Light emitting device i.e. industrial light emitting device such as traffic signal, has wavelengths converting material surrounding LED, and including filler particles whose concentration is lowest in areas where color conversion is smaller

摘要

The device (200) has a light source with a LED e.g. blue LED, and a wavelength converting material arranged such that the material surrounds the LED. The material is formed as a light-transparent material and partial light-transparent material and includes a number of luminescent pigments (202) for color conversion. The material includes heat-conducting filler particles (204) whose concentration is highest in areas where most converted light is produced and is lowest in areas where the color conversion is smaller within parts of the partial transparent material. An independent claim is also included for a method for increasing thermal color stability of a light emitting device.