A method of embossing a sheet material includes: heating at least a portion of the sheet directly or indirectly with radiant energy from a radiant energy source; pressing a tool against the heated portion of the sheet, thereby patterning a surface of the sheet; and separating the sheet and the tool. The main cutting tooth has a honing angle, and the sub cutting tooth has a honing angle. The control unit is configured to cause the array to display the first sub-frame using the first plurality of pixels, and the control unit is configured to cause the array to display the second sub-frame using the second plurality of pixels. The second substrate structure includes a second substrate, a second common electrode and a second alignment film. An onoff pneumatic valve switch automatically shuts off the pneumatic pressure when a semicylindrical shield which covers the blade portion not being sharpened is rotated back away from the blade.