| 摘要 |
PURPOSE:To realize a small-sized and thin optical head device and simultaneously, to attain high-speed access by using a hologram element provided with a mirror function to reflect the optical path of a laser beam to the direction of a recording medium and the function of an objective lens to converge the laser beam to the recording medium in the optical head device. CONSTITUTION:An elliptic laser beam emitted from a laser light source 1 is made parallel by a collimate lens 2, and is made nearly circular by a shaping prism 3, and is transmitted through a beam splitter 4, and by reflecting and converging its optical path to the direction of the recording medium by a reflection type hologram lens 5, information recorded on the recording medium 6 is reproduced. Or the information is recorded and reproduced or recorded, reproduced and erased to/from the recording medium 6. |
