| 摘要 |
PROBLEM TO BE SOLVED: To embody an optical pickup which is capable of dealing with >=2 kinds of optical disks used with laser beams of different wavelengths, is capable of well executing recording and reproducing and is yet compact and inexpensive. SOLUTION: This optical pickup has plural semiconductor lasers 2 and 3 which radiate the laser beams of the wavelengths varying from each other, an anamporphic coupling lens 5 which couples the respective laser beam fluxes from the plural semiconductor lasers 2 and 3 to approximately parallel beam fluxes, an objective lens 7 which condenses the laser beams coupled as the parallel beam fluxes by the coupling lens 5 as a light spot onto the recording surface of the optical disk 8 and luminous flux detecting means 4 and 9 which detect the reflected light by the recording surface as a return luminous flux. The focal length: fX in the X direction and the focal length fY in the Y direction of the coupling lens are 0<fX<fY when the optical axis direction of the coupling lens 5 is defined as a Z direction and the two directions which are orthogonal with the Z direction and are orthogonal with each other are defined as the X direction and the Y direction. The respective light emitting parts of the semiconductor lasers 2 and 3 are arrayed in the X-Z plane. |
