Spectral imaging apparatus provided with spectral transmittance variable element and method of adjusting spectral transmittance variable element in spectral imaging apparatus

Abstract

A spectral imaging apparatus includes: a spectral transmittance variable element having a spectral transmittance characteristics such that a transmittance periodically varies with wavelength and being capable of changing the variation period, for converting light from an object under observation into light having a plurality of peak wavelengths; a light extracting device for extracting, from the light having a plurality of peak wavelengths, light for imaging that contains a peak wavelength proximate to a predetermined command wavelength designated by a user and light for calibration that contains a peak wavelength other than the peak wavelength proximate to the command wavelength; an image sensor for capturing an image of the object under observation formed of the light for imaging; a detector for detecting, from the light for calibration, the peak wavelength other than the peak wavelength proximate to the command wavelength; and a control unit including, an operation processing section that calculates the peak wavelength that is proximate to the command wavelength and is contained in the light for imaging, from the peak wavelength that is other than the peak wavelength proximate to the command wavelength, is contained in the light for calibration and is detected by the detector, calculates an amount of shift between the peak wavelength proximate to the command wavelength as calculated and the command wavelength, and determines an amount of adjustment of the variation period on a basis of the amount of shift, and a drive processing section that drives the spectral transmittance variable element for changing the variation period.