Patent ID: 8165003

Claim:
An optical pickup device, comprising: a first laser source which emits laser light having a first wavelength which is suited for recording and replaying a first signal to and from a digital versatile disc (DVD); and a second laser source which is arranged in an optical path apart from that of the first laser source and emits laser light having a second wavelength which differs from the first wavelength and which is suited for recording and replaying a second signal to and from a compact disc (CD) recording medium; wherein the optical pickup device is configured such that each of the laser light rays emitted from the first and the second laser source is directed into a common optical path by means of a polarizing beam splitter, the laser light directed into the common optical path is reflected by a plate-like beam splitter so as to be directed to an objective lens, the laser light is then converged by means of the objective lens and irradiated on a signal recording medium, and laser light reflected off of the signal recording medium is transmitted through the plate-like beam splitter and directed to an optical detector; the first laser source is arranged on a transmitting side of the polarizing beam splitter, while the second laser source is arranged on a reflecting side of the polarizing beam splitter; the polarizing beam splitter includes a splitting surface which substantially transmits s-polarization and p-polarization components of the laser light having the first wavelength and substantially reflects s-polarization component of the laser light having the second wavelength and substantially transmits p-polarization component of the laser light having the second wavelength; and the plate-like beam splitter includes a splitting surface which has a reflectance that is higher than its transmittance for both s-polarized and p-polarized light, regardless of whether the laser light has the first wavelength or the second wavelength, and the transmittance of the plate-like beam splitter splitting surface for p-polarized light is in the range of 15% -20% for laser light having the first wavelength and for laser light having the second wavelength.