Patent ID: 9019246
Filing Date: 2015-04-28
Classification: G06F

Abstract:
1. An electronic writing system, comprising: a display device for drawing a pattern with a handwriting device, the display device having a plurality of pixel regions and a plurality of sensing regions, a plurality of portions of the display device in the pixel regions being used for displaying an image respectively, a plurality of portions of the display device in the sensing regions being used for sensing light respectively emitted from the handwriting device or an image eraser, and wherein the handwriting device and the image eraser are two independent devices, each of the sensing regions being corresponding to at least one of the pixel regions to enable that when a portion of the display device in one of the sensing regions receives a light, the portion of the display device in the sensing region sends out a display signal to the portion of the display device in corresponding pixel region, wherein the display device comprises a plurality of first color filters having a first color, a plurality of second color filters having a second color and a plurality of third color filters having a third color respectively disposed in each of the sensing regions; switching on the image eraser for generating a first light with a fourth color, the fourth color being a mixture of at least two colors selected from the first color, the second color and the third color, wherein the image eraser comprises: a holder; a first light guide plate, disposed in the holder, the first light guide plate having at least one first light entrance surface and a first light exit surface, wherein the first light guide plate has a bottom surface disposed opposite to the first light exit surface, and the bottom surface has a plurality of micro structures; a reflective or a transflective layer disposed between the first light guide plate and the holder, wherein the micro structures directly contact the reflective laver or the transflective laver; at least one first light source, disposed on the first light entrance surface of the first light guide plate, for generating the first light, wherein the first light enters the first light guide plate through the first light entrance surface and emits out of the first light guide plate from the first light exit surface; and at least one first optical film, covering the first light exit surface of the first light guide plate; and wherein the first optical film comprises a lower diffuser, two brightness enhancement films, and an upper diffuser, and the lower diffuser, the two brightness enhancement films, and the upper diffuser are disposed on the first light exit surface of the first light guide plate from bottom to top in order, illuminating the display device with the first light for erasing a portion of the pattern.