A color filter manufacturing method for a plastic substrate uses an
extrusion process to form a plastic substrate with multiple grooves.
Then, it uses inkjet printing method to jet photo resists into the groove
of the plastic substrate after defining the primary colors of red R.,
green G., and blue B. The method can overcome the problem happened in the
conventional CF photolithography process. This, therefore, can simplify
the manufacturing process, and can apply to the large-area plastic
substrate of a color filter.