Encapsulated electroluminescent phosphor particles

Claim 2

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating; wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50 percent of the initial electroluminescent brightness of the uncoated phosphor particles, and wherein the percent of luminescent brightness retained following 100 hours operation in an environment having a relative humidity of at least 95 percent is greater than about 70 percent of the intrinsic brightness retained following 100 hours operation, wherein initial change in electroluminescent brightness in an environment having a relative humidity of at least 95 percent and intrinsic brightness change are measured under substantially equivalent operating conditions of temperature, voltage, and frequency.

Claim 3

The encapsulated phosphor particles of claim 1 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 70 percent of the initial luminescent brightness of the uncoated phosphor particles.

Claim 4

The encapsulated phosphor particles of claim 1 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 80 percent of the initial luminescent brightness of the uncoated phosphor particles.

Claim 5

The encapsulated phosphor particles of claim 1 wherein said retained electroluminescent brightness is greater than about 80 percent of said intrinsic brightness.

Claim 6

The encapsulated phosphor particles of claim 1 wherein said retained electroluminescent brightness is greater than about 90 percent of said intrinsic brightness.

Claim 7

The encapsulated phosphor particles of claim 1 wherein said particles contain minor amounts of one or more of the following: cadmium, selenium, copper, bromine, chlorine, manganese, or silver.

Claim 8

The encapsulated phosphor particles of claim 1 wherein said particles are between about 1 and about 50 microns in diameter.

Claim 9

The encapsulated phosphor particles of claim 1 wherein said particles are between about 10 and about 40 microns in diameter.

Claim 10

The encapsulated phosphor particles of claim 1 wherein said coating is between about 0.1 and about 3.0 microns thick.

Claim 11

The encapsulated phosphor particles of claim 1 wherein said coating is between about 0.1 and about 0.5 microns thick.

Claim 12

The encapsulated phosphor particles of claim 1 wherein said coating comprises at least one of the following: titania, silica, alumina, tin oxide, zirconia, or mullite.

Claim 13

The encapsulated phosphor articles of claim 11 wherein said coating comprises at least one of titania or silica.

Claim 14

The encapsulated phosphor particles of claim 1 wherein said oxide coating was formed via the reaction of vapor phase metal oxide precursors at a temperature between about 25° C. and about 170° C.

Claim 15

The encapsulated phosphor particles of claim 13 wherein said oxide coating was formed via hydrolysis.

Claim 16

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating; wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50 percent of the initial electroluminescent brightness of the uncoated phosphor particles, said metal oxide coating having been formed via hydrolysis of vapor phase metal oxide precursors.

Claim 17

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating; wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50 percent of the initial electroluminescent brightness of the uncoated phosphor particles, said metal oxide coating having been formed via hydrolysis of vapor phase metal oxide precursors.

Claim 18

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating; wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50 percent of the initial electroluminescent brightness of the uncoated phosphor particles, and wherein the percent of electroluminescent brightness retained following 100 hours operation in an environment having a relative humidity of at least 95 percent is greater than about 70 percent of the intrinsic brightness retained following 100 hours operation, wherein initial brightness and change in electroluminescent brightness in an environment having a relative humidity of at least 95 percent and intrinsic brightness change are measured at ambient temperature under substantially equivalent operating conditions, including an applied electric field of 2.20 volts per micron and a frequency of 400 Hertz.

Claim 19

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating; wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50 percent of the initial electroluminescent brightness of the uncoated phosphor particles, and wherein the percent of electroluminescent brightness retained following 100 hours operation in an environment having a relative humidity of at least 95 percent is greater than about 70 percent of the intrinsic brightness retained following 100 hours operation, wherein initial brightness and change in electroluminescent brightness in an environment having a relative humidity of at least 95 percent and intrinsic brightness change are measured at ambient temperature under substantially equivalent operating conditions, including an applied electric field of 2.20 volts per micron and a frequency of 400 Hertz.

Claim 20

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating formed via hydrolysis of vapor phase metal oxide precursors; and wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50% of the initial electroluminescent brightness of the uncoated phosphor particle, and the percent of electroluminescent brightness retained by the encapsulated phosphor particles following 100 hours operation in an environment having a relative humidity of at least 95 percent is greater than about 70 percent of the intrinsic brightness retained following 100 hours operation, the initial brightness and change in electroluminescent brightness in an environment having a relative humidity of at least 95 percent and intrinsic brightness change being measured under substantially the same operating conditions.

Claim 21

Encapsulated electroluminescent phosphor particles, each comprising a particle of zinc sulfide-based electroluminescent phosphor which is essentially completely encapsulated within a substantially transparent, continuous metal oxide coating formed via hydrolysis of vapor phase metal oxide precursors; and wherein said encapsulated phosphor particles have an initial electroluminescent brightness which is equal to or greater than about 50% of the initial electroluminescent brightness of the uncoated phosphor particle, and the percent of electroluminescent brightness retained by the encapsulated phosphor particles following 100 hours operation in an environment having a relative humidity of at least 95 percent is greater than about 70 percent of the intrinsic brightness retained following 100 hours operation, the initial brightness and change in electroluminescent brightness in an environment having a relative humidity of at least 95 percent and intrinsic brightness change being measured under substantially the same operating conditions.

Claim 22

The encapsulated phosphor particles of claim 17 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 70 percent of the initial electroluminescent brightness of the uncoated phosphor particles.

Claim 23

The encapsulated phosphor particles of claim 17 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 80 percent of the initial electroluminescent brightness of the uncoated phosphor particles.

Claim 24

The encapsulated phosphor particles of claim 17 wherein said retained electroluminescent brightness is greater than about 80 percent of the retained intrinsic brightness.

Claim 25

The encapsulated phosphor particles of claim 17 wherein said retained electroluminescent brightness is greater than about 90 percent of the retained intrinsic brightness.

Claim 26

The encapsulated phosphor particles of claim 17 wherein said coating is between about 0.1 and about 3.0 microns thick.

Claim 27

The encapsulated phosphor particles of claim 17 wherein said coating is between about 0.1 and about 0.5 microns thick.

Claim 28

The encapsulated phosphor particles of claim 17 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 70 percent of the initial electroluminescent brightness of the uncoated phosphor particles, and the retained electroluminescent brightness is greater than about 80 percent of the retained intrinsic brightness.

Claim 29

The encapsulated phosphor particles of claim 24 wherein the retained electroluminescent brightness is greater than about 90 percent of the retained intrinsic brightness.

Claim 30

The encapsulated particles of claim 24 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 80 percent of the initial electroluminescent brightness of the uncoated phosphor particles.

Claim 31

The encapsulated phosphor particles of claim 17 wherein the initial electroluminescent brightness of said particles is equal to or greater than about 80 percent of the initial electroluminescent brightness of the uncoated phosphor particles, and the retained electroluminescent brightness is greater than about 90 percent of the retained intrinsic brightness.