Light generator for introducing light into a bundle of optical fibers

• US 6,402,347 B1
• Filed: 12/15/1999
• Issued: 06/11/2002
• Est. Priority Date: 12/17/1998
• Status: Expired due to Term

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ansems, Johannes P. M., Maas, Theodorus F. M. M., Begemann, Simon H. A.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Alavi, Ali
• Application Number:
  US09/464,002
• Time in Patent Office: 909 Days
• Field of Search: 362/554, 362/556, 362/555, 362/294, 362/238, 362/255, 362/558, 362/230, 362/231, 362/373, 362/547, 362/574, 315/169.3, 315/160, 315/312, 315/291, 315/219, 315/209.R
• US Class Current: 362/294
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/745 the fins or blades being planar and inclined with respect to the joining surface from which the fins or blades extend
• CPC Class Codes: F21V 29/767 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21V 5/007 Array of lenses or refractors for a cluster of light sources, e.g. for arrangement of multiple light sources in one plane combination of two or more refractors F21V5/008
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298

Abstract

The light generator comprises a housing (1) with a light source in the form of a plurality of LEDs (3, 3′, . . . ), each having a luminous flux of at least 5 lm during operation. The housing (1) also comprises a collimating lens (6) and a Fresnel lens (8) for focusing the beam generated by the LEDs (3, 3′, . . . ). The light engine is further provided with drive means in a box (10) for driving the LEDs (3, 3′, . . . ). Preferably, the collimator lens (6) has a number of sub-lenses (7, 7′, . . . ), the optical axis of each of the sub-lenses coinciding with the optical axis of a respective one of the LEDs (3, 3′, . . .).

Claims

1. A light generator comprising a housing accommodating a light source and an optical system for directing the radiation to be generated by the light source, wherein

the light source comprises at least one LED having a luminous flux which is at least 5 lm during operation of the light source;

the optical system comprises a collimating system for incident light from the light source, said collimating system including collimator elements which exhibit total internal reflection of a portion of said light;

said optical system further comprising a focusing lens to focus within the housing, light incident from the collimating system;

the housing is provided with cooling fins; and

the light generator further comprises drive electronics for driving the LED and a metal-core printed circuit board on which the LED is mounted.

2. A light generator as claimed in claim 1, wherein the housing is made of metal, and

the metal-core printed circuit board is in contact with the metal housing via a heat-conducting connection.

3. A light generator as claimed in claim 1, further comprising means for forced air cooling the metal-core printed circuit board.

4. A light generator as claimed in claim 1, wherein

the light source comprises a plurality of LED'"'"'s, and

the collimator system comprises a collimator lens which is composed of a plurality of sub-lenses, each of the sub-lenses having an optical axis which coincides with an optical axis of a respective one of the LED'"'"'s.

5. A light generator as claimed in claim 1, wherein

the light source comprises a plurality of LED'"'"'s, and

the optical system comprises a plurality of said collimating elements, each LED being associated with one collimating element, and an optical axis of each one of the LED'"'"'s coinciding with an optical axis of the associated collimating element.

6. A light generator as claimed in claim 5, wherein the LED'"'"'s and the associated collimating elements are arranged in a hexagonal array.

7. A light generator as claimed in claim 1, wherein the focusing lens is a Fresnel lens.

8. A light generator as claimed in claim 1, wherein the drive electronics comprise means for changing the luminous flux of the LED.

9. A light generator as claimed in claim 1, wherein the light source comprises LED'"'"'s which generate radiation of different wavelengths,

and the drive electronics comprise means for adjusting the ratio between the luminous fluxes of the LED'"'"'s.