CONDENSING OPTICAL SYSTEM AND IMAGE RECORDER

摘要

PROBLEM TO BE SOLVED: To make the depth of focus deep with a stable spot diameter and to prevent light quantity from being lowered. SOLUTION: By using a high-output broad area type semiconductor laser (BLD), the shallowness of the depth of focus occurring because of the broadness of an active layer being the defect of the BLD is eliminated only by the relative positional relation of a condensing optical system 16. Thus, the depth of focus can be made deep by simple constitution (condensing optical system 16).