Colorimetric apparatus and colorimetric method
AssigneeCanon Kabushiki Kaisha
InventorToshiki Miyazaki
Life of this patent
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Abstract
In an apparatus including an irradiation unit capable of irradiating a sheet selectively with visible light and ultraviolet light, and a measurement unit which measures a spectral reflectance based on light reflected by the sheet, whether to cause the irradiation unit to emit the ultraviolet light when measuring the spectral reflectance of a patch image printed on the sheet is determined based on the spectral reflectance of a reference image of the color of the sheet that has been measured by the measurement unit which measures a spectral reflectance while the ultraviolet light is emitted.
Claims9
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 image of a color of the sheet that is measured by said measurement unit while the ultraviolet light is emitted, whether to cause said irradiation unit to emit the ultraviolet light when measuring a spectral reflectance of a patch image printed on the sheet.
A colorimetric method comprising:
- a first measurement step of measuring a spectral reflectance of a reference image of a color of a sheet while irradiating the sheet with ultraviolet light;
- a second measurement step of measuring a spectral reflectance of a patch image printed on the sheet while irradiating the sheet with visible light;
- and
- a determination step of determining, based on whether the spectral reflectance measured in the first measurement step contains a spectral reflectance of a wavelength region of visible light, whether to measure the spectral reflectance of the patch image while irradiating the sheet with ultraviolet light.
Dependencies are inferred from the claim text.