Patent ID: 7787085

Claim:
A pretilt angle producing method, comprising: preparing a photo-alignment substrate coated with a photo-alignment film material; preparing a light source for exposing the photo-alignment substrate to light; installing a photomask having slits as wide as 2 to 100 μm between the photo-alignment substrate and the light source; applying light toward the photomask from the light source; generating periodically intensity-modulated linearly polarized ultraviolet radiation toward the photo-alignment substrate through the photomask vertically; and moving the photo-alignment substrate and the photomask relative to each other at a scanning speed of 50 to 500 μm/sec to apply the periodically intensity-modulated linearly polarized ultraviolet radiation to the film from the photomask in a vertical direction to produce the light and shade with the each edge of the silts as a boundary so as to develop a pretilt angle at the each boundary portion on the photo-alignment film.