LIGHT CONTROL DEVICE EXHIBITING BATWING LUMINOUS INTENSITY DISTRIBUTIONS IN UPPER AND LOWER HEMISPHERES

• US 20080285267A1
• Filed: 04/09/2008
• Published: 11/20/2008
• Est. Priority Date: 04/10/2007
• Status: Active Grant

• Current Assignee: Lumec Holding ULC
• Original Assignee: Ledalite Architectural Products
• Inventors: Santoro, Scott
• Granted Patent: US 8,047,673 B2
• Time in Patent Office: Days
• US Class Current: 362/224
• CPC Class Codes: F21S 8/06 by suspension
• CPC Class Codes: F21V 11/14 with many small apertures
• CPC Class Codes: F21V 21/00 Supporting, suspending, or attaching arrangements for lighting devices F21V17/00, F21V19/00 take precedence; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q, stands for supporting apparatus or articles in general F16M11/00; Hand grips
• CPC Class Codes: F21V 5/002 using microoptical elements for redirecting or diffusing light
• CPC Class Codes: F21V 5/02 of prismatic shape F21V5/04 takes precedence
• CPC Class Codes: F21V 7/0016 on lighting devices that also provide for direct lighting, e.g. by means of independent light sources, by splitting of the light beam, by switching between both lighting modes
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21Y 2103/00 Elongate light sources, e.g. fluorescent tubes
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements

Abstract

A light control device implemented as a luminaire exhibits an ultra-wide batwing luminous intensity distribution in an upper hemisphere that provides substantially uniform illumination of a ceiling surface, even when the luminaire is mounted very close to the ceiling. Luminous side panel diffusers facilitate blending the luminaire with the ceiling surface as they create a batwing luminous intensity distribution in a lower hemisphere to evenly illuminate a work plane.

Claims

1. A light control device implemented with multiple diffusers exhibiting, in response to incident light, multiple controllable intensity distribution patterns that cooperate to accomplish upwardly directed illumination of a ceiling surface and downwardly directed illumination of a work surface, comprising:

a light source emitting first and second sets of light rays;

a first diffuser positioned to receive direct light emitted by the light source and carried by a first subset of the first set of light rays, the first diffuser having a light diffusing surface that partly transmits and partly scatters the first subset of the first set of light rays that, respectively, propagate as a divergent fan of light rays downwardly toward the work surface and propagate as two divergent fans of light rays upwardly and uninterrupted toward the ceiling surface; and

a second diffuser positioned to receive direct light emitted by the light source and carried by the second set of light rays, the second diffuser having a light diffusing surface that scatters the second set of light rays that propagate as two partly overlapping fans of light rays upwardly toward the ceiling surface,

whereby the two divergent fans of light rays propagating from the first diffuser, the two partly overlapping fans of light rays propagating from the second diffuser, and direct light propagating from the light source combine and exit the light control device in a batwing luminous intensity distribution pattern toward the ceiling surface.

2. The light control device of claim 1, further comprising a lambertian light transmitting diffuser positioned to receive the partly transmitted light rays propagating from the first diffuser and being of a character that diffuses the partly transmitted light rays to form diffused light that exits the light control device in a lambertian luminous intensity distribution pattern toward the work surface.

3. The light control device of claim 2, in which the lambertian light transmitting diffuser comprises a perforated basket.

4. The light control device of claim 2, further comprising first and second downlight diffusers positioned adjacent the lambertian light transmitting diffuser and to receive a second subset of the first set of light rays to form diffused light exhibiting a distribution pattern of luminous intensity, the first and second downlight diffusers and the lambertian light transmitting diffuser having optical properties cooperating such that the diffused light propagating from the first and second downlight diffusers and the diffused light propagating from the lambertian light transmitting diffuser exit the light control device in a batwing luminous intensity distribution pattern toward the work surface.

5. The light control device of claim 4, in which each of the first and second downlight diffusers includes a film material that has a surface relief light diffusing structure.

6. The light control device of claim 5, in which the first and second downlight diffusers are of a kinoform type.

7. The light control device of claim 4, in which the first and second downlight diffusers each have proximal and distal sides, and further comprising first and second side reflectors, the proximal sides of the first and second downlight diffusers positioned adjacent the lambertian light transmitting diffuser and the distal sides of the first and second downlight diffusers positioned adjacent the respective first and second side reflectors.

8. The light control device of claim 1, in which the second diffuser includes a pair of side diffusers separated by a light reflector.

9. The light control device of claim 1, further comprising an elongated housing that supports the first and second diffusers, and in which the light source is of tubular shape, positioned within the housing, and cooperates with the first and second diffusers to form a luminaire.

10. The light control device of claim 9, in which the tubular light source includes a fluorescent lamp.

11. The light control device of claim 1, in which the light source includes multiple lamps.