Lighting device, corresponding lamp and method

Patent metadata

Field	Value
Publication number	US-10436408-B2
Application number	US-201815859793-A
Country	US
Kind code	B2
Filing date	Jan 2, 2018
Priority date	Jan 3, 2017
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A lighting device, which may be employed e.g. as a retrofit bulb for vehicle lamps, includes a light radiation source, e.g. a LED source, and a beam-narrowing optical system facing the light radiation source, for propagating a narrowed light radiation beam of the same source along a longitudinal axis of the device. Arranged distally of the beam-narrowing optical system along said longitudinal axis, there is moreover provided a cascaded arrangement of: a light-condensing lens, a light-driving lens, a filament-like body including annular reflective surfaces extending around the longitudinal axis and exposed to light radiation from the light radiation source propagated through the light-condensing lens and the light-driving lens, a distal mirror member having a reflective surface facing towards the filament-like body, to reflect light radiation towards annular reflective surfaces in said plurality of annular reflective surfaces.

First claim

What is claimed is:

1. A lighting device, comprising:
an electrically-powered light radiation source,
a beam-narrowing optical system facing the light radiation source and propagating a narrowed light radiation beam from said source along a longitudinal axis of the device, and
arranged distally of the beam-narrowing optical system along said longitudinal axis, a cascaded arrangement of:
a light-condensing lens,
a light-driving lens,
a filament-like body including a plurality of annular reflective surfaces extending around said optical axis and exposed to light radiation of the light radiation source propagated through the light-condensing lens and the light-driving lens,
a distal mirror member having a reflective surface towards the filament-like body to reflect light radiation towards annular reflective surfaces in said plurality of annular reflective surfaces,

wherein light radiation reflected by the annular reflective surfaces of the filament-like body is spread radially outwardly of the longitudinal axis of the device.

2. The lighting device of claim 1 , wherein the a beam-narrowing optical system includes at least one planar-convex lens having the planar surface towards the light radiation source.

3. The lighting device of claim 1 , including a gap between the light radiation source and the beam-narrowing optical system.

4. The lighting device of claim 1 , wherein the light radiation source includes an array of light-emitting elements.

5. The lighting device of claim 4 , wherein the beam-narrowing optical system includes an array of optical elements coupled with respective light-emitting elements of the light radiation source.

6. The lighting device of claim 4 , wherein the light-emitting elements of the light radiation source are offset with respect to said longitudinal axis, wherein light radiation from each light-emitting element is directed partly towards the filament-like body and partly towards the distal mirror member.

7. The lighting device of claim 1 , wherein the light-condensing lens includes:
an aspheric lens, and/or
a convex surface towards the beam-narrowing optical system and a concave surface towards the light-driving lens.

8. The lighting device of claim 1 , wherein the light-driving lens includes:
a convex surface towards the light condensing lens,
a tapered surface towards, and preferably carrying, the filament-like body.

9. The lighting device claim 1 , wherein the filament-like body includes a spindle-like body having said annular reflective surfaces staggered along the length thereof, said annular reflective surfaces preferably adjoining to each other.

10. The lighting device claim 1 , wherein said distal mirror member includes a body which provides a shield for countering light propagation along said longitudinal axis distally of the mirror member.

11. The lighting device of claim 1 , wherein the light radiation source includes at least one LED source, preferably with blue emission and phosphor conversion to visible light.

12. A light comprising:
a lighting device, wherein the lighting device comprises:
an electrically-powered light radiation source,
a beam-narrowing optical system facing the light radiation source and propagating a narrowed light radiation beam from said source along a longitudinal axis of the device, and
arranged distally of the beam-narrowing optical system along said longitudinal axis, a cascaded arrangement of:
a light-condensing lens,
a light-driving lens,
a filament-like body including a plurality of annular reflective surfaces extending around said optical axis and exposed to light radiation of the light radiation source propagated through the light-condensing lens and the light-driving lens,
a distal mirror member having a reflective surface towards the filament-like body to reflect light radiation towards annular reflective surfaces in said plurality of annular reflective surfaces,

wherein light radiation reflected by the annular reflective surfaces of the filament-like body is spread radially outwardly of the longitudinal axis of the device; and

a casing for said lighting device, said casing including at least one light-permeable portion for emitting light radiation from the lighting device.

13. A method of providing a lighting device, the method comprising:
providing an electrically-powered light radiation source,
arranging a beam-narrowing optical system facing the light radiation source and propagating a narrowed light radiation beam from said source along a longitudinal axis of the device, and
arranging distally of the beam-narrowing optical system along said longitudinal axis, a cascaded arrangement of:
a light-condensing lens,
a light-driving lens,
a filament-like body including a plurality of annular reflective surfaces extending around said optical axis and exposed to light radiation of the light radiation source propagated through the light-condensing lens and the light-driving lens,
a distal mirror member having a reflective surface towards the filament-like body to reflect light radiation towards annular reflective surfaces in said plurality of annular reflective surfaces,

wherein light radiation reflected by the annular reflective surfaces of the filament-like body is spread radially outwardly of the longitudinal axis of the device.

Assignees

• Osram Gmbh

Inventors

• Schiccheri Nicola
• Bizzotto Alessandro
• Munarin Marco

Classifications

• F21K9/232

  specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb · CPC title

• F21S41/435

  Hoods or cap-shaped · CPC title

• F21K9/68

  Details of reflectors forming part of the light source · CPC title

• F21W2102/00

  Exterior vehicle lighting devices for illuminating purposes · CPC title

• F21S41/321

  the reflector being a surface of revolution or a planar surface, e.g. truncated · CPC title