Image recording apparatus

摘要

A laser beam emitted from a semiconductor laser is guided to a sensitive recording medium on a drum by a focusing optical system and an optical anisotropic element. The optical anisotropic element separates the laser beam along its optical axis to produce a laser beam having two focused positions for thereby increasing the depth of focus. With the increased depth of focus, it is possible to record a highly accurate image on the sensitive recording medium even if the sensitive recording medium is displaced because the drum has its outer circumferential surface not concentric with its axis or the sensitive recording medium is lifted off the drum.