EP0616488A2
Expired / Lapsed
EP
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Light-emitting elements
Assignee: Hitachi Ltd
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Filing: 1994-03-07
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Granted: —
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Expires: 2014-03-07
Abstract
Abstract A multi-color light-emitting element has at least two optical micro-cavity structures (102-106) having respectively different optical lengths determining their emission wavelengths. Each micro-cavity structure contains a film (105) of organic material as a light-emitting region. These may be a single film (105) of uniform thickness in the element.
Inventors
- 👤 Takahiro Nakayama
- 👤 Atsushi Kakuta
- 👤 Takao Iwayanagi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 17:50
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/26; H05B33/28; H05B33/22; H10; H10K; H10K50/00; H10K50/10; H10K50/11; H10K50/125; H10K50/80; H10K50/85; H10K50/852; H10K59/00; H10K59/80; H10K59/875; H10K59/876
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
49 words
A light-emitting element comprising an optical micro-cavity structure (102-106), characterised in that the element is a multi-color element having at least two optical micro-cavity structures having respectively different optical lengths determining their emission wavelengths, each said micro-cavity structure containing a film (105) of organic material as a light-emitting region.
Claim 2
Dependent Claim
26 words
A light-emitting element according to claim 1, wherein said film (105) of organic material is made of the same material in each said optical micro-cavity structure.
Claim 3
Dependent Claim
24 words
A light-emitting element according to claim 2, wherein said films (105) of organic material are respective portions of a layer of said organic material.
Claim 4
Dependent Claim
47 words
A light-emitting element according to any one of claims 1 to 3 wherein each said optical micro-cavity structure comprises, between said reflecting surfaces (102,106) thereof, at least one further film (103,104) selected from a transparent electrode, a hole-injection film, an electron-injection film and a transparent spacer film.
Claim 5
Dependent Claim
49 words
A light-emitting element according to claim 4, wherein the thickness of said further film (103,104) in a first one of said optical micro-cavity structures is different from the thickness of said further film in a second one of said optical micro-cavity structures, thereby to provide said different optical lengths.
Claim 6
Dependent Claim
34 words
A light-emitting element according to any one of claims 1 to 5, wherein each said micro-cavity structure comprises a pair of electrodes (103,106) for passing electrical current through said film (105) of organic material.
Claim 7
Dependent Claim
23 words
A light-emitting element according to any one of claims 1 to 6, wherein said optical micro-cavity structures are mounted on a common substrate.
Claim 8
Dependent Claim
36 words
A light-emitting element according to any one of claims 1 to 7, wherein a path for light emission from each said optical micro-cavity structure is provided by a half-mirror (102) which also provides a reflecting surfaces.
Claim 9
Dependent Claim
59 words
A light-emitting element according to any one of claims 1 to 8, wherein in each said optical micro-cavity structure, said optical length between reflecting surfaces thereof is in the range of 0.9 to 1.1 times one of (a) the peak wavelength of the light emitted by the optical micro-cavity structure and (b) an integral multiple of said peak wavelength.
Claim 10
Dependent Claim
80 words
A light-emitting element according to any one of claims 1 to 9, wherein, in each said optical micro-cavity structure, said optical length between said reflecting surfaces is in the range 0.9 P to 1.1. P, where P = 1/2 λ (m - A/2 π), where λ is the peak wavelength of the light emitted by the optical micro-cavity structure, m is an integer and A is the phase shift in radians of light reflected at each of said reflecting surfaces.
Claim 11
Dependent Claim
82 words
A light-emitting element having a substrate and formed on said substrate a plurality of pixels of each of at least two types respectively emitting light of different wavelength, characterised in that each said pixel has an optical micro-cavity (102-106) structure containing as light-emitting region (105) a thin film of organic material adapted to emit light of the wavelength of the pixel, said optical micro-cavity structure having an optical length determining the peak wavelength of the light emitted by it under resonant condition.
Claim 12
Dependent Claim
48 words
A light-emitting element according to claim 11 wherein each of said pixels includes, in said micro-cavity structure, a pair of electrodes (103,106) for passing current through said thin film (105) of organic material to cause light emission therein, said electrodes of said pixels being interconnected as an array.
Claim 13
Dependent Claim
51 words
A substrate for use in the manufacture of a multi-color light-emitting element according to claim 1, comprising a transparent substrate (101), a half mirror structure (102) formed on said substrate and consisting of a plurality of dielectric films and a transparent conductive layer (103) formed on said half mirror structure (102).
References Cited (Backward Citations)
No citation records indexed.
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