Lens unit, LED head, exposure device, image forming device, and scanning device

摘要

A lens unit includes first and second arrays of microlenses. The microlenses in the first array have mutually parallel optical axes and are aligned in a meridional direction orthogonal to their optical axes. The microlenses in the second array are aligned in the same direction as the lenses in the first array, and have optical axes that coincide with the optical axes of corresponding microlenses in the first array. The microlenses in the first array collimate light incident in a sagittal plane orthogonal to the meridional direction. The microlenses in the second array focus the collimated light in the sagittal plane. The lens unit is useful in the scanning heads of scanning devices, the LED heads of LED printers, and in the exposure devices of other electrophotographic image forming apparatus.