PURPOSE: To increase the quantity of light and to improve the read resolving power by forming a beam spot which is short in an X-axis direction and long in an Y-axis direction on a record carrier.

CONSTITUTION: Light emitted from a light source 11 while converged once is passed through the pinhole of a stop plate 13 which has the hole whose major axis length and minor axis length are different from each other to be focused in a beam shape which is short in a relative movement direction (X-axis direction) and long perpendicularly to it (Y-axis direction) on the record carrier 15 having a signal recorded in a stripe. Consequently, while the quantity of light detemined by the diameter of the beam in the beam is secured, the read resolving power determined by the beam diameter in the relative movement direction (X-axis direction) is improved.