Patent ID: 7502303

Claim:
An optical pick-up device comprising: a laser diode; an objective lens focusing a light beam emitted from the laser diode on an optical disc; an optical detector receiving a light beam reflected from the optical disc; a beam splitter passing the light beam emitted from the laser diode and the reflected beam therethrough or reflecting the light beam emitted from the laser diode and the reflected beam; a front monitor receiving the light beam emitted from the laser diode; and a front monitor light-guiding plate guiding a part of the light beam emitted from the laser diode to the front monitor; wherein the front monitor light-guiding plate is arranged between the laser diode and the objective lens; and wherein a region of the front monitor light-guiding plate illuminated by the light beam emitted from the laser diode includes a first region having a predetermined shape for causing the part of the light beam emitted from the laser diode to change a traveling direction thereof by refraction and then reach the front monitor.