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US 7,002,758 B2Granted
Collimator optical system and optical information storage device
AssigneeFujitsu Limited
InventorsKazushi Uno, Shingo Hamaguchi
Life of this patent
Estimating the term…
Abstract
The present invention is intended, as an object thereof, to improve stability against both temperature changes and light source output changes, and includes an achromatic lens having a composite structure of glass or a plastic lens having a diffraction grating counteracting a focal length change due to a wavelength change of light, where a lens holder is adhered to an opposite side to a light source of an overhang of the achromatic lens made of glass while the lens holder is adhered to a light source side of the overhang of the plastic lens with the diffraction grating.
Claims5
A collimator optical system comprising:
- a base;
- a light source fixed on the base and emitting diffused pencils of light;
- an achromatic lens having an overhang on its rim and having a composite structure of glass, the lens converting diffused pencils of light emitted by the light source to parallel pencils of light;
- and
- a lens holder fixed on the base and adhered to an opposite side to the light source of the overhang of the achromatic lens to hold the achromatic lens.
2 more elements
Dependencies are inferred from the claim text.