The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 1995
Filed:
May. 20, 1993
William E Brown, Blue Springs, MO (US);
Charles W Dietterich, Brodheadsville, PA (US);
Richard M Mandle, Woodcliff Lake, NJ (US);
Binney & Smith Inc., Easton, PA (US);
Abstract
A thermochromic drawing device is disclosed which can be marked and erased by selectively changing the temperature of its drawing surface. The drawing surface of the drawing device consists of a flexible substrate printed with thermochromic inks having at least two color states. The flexible substrate has low thermal mass thereby enabling it to readily assimilate temperatures induced by a user and, consequently, facilitating the transition of the thermochromic inks from one color state to another. The drawing surface is further provided with an insulating layer which isolates the flexible substrate from unwanted heat sinks and heat sources thereby preventing unwanted color transitions of the thermochromic inks. Thus, a user can selectively change the color state of portions of the drawing surface to create distinctive markings.