the light sources 32 a and 32 b for example a luminous device includes more light sources and a light pervious optical element which is a kind of covering means such as a lampshade a tube a lens a cover a sticker a plate and a film and covered by coupled to or mixed with the wavelength converter 34 positioned on the light path of the light source and used to convert the original wavelength of the light source in addition the wavelength converter 34 can be optionally formed on a reflective inner surface of the luminous device and used to convert the light coming from the light source and then reflected by the inner surface or being reflected to transmit the wavelength converter 34 table 1 shows an experimental result obtained by implementing an embodiment of the invention two 15 mil u00d7 15 mil nitride series light emitting diode chips are operated under controllable current and positioned adjacent to each other in a package equipped with a silver reflector among the two chips one has a dominant wavelength of 450 nm and the other one has a dominant wavelength of 470 nm the silicate based phosphor and yag phosphor in a weight ratio of about 1 08 0 26 g 0 24 g are mixed with epoxy and disposed on the two light emitting diode chips the input currents to the respective two light emitting diode chips are controlled to oppositely change in a range between 0 ma u02dc 20 ma i e.