Lens system for optical beam scanner.

摘要

The present invention relates to a lens system for an optical beam scanner which scans a plurality of optical beams. The lens system comprises: a first lens group (FL) having an entrance pupil and including first and third lenses (L1, L3) each in the form of meniscus having a positive power, a fourth lens (L4) having a positive power, and a second lens (L2) having a negative power; and a second lens group (RL) including a fifth lens (L5) having a positive power. The first to fifth lenses are successively disposed in that order from the entrance pupil side. The resulting lens system has a telecentric and an f-sin theta characteristic.