| 摘要 |
PURPOSE:To prevent gradation from decreasing when color information is read by using a light source which has irregular spectral characteristics such as a halogen lamp by making the sampling density of one of plural photodetecting element different from that of others. CONSTITUTION:The sample density of one of the plural photodetecting elements 64R, 64G, and 64B is made different from that of others. Then when a halogen lamp is used as the light source, the sampling density of the photodetecting element 64B corresponding to blue is only lowered. In this case, the sampling density of the photodetecting element 64B corresponding to blue is set 1/N (N=2, 3 ...) as large as the sampling density of the photodetecting elements 64R and 64G corresponding to red and green. Consequently, the quantity of exposure to blue increases and a sufficient output is obtained from the photodetecting element corresponding to blue and outputs with good balance are therefore obtained as to the respective colors. Consequently, the gradation is prevented from decreasing.
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