Electroluminescence panel

• US 20050280364A1
• Filed: 06/20/2005
• Published: 12/22/2005
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Nishikawa, Ryuji, Omura, Tetsuji
• Granted Patent: US 7,548,019 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/80 Constructional details
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

An electroluminescence panel having an electroluminescence element in each pixel, wherein the electroluminescence element comprises an emissive element layer having at least a light emitting function between a reflective film and a semi-transmissive film which is provided opposing the reflective film and have portions having different cavity lengths in one pixel, the cavity length being a distance between the reflective film and the semi-transmissive film. Such a structure can be realized, for example, by changing a thickness of a transparent electrode which is a lower electrode of the element. Because peak wavelength that can be intensified can be varied among regions in one pixel having different cavity lengths, a viewing angle dependency is improved.

Claims

1. An electroluminescence panel having an electroluminescence element in each pixel, wherein

the electroluminescence element in each pixel has a layered structure with an emissive element layer having at least a light emitting function provided between a reflective film and a semi-transmissive film which opposes the reflective film, the electroluminescence element having a microcavity in which a cavity length which is a distance between the reflective film and the semi-transmissive film is set to intensify light of a predetermined wavelength, and

each pixel has portions having different cavity lengths.

2. An electroluminescence panel according to claim 1, wherein

the electroluminescence element has an emissive element layer between a transparent electrode and a metal electrode,

a semi-transmissive film is provided external to the transparent electrode,

the metal electrode functions as a reflective film, and

the microcavity comprises the transparent electrode and the emissive element layer.

3. An electroluminescence panel according to claim 2, wherein

a thickness of the transparent electrode is varied within each pixel to provide the portions having different cavity lengths.

4. An electroluminescence panel according to claim 3, wherein

an insulating layer is provided covering a step portion, of the transparent electrode, in which the thickness is varied.

5. An electroluminescence panel according to claim 2, wherein

a transparent insulating layer is partially provided between the semi-transmissive film and the transparent electrode within one pixel to form the portions having different cavity lengths.

6. An electroluminescence panel according to claim 1, wherein

each pixel comprises at least two regions including a first region and a second region having different cavity lengths, and

a difference between a cavity length of the first region and a cavity length of the second region is 200 nm or less.

7. An electroluminescence panel according to claim 1, wherein

each pixel comprises at least two regions including a first region and a second region having different cavity lengths,

a resonance wavelength which is a wavelength of light to be intensified in the second region is longer than the resonance wavelength of the first region, and

an area of the second region within a pixel is 10% to 60% of the area of the pixel.

8. An electroluminescence panel according to claim 1, wherein

each pixel comprises at least two regions including a first region and a second region having different cavity lengths,

a resonance wavelength which is a wavelength of light to be intensified in the second region is longer than the resonance wavelength of the first region, and

the second region is provided in each pixel in divided portions, each divided portion having an area which is 25% or less of the area of the pixel.

9. An electroluminescence panel according to claim 1, wherein

a plurality of pixels corresponding to different colors are formed on the panel, and

each pixel of at least pixels corresponding to one color comprises the portions having different cavity lengths.

10. An electroluminescence panel according to claim 1, wherein

a plurality of pixels corresponding to different colors are formed on the panel,

each pixel of at least pixels corresponding to one color comprises a first region and a second region having different cavity lengths within the pixel,

a resonance wavelength which is a wavelength of light to be intensified in the second region is longer than the resonance wavelength of the first region, and

a percentage of the area of the second region within a pixel differs from a percentage of the area of the second region within a pixel of a different color.

11. An electroluminescence panel according to claim 1, wherein

each pixel comprises a corresponding color filter.

12. An electroluminescence panel according to claim 11, wherein

the electroluminescence element of each pixel comprises an emissive element layer having a light emission function of color assigned to each pixel.

13. An electroluminescence panel according to claim 11, wherein

the electroluminescence element of each pixel comprises an emissive element layer having a light emitting function of common color for each pixel.

14. An electroluminescence panel according to claim 1, wherein

each pixel comprises at least two regions including a first region and a second region having different cavity lengths, and

a color filter assigned to each pixel is formed in only one of the first region and the second region.