Lighting device

• US 20070103911A1
• Filed: 11/02/2004
• Published: 05/10/2007
• Est. Priority Date: 11/17/2003
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Meekes, Gabrielle Johanna
• Application Number:
  US10/579,153
• Publication Number:
  US 20070103911A1
• Time in Patent Office: Days
• US Class Current: 362/341
• CPC Class Codes: F21V 3/04 characterised by materials, surface treatments or coatings
• CPC Class Codes: F21V 5/00 Refractors for light sources characterised by cooling arrangements F21V29/504
• CPC Class Codes: F21Y 2103/00 Elongate light sources, e.g. fluorescent tubes
• CPC Class Codes: G02B 27/024 comprising a light source, e.g. for viewing photographic slides, X-ray transparancies G02B27/023, and photographic, cine and overhead projectors G03B21/00 and subgroups
• CPC Class Codes: G02B 5/021 the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0263 with positional variation of the diffusing properties, e.g. gradient or patterned diffuser
• CPC Class Codes: G09F 13/14 Arrangements of reflectors therein

Abstract

A lighting device (1) comprising at least one light source (4) arranged in a housing (2) for emitting a lighting beam through a light-transmitting plate (3) of the housing (2), wherein said plate (3) is provided with means which reflect incident light on the plate (3), in such a manner that light which locally has a higher intensity is reflected more strongly at that location than light which locally has a lower intensity, with the special feature that said light-transmitting plate (3) and said means together form a constructional element made in one piece of a diffuse reflective material.

Claims

1. A lighting device comprising at least one light source arranged in a housing for emitting a lighting beam through a light-transmitting plate of the housing, wherein said plate is provided with means which reflect incident light on the plate, in such a manner that light which locally has a higher intensity is reflected more strongly at that location than light which locally has a lower intensity, characterized in that said light-transmitting plate and said means together form a constructional element made in one piece of a diffuse reflective material.

2. A lighting device according to claim 1, wherein said element is made of a plastic material comprising diffuse reflective particles.

3. A lighting device according to claim 2, wherein said diffuse reflective particles comprise calcium halophosphate, calcium pyrophosphate, MgO, YBO₃, TiO₂ or Al₂O₃ particles.

4. A lighting device according to claim 2, wherein said plastic material is chosen from the group consisting of acrylic plastics, fluoroplastics, polysiloxanes, polyesters, polycarbonates.

5. A lighting device according to claim 1, wherein said element comprises a profile with a varying thickness in such a manner that the thickness of the element at a location close to the light source is larger than at a location further removed from the light source.

6. A lighting device according to claim 5, wherein said profile is made through grinding or embossing.

7. A lighting device according to claim 5, wherein said profile is made through moulding or extrusion.

8. A method for laterally homogenising of the intensity of light emitted from a lighting device comprising at least one light source arranged in a housing for emitting a lighting beam through a light-transmitting plate of the housing, wherein said plate is provided with means which reflect incident light on the plate, in such a manner that light which locally has a higher intensity is reflected more strongly at that location than light which locally has a lower intensity, characterized in that said light-transmitting plate and said means together are formed as a constructional element made in one piece of a diffuse reflective material.