SHIELDING MECHANISM OF KTN OPTICAL SCANNER

摘要

PROBLEM TO BE SOLVED: To solve the problem that the deflection width of a deflection angle is gradually reduced in a KTN light deflector in spite of application of a burst voltage by continuous long-time application of a driving voltage and results in variation in performance of the light deflector to considerably limit the range of use of the light deflector using a KTN crystal.SOLUTION: An operation mechanism of a KTN crystal is provided which has a light shielding structure for shielding, from external light, the KTN crystal and tools and the like required for operating it. A light deflector is provided with a shielding structure which shields an electro-optic crystal like a KTN crystal from light in the band of a wavelength causing light absorption due to a trap level of the electro-optic crystal and wavelengths shorter than the wavelength causing light absorption and has at least one window through which incident light to the electro-optic crystal and emitted light from the electro-optic crystal pass.