Patents Represented by Attorney Chittaranjan Nirmel
  • Patent number: 4696860
    Abstract: Fine particles, preferably of brown alumina (approximately 96% Al.sub.2 O.sub.3), are disposed between closely spaced and normally parallel surfaces of two adjacent transparent layers, such as are typically found in a touch sensitive overlay (TSO). The particles are preferably of a size within the range 3-100 microns, and are distributed in a density preferably in the range 300-3,000 particles per square inch, so that the larger particles are in simultaneous contact with both the parallel surfaces. Local pressure on a TSO panel with this distribution of particles of non-uniform size allows operation of the panel without the generation of distracting Newton rings between the surfaces contacting the particles. These particles may be conveniently sprayed onto either of the parallel surfaces in suspension with a fluid carrier that evaporates to leave the particles adhering to the sprayed surface.
    Type: Grant
    Filed: September 26, 1985
    Date of Patent: September 29, 1987
    Assignee: John Fluke Mfg. Co., Inc.
    Inventor: David L. Epperson