and on which light reflected by the measurement target is incident;

a distance detector that detects a distance between the measurement target and the spectroscope; and

a second optical path adjusting unit that adjusts an optical path of the illumination light emitted from the light source according to the distance detected by the distance detector,

wherein the illumination optical system includes a second reflecting mirror that reflects the illumination light from the light source toward the measurement target, and

the second optical path adjusting unit adjusts the optical path by changing an angle between a surface of the second reflecting mirror and a direction from light source toward the second reflecting mirror such that the angle becomes smaller as the distance increases.

12. The spectrometry device according to claim 11 ,

wherein the second optical path adjusting unit adjusts the optical path of the light emitted from the light source so that light that is reflected toward the light receiving optical system from a region in the measurement target irradiated with the illumination light is incident on the light receiver.

13. The spectrometry device according to claim 11 ,

wherein the illumination optical system includes a second reflecting mirror that reflects the light from the light source toward the measurement target, and

the second optical path adjusting unit moves the second reflecting mirror.

14. The spectrometry device according to claim 11 ,

wherein the second optical path adjusting unit moves the light source.

15. The spectrometry device according to claim 14 ,

wherein the second optical path adjusting unit parallelly moves the light source.

16. The spectrometry device according to claim 14 ,

wherein the illumination optical system includes an illumination-side aperture that passes part of the light emitted from the light source, and

the second optical path adjusting unit pivots the light source around the illumination-side aperture.

17. The spectrometry device according to claim 11 ,

wherein the second optical path adjusting unit rotates the light source.

18. A spectrometry device comprising:

a spectroscope that includes an illumination optical system including a light source and irradiating a measurement target with illumination light and a light receiving optical system including a light receiver and on which light reflected by the measurement target is incident,

wherein the light receiver includes a light receiving region of a size in which the light reflected from a predetermined range of measurement in the measurement target is received when a distance between the measurement target and the spectroscope is in a predetermined allowable distance,

wherein the light receiving optical system includes a first reflecting mirror that reflects the light incident on the light receiving optical system toward the light receiver, and

an optical path of the light incident on the light receiving optical system from the measurement target is adjusted by changing an angle between a surface of the first reflecting mirror and a direction from the first reflecting mirror toward the ht receiver such that the angle becomes smaller as the distance increases.