Lighting unit

• US 9,939,126 B2
• Filed: 09/24/2014
• Issued: 04/10/2018
• Est. Priority Date: 09/24/2013
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Inventors: Dingemans, Antonius Petrus Marinus, Vissenberg, Michel Cornelis Josephus Marie
• Primary Examiner(s): Labaze, Edwyn
• Application Number:
  US15/024,569
• Publication Number:
  US 20160230952A1
• Time in Patent Office: 1,294 Days
• Field of Search: 362235, 362 84, 362241, 362343, 362606-608
• CPC Class Codes: F21S 8/026 intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling
• CPC Class Codes: F21V 5/007 Array of lenses or refractors for a cluster of light sources, e.g. for arrangement of multiple light sources in one plane combination of two or more refractors F21V5/008
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A lighting panel comprises a light source and a light modifying panel positioned over the light source, in the form of a set of protrusions over the base, the protrusions facing the light source. The protrusions comprise circular/elliptical/polygonal cylinders or cone sections with a small cone taper angle.

Claims

1. A lighting unit, comprising:

a light source comprising an array of LEDs with a first pitch; and

a light modifying panel positioned over the light source for modifying the light output from the light source before it enters a space to be illuminated,

wherein the panel comprises a base and a set of protrusions over the base, the protrusions facing the light source, the set of protrusions having a second pitch different from the first pitch,

wherein the protrusions comprise circular, elliptical or at least 5-sided polygonal cylinders, or circular, elliptical or at least 5-sided polygonal cone sections, having a flat circular elliptical or polygonal top, wherein for cone sections the cone taper angle is less than 5 degrees.

2. A unit as claimed in claim 1, wherein for cone sections, the cone taper angle is less than 2 degrees.

3. A unit as claimed in claim 1, wherein for cone sections, the cone taper angle is less than 1 degree.

4. A unit as claimed in claim 1, wherein the base comprises a light scattering surface on a side opposite the protrusions.

5. A unit as claimed in claim 1, wherein the tips of the protrusions are provided with a scattering surface.

6. A unit as claimed in claim 1, further comprising a diffuser between the light source and the panel.

7. A unit as claimed in claim 1, wherein the panel is injection moulded.

8. A unit as claimed in claim 1 comprising a ceiling luminaire.

9. A lighting unit, comprising:

a light source comprising an array of LEDs with a first pitch; and

a light modifying panel positioned over the light source for modifying the light output from the light source before it enters a space to be illuminated,

wherein the panel comprises a base and a set of protrusions over the base, the protrusions facing the light source, the set of protrusions having a second pitch different from the first pitch,

wherein the protrusions comprise circular, elliptical or at least 5-sided polygonal cylinders, or circular, elliptical or at least 5-sided polygonal cone sections, having a flat circular elliptical or polygonal top, wherein for cone sections the cone taper angle is less than 5 degrees,

wherein the protrusions each have a height H which satisfies H>

N (D−

H*tan α

), where α

is the cone taper angle with α

=0 for cylinders, D is the diameter of the tip, and N is given by 1/N=tan(sin<sup>−

1</sup>(sin 35/n)) where n is the refractive index of the panel material.

10. A unit as claimed in claim 9, wherein N is in the range 2.3 to 2.7.

11. A unit as claimed in claim 10, further comprising a beam shaping optical arrangement provided over the LED array.

12. A unit as claimed in claim 11, wherein the beam shaping optical arrangement performs a collimation function.

13. A unit as claimed in claim 11, wherein the beam shaping optical arrangement performs a batwing optical distribution function.

14. A unit as claimed in claim 11, wherein the beam shaping optical arrangement comprises at least first and second different types of lens.