Calibration light source
The invention relates to a calibration radiation source comprising the following: a housing ( 2 ) having an opening ( 12 ), a board ( 22 ) held in the housing ( 2 ), a semiconductor radiation source ( 18 ) mounted on the board ( 22 ) for generating a light beam, and an exit opening support element ( 14 ) having, in the area of the opening ( 12 ), a light exit opening ( 15 ) through which the light beam radiates outwards from the housing ( 2 ). The exit opening support element ( 14 ) is decoupled from the housing ( 2 ), and is attached to the board ( 22 ) of the semiconductor radiation source ( 18 ).
1. A calibration light source comprising:
a housing ( 4 ) having an opening ( 12 ),
a board ( 22 ) held in the housing ( 4 ),
a semiconductor light source ( 18 ) held by the board ( 22 ), the semiconductor light source to generate a light beam,
an exit opening support element ( 14 ) having, in an area of the opening ( 12 ), a light exit opening ( 15 ), functioning as an aperture through which the light beam generated by the semiconductor light source ( 18 ) radiates outwards from the housing ( 4 ),
an active cooling device ( 30 ) connected to the board ( 22 ), the active cooling device to cool the semiconductor light source ( 18 ),
a first thermally conductive connecting element ( 28 ) connecting a cold side of the cooling device ( 30 ) with the board ( 22 ) of the semiconductor light source ( 18 ) to convey heat away from the semiconductor light source ( 18 ) and to the cooling device ( 30 ), a thermally isolating holder ( 38 ),
a second thermally conductive connecting element ( 34 ) connected to a hot side of the cooling device ( 30 ), the second connecting element ( 34 ) held in the housing ( 4 ) by a thermally isolating holder ( 38 ),
wherein the active cooling device ( 30 ), the first thermally conductive connecting element ( 28 ) the exit opening support element ( 14 ) and the semiconductor light source ( 18 ) are suspended in the housing via the thermally isolating holder in an area adjacent to a portion of the second connecting element ( 34 ) toward an end opposing the active cooling device ( 30 ), wherein the exit opening support element ( 14 ) is attached to the board ( 22 ) of the semiconductor light source ( 18 ), and wherein a gap ( 13 ) is provided between a sidewall of the exit opening support element ( 14 ) and an inner edge of the opening ( 12 ).
2. The calibration light source of claim 1 wherein the light exit opening ( 15 ) includes a diffuser ( 16 ).
3. The calibration light source of claim 1 wherein the semiconductor light source ( 18 ) comprises a high-powered LED.
4. The calibration light source of claim 1
wherein the first connecting element ( 28 ) is dimensioned so that the hot side of the cooling device ( 30 ) is sufficiently far from the semiconductor light source ( 18 ) to ensure that the heat generated there is kept at a distance from the semiconductor light source ( 18 ), yet close enough to the semiconductor light source ( 18 ) to ensure that heat exchange between the cooling device ( 30 ) and the semiconductor light source ( 18 ) takes place sufficiently quickly.
5. The calibration light source of claim 4 further comprising:
a heat sink ( 36 ) attached to the end of the second connecting element ( 34 ) at an end opposing the cooling device ( 30 ) having an enlarged heat exchange surface to disperse the heat into ambient air, and
a fan ( 40 ) to carry heated ambient air away from the heat sink ( 36 ).
6. The calibration light source of claim 1 , in which the housing ( 4 ) and the exit opening support element ( 14 ) are made of a material having good heat insulating properties.
7. The calibration light source according to claim 1 further comprising:
a temperature sensor ( 32 ) arranged in proximity to the semiconductor light source ( 18 ) to measure a temperature of the semiconductor light source ( 18 ), and
a temperature regulator ( 42 ) to regulate power supplied to the active cooling device ( 30 ) as a function of the temperature measured by the temperature sensor ( 32 ).
8. The calibration light source of claim 7 ,
wherein the temperature regulator ( 42 ) is set to keep the temperature constant at a fixed specified value.
9. The calibration light source of claim 1 wherein the semiconductor light source ( 18 ) comprises a plurality of high-powered LEDs ( 44 ) arranged on a chip array ( 46 ) with the temperature sensor ( 32 ).
10. The calibration light source of claim 1 wherein the active cooling device ( 30 ) comprises a Peltier element.
11. The calibration light source according to claim 1 wherein the exit opening support element ( 14 ) is a hollow body having a closed sidewall and an open light exit opening ( 15 ).
12. The calibration light source of claim 1 wherein the gap is filled with a thermally insulating air buffer.
13. The calibration light source of claim 1 wherein an optically transparent window made of an optically transparent material is provided in light exit opening ( 15 ).
14. The calibration light source of claim 13 wherein the optically transparent material is glass or quartz.