LIGHT EMITTING DEVICE

• US 20120049170A1
• Filed: 02/22/2010
• Published: 03/01/2012
• Est. Priority Date: 02/24/2009
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamae, Kazuyuki, Tanaka, Kenichiro
• Granted Patent: US 8,772,761 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses

Abstract

The light emitting device includes an organic electroluminescent element (20) and a diffractive optical element (30). The organic electroluminescent element (20) includes an anode layer (21), a cathode layer (22), and plural light emitting layers (231 and 232) interposed between the anode layer (21) and the cathode layer (22) and configured to emit light rays with different wavelengths. The diffractive optical element (30) is positioned in paths of light rays emitted from the organic electroluminescent element (20). The diffractive optical element (30) is designed to have different grating patterns (311 and 312) diffracting the light rays respectively emitted from the light emitting layers (231 and 232) for reducing chromatic aberration.

Claims

1. A light emitting device comprising:

an organic electroluminescence element configured to emit light rays of different wavelengths; and

a diffractive optical element located in paths of the light rays emitted from said organic electroluminescence element,

wherein

said diffractive optical element is designed to have different grating patterns diffracting the light rays emitted from said organic electroluminescence element for reducing chromatic aberration.

2. The light emitting device as set forth in claim 1, wherein

said organic electroluminescence element comprises:

an anode layer;

a cathode layer;

light emitting layers interposed between said anode layer and said cathode layer, said light emitting layers being configured to emit the light rays of the different wavelengths in the predetermined direction, respectively; and

,

a substrate having a first surface and a second surface, said substrate being located in the paths of the light rays respectively emitted from said light emitting layers, and said substrate having transparency for the light rays respectively emitted from said light emitting layers,

said anode layer, said cathode layer, said plural light emitting layers being stacked on said first surface, and

at least one of said grating patterns being defined by said second surface having grooves periodically arranged thereon.

3. The light emitting device as set forth in claim 1, wherein

said organic electroluminescence element comprises:

an anode layer;

a cathode layer;

light emitting layers interposed between said anode layer and said cathode layer, said light emitting layers being configured to emit the light rays of the different wavelengths in the predetermined direction, respectively; and

,

a substrate located in the paths of the light rays respectively emitted from said light emitting layers, said substrate having transparency for the light rays respectively emitted from said light emitting layers, and

at least one of said grating patterns defined by regions which are formed inside of said substrate at predetermined intervals and have a different refractive index from that of said substrate.