Abstract: The present invention provides a method of producing a latent polarized image having high contrast characteristics with no apparent contours or traces of the image under normal visualization. A polymer solution is prepared in an organic solvent, and then applied onto a light-reflecting substrate. The polymer layer is dried to produce an optically isotropic polymer layer and anisotropic images are formed on the polymer layer. The polymer solution's concentration is from 5 to 30% by weight, and the images are formed by application of micro-lines by thermo-mechanical means, having depths from 1 to 3 ?m and being separated from one another by 4 to 6 ?m at a process rate from 10 to 50 m/min. The thermomechanical means operates at a temperature that is 10 to 60% less than the polymer melting/disintegration temperature and contacts the polymer layer to form micro-lines for 0.015 to 0.650 msec.

Abstract: This utility patent is a single-handed vertical solid material grinder. It includes a shell, a handle set with a motion handle and a mounted handle, and a grinding set. The grinding set has a sector unit that is a sector cylinder with parallel teeth and a grinding unit with fixed teeth. The mounted handle is placed inside the shell. Between the motion handle and the shell is an elastic repositioning unit. There is a driving set between the motion handle and the sector unit. When using one hand to pull and then release the handle set, through the handle set inside the shell and the grinding set of sector unit and grinding unit, the motion handle will drive the sector unit move back and forth around the spinning axis, thus pushing the parallel teeth on the sector surface to smash back and forth through the fixed teeth on the grinding unit's surface. Thus the solid raw material is caught between the surfaces of the parallel teeth and the fixed teeth and is grinded down.