illustrates an enlarged protrusion end of a cut substrate.FIG. 3 is a plan view schematically illustrating the structure of a common grinder wheel.FIG. 4 is a plan view schematically illustrating the structure of a unit liquid crystal display panel cut by a grinder wheel according to the present invention.FIGS. 5A and 5B are a sectional view and a plan view schematically illustrating a grinder wh