Fabrication and performance of a one-to-one erect imaging microlens array for fax

摘要

Microlens arrays which image a full size document onto a photoreceptor for copying or transmitting purposes are currently of much interest. In particular those arrays which have total conjugate distances less than 10 mm are important because of the compactness they afford in the contact image sensor (CIS) unit design. In this paper the fabrication of such a one-to-one array utilizing the photosensitive glass-based SMILE $+tm$/ process is described. The performance of the array in terms of contrast vs. spatial frequency for a facsimile document reader application is tested in a commercial CIS unit. The overall measured performance is examined in terms of the process parameters involved in the lens fabrication. Advantages and disadvantages of the microlens array relative to other methods are considered.