Patent ID: 8947730
Filing Date: 2015-02-03
Classification: B41F,G01J,G01N

Abstract:
1. A colorimetric apparatus comprising: an irradiation unit configured to irradiate a sheet selectively with visible light and ultraviolet light; a measurement unit configured to measure a spectral reflectance based on light reflected by the sheet; and a determination unit configured to determine, based on a spectral reflectance of a reference on the sheet that is measured by said measurement unit during an emission of the ultraviolet light, whether to cause said irradiation unit to emit the ultraviolet light when measuring a spectral reflectance of each of color patches on the sheet, wherein, said irradiation unit includes a first ultraviolet light source and a second ultraviolet light source having a wavelength different from that of the first ultraviolet light source, and wherein, in a case where the spectral reflectance of the reference contains a wavelength region of visible light, said measurement unit measures each of the color patches on the sheet by the first ultraviolet light source and the second ultraviolet light source respectively.