LED collimator element with a semiparabolic reflector

• US 7,513,642 B2
• Filed: 09/12/2005
• Issued: 04/07/2009
• Est. Priority Date: 09/20/2004
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Sormani, Joseph
• Primary Examiner(s): Husar; Stephen F
• Application Number:
  US11/575,330
• Publication Number:
  US 20070211487A1
• Time in Patent Office: 1,303 Days
• Field of Search: 362/241, 362/245, 362/307, 362/311, 362/326, 362/327, 362/247, 362/545, 362/800, 257/98
• US Class Current: 362/245
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/151 arranged in one or more lines
• CPC Class Codes: F21S 41/285 Refractors, transparent cover plates, light guides or filters not provided in groups F21S41/24-F21S41/28
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The invention relates to an LED lighting device, in particular for motor vehicle headlamps, which comprises an LED element (3), a collimator (1) which emits the light emitted by the LED element (3) through a collimator opening (5) in a collimated manner, and a reflector (7) which has a semiparabolic concave reflective surface (8), an irradiated plane (9), a focal point (F) in the irradiated face (9) and an emission plane (10) which emits light in an emission direction of the reflector (7) and encloses an angle with the irradiated face (9). According to the invention, the collimator (1) is designed and/or arranged in such a way that the collimated light coming from the collimator (1), as seen in the emission direction, is irradiated into the irradiated face (9) either completely in front of or completely behind the focal point (F).

Claims

1. An LED lighting device comprising:

an LED element configured to emit light;

a collimator including a truncated collimator element having a top face forming a base with a first cross-section, a bottom face forming a collimator opening with a second cross-section, wherein the second cross-section is larger than the first cross-section, and a lateral face disposed between the top face and the bottom face at an angle with respect to an axis of the collimator, the collimator configured to collimate the light emitted by the LED element and irradiate the collimated light through the collimator opening in a collimated manner; and

a reflector which has (i) a semiparabolic concave reflective surface, (ii) an irradiated face, (iii) a focal point (F) in the irradiated face and (iv) an emission face from which light is emitted in an emission direction of the reflector during operation and which encloses an angle with the irradiated face, wherein the collimator is further configured to enable the collimated light coming from the collimator through the collimator opening, as seen in the emission direction, to be irradiated into the irradiated face either completely in front of or completely behind the focal point (F).

2. An LED lighting device as claimed in claim 1, wherein the reflector is curved in a two-dimensional manner and wherein the focal point comprises a focal line (F) in the irradiated face, and the collimated light is irradiated into the irradiated face either completely in front of or completely behind the focal line (F).

3. An LED lighting device as claimed in claim 1, wherein the collimator opening is arranged in the irradiated plane between the focal point (F) or the focal line and an edge of the irradiated plane.

4. An LED lighting device as claimed in claim 1, wherein the collimator opening is round.

5. An LED lighting device as claimed in claim 1, wherein the collimator opening is one selected from the group consisting of rectangular and square.

6. An LED lighting device as claimed in claim 1, wherein the LED element and collimator comprise an asymmetrical LED collimator element.

7. An LED lighting device as claimed in claim 1, wherein the LED element comprises a number of LED elements arranged next to one another and jointly irradiate via the collimator into the reflector, wherein the collimator comprises one or more collimators configured to collimate light from the LED elements and irradiate the collimated light in a substantially bundled manner at a corresponding collimator opening face.

8. An LED lighting device as claimed in claim 7, wherein the collimator comprises a plurality of collimators, each of which is assigned an LED element or a group of LED elements.

9. A headlamp system, in particular for motor vehicles, comprising a lighting device as claimed in claim 1.

10. An LED lighting device comprising:

an LED element configured to emit light at an emission angle θ

₁ with respect to a main emission direction;

a collimator including a truncated collimator element having a top face forming a base with a first cross-section, a bottom face forming a collimator opening with a second cross-section, wherein the second cross-section is larger than the first cross-section, and a lateral face disposed between the top face and the bottom face at an angle with respect to an axis of the collimator, the collimator configured to collimate the light emitted by the LED element and irradiate the collimated light through the collimator opening in a collimated manner, further at an emission angle θ

₂ smaller than θ

₁; and

a reflector which has a semiparabolic concave reflective surface, (ii) an irradiated face, (iii) a focal point (F) in the irradiated face and (iv) an emission face from which light is emitted in an emission direction of the reflector during operation and which encloses an angle with the irradiated face, wherein the collimator is further configured to enable the collimated light coming from the collimator through the collimator opening, as seen in the emission direction, to be irradiated into the irradiated face either completely in front of or completely behind the focal point (F).