High Resolution CRT Display Overlay for Probe Position Determination
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
An improved CRT overlay is described which makes use of the piezoelectric effect produced when a stress (force) is applied to polyvinylidene fluoride film in a direction perpendicular to the film. A stylus (i.e., ballpoint pen) or finger will serve as the source of stress. Other applications exist, for example, in robotics for tactile sensing (Image Omitted) and flat surface object recognition. Typical piezoelectric film (e.g., type "KF" from Kureha Corp.) is fabricated with top and bottom surface lines of metallized aluminum. For the CRT display overlay application, metallized indium-tin oxide is used because it is a transparent conductor. Fig. 1 illustrates in simplistic form a layout for touch panel 1 carried on an electronic circuit board 2 which carries appropriate scan logic (Fig. 2).