Optical pick-up device

Abstract

An optical pick-up device is provided that reduces aberrations in light irradiated from an optical recording meidu. The device includes a light source that outputs light for recordation and reproduction of information onto the optical recording medium. An objective lens irradiates the light onto the optical recording medium by concentrating the light. An actuator adjusts the movement of the objective lens to focus the light on at least one or more layers of the optical recording medium. A controller moves the objective lens to substantially reduce the aberration occurring in the light irradiated from the optical recording medium by driving the actuator, such that aberrations, such as asymmetrical aberrations or coma aberrations, may be reduced and corrected.

Description

technical field [0001] The invention relates to an optical pickup device. More particularly, the present invention relates to an optical pickup device equipped with an actuator drivable in three directions. Background technique [0002] Commonly used optical recording media include compact discs (CDs) and digital versatile discs (DVDs). In addition to conventional and widely used optical discs, such as DVD and CD, there are various technologies regarding optical pickup devices compatible with high-density optical discs. Recently, a Blu-ray Disc using Blu-ray has been released. A new optical disc recording medium for high-density recording, which can be achieved by shortening the wavelength of a light source or increasing the numerical aperture (NA) of an objective lens, is urgently needed. [0003] While DVDs use a wavelength of 650nm and an NA of 0.6, a blue light source having a wavelength of 408nm and an objective lens increased to an NA of 0.8...

AI Technical Summary

Problems solved by technology

[0004] However, with the promotion of a short-wavelength laser light source or a higher NA objective lens, there arises a problem that an optical pickup device having a combination of a low NA objective lens and a relatively long-wavelength laser light source can only be used for conventional recordings such as CDs and DVDs. Optical discs perform recording and reproduction of information

[0005] One problem is that spherical aberration occurs in the objective lens due to the change of the small oscillation wavelength in the laser light source

[0006] Another problem is that even in an optical pickup using a finite optical system, the incident angle of light changes in response to movement of the objective lens, making the optical pickup susceptible to the occurrence of astigmatism or coma

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