Laminated printed color conversion phosphor sheets
Embodiments are related generally to electronic displays and, more particularly, to emissive displays made with transparent sheets having phosphor dots on the surface for the purpose of color conversion.
1. An emissive display using printed phosphor color conversion sheets, the display comprising:
a backplane comprising a top surface with a first number of light emitting diode (LED) devices aligned in an array and configured to emit light in a visible spectrum with a first color;
a first transparent substrate attached to the top surface of the backplane, wherein the first transparent substrate includes a top surface having a second number of printed phosphor dots configured to emit light in the visible spectrum with a second color different than the first color, and wherein the second number of printed phosphor dots overly a first subset of the first number of the LED devices; and,
a second transparent substrate attached to the top surface of the first transparent substrate, wherein the second transparent substrate includes a pattern of a third number of printed phosphor dots overlying a second subset of the first number of LED devices, and wherein the first subset of the first number of LED devices is exclusive of the second subset of the first number of LED devices, and wherein the third number is less than the first number.
2. The display of claim 1 , wherein the first transparent substrate and the second transparent substrate are organized into a plurality of pixels, each pixel comprising:
a first area on the first transparent substrate including: one of the second number of printed phosphor dots configured to emit light in the visible spectrum with the second color, and a first adjacent region exposing two of the first number of LED devices underlying the first adjacent region; and,
a second area on the second transparent substrate including: one of the third number of printed phosphor dots configured to emit light in the visible spectrum with the third color, and a second adjacent region exposing one of the second number of printed phosphor dots and one of the two of the first number of LED devices underlying the first adjacent region.
3. The display of claim 1 , wherein the second number of printed phosphor dots on the first transparent substrate are formed of a first type of phosphor material having a first luminescence and a first light absorption characteristic, with a first diameter responsive to the first luminescence and a first thickness responsive to the first light absorption characteristic; and
wherein the third number of printed phosphor dots on the second transparent substrate exhibit a second luminescence and second light absorption characteristic, different than the first luminescence and first light absorption characteristic, with a second diameter responsive to the second luminescence and a second thickness responsive to the second light absorption characteristic, different than the first diameter and first thickness.
4. The display of claim 3 , wherein the first subset of the first number of LED devices each have a third diameter, the second subset of the first number of LED devices each have a fourth diameter, and a third subset of the first number of LED devices exposed through both the first transparent substrate and the second transparent substrate each have a fifth diameter.
5. The display of claim 1 , wherein the display further comprises a transparent adhesive interposed between the first transparent substrate and the top surface of the backplane.
6. The display of claim 5 , wherein the first transparent substrate and transparent adhesive have a combined thickness of greater than 20 microns.
7. The display of claim 1 , wherein the first transparent substrate is formed of a material selected from the group consisting of: plastic and glass.
8. The display of claim 1 , wherein the first transparent substrate is formed of a plastic material selected from the group consisting of: polyethylene naphthalate (PEN), and polyethylene terephthalate (PET).