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AssigneeCanon Kabushiki Kaisha
InventorMakoto Torigoe
Estimating the term…
In a prior art, since the wavelengths of R, G, and B LEDs serving as the light sources of a CIS scanner vary, read colors vary between individual scanners. Since the behavior of metamerism also changes due to the same reason, measures against the metamerism are hard to take. To solve this problem, a color patch is irradiated with light from an LED, and its spectral reflectivity is measured using a spectroreflectometer, thereby estimating the emission wavelength of the light source LED. A signal change characteristic representing the relationship to the output signals of three LEDs obtained from the spectral reflectivity of the patch is stored in a memory. In actual image reading, color correction is performed based on the signal change characteristic stored in the memory.
An LED emission wavelength estimation method of estimating emission wavelengths of three LEDs which are mounted in an image reading apparatus to emit light of three primary colors, comprising:
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