×

Patterned indicators

  • US 5,719,828 A
  • Filed: 10/22/1990
  • Issued: 02/17/1998
  • Est. Priority Date: 01/04/1990
  • Status: Expired due to Fees
First Claim
Patent Images

1. An indicator comprising:

  • a first substrate having first and second surfaces;

    an ink pattern on said first surface of said first substrate;

    a second substrate having first and second surfaces;

    a chemical agent on the first surface of the second substrate;

    wherein the first surfaces of each substrate overlay and are in contact with each other, the chemical agent and the ink pattern coacting to cause the ink pattern to bleed along the first surface of the first substrate to cause a visually perceptible change in the pattern over a selected time interval.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×