Organic luminescent devices with a multiplex structure

• US 5,682,402 A
• Filed: 01/11/1996
• Issued: 10/28/1997
• Est. Priority Date: 01/10/1995
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kakuta, Atsushi, Nakayama, Takahiro
• Primary Examiner(s): Scott, Jr., Leon
• Application Number:
  US08/584,473
• Time in Patent Office: 656 Days
• Field of Search: 372/39, 372/69, 372/44, 372/50, 372/7, 372/45, 359/42, 359/92
• US Class Current: 372/99
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine

Abstract

A first half-mirror, a buffer layer, a second half-mirror, a transparent electrode, an organic luminescent layer and a metal electrode which also serves as a reflector are formed on a transparent substrate thereby to constitute a first resonator between the second half-mirror and the metal electrode and a second resonator between the first half-mirror and the metal electrode. Light output of a desired wavelength is obtained from the light emitted from the organic luminescent layer utilizing resonance characteristics of the first and second resonators.

Claims

1. An organic luminescent device with a multiplex structure, comprising:

a light-excited luminescent device made up of a substrate, a first half-mirror layer overlying said substrate, an organic luminescent layer, overlying said first half-mirror layer, that emits light, and a reflector overlying said organic luminescent layer, wherein at least one of a buffer layer and a second half-mirror layer is formed between said first half-mirror layer and said organic luminescent layer such that resonators are formed between said reflector and said first half-mirror layer, and between said reflector and any second half-mirror layer.

5. An organic luminescent device with a multiplex structure according to claim 1 or 2, including both said buffer layer and said second half-mirror layer, said buffer layer being sandwiched between the first half-mirror layer and the second half-mirror layer and the organic luminescent layer overlying the second half-mirror layer, resonators respectively being formed between said reflector and the first half-mirror layer, and between said reflector and the second half-mirror layer.

6. An organic luminescent device with a multiplex structure according to claim 1 or 2, including said second half-mirror layer, between said organic luminescent layer and said first half-mirror layer, such that resonators are respectively provided between said reflector and said first half-mirror layer, and between said reflector and said second half-mirror layer.

7. An organic luminescent device with a multiplex structure according to any one of claims 1, 2, 3 and 4, wherein said substrate is a transparent substrate.

2. An organic luminescent device with a multiplex structure, comprising:

a luminescent device made up of a substrate, a first half-mirror layer overlying said substrate, an electrode layer overlying said first half-mirror layer, an organic luminescent layer, overlying said electrode layer, that emits light, and a metal layer, serving as both a reflector and an electrode, overlying said organic luminescent layer, wherein at least one of a buffer layer and a second half-mirror layer is formed between said first half-mirror layer and said organic luminescent layer such that resonators are formed between said reflector and said first half-mirror layer, and between said reflector and any second half-mirror layer.

3. An organic luminescent device with a multiplex structure, comprising:

a substrate, a first half-mirror overlying said substrate, a transparent buffer layer overlying said first half-mirror, a second half-mirror overlying said buffer layer, an organic luminescent layer, that emits light when irradiated with light, overlying said second half-mirror, and a metal layer, serving as a reflector, overlying said organic luminescent layer, wherein a first resonator is provided between said reflector and said second half-mirror, and a second resonator is provided between said reflector and said first half-mirror.

8. An organic luminescent device with a multiplex structure according to claim 3 or 4, wherein said buffer layer varies an optical path length of light emitted by the organic luminescent layer response to signals from an external unit.

9. An organic luminescent device with a multiplex structure according to claim 8, wherein said buffer layer includes a sandwich of a layer of liquid crystal between transparent electrodes, provided between the first half-mirror and the second half-mirror.

4. An organic luminescent device with a multiplex structure, comprising:

a substrate, a first half-mirror overlying said substrate, a transparent buffer layer overlying said first half-mirror, a second half-mirror overlying said transparent buffer layer, a transparent electrode overlying said second half-mirror, an organic luminescent layer, that emits light, overlying said transparent electrode, and a metal layer, serving as a reflector and an electrode, overlying said organic luminescent layer, wherein a first resonator is provided between the reflector of said metal layer and said second half-mirror, and a second resonator is provided between said reflector and said first half-mirror.