| 摘要 |
PURPOSE:To obtain a thin type optical head device by arranging a beam splitter inside an actuator and constituting a detection optical system with a light wave path element. CONSTITUTION:Inside a main body 28, the beam splitter 32 and the actuator 34 are provided, and inside the actuator 34, the beam splitter 32 is arranged. And at the lower end part of the main body 28, the light wave path element 46 is fixed and the luminous flux reflected on the surface of a disk 42 passes an aperture part 44 through an objective lens 40 and the beam splitter 32, then it is diffracted by a diffraction grid 48, totally reflected several times in the light wave path element 46 and focused on a sensor 50. Thus the height of the whole device is equal to the sum obtained by adding the height of the actuator 34 to the thickness of the light wave path element 46, so that it is possible to thin the device to about 10mm in thickness. |
