Patent ID: 9213446
Filing Date: 2015-12-15
Classification: G06F,G06K

Abstract:
1. A handwriting input device comprising: a transparent or translucent object to be coated capable of guiding non-visible light therewithin by total internal reflection; a light source part configured to emit non-visible light which is incident into the object to be coated and is guided therewithin by total internal reflection; a detection unit configured to periodically optically detect an area of the object to be coated on which a coating material has been deposited by distinguishing non-visible light transmitted from the object to be coated and through the coating material due to an optical coupling between the object to be coated and the coating material, the optical coupling thereby destroying the total internal reflection and transmitting the non-visible light through the coating material; and a display unit configured to periodically cause a visual change in a visible image in accordance with the detection of the area of the object to be coated on which the coating material has been deposited, wherein the coating material is physically removable from the object to be coated, and the display unit is further configured to change the visible image based on a removal of the coating material.