Camera flash with reconfigurable emission spectrum

Abstract

A method and an apparatus for spectrum synthesis for use in a flash unit, wherein the spectrum synthesis includes combining a plurality of emissive light sources in order to provide a combine output beam and producing the output spectrum for the combined output beam at least based on a reference spectrum. The reference spectrum can be obtained by sensing the spectrum of ambient light or selected from a plurality of stored spectra. The flash unit has at least two emissive light sources and each of the light sources can be adjusted relative to each other so that the outputs from the light sources can mimic a selected illumination scenario. It is possible to use a mixture of quantum dots to tailor each light source so that the combined spectra from different light sources can reasonably mimic a number of frequently used illumination scenario.

What is claimed is: 
     
         1 . A method for producing an output spectrum of a flash unit, comprising:
 displaying one or more illumination scenarios, the illumination scenarios each having a particular illuminant spectral distribution;   receiving a selection of an illumination scenario; and   adjusting base spectra of a plurality of light sources to create a combined output beam having an output spectrum that corresponds to the selected illumination scenario's spectral distribution.   
     
     
         2 . The method of  claim 1 , further comprising:
 determining the spectral distribution of ambient light surrounding the flash unit;   comparing the spectral distribution of the ambient light to the selected illumination scenario's spectral distribution; and   adjusting the base spectra at least partially based on the comparison.   
     
     
         3 . The method of  claim 2 , further comprising sensing the spectral distribution of ambient light to providing a reference spectrums. 
     
     
         4 . The method of  claim 1 , wherein the illumination scenarios include at least one of sunlight, cloudy sky, tungsten lamp, fluorescent light, and candle light. 
     
     
         5 . The method of  claim 1 , further comprising:
 sensing a spectrum of ambient light for providing a sensed spectrum; and   selecting a reference spectrum at least partly based on the sensed spectrum.   
     
     
         6 . An apparatus for producing an output spectrum of a flash unit, the apparatus comprising:
 a user interface for displaying one or more illumination scenarios, the illumination scenarios each having a particular illuminant spectral distribution;   a unit that receives a selection of an illumination scenario; and   a control module in communication with the user interface and the unit, the control module adjusts spectra of a plurality of light sources to create a combined output beam having an output spectrum that corresponds to the selected illumination scenario's spectral distribution.   
     
     
         7 . The apparatus of  claim 6 , wherein the unit determines the spectral distribution of ambient light surrounding the flash unit. 
     
     
         8 . The apparatus of  claim 7 , wherein the unit compares the spectral distribution of the ambient light to the selected illumination scenario's spectral distribution. 
     
     
         9 . The apparatus of  claim 8 , wherein the unit adjusts the base spectra at least partially based on the comparison the spectral distribution of the ambient light to the selected illumination scenario's spectral distribution. 
     
     
         10 . The apparatus of  claim 6  further comprising:
 a connector for receiving the flash unit; and 
 a processor in communication with the control module, the processor is configured, at least, to adjust electric current to the light source. 
 
     
     
         11 . The apparatus of  claim 6  further comprising a camera. 
     
     
         12 . The apparatus of  claim 6  further comprising a mobile terminal. 
     
     
         13 . The apparatus of  claim 6  further comprising a sensor for sensing a spectrum of ambient light for providing a sensed spectrum, wherein a reference spectrum is selected at least partly based on the sensed spectrum.