Patent ID: 7555760

Claim:
An optical head for recording/reading data by irradiating an optical disk with a laser beam, comprising: a slide base for holding a laser beam source for emitting a laser beam, a mirror for reflecting the laser beam, a collimator lens for collimating the laser beam into a parallel beam, a beam splitter for splitting the beam reflected on the optical disk and a light receiving element for receiving and converting a light into electric signals; and an actuator for holding an objective lens mounted on the slide base for irradiating the optical disk with the laser beam; wherein the slide base includes: a spring stopper rib having a post portion protruding from the slide base, and a spring stopper portion arranged perpendicular to the post portion and in parallel with the slide base; and three ball seats for forming a common spherical face; the actuator includes: a lens holder for holding the objective lens; an actuator base for arranging the lens holder therein; a spring for biasing the actuator base; and screws for adjusting the angle of and fixing the actuator base; the actuator base includes: a rectangular bottom portion; rising portions rising from the four sides of the bottom portion; a cylindrical shaft protruding from the substantial center of the bottom portion and fitted rotatably and slidably in the lens holder; three protrusions arranged on the back side of the bottom portion and having their leading ends formed into ball shapes to abut against the ball seats; a spring receiving portion protruding from the vicinity of a predetermined corner of the bottom portion to the same plane as that of the bottom portion, for receiving the spring; and angle adjusting portions formed at such two of the rising portions as continue to the corner arranged orthogonally of the corner having the spring receiving portion arranged therein, for receiving the screws and for adjusting the angle with the screws; when the protrusions are arranged to abut against the ball seats, the spring stopper portion and the spring receiving portion confront each other, the spring stopper portion has a protrusion provided with a slope formed to confront the post portion whereas the spring receiving portion is provided, on its side facing the side of the post portion, with a recess having no side wall portion; and the spring has its one end portion fitted on the protrusion and its other end portion fitted in the protrusion thereby to prevent the spring from coming out and to apply an elastic force to the slide base through the spring receiving portion.