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US 3,978,340 AGranted
Luminescent backing sheet for reading and writing in the dark
OwnerBecky J. Schroederinventor
Life of this patent
Estimating the term…
Abstract
A phosphorescent backing sheet for use in underlying relation with light transmitting writing sheets, drawing sheets or sheets having reading or other intelligible matter thereon in lines thick enough to permit a person to read in the dark as well as write in the dark.
Claims6
A luminescent backing assembly for making intelligible matter visible in darkness comprising;
- a backing member having a luminescent glow surface,
- an overlay sheet of material through which luminescent glow light can pass overlying said backing surface,
- said overlay sheet having intelligible matter thereon comprising contrasting luminescent reading matter of different activated color from said luminescent surface and which in combination with said luminescent surface causes said matter to be silhouetted against said luminescent surface and visibly discernable in the dark.
A luminescent surface member adaptable to making intelligible matter visible in darkness comprising;
- a surface having intelligible matter defined by phosphorescent and fluorescent materials,
- said phosphorescent and fluorescent materials having matched activated glow colors such that neither is substantially visible against the other when activated and upon removal from influence of the activating source, the phosphorescent material will continue to glow while said fluorescent material ceases to glow.
Dependencies are inferred from the claim text.