Patent ID: 7911920

Claim:
An optical pick-up apparatus for multi-recording/reproducing, comprising: an optical source module comprising a CD optical source and a DVD optical source; a diffracting grating to divide a light beam output from the optical source module into at least three divided light beams; a first optical divider to change a propagation path of the divided light beams onto an optical disk; a second optical divider to reflect and forward the divided light beams reflected from the optical disk along a predetermined ratio; a first optical detector comprising a single optical sensor to receive one of the divided light beams as reflected from the second optical divider; and a second optical detector comprising at least three optical detection sensors for receiving one of the divided light beams as forwarded through the second optical divider, wherein the first optical divider and the second optical divider are arranged in opposite directions along a predetermined inclination angle, wherein the first optical detector obtains a focus error signal by using a beam size detection method for controlling a focus servo of a DVD-RAM type optical disk.