Optical pick-up device

An optical pick-up device, comprising:

• a light emitting element which emits a laser beam;
• a polarization semi-reflective member which reflects or transmits the laser beam;
• a quarter wavelength plate with a reflective film which reflects and polarizes the laser beam;
• an objective lens which projects the laser beam onto a recording surface of an optical disc;
• and
• a light receiving element which receive the laser beam;
• wherein the objective lens, the quarter wavelength plate, the polarization semi-reflective member, and the quarter wavelength plate with a reflective film are arranged in this order from the side of the recording surface of the optical disc in a vertical direction with respect to the recording surface of the optical disc;
• and the light emitting element and the light receiving element are respectively arranged on the opposite sides of the polarization semi-reflective member in a direction parallel to the recording surface of the optical disc;
• and
• wherein in an outward path for projecting the laser beam onto the recording surface of the optical disc, the laser beam emitted from the light emitting element is reflected on the polarization semi-reflective member, polarized by the quarter wavelength plate, and then passed through the objective lens so that the laser beam is focused on the recording surface of the optical disc, and in a returning path for receiving the laser beam reflected on the recording surface of the optical disc, the laser beam reflected on the recording surface of the optical disc is polarized by the quarter wavelength plate, transmitted through the polarization semi-reflective member, reflected on the reflective film of the quarter wavelength plate with a reflective film, and then reflected on the polarization semi-reflective member so that the laser beam is received by the light receiving element.