Optical head device for forming light spot on disc-shaped information medium

An optical head device has at least one upward-reflecting mirror, objective lenses, an objective lens actuator, and a moving mechanism. The upward-reflecting mirror receives an incident luminous flux having a wavelength emitted from a semiconductor, and changes its direction. The objective lenses having mutually different numerical apertures condense the luminous flux whose direction has been changed by the upward-reflecting mirror to radiate a condensed luminous flux onto an information recording medium. The objective lens actuator moves the objective lenses in the focus direction of the information recording medium so that the luminous flux incident on the information recording medium attains a focused state. The moving mechanism moves the upward-reflecting mirror so that the luminous flux is incident on the information recording medium via any one of the objective lenses.