Abstract: A skew adjusting apparatus is provided. The skew adjusting apparatus includes a plurality of skew support members provided on a base mold coupled to a base chassis to have an elastic force, and a plurality of skew screws configured to couple a motor plate that supports a spindle motor to the base mold.

Abstract: An optical pickup control circuit includes an adding portion that adds a tracking driving signal which is for moving an objective lens, provided to face a discoid optical information recording medium, in a tracking direction of the corresponding optical information recording medium, to a tilt driving signal which is for moving the corresponding objective lens in a tilt direction of the corresponding optical information recording medium, and supplies the signal to a tilt actuator.

Abstract: In an optical head device which performs recording or reading of data in/from a high-density optical disc using an objective lens with a large NA, a saw-tooth shape diffraction element is used for also performing recording or reading of data in/from a conventional optical disc, such as DVD, CD, or the like. A step difference that produces an optical path length for blue light which is equal to or longer than the wavelength of the blue light and optical path lengths for red and infrared light which are shorter than the wavelengths of the red and infrared light is utilized so as to exert an inverse action on the blue light to those exerted on the red and infrared light. The effect of increasing the working distances for CD and DVD enables multiple compatibility. The above optical element is integrally combined with the objective lens to perform a tracking servo following operation.