发明授权
US06236633B1 Bifocal optical pickup head 有权
双焦光学拾音头

Bifocal optical pickup head
摘要:
A bifocal optical pickup head is disclosed for use in a optical pickup apparatus having a single objective lens, for generating two different focuses (bifocus) to access a compact disc (CD) and a digital versatile disc (DVD), which the thickness is different. When a beam passes through an optical element disclosed in the present invention, numerical aperture is controlled and spherical aberration is reduced by the optical element due to variations in optical path and radius. Therefore, after beams having different numerical apertures are focused by an objective lens, various focuses can be obtained.
信息查询
0/0