Substrate design for optimized performance of up-conversion phosphors utilizing proper thermal management

• US 7,075,707 B1
• Filed: 05/07/2004
• Issued: 07/11/2006
• Est. Priority Date: 11/25/1998
• Status: Expired

• Current Assignee: University of Central Florida (State University System of Florida)
• Original Assignee: University of Central Florida (State University System of Florida)
• Inventors: Rapaport, Alexandra, Milliez, Anne Janet, Jenssen, Hans, Bass, Michael
• Primary Examiner(s): Lee, John D.
• Application Number:
  US10/841,188
• Time in Patent Office: 795 Days
• Field of Search: 524/403, 524/413, 524/130, 524/132, 359/326, 365/151
• US Class Current: 359/326
• CPC Class Codes: C09K 11/602 Chalcogenides
• CPC Class Codes: C09K 11/616 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/7705 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/7711 with halogens
• CPC Class Codes: C09K 11/7757 Halogenides
• CPC Class Codes: C09K 11/7758 Aluminates; Silicates
• CPC Class Codes: C09K 11/7766 containing two or more rare earth metals
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: C09K 11/7772 Halogenides C09K11/7767 takes precedence
• CPC Class Codes: C09K 11/7773 with alkali or alkaline earth metal
• CPC Class Codes: C09K 11/7776 Vanadates; Chromates; Molybdates; Tungstates
• CPC Class Codes: C09K 11/7778 with alkaline earth metals
• CPC Class Codes: G02F 2/02 Frequency-changing of light, e.g. by quantum counters

Abstract

Methods and compositions for using an up-conversion phosphor as an emitting material in a reflective displays and Polymer compositions for display mediums, and blue green red (BRG) display mediums. Roles of the pumping duration and character on the temperature and the efficiency of the up-conversion process in (Ytterbium, Erbium or Thulium) co-doped fluoride crystals are set forth. Methods, compositions and display mediums for using up-conversion phosphors in both reflective and transmissive displays in which the substrate and pixel shapes are designed to maximally remove heat deposited in the emitting material and thereby improve the efficiency of up conversion.

Claims

1. A method for using an up-conversion phosphor as an emitting material in a reflective display comprising the step of:

designing a shape of said display to hold said up-conversion phosphor;

pumping said display from a source with an intensity and a duration to excite said up-conversion phosphor;

selecting said display to maximally remove any heat developed in the up-conversion phosphor in the emitting material during said pumping to optimize a performance of said up-conversion phosphor, wherein the luminescent efficiency of said up-conversion phosphor is substantially increased.

2. The method according to claim 1 wherein said reflective display is a pixel.

3. The method according to claim 1 wherein said reflective display is a substrate.

4. The method according to claim 3 wherein said reflective display is heat conductive.

5. The method according to claim 3 wherein said reflective display is copper.

6. The method according to claim 3 wherein said reflective display is aluminum.

7. The method according to claim 3 wherein said reflective display is chemical vapor deposition (CVD) diamond.

8. A method for using an up-conversion phosphor as an emitting material in a transmissive display comprising the step of:

designing a shape and material of said display to maximally remove any heat developed in the emitting material when pumped with an intensity and a duration, wherein the luminescent efficiency of said up-conversion phosphor is substantially increased.

9. The method according to claim 8 wherein said transmissive display is a pixel.

10. The method according to claim 8 wherein said transmissive display is a substrate.

11. The method according to claim 8 wherein said transmissive display is heat conductive.

12. The method according to claim 8 wherein said transmissive display is copper.

13. The method according to claim 8 wherein said transmissive display is aluminum.

14. The method according to claim 8 wherein said transmissive display is chemical vapor deposition (CVD) diamond.

15. A blue green red (BRG) display medium comprising:

(a) pixels having a blue, a green and a red emitter dispersed on a high heat conductive substrate; and

,

(b) means for pulsing said pixels with a beam of light with wavelength near approximately 980 μ

m, wherein said high heat conductive substrate provides thermal management to optimize performance of said pixels to emit appropriate blue, green and red luminescence when pumped with the 980 μ

m wavelength beam of light.

16. The blue green red (BRG) display medium according to claim 15 wherein said means is by short pulse excitation.

17. An up conversion display comprising:

a three color up-conversion material having three different emitters;

a heat-conductive substrate to reduce the operating temperature of the three color up-conversion material, wherein the substrate has a shape to hold the three color up-conversion material; and

a pumping source for providing a pulse having an intensity and a duration for exciting the three color up-conversion material, wherein the three color up-conversion material and the pulse intensity and pulse duration are selected to optimize the up-conversion process to emit the three colors and improve the efficiency of the display.