广角镜头及其摄像单元与监视装置;WIDE-ANGLE LENS AND IMAGE PICK-UP UNIT AND MONITOR DEVICE THEREOF

摘要

一种广角镜头及其摄像单元与监视装置，此广角镜头包括由物侧至像侧依序排列的：具有负屈光度的第一透镜，其像侧面为凹面；孔径光阑；具有正屈光度的第二透镜，其像侧面为凸面；具有正屈光度的第三透镜；以及具有负屈光度的第四透镜，其系与第三透镜构成一双胶合透镜。其中，广角镜头需满足特定条件，以达到全长短且视角广的效果。; an aperture stop; a second lens with a positive refractive power including a convex surface facing the image side; a third lens with a positive refractive power; and a fourth lens with a negative refractive power constituting a doublet cemented lens with the third lens. The wide-angle lens satisfies a specific condition to achieve a shorter total track length and a wider field of view is provided.