White light emitting device
View Patent ↗There is provided a white light emitting device that prevents a red phosphor from resorbing wavelength-converted light to improve white luminous efficiency. A white light emitting device according to an aspect of the invention includes a package body; at least two LED chips mounted to the package body and emitting excitation light; and a molding unit including phosphors, absorbing the excitation light and emitting wavelength-converted light, in regions of the molding unit divided according to the LED chips and molding the LED chips. According to the aspect of the invention, since the phosphor for converted red light can be prevented from resorbing light generated from other regions of the molding unit, the white light emitting device that can improve white luminous efficiency or control color rendering and color temperature by adjusting a mixing ratio of converted light for white light emission.
1. A white light emitting device comprising:
a package body having a recess;
at least two LED chips mounted within the recess of the package body and emitting excitation light;
at least two molding units formed in the recess of the package body, each of the molding units being located in divided areas of the recess of the package body according to the at least two LED chips and molding each of the LED chips, respectively, wherein each of the molding units include phosphors, absorbing the excitation light and emitting wavelength-converted light, respectively;
a reflective film formed of high-reflective metal at a boundary between the molding units and dividing the molding units in the recess of the package body; and
a mold lens unit provided above the molding units and the reflective film, and scattering the wavelength-converted light to emit the scattered light to the outside.
2. The white light emitting device of claim 1 , wherein at least one of the regions of the molding unit comprises a phosphor for converted red light, and
the phosphor for the converted red light is a rare earth oxide, sulfide, or nitride-based phosphor that is any one selected from the group consisting of aAlSiN 3 :Eu 2+ , (Sr x ,Ca 1-x )AlSiN 3 :Eu 2+ (0≦x≦1), Sr 3 SiO 5 :Eu 2+ , (Srx,Ca 1-x ) 2 SiO 4 :Eu 2+ , (Sr x ,Ca 1-x )AlSiN y O 1-y (0≦x≦1), MS:Eu 2+ (M=Ca,Sr,Ba), M 2 O 3-x Sx:Eu 3+ (1≦x≦3, M=Y,Gd,La), Y,Lu,Sc,La,Gd,Sm) 3 (Al,Ga,In) 5 ) 12 :Ce, and (Y,Ca,Sr) 3 (Al,Ga,Si) 5 (O,S) 12 :(Ce, Tb), or a combination thereof.
3. The white light emitting device of claim 1 , wherein at least one of the regions of the molding unit comprises a phosphor for converted red light, and
the phosphor for the converted red light is a semiconductor nitride, sulfide, oxide, or phosphide-based phosphor that is any one selected from the group consisting of Zn 1-x Cd x S y Se 1-y (0≦x≦1, 0≦y≦1), Zn 1-x Cd x S y O 1-y (0≦x≦1, 0≦y≦1), Al 1-x-y Ga x In y N((0≦x≦1, 0≦y≦1), and Al 1-x-y Ga x In y P((0≦x≦1, 0≦y≦1), or a combination thereof.
4. The white light emitting device of claim 1 , wherein the molding unit comprises a first molding unit including a phosphor for converted red light and a second molding unit including phosphors for converted blue light and converted green light.
5. The white light emitting device of claim 1 , wherein the molding unit comprises the phosphors, and
the phosphors include a phosphor for converted red light.
6. The white light emitting device of claim 1 , wherein the mold lens unit comprises a plurality of optically transparent scatterers scattering the wavelength-converted light, and
the scatterer is any one material selected from the group consisting of optical glass, silica, talc, zirconium, a zinc oxide, and a titanium dioxide, or a combination thereof.
7. The white light emitting device of claim 1 , wherein each of the at least two molding units occupies one of vertically divided areas of the recess.
8. The white light emitting device of claim 7 , wherein the vertically divided areas of the recess have a predetermined ratio between the divided areas such that converted light from the at least two molding units have the predetermined ratio with each other.