Organic electroluminescent display

• US 9,136,309 B2
• Filed: 10/31/2013
• Issued: 09/15/2015
• Est. Priority Date: 07/21/2010
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hamaguchi, Atsushi, Mizuno, Nobutaka
• Primary Examiner(s): Oh, Jaehwan
• Application Number:
  US14/069,177
• Publication Number:
  US 20140054576A1
• Time in Patent Office: 684 Days
• US Class Current: 1/1
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/353 characterised by the geometrical arrangement of the RGB subpixels

Abstract

An organic electroluminescent (EL) display includes a plurality of organic EL devices for red, green, and blue subpixels, each including a first electrode on a light output side, a second electrode opposite the first electrode, and an organic compound layer including a light-emitting layer therebetween. The organic EL devices have a resonator structure between a first reflective surface closer to the first electrode than the organic compound layer and a second reflective surface closer to the second electrode than the organic compound layer. A predetermined white color is displayed by mixing the three colors such that an optical distance of the organic EL devices of each color between an emission position in the light-emitting layer and the second reflective surface is set within ±10% from an optical distance corresponding to an nth-order minimum of a curve of required current density against at least the optical distance.

Claims

1. An organic electroluminescent apparatus comprising:

an organic EL element emitting light of red color, an organic EL element emitting light of green color and an organic EL element emitting light of blue color,

wherein each of the organic EL elements includes a first electrode on a light output side, a second electrode opposite the first electrode, and an organic compound layer including a light-emitting layer between the first electrode and the second electrode,

wherein each of the organic EL elements has a resonator structure configured to resonate light emitted from the light-emitting layer between a first reflective surface closer to the first electrode than the organic compound layer and a second reflective surface closer to the second electrode than the organic compound layer, and

wherein an optical distance of the organic EL elements of each color between an emission position in the light-emitting layer and the second reflective surface is set within ±

10% from an optical distance corresponding to an nth-order minimum of a curve of required current density, which is necessary when a predetermined white color is displayed by the organic EL element emitting light of red color, the organic EL element emitting light of green color and the organic EL element emitting light of blue color.

2. The organic electroluminescent apparatus according to claim 1, wherein the optical distance is set on the basis of a second-order minimum of the curve of required current density.

3. The organic electroluminescent apparatus according to claim 1, wherein an optical distance of the organic EL elements of each color between the first and second reflective surfaces is set within ±

10% from an optical distance corresponding to an nth-order minimum of a curve of required current density against the optical distance between the emission position in the light-emitting layer and the second reflective surface and an optical distance between the emission position in the light-emitting layer and the first reflective surface.

4. An organic electroluminescent apparatus comprising:

an organic EL element emitting light of red color, an organic EL element emitting light of green color and an organic EL element emitting light of blue color,

wherein each of the organic EL elements includes a first electrode on a light output side, a second electrode opposite the first electrode, and an organic compound layer including a light-emitting layer between the first electrode and the second electrode,

wherein each of the organic EL elements has a resonator structure configured to resonate light emitted from the light-emitting layer between a first reflective surface closer to the first electrode than the organic compound layer and a second reflective surface closer to the second electrode than the organic compound layer, and

wherein an optical distance of at least one of the organic EL elements between an emission position in the light-emitting layer and the second reflective surface is set within ±

10% from an optical distance corresponding to an nth-order minimum of a curve of required current density, which is necessary when a predetermined white color is displayed by the organic EL element emitting light of red color, the organic EL element emitting light of green color and the organic EL element emitting light of blue color.

5. The organic electroluminescent apparatus according to claim 4,

wherein the optical distance of the organic EL elements which emit blue light between an emission position in the light-emitting layer and the second reflective surface is set within ±

10% from an optical distance corresponding to an nth-order minimum of a curve of required current density.

6. The organic electroluminescent apparatus according to claim 4, wherein the optical distance is set on the basis of a second-order minimum of the curve of required current density.

7. The organic electroluminescent apparatus according to claim 4, wherein an optical distance of the organic EL elements of each color between the first and second reflective surfaces is set within +10% from an optical distance corresponding to an nth-order minimum of a curve of required current density against the optical distance between the emission position in the light-emitting layer and the second reflective surface and an optical distance between the emission position in the light-emitting layer and the first reflective surface.