Patent ID: 7177258

Claim:
An optical pickup apparatus for reading/reproducing data on an optical recording medium, comprising: a light source configured to emit a light beam; a diffracting device configured to transmit the light beam emitted from the light source, and to diffract a light beam reflected from the optical recording medium; an optical device having a reflecting portion and a transmitting portion, configured to reflect one part of the light beam emitted from the light source to the diffracting device by the reflecting portion and to transmit another part of the light beam emitted from the light source to the optical recording medium by the transmitting portion, and to transmit the light beam reflected from the optical recording medium to the diffracting device by the transmitting portion; a transmissive type hologram for signal light detection and monitor light detection, said transmissive hologram comprising said diffracting device and said optical device, said transmissive hologram having said transmitting portion between said diffracting device and said reflecting portion, a photodetecting device configured to detect the light beam reflected from the optical recording medium through the optical device and the diffracting device, for signal light detection; and wherein the diffracting device includes a diffracting portion to diffract the one part of the light beam reflected by the reflecting portion of the optical device to the photodetecting device for monitor light detection of the light source.