INCLINATION SENSOR, OPTICAL PICKUP APPARATUS, AND OPTICAL DISK APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an inclination sensor capable of precisely outputting a signal containing information on the two-direction inclination of an object.

SOLUTION: A luminous flux enters optical diffraction means (113 and 114) via the object, diffracted in a direction corresponding to the direction of a first axis at diffraction efficiency corresponding to an angle of incidence on the direction corresponding to the direction of the first axis, and diffracted in a direction corresponding to the direction of a second axis at diffraction efficiency corresponding to an angle of incidence on the direction corresponding to the direction of the second axis. Diffracted light from a diffracting element is received by a photodetector PD to output a photoelectric conversion signal corresponding to the quantity of received light from the photodetector. The photoelectric conversion signal outputted from the photodetector thereby contains both information on the inclination of the object in the direction of the first axis and information on its inclination in the direction of the second axis. Since the quantity of received light itself at the photodetector contains information on the inclination of the object, it is possible to precisely output the signal containing information on the two-directional inclination of the object.

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