Optical design of the f-θ lens in laser scanning system

f-θ lens is one of the most important parts of laser scanning system,and has been widely used in many equipments,such as laser marking machine,faxes,laser printer,laser pattern generator for semiconductor integrated circuit,laser scanning in the precision meter equipment and so on.An f-θ lens of laser scanning in non-contact is designed.The lens,besides having negative distortion,belonging to far center ray in image space,imaging with homogeneous light,with the requirement of the image quality for wavefront less than λ/4,also requires that the image quality in the whole image surface should be consistent,and the image surface should be plane with no vignetting.The designed lenses are simple、compact,its focus is short and their cost are low with high precision.The focusing performances are within diffraction limit,the relative illuminations quite uniform and the distortion relative to the f-θ linear relation small.