| 摘要 |
A high-resolution light-beam scanning apparatus utilizing only mass-producable holograms instead of utilizing auxiliary optical systems such as optical lenses or a mirror having curvature. The light beam scanning apparatus is capable of compensating for disadvantages including scanning beam thickening and variation, failure of a rotatable hologram to rotate at a constant velocity, displacement of a scanning beam position in the scanning direction and the cross scanning direction due to a mode hop of a wavelength of a semiconductor laser, and deviation of a base of a rotatable hologram from a parallel state, which disadvantages are detrimental to efforts for increasing the resolution of a hologram scanner and lowering the cost thereof. The light beam scanning apparatus incudes at least two holograms with an optical path length difference DELTA PHI <( lambda 2/D lambda ) where < is a constant less than 0.5. The path length is related per the above equation to a wavelength, lambda , at the center of the light surface, and a wavelength displacement DELTA lambda measured from the wavelength +558 at the center of the light surface.
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