PURPOSE: To form a lens array on a base plate without using mask or precise registration by a method in which the range of low transmittance to photosensitive wave length is provided on a base plate like a lattice or a stripe, and said range is coated with photosensitive resin, and then said photosensitive resin is exposed to light from its rear surface, and further the unexposed part to the light of the photosensitive resin is removed by developing treatment.
CONSTITUTION: The base plate 10 in which a latticelike or stripelike light shielding range 11 is formed, is coated with the photosensitive resin 12 of negative type in which the part having received the radiation of light is to remain. The photosensitive resin 12 is exposed to the light including the photosensitive wave length of the photosensitive resin 12 from the rear surface opposite to the surface coated with the photosensitive resin 12. By means of developing treatment, the photosensitive resin having been unexposed to the light is removed by the latticelike or stripelike light shielding range 11, and at this state, when the lens shape with desired characteristics is not obtained, the photosensitive resin pattern 14 of a semispherical lens is formed by making the viscous fluidity at the temperature equal to the glass transition temperature of the photosensitive resin or higher.
KAMIHIRA KAZUTAKE
WADA TSUTOMU
