Method of manufacturing microlens substrate, and microlens exposure optical system
Provided is a method of manufacturing a microlens substrate capable of facilitating optical axis alignment and simplifying manufacturing processes by patterning a lens shape of a second microlens array using a first microlens array. The lens shape of the cylindrical second microlens array is patterned by irradiating the first microlens array with ultraviolet rays. Light emitted from a linear light source which is variable in its position is imaged on a focal surface of the first microlens array by a collimator lens and the first microlens array, and a resist layer formed by being coated on the focal surface is exposed. By performing exposure while changing the position of the linear light source, a resist pattern of a desired cylindrical shape can be obtained. Thereafter, etching is performed to transfer the shape of the resist pattern onto an intermediate glass layer, and recesses are buried with a high refractive index UV curable resin.
1. A microlens exposure optical system used for manufacturing a microlens substrate having a first microlens array, an intermediate layer and a second microlens array laminated in this order on a transparent substrate, the microlens exposure optical system comprising:
a linear light source emitting lights having a uniform intensity;
a collimator lens collimating the lights emitted from the linear light source; and
the transparent substrate having a photosensitive resin layer formed on the intermediate layer, the lights passed through the collimator lens being imaged on the photosensitive resin layer via the first microlens array and the intermediate layer.
2. The microlens exposure optical system according to claim 1 , wherein
a position of the linear light source is variable.
3. The microlens exposure optical system according to claim 1 , wherein
the transparent substrate is rotatably arranged so that a tilt angle formed between a normal of the transparent substrate and an optical axis of each light is variable.
4. The microlens exposure optical system according to any one of claims 1 to 3 , further comprising:
a narrow band-pass optical filter inserted into an optical path of the lights emitted from the linear light source.