LED LIGHTING DEVICE

• US 20110018012A1
• Filed: 03/24/2009
• Published: 01/27/2011
• Est. Priority Date: 03/24/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Fukuoka, Akira, Tanaka, Kenichiro
• Granted Patent: US 8,742,435 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: F21V 11/14 with many small apertures
• CPC Class Codes: F21V 13/02 Combinations of only two kinds of elements
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

The LED lighting device in this invention comprises a light source, a first face sheet, and a reflection sheet. The light source comprises a plurality of LED chips which are configured to emit lights having wavelengths which are different from each other. The first face sheet has a rear surface. The rear surface is defined as a diffusing and reflecting surface which is being configured to diffuse and reflect the lights which are emitted from the LED chips. The first face sheet is provided with a plurality of apertures. The reflection sheet has a second reflecting surface. The second reflecting surface is configured to reflect the light which is reflected from the diffusing and reflecting surface of the first face sheet toward the first face sheet. Each the aperture is shaped to pass the light which is reflected from the second reflecting surface. Each the aperture is configured to prevent the light which is directly emitted by the light from being passed through the aperture without being subjected to any reflection.

Claims

1. An LED lighting device comprising:

a light source comprising a plurality of LED chips which are configured to emit lights having wavelengths which are different from each other;

a first face sheet having a front surface and a rear surface, said rear surface being defined as a diffusing and reflecting surface being configured to diffuse and reflect the lights which are emitted from said LED chips,

said first face sheet being disposed such that said rear surface being faced to said light source, said first face sheet having a center axis and a plurality of apertures, each said aperture having a width which extends along a direction perpendicular to the center axis, and a depth along the center axis;

a reflection sheet having a second reflecting surface, said reflection sheet being disposed such that said second reflecting surface is faced to said rear surface of said first face sheet,

said reflection sheet being spaced from said first face sheet by a predetermined distance,

said second reflecting surface being configured to reflect the light, being reflected by said diffusing and reflecting surface, toward said first face sheet,

wherein

said light source is aligned with said center axis,

said apertures being configured to pass the light which is reflected by said second reflecting surface, and

each said apertures having a shape so as not to pass the light which is emitted and directly traveled from said light source to said apertures, whereby the light which is emitted from said light source is not passed through said aperture without being subjected to any reflection.

2. The LED lighting device as set forth in claim 1, wherein

each said aperture has an inside surface which diffuse and reflect the light which is emitted from said light source, whereby the light, being emitted from said light source, is diffused and reflected by said inside surface of said aperture to direct toward an outside of said LED lighting device.

3. The LED lighting device as set forth in claim 1, wherein

said reflecting sheet is spaced from said first face sheet by the predetermined distance so as to leave a space between said first face sheet and said reflecting sheet, and

said space being filled with air.

4. The LED lighting device as set forth in claim 1, wherein

each said aperture has an opening dimension which is perpendicular to the center axis,

said opening dimensions of said apertures being made smaller toward said center axis,

said aperture is shaped to have an aspect ratio which is determined by a ratio of the depth to the width,

said aperture being shaped to have the aspect ratio so as not to directly pass the light, being emitted from said light source, without any reflection.

5. The LED lighting device as set forth in claim 1, wherein

said depths of said apertures being made greater toward said center axis,

each said aperture being shaped to have an aspect ratio which is determined by a ratio of said depth to said width,

said aperture being shaped to have the aspect ratio so as not to directly pass the light, being emitted from said light source, without any reflection.

6. The LED lighting device as set forth in claim 1, wherein

said aperture has a first inside surface and a second inside surface which is faced to said first inside surface, said first inside surface being located on a near side of the center axis,

each said width becoming smaller toward said rear surface from said front surface,

said second inside surface extending in parallel to said center axis.

7. The LED lighting device as set forth in claim 1, wherein

each said aperture having a periphery with a far portion which is located far way from said center axis than a rest of said aperture,

said face sheet further comprising reflecting walls, each said reflecting wall extending toward a front direction from each said far portions.

8. The LED lighting device as set forth in claim 1, wherein

said LED lighting device further comprises a light guide plate which is disposed on said front surface of said face sheet.

9. The LED lighting device as set forth in claim 7, wherein

said light guide plate has a fixing surface being attached to said front surface of said face sheet, and an exposed surface being opposite of said fixing surface,

said exposed surface being shaped to have a convex-concave profile, whereby a light extraction effect is improved.

10. The LED lighting device as set forth in claim 1, wherein

said LED lighting device further comprises a second face sheet,

said second face sheet having a front surface and a rear face which is defined as a diffusing and reflecting surface being configured to diffuse and reflect the lights which is emitted from said LED chips, said second face sheet being shaped to have a plurality of second apertures each of which has a width and a depth,

said second face sheet being opposite of said LED chips from said first face sheet,

each said second aperture being shaped to pass the light which is reflected by said second reflecting surface, and

each said second aperture having a shape so as not to pass the light directly from said light source, without any reflection.

11. The LED lighting device as set forth in claim 1, wherein

said LED lighting device further comprising a spacer, said spacer being disposed between said first face sheet and said reflection sheet so as to leave a space between said first face sheet and said reflection sheet, and

said first face sheet being cooperative with said reflection sheet and said spacer to define a housing.