Self-erasing thermochromic writing board and system

摘要

A self-erasing writing system includes a writing surface structure, a writing instrument, and an erasing structure. The writing surface is preferably a laminate structure having a layer of a thermochromic material. The thermochromic material is of one color when within a certain temperature range (e.g. room temperature), but changes to a second color when the material is brought into a second temperature range (e.g. a lower temperature). The writing instrument is a temperature controlled cooled tip device that lowers the thermochromic material to within the second temperature range at the point of contact such that the points of contact become the second color. The thermochromic material has a "memory" that retains the second color until the temperature is raised to within a third temperature range at which time the thermochromic material changes back to its first color. The erasing structure is a heater either layered integral with the laminate structure or a separately applied heater as in the form of a conventional eraser. Several layers of thermochromic material may be used to provide various colors when used with a variable temperature writing instrument.