LIGHT EMITTING DEVICE AND METHOD FOR DRIVING LIGHT EMITTING DEVICE

• US 20100066258A1
• Filed: 01/07/2008
• Published: 03/18/2010
• Est. Priority Date: 01/11/2007
• Status: Active Grant

• Current Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Original Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Inventors: Yasuda, Takaki
• Granted Patent: US 8,188,670 B2
• Time in Patent Office: Days
• US Class Current: 315/186
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/30 Driver circuits
• CPC Class Codes: H05B 45/42 Antiparallel configurations

Abstract

A light emitting device which can emit light of an arbitrary color temperature and a process for producing a light emitting device which can emit light of an arbitrary color temperature are provided. Such a light emitting device includes a first light emitting diode device 2 and a second light emitting diode device 3 which are connected together in parallel, and a power-supply apparatus 4 which is capable of reversing polarity, in which the color temperature of the first light emitting diode device 2 is set to be higher than the color temperature of the second light emitting diode device 3.

Claims

1. A light emitting device comprising plural light emitting diode devices which are connected together in parallel, and a power-supply apparatus which is capable of reversing polarity, wherein a color temperature of each of the light emitting diode devices is set to a different color temperature.

3. The light emitting device according to claim 1, wherein the power-supply apparatus which is capable of reversing polarity comprises a pair of direct-current power supplies which are connected together in parallel so as to have opposite polarities, and a pair of switching devices which are connected in series to the direct-current power supplies.

4. The light emitting device according to claim 1, wherein at least one of the light emitting diode device consists of plural light emitting diode devices which are connected together in series.

2. A light emitting device comprising a first light emitting diode device and a second light emitting diode device which are connected together in parallel, so as to have opposite polalities and a power-supply apparatus which is capable of reversing polarity, wherein color temperature of the first light emitting diode device is set to be higher than the color temperature of the second light emitting diode device.

9. The light emitting device according to claim 2, wherein the power-supply apparatus which is capable of reversing polarity comprises a pair of direct-current power supplies which are connected together in parallel so as to have opposite polarities, and a pair of switching devices which are connected in series to the direct-current power supplies.

10. The light emitting device according to claim 2, wherein at least one of the light emitting diode device consists of plural light emitting diode devices which are connected together in series.

5. A process for driving a light emitting device comprising plural light emitting diode devices which are connected together in parallel, and a power-supply apparatus which is capable of reversing polarity, wherein color temperature of each of the light emitting diode devices is set to be a different color temperature, and alternating current is generated by the power-supply apparatus which is capable of reversing polarity to allow each of the light emitting diode devices to alternately emit light, thereby emitting light with a color temperature in which each of the color temperature of the light emitting diode devices is synthesized.

6. A process for driving a light emitting device comprising a first light emitting diode device and a second light emitting diode device which are connected together in parallel so as to have opposite polalities, and a power-supply apparatus which is capable of reversing polarity, wherein a color temperature T₁ of the first light emitting diode device is set to be higher than a color temperature T₂ of the second light emitting diode device, and alternating current is generated by the power-supply apparatus which is capable of reversing polarity to allow each of the first and the second light emitting diode devices to alternately emit light, thereby emitting synthesized light with a color temperature which is higher than T₂ and less than T₁.

7. A process for driving a light emitting device comprising plural light emitting diode devices which are connected together in parallel, and a power-supply apparatus which is capable of reversing polarity, wherein color temperature of each of the light emitting diode devices is set to a different color temperature, wherein alternating current is generated by the power-supply apparatus which is capable of reversing polarity to allow a part or all of the light emitting diode devices to emit light.

8. A process for driving a light emitting device comprising a first light emitting diode device and a second light emitting diode device which are connected together in parallel so as to have opposite polalities, and a power-supply apparatus which is capable of reversing polarity, wherein color temperature T₁ of the first light emitting diode device is set to be higher than the color temperature T₂ of the second light emitting diode device, and direct current is generated by the power-supply apparatus which is capable of reversing polarity to allow any one of the first and the second light emitting diode devices to emit light.