Lighting device, corresponding lamp and method

Patent metadata

Field	Value
Publication number	US-10119676-B2
Application number	US-201615250988-A
Country	US
Kind code	B2
Filing date	Aug 30, 2016
Priority date	Jun 10, 2016
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A lighting device, which may be used e.g. to produce motor vehicle lamps, may include a light radiation source, e.g. a LED source, having a light-permeable body arranged facing source for propagating light radiation along a longitudinal axis. The light-permeable body includes a collimator exposed to light radiation source and adapted to collect light radiation and to inject it into light-permeable body, a tapered portion coupled to collimator for receiving light radiation and directing it towards an output end, a distal portion acting as an emission filament, coupled to the output end of tapered portion, with an output mirror having a shank portion extending in said distal portion and a head portion, the output mirror reflecting light radiation radially from longitudinal axis and proximally towards said light radiation source.

First claim

The invention claimed is:

1. A lighting device, comprising:
an electrically-powered light radiation source,
a light-permeable body having a longitudinal axis arranged facing said light radiation source for propagating light radiation from said source distally of the light radiation source along said longitudinal axis, the light-permeable body comprising:
a collimator exposed to said light radiation source for collecting light radiation from said light radiation source and injecting it into said light-permeable body,
a portion tapered from an input end towards an output end, the input end of said tapered portion coupled to said collimator for receiving light radiation collimated thereby and directing said collimated radiation towards said output end, and
a distal portion coupled to the output end of said tapered portion,
the device further comprising an output mirror with a shank portion extending in said distal portion and a head portion, said output mirror reflecting light radiation radially from said longitudinal axis and proximally towards said light radiation source;
wherein the shank portion extending in the distal portion of said output mirror has a layered dichroic filter structure;
wherein said layered dichroic filter structure includes a first and a second layer, said first layer having a dichroic filtering surface, wherein light radiation is partially reflected from said first surface and partially propagates through said first layer towards said second layer to be reflected from said second layer.

2. The lighting device of claim 1 , wherein said collimator comprises:
a lenticular surface exposed to said light radiation source to collect light radiation emitted by said light radiation source within a certain solid angle, and
an outer surface around said lenticular surface to reflect light radiation emitted by said light radiation source outside said solid angle.

3. The lighting device of claim 2 , wherein said collimator includes a proximal cavity facing said light radiation source, said cavity having a peripheral wall surrounding a bottom wall, said bottom surface including said lenticular surface.

4. The lighting device of claim 1 , wherein said collimator and/or said tapered portion and/or said distal portion have symmetry of revolution around said longitudinal axis.

5. The lighting device of claim 1 , wherein said distal portion is filament-like.

6. The lighting device of claim 1 , wherein said output mirror,
is specularly reflective and/or
is diffusively reflective and/or
is partly specularly reflective and partly diffusively reflective.

7. The lighting device of claim 1 , wherein said light radiation source includes a LED source.

8. A lamp comprising:
a lighting device, said lighting device, comprising:
an electrically-powered light radiation source,
a light-permeable body having a longitudinal axis arranged facing said light radiation source for propagating light radiation from said source distally of the light radiation source along said longitudinal axis, the light-permeable body comprising:
a collimator exposed to said light radiation source for collecting light radiation from said light radiation source and injecting it into said light-permeable body,
a portion tapered from an input end towards an output end, the input end of said tapered portion coupled to said collimator for receiving light radiation collimated thereby and directing said collimated radiation towards said output end, and
a distal portion coupled to the output end of said tapered portion,
the device further comprising an output mirror with a shank portion extending in said distal portion and a head portion, said output mirror reflecting light radiation radially from said longitudinal axis and proximally towards said light radiation source,
wherein the shank portion extending in the distal portion of said output mirror has a layered dichroic filter structure;
wherein said layered dichroic filter structure includes a first and a second layer, said first layer having a dichroic filtering surface, wherein light radiation is partially reflected from said first surface and partially propagates through said first layer towards said second layer to be reflected from said second layer; and
a casing for said lighting device, said casing including at least one light-permeable portion for emitting light radiation from said lighting device.

9. A method of providing a lighting device, the method comprising:
providing an electrically-powered light radiation source,
arranging facing said light radiation source a light-permeable body having a longitudinal axis for propagating light radiation from said source distally of the light radiation source along said longitudinal axis, the light-permeable body comprising:
a collimator exposed to said light radiation source for collecting light radiation from said light radiation source and injecting it into said light-permeable body,
a portion tapered from an input end towards an output end, the input end of said tapered portion coupled to said collimator for receiving light radiation collimated thereby and directing said collimated radiation towards said output end, and
a distal portion coupled to the output end of said tapered portion,
providing an output mirror with a shank portion extending in said distal portion and a head portion, said output mirror reflecting light radiation radially from said longitudinal axis and proximally towards said light radiation source;
wherein the shank portion extending in the distal portion of said output mirror has a layered dichroic filter structure;
wherein said layered dichroic filter structure includes a first and a second layer, said first layer having a dichroic filtering surface, wherein light radiation is partially reflected from said first surface and partially propagates through said first layer towards said second layer to be reflected from said second layer.

Assignees

• Osram Gmbh

Inventors

• Schiccheri Nicola
• Bizzotto Alessandro
• Munarin Marco

Classifications

• F21V9/08

  for producing coloured light, e.g. monochromatic; for reducing intensity of light (with provision for controlling the colour F21V9/40) · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21V23/004

  arranged on a substrate, e.g. a printed circuit board · CPC title

• F21K9/61

  using light guides · CPC title

• F21S41/322

  the reflector using total internal reflection · CPC title