Patent Document ID: 9514346
Application ID: 14272341
Patent Status: 1

Claim One:
1. An apparatus comprising: a first phosphor layer comprised of inorganic, ceramic materials on top of a substrate, the first phosphor layer having luminescent properties such that when it is illuminated by light having a first wavelength, it emits light having a second wavelength, the first phosphor layer is divided into a first two-dimensional grid of cells arranged in a first spatial pattern, wherein each cell of the first two-dimensional grid of cells corresponds to one bit of an identification code, a first portion of the first phosphor layer is removed from a first number of cells of the first two-dimensional grid of cells to expose the substrate for the first number of cells; and a second phosphor layer on top of the first phosphor layer, the second phosphor layer having luminescent properties such that when it is illuminated by light having a third wavelength, it emits light having a fourth wavelength, the second phosphor layer is divided into a second two-dimensional grid of cells arranged in the first spatial pattern such that each cell of the second two-dimensional grid of cells is directly above a cell of the first two-dimensional grid of cells, wherein each cell of the second two-dimensional grid of cells corresponds to the cell of the first two-dimensional grid of cells below it, a second portion of the second phosphor layer is removed from a second number of cells of the second two-dimensional grid of cells.