Laser machining apparatus with rotatable phase grating

Abstract

A laser machining method and apparatus for performing high-speed and high-precision machining on a thin film deposited on a substrate, as well as a liquid crystal panel. The apparatus includes: a plurality of pulse laser generators; a system for alternately driving a plurality of pulse laser generators so that the plurality of pulse laser generators generate laser beams having a delay in phase between each other; a system for making the laser beams generated by the plurality of laser beam generators equal in quality; a system for converting the laser beams generated by the plurality of laser beam generators into elliptically polarized laser beams; and a system for dividing each laser beam emitted by each of the plurality of laser beam generators into a plurality of laser beams; whereby an object to be processed is selectively illuminated with the plurality of laser beams produced by the beam-dividing system. The system for dividing each laser beam emitted by each of the plurality of laser beam generators into a plurality of laser beams is embodied by a phase grating. The phase grating has a structure on its surface which divides each laser beam into a sub plurality of laser beams having equal intensity, from which open grooves having a uniform shape and uniform quality can be formed. The liquid crystal panel includes an electrode structure in which open grooves are formed on an ITO film by using the apparatus. Open grooves (electrode gaps) having a constant width less than 10 .mu.m are uniformly formed in a display area at constant intervals. Thus, the liquid crystal panel according to the present invention provides a much greater contrast ratio and much better visibility performance than conventional techniques, wherein these are primary factors which doming the display quality.