| 摘要 |
An LED light source has two vertically stacked LEDs (200,300) generating light of different colour from each other, thus enabling white light to be produced. The light source may have a fluorescent translucent layer (421) arranged to provide light of a wavelength between the wavelengths of the light emitted from the two LEDs (200,300). Mixing of the light emitted from the LEDs (200,300) enables the colour of light emitted from the source to be changed. The light source may have a metal heat sink (460) located within 40 microns from the active region of the LEDs to absorb heat generated in the active regions. The light source may have cavities (14, Fig. 2) to extract light guided by reflectors (16, Fig. 3), improving light extraction from the device. |
