An optical system includes a diffractive optical element and a refractive optical element. The diffractive optical element corrects a chromatic aberration flare component of wavelengths other than a predetermined wavelength (a design wavelength) remaining in the refractive optical element by means of an aspherical component given by the grating pitch of a diffraction grating included in a diffractive portion of the diffractive optical element. In addition, a refractive portion of the diffractive optical element is adapted to correct an aberration component as a composite of the aberration component of the design standard wavelength shifted by the correction and the aberration component of the design standard wavelength of the refractive optical element.

 
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< Electrophoretic display apparatus

< Facsimile apparatus

> Optical scanner and image forming apparatus using the same

> Image processing for correcting defects of read image

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