System for visual communication
US4084332A · kind A · utility
Inventors
Key dates
| Filing date | Mar 7, 1977 |
| Grant date | Apr 18, 1978 |
| Priority date | — |
| Expiry date | Mar 7, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09B3/085
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A system for visual communication, the system being particularly useful in designing and producing games, puzzles, autocorrective tests, programed teaching materials, coloring sets or sheets, graphic arts supplies and various other educational, game and amusement devices. The system involves a substrate defining a marking surface, at least one visible stable dye, at least one normally visible reactive dye of a color different than that of the stable dye, an activator chemically isolated from at least the reactive dye prior to use of the system, and a solvent common to both the dyes and activator. In operation the system involves the steps of applying at least one of the dyes to a selected area of the marking surface to form a first visible indicium thereon, and of bringing the dyes and activator into contact with one another in at least a portion of the selected area in the presence of the solvent, such contact resulting in a reaction between the reactive dye and activator to change or eliminate the color of the reactive dye, thereby providing a second visible indicium of a color distinctly different than that of the first visible indicium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.