Imaging unit and measurement device
A measurement apparatus includes an inclined dichroic mirror configured to separate light from a sample by transmitting or reflecting the light according to wavelengths, a total reflection mirror configured to reflect one part of light either transmitted or reflected by the inclined dichroic mirror, an imaging element configured to photograph the other part of the light transmitted or reflected by the inclined dichroic mirror in a first imaging region and photograph light reflected by the total reflection mirror in a second imaging region different from the first imaging region, and a control apparatus configured to correct images photographed in the first imaging region and the second imaging region based on optical characteristics related to a change in transmittance and reflectance with respect to a wavelength in the inclined dichroic mirror.
1 . An imaging unit comprising:
a separation optical element configured to separate light from an object by transmitting or reflecting the light according to wavelengths, an edge shift width of the separation optical element having a predetermined width, the edge shift width being a width of a wavelength band in which a transmittance and a reflectance change linearly according to a change in wavelength;
a first area sensor configured to capture the light transmitted through the separation optical element;
a second area sensor configured to capture the light reflected by the separation optical element; and
a processer configured to derive a wavelength center of gravity of each wavelength based on a transmitted image captured by the first area sensor, a reflected image captured by the second area sensor, and the edge shift width of the separation optical element.
2 . The imaging unit according to claim 1 , wherein the processer stores in advance correction data considering optical characteristics related to a change in transmittance and reflectance with respect to a wavelength in the separation optical element, and corrects images captured by the first area sensor and the second area sensor using the correction data.
3 . The imaging unit according to claim 1 , wherein the processer receives correction data considering optical characteristics related to a change in transmittance and reflectance with respect to a wavelength in the separation optical element, and corrects images captured by the first area sensor and the second area sensor using the correction data.
4 . The imaging unit according to claim 1 , wherein the processer corrects uneven color caused by an incident angle of light on the separation optical element.
5 . The imaging unit according to claim 1 , wherein the processer corrects a shift of a detection wavelength caused by a boundary between a wavelength band in which a transmittance and a reflectance change according to a change in wavelength and a wavelength band in which the transmittance and the reflectance do not change.
6 . The imaging unit according to claim 1 , wherein the processor is configured to derive a wavelength difference with respect to a wavelength having a transmittance of 50% based on an amount of transmittance derived from the transmitted image, an amount of reflectance derived from the reflected image and the edge shift width, and derive the wavelength center of gravity based on the wavelength difference.
7 . A measurement apparatus comprising:
the imaging unit according to claim 1 ; and
an analyzer configured to analyze a processing result in the imaging unit including an image corrected by the processer.