Patent US5422489A successfully refreshed from Google Patents.
US5422489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light emitting device
Assignee: Nanocrystals Technology LP
•
Filing: 1994-01-24
•
Granted: 1995-06-06
•
Expires: 2014-01-24
Abstract
Abstract A glowing device comprises a substrate which is substantially transparent to radiation in a first spectral region and supports a nanoparticle or nanocrystal active layer, which is a thin layer constituted of separated tiny particles with nanometer dimensions, typically 100 Å or less in size. When the nanocrystal layer comprises one of certain luminescent materials activated with certain activators, the layer when excited will efficiently emit radiation characteristic of the activator. Since the particles making up the active layer are very small, the layer can be made very thin, of the order of 1000 Å or less. With this small thickness, the layer will be substantially transparent to radiation except for a narrow range of radiation capable of being absorbed by the active layer and thus capable of exciting the nanocrystal layer. When thus excited, the active layer will emit radiation in a narrow wavelength range. When the incident radiation extends over a broad spectral region, then part of the spectral energy will be absorbed and converted to the radiation characteristic of the nanocrystal layer, and the rest will pass through the nanocrystal layer and substantially transparent substrate, which to an observer will appear to glow with light in the narrow wavelength range. By providing multiple layers of nanocrystals, each responsive to a different part of the spectrum, a larger part of the incident radiation energy will be converted to glowing light.
Inventors
- 👤 Rameshwar N. Bhargava
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:58
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/88; C09K11/881; C09K11/883; F; F21; F21K; F21K2/00
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
91 words
A glowing device comprising: (a) a substrate substantially transparent in a first spectral region and substantially absorbent in a second spectral region, (b) a thin active layer on said substrate, said active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a third spectral region, said active layer having a thickness less than about 1000 Angstroms, (c) said device being positioned such that the active layer faces in the direction of and can receive incident radiation in said third spectral region.
Claim 2
Dependent Claim
91 words
A glowing device comprising: (a) a substrate substantially transparent in a first spectral region and substantially absorbent in a second spectral region, (b) a thin active layer on said substrate, said active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a third spectral region, said active layer having a thickness less than about 1000 Angstroms, (c) said device being positioned such that the active layer faces in the direction of and can receive incident radiation in said third spectral region.
Claim 3
Dependent Claim
23 words
The glowing device as claimed in claim 1, wherein the third spectral region has a wider wavelength range than the first spectral region.
Claim 4
Dependent Claim
52 words
The glowing device as claimed in claim 1, wherein the nanoparticles each comprise a host compound doped with an activator, said host compound having a bandgap capable of absorbing radiation in said third spectral region, said activator forming in the host bandgap energy levels providing radiating transitions in the first spectral region.
Claim 5
Dependent Claim
18 words
The glowing device as claimed in claim 1, wherein said active layer is less than 500 Å thin.
Claim 6
Dependent Claim
25 words
The glowing device as claimed in claim 1, wherein said substrate and active layer are substantially transparent to visible light in the first spectral region.
Claim 7
Dependent Claim
88 words
The glowing device as claimed in claim 1, wherein the nanoparticles each comprise a mixture of a first and a second host compound doped with an activator, said first host compound having a bandgap capable of absorbing radiation in a first part of said third spectral region, said second host compound having a bandgap capable of absorbing radiation in a second part of said third spectral region, said activator forming in the first and second host compound bandgaps energy levels providing radiating transitions in the first spectral region.
Claim 8
Dependent Claim
105 words
A glowing device comprising: (a) a substrate substantially transparent in a first spectral region, (b) a filter associated with said substrate and substantially transparent in said first spectral region and substantially absorbent in a second spectral region, (c) a thin active layer on said substrate, said active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a third spectral region, said nanoparticles having a thickness less than abut 100 Angstroms, (d) said device being positioned such that the active layer faces in the direction of and can receive incident radiation in said third spectral region.
Claim 9
Dependent Claim
105 words
A glowing device comprising: (a) a substrate substantially transparent in a first spectral region, (b) a filter associated with said substrate and substantially transparent in said first spectral region and substantially absorbent in a second spectral region, (c) a thin active layer on said substrate, said active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a third spectral region, said nanoparticles having a thickness less than abut 100 Angstroms, (d) said device being positioned such that the active layer faces in the direction of and can receive incident radiation in said third spectral region.
Claim 10
Dependent Claim
23 words
The glowing device as claimed in claim 7, wherein the third spectral region has a wider wavelength range than the first spectral region.
Claim 11
Dependent Claim
52 words
The glowing device as claimed in claim 7, wherein the nanoparticles each comprise a host compound doped with an activator, said host compound having a bandgap capable of absorbing radiation in said third spectral region, said activator forming in the host bandgap energy levels providing radiating transitions in the first spectral region.
Claim 12
Dependent Claim
18 words
The glowing device as claimed in claim 9, wherein said nanoparticles are less than 100 Å in size.
Claim 13
Dependent Claim
25 words
The glowing device as claimed in claim 9, wherein said substrate and active layer are substantially transparent to visible light in the first spectral region.
Claim 14
Dependent Claim
38 words
The glowing device as claimed in claim 7, wherein said third spectral region is substantially the same as that of solar radiation, and the first spectral region is a narrow band of wavelengths within the solar energy spectrum.
Claim 15
Dependent Claim
20 words
The glowing device as claimed in claim 12, wherein the activator is Mn and the first spectral region is yellow.
Claim 16
Dependent Claim
146 words
A glowing device comprising: (a) a substrate substantially transparent in a first spectral region, (b) a filter associated with said substrate and substantially transparent in said first spectral region and substantially absorbent in a second spectral region, (c) a first thin active layer on said substrate, said first active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a third spectral region, (d) a second thin active layer on said first active layer, said second active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a fourth spectral region that encompasses shorter wavelengths than the third spectral region, (e) said device being positioned such that the second active layer faces in the direction of and can receive incident radiation in said third and fourth spectral regions.
Claim 17
Dependent Claim
146 words
A glowing device comprising: (a) a substrate substantially transparent in a first spectral region, (b) a filter associated with said substrate and substantially transparent in said first spectral region and substantially absorbent in a second spectral region, (c) a first thin active layer on said substrate, said first active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a third spectral region, (d) a second thin active layer on said first active layer, said second active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a fourth spectral region that encompasses shorter wavelengths than the third spectral region, (e) said device being positioned such that the second active layer faces in the direction of and can receive incident radiation in said third and fourth spectral regions.
Claim 18
Dependent Claim
87 words
The glowing device as claimed in claim 14, wherein the nanoparticles each comprise a host compound doped with an activator, said host compound in said first active layer having a bandgap capable of absorbing radiation in said third spectral region, said host compound in said second active layer having a bandgap capable of absorbing radiation in said fourth spectral region, said activator forming in the bandgap of the host compound in said first and second active layers energy levels providing radiating transitions in the first spectral region.
Claim 19
Dependent Claim
27 words
The glowing device as claimed in claim 15, wherein the host compound is different in said first and second active layers, but the activator is the same.
Claim 20
Dependent Claim
25 words
The glowing device as claimed in claim 16, wherein said substrate and active layers are substantially transparent to visible light in the first spectral region.
Claim 21
Dependent Claim
34 words
The glowing device as claimed in claim 17, wherein said host compound in said first active layer is ZnS, said host compound in said second active layer is ZnSe, and the activator is Mn.
Claim 22
Dependent Claim
55 words
The glowing device as claimed in claim 17, further comprising a third thin active layer on said second active layer, said third active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a fifth spectral region that encompasses shorter wavelengths than the fourth spectral region.
Claim 23
Dependent Claim
55 words
The glowing device as claimed in claim 19, further comprising a fourth thin active layer on said third active layer, said fourth active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to incident radiation in a sixth spectral region that encompasses shorter wavelengths than the fifth spectral region.
Claim 24
Dependent Claim
32 words
The glowing device as claimed in claim 20, wherein the third and fourth active layers have different host compounds from that of the first and second active layers but the same activator.
Claim 25
Dependent Claim
24 words
The glowing device as claimed in claim 21, wherein the first, second, third and fourth active layers comprise, respectively, CdSe, CdS, ZnSe, and ZnS.
Claim 26
Dependent Claim
11 words
The glowing device of claim 22, wherein the activator is Mn.
Claim 27
Dependent Claim
114 words
A glowing device comprising: a) a substrate substantially transparent in a first visible spectral region and substantially absorbent in a second visible spectral region, b) a thin active layer on said substrate, said active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to absorption of incident radiation in a third spectral region, said active layer being substantially transparent to all visible radiation longer in wavelength than that of the third spectral region, said nanoparticles having a size less than about 100 Angstroms, (c) said device being positioned such that the active layer faces in the direction of and can receive incident radiation in said third spectral region.
Claim 28
Dependent Claim
114 words
A glowing device comprising: a) a substrate substantially transparent in a first visible spectral region and substantially absorbent in a second visible spectral region, b) a thin active layer on said substrate, said active layer comprising separate nanoparticles capable of emitting radiation in said first spectral region in response to absorption of incident radiation in a third spectral region, said active layer being substantially transparent to all visible radiation longer in wavelength than that of the third spectral region, said nanoparticles having a size less than about 100 Angstroms, (c) said device being positioned such that the active layer faces in the direction of and can receive incident radiation in said third spectral region.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-05 | 1998-12-05 | 1999-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-05 | 2002-12-05 | 2003-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-05 | 2006-12-05 | 2007-06-06 | $7700.00 | Window Closed / Lapsed |