Optoelectronic module and projection apparatus comprising the optoelectronic module
An optoelectronic module for emitting monochromatic radiation in the visible wavelength range is specified. The module has a plurality of light emitting diode chips which generate UV radiation. The UV radiation is converted into light in the visible range, for example, into green light, by a wavelength converter. The coupling-out of light from the module is optimized by the use of two selectively reflecting and transmitting filters. This module can be used as a light source in a projection apparatus.
1. An optoelectronic module comprising:
a plurality of light emitting diode chips that generate UV radiation;
a wavelength converter disposed downstream of the light emitting diode chips in an emission direction, wherein the wavelength converter converts the UV radiation at least partly into radiation in a visible wavelength range;
at least one common visible filter for the plurality of light emitting diode chips, the common visible filter being disposed downstream of the wavelength converter in the emission direction and having a high transmissivity for the radiation in the visible wavelength range and a high reflectivity for the UV radiation; and
at least one UV filter having a high transmissivity for the UV radiation and a high reflectivity for the radiation in the visible wavelength range, wherein the at least one UV filter is monolithically integrated into one light emitting diode chip or is fixed to at least one radiation-emitting side of the light emitting diode chip.
2. The optoelectronic module as claimed in claim 1 , wherein the at least one UV filter is situated between the wavelength converter and a light emitting diode chip.
3. The optoelectronic module as claimed in claim 1 , wherein the at least one common visible filter is arranged on a radiation-transmissive carrier having a high thermal conductivity.
4. The optoelectronic module as claimed in claim 3 , wherein the wavelength converter is contained in the radiation-transmissive carrier.
5. The optoelectronic module as claimed in claim 1 , wherein at least two light emitting diode chips operate with the wavelength converter.
6. The optoelectronic module as claimed in claim 1 , wherein a filter is spaced apart from the wavelength converter in the emission direction.
7. The optoelectronic module as claimed in claim 6 , further comprising air or a potting compound situated between the filter and the wavelength converter.
8. The optoelectronic module as claimed in claim 1 , wherein the at least one UV filter is monolithically integrated into a light emitting diode chip.
9. An optoelectronic module comprising:
at least three light emitting diode chips;
at least three UV filters, each UV filter transmitting UV radiation and being assigned one-to-one and disposed directly downstream of an associated light emitting diode chip, wherein each light emitting diode chip is monolithically integrated with its associated UV filter;
exactly one wavelength converter disposed downstream of the light emitting diode chips and UV filters; and
exactly one visible filter disposed downstream of the wavelength converter.
10. A projection arrangement comprising a light source, the light source comprising an optoelectronic module as claimed in claim 1 .
11. The projection arrangement as claimed in claim 10 , further comprising a heat-conducting frame, wherein the optoelectronic module is surrounded by the heat-conducting frame.
12. The optoelectronic module as claimed in claim 5 , wherein all light emitting diode chips operate with the wavelength converter.
13. The optoelectronic module as claimed in claim 1 , wherein the wavelength converter comprises one of a plurality of wavelength converters disposed downstream of the light emitting diode chips.
14. The optoelectronic module as claimed in claim 1 , wherein the visible filter transmits at least 75% of the visible radiation impinging on the visible filter and reflects at least 75% of the UV radiation impinging on the visible filter, and wherein the UV filter transmits at least 75% of the UV radiation impinging on the UV filter and reflects at least 75% of the visible radiation impinging on the UV filter.
15. The optoelectronic module as claimed in claim 1 , wherein all of the LEDs have a common wavelength converter and a common UV filter, wherein the common UV filter is disposed downstream of the LEDs in the emission direction and covers the LEDs completely, and wherein the wavelength converter is arranged between the common UV filter and the common visible filter, wherein the common visible filter covers the wavelength converter completely.
16. The optoelectronic module as claimed in claim 1 , wherein the wavelength converter converts the UV radiation into green light having a peak wavelength in the range of 490 nm to 545 nm and the common visible filter is only transmissive for green light in the wavelength range between 490 nm and 545 nm.
17. The optoelectronic module as claimed in claim 1 , wherein the at least one UV filter is fixed to at least one radiation-emitting side of the light emitting diode chip.