US 10,368,409 B2
Light emitting device and LED light bulb
Hiroyasu Kondo, Yokohama (JP); Masahiko Yamakawa, Yokohama (JP); Yasuhiro Shirakawa, Yokohama (JP); Ryoji Tsuda, Yokohama (JP); Atsuji Nakagawa, Himeji (JP); Toshitaka Fujii, Himeji (JP); and Tomohiko Inoue, Himeji (JP)
Assigned to Toshiba Materials Co., Ltd., Yokohama-Shi (JP)
Filed by Toshiba Materials Co., Ltd., Yokohama-Shi (JP); and Phoenix Electric Co., Ltd., Himeji-Shi (JP)
Filed on Oct. 24, 2017, as Appl. No. 15/791,932.
Application 15/791,932 is a continuation of application No. 15/259,481, filed on Sep. 8, 2016.
Application 15/259,481 is a continuation of application No. PCT/JP2015/001512, filed on Mar. 18, 2015.
Claims priority of application No. 2014-057335 (JP), filed on Mar. 20, 2014.
Prior Publication US 2018/0049285 A1, Feb. 15, 2018
Int. Cl. H05B 33/08 (2006.01); F21K 9/232 (2016.01); F21K 9/238 (2016.01); F21K 9/235 (2016.01); C09K 11/08 (2006.01); C09K 11/66 (2006.01); C09K 11/77 (2006.01); F21V 3/02 (2006.01); F21V 23/00 (2015.01); H01L 33/50 (2010.01); H01L 25/075 (2006.01); H01L 25/16 (2006.01); F21Y 103/10 (2016.01); F21Y 115/10 (2016.01)
CPC H05B 33/0827 (2013.01) [C09K 11/0883 (2013.01); C09K 11/665 (2013.01); C09K 11/778 (2013.01); C09K 11/7734 (2013.01); C09K 11/7739 (2013.01); C09K 11/7787 (2013.01); C09K 11/7789 (2013.01); F21K 9/232 (2016.08); F21K 9/235 (2016.08); F21K 9/238 (2016.08); F21V 3/02 (2013.01); F21V 23/005 (2013.01); H01L 33/504 (2013.01); H05B 33/0821 (2013.01); H05B 33/0845 (2013.01); H05B 33/0857 (2013.01); F21Y 2103/10 (2016.08); F21Y 2115/10 (2016.08); H01L 25/0753 (2013.01); H01L 25/167 (2013.01); H01L 2924/0002 (2013.01); Y02B 20/181 (2013.01); Y02B 20/341 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A light emitting device comprising:
a first light source configured to emit a first white light and including a plurality of first diode groups, each first diode group having N pieces of first white light emitting diodes where N is a natural number equal to or more than 2, the first white light emitting diodes of each first diode group being connected in series to one another in a forward direction, the series-connected diodes of one of the first diode groups being connected in parallel with the series-connected diodes of another one of the first diode groups, the first white light having a first color temperature; and
a second light source connected in parallel to the first light source, configured to emit a second white light, and including a plurality of second diode groups and a first resistance element, each second diode group having M pieces of second white light emitting diodes where M is a natural number less than N, the second white light emitting diodes of each second diode group being connected in series to one another in a forward direction, the series-connected diodes of one of the second diode groups being connected in parallel with the series-connected diodes of another one of the second diode groups, the first resistance element being connected in series to the series-connected diodes of each second diode group and having a first resistance value, and the second white light having a second color temperature lower than the first color temperature,
wherein each of the first white light emitting diodes and the second white light emitting diodes has a phosphor film, the film containing a silicone resin and a phosphor dispersed in the resin,
wherein the device is configured to emit a mixed white light of the first white light and the second white light,
wherein a ratio of a drive current of the first light source to a drive current of the second light source is 10 or more,
wherein a drive voltage of the first light source is higher than a drive voltage of the second light source, and
wherein a color temperature of the mixed white light is higher as a total luminous flux of the mixed white light is higher.