Spectrometer and image forming apparatus having the same

摘要

There is provided is a spectrometer having a concave reflection type diffraction element, wherein, among surfaces other than a diffraction surface of the diffraction element, non-diffraction surfaces which are located outside the diffraction surface at the same side as the diffraction surface are a glossy surface, the spectrometer includes a light detection unit which is located at an imaging position of a first-order diffracted light diffracted by the diffraction element to receive the first-order diffracted light, and the light detection unit is disposed inside optical paths of light beams regularly reflected on the non-diffraction surfaces outside the diffraction surface. Accordingly, it is possible to effectively suppress a stray light reflected on the surfaces other the diffraction surface from being incident into the light detection unit and to detect the light spectrally diffracted by the diffraction surface at high accuracy.

主权项

1. A spectrometer comprising:
a reflection type diffraction element having a diffraction area that diffracts an incident light beam, and a non-diffraction area located outside the diffraction area; and a light detection unit configured to receive a diffracted light diffracted by the diffraction element, wherein the diffraction area and the non-diffraction area are integrally composed of a resin, wherein a reflection ratio of the diffraction area is higher than a reflection ratio of the non-diffraction area, wherein the light detection unit is disposed inside optical paths of light beams regularly reflected on the non-diffraction area, and wherein the diffraction area has a base surface that is anamorphic.