PURPOSE: To produce microlens array of flat plate readily and inexpensively, by forming a mask of microlens array on a silica porous plate, diffusing a solution containing an element to change refractive index from the mask and sintering the silica porous material.
CONSTITUTION: A negative type resist 2 is formed on the surface of a dry gel using fine powder silica as a raw material or porous gel obtained by heat- treating the dry gel of a highly siliceous porous glass plate 1 and light is exposed through a photo mask 3 to the plate. The circumference of the prepared sintered gel with the mask having formed pattern is taped, a solution 7 of titanium ethoxide in ethanol to change refractive index is added onto the mask 3 and diffused into the sintered gel. Then, the gel is dried at 60°C, put in an electric furnace, heat-treated at 400°C to decompose and release the resist of the mask. The heat treatment temperature is further raised, the gel is sintered in a He atmosphere at 1,400°C, to produce microlens array of flat plate readily.
KANBE SADAO
MIYASHITA SATORU
TAKEUCHI TETSUHIKO
KITABAYASHI HIROHITO
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