LED drive circuit, LED drive device, and LED drive system

Patent metadata

Field	Value
Publication number	US-10820385-B2
Application number	US-201816480327-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Jan 31, 2017
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

An LED drive circuit drives an LED module. The LED module has a light-emitting diode, and an identification unit having characteristic information relating to light-emitting characteristics of the light-emitting diode. The LED drive circuit includes a detection unit and a drive circuit. The detection unit is provided for detecting characteristic information, and generates a detection signal that corresponds to the characteristic information. The drive circuit generates drive current by a drive signal supplied according to the characteristic information based on the detection signal, and supplies the drive current to drive the light-emitting diode.

First claim

The invention claimed is:

1. An LED driving circuit that drives an LED module including a light emitting diode and an identification unit having characteristic information related to light emission characteristics of the light emitting diode, the LED driving circuit comprising:
a detector that detects the characteristic information and generates a detection signal corresponding to the characteristic information; and
a driving circuit that generates a drive current with a drive signal provided in accordance with the characteristic information based on the detection signal and supplies the drive current to drive the light emitting diode, wherein
the identification unit includes a resistance element having a resistance value corresponding to the characteristic information,
the detector detects the characteristic information from a voltage value when current flows to the resistance element, and
the detector includes:
a detection circuit that generates a voltage corresponding to the resistance element; and
a conversion circuit that converts the voltage into the characteristic information.

2. The LED driving circuit according to claim 1 , wherein
the LED module includes a plurality of the light emitting diodes,
the characteristic information includes at least one of information related to a color rank of emitted light produced by the plurality of light emitting diodes and information related to a brightness of emitted light produced by the plurality of light emitting diodes, and
the driving circuit generates the drive current based on the characteristic information for each of the plurality of light emitting diodes and supplies the drive current to drive each of the plurality of light emitting diodes.

3. The LED driving circuit according to claim 1 , wherein:
the light emitting diode includes a first light emitting diode that emits red light, a second light emitting diode that emits green light, and a third light emitting diode that emits blue light;
the characteristic information includes at least one of information related to a color rank of emitted light produced by the first light emitting diode, the second light emitting diode, and the third light emitting diode and information related to a brightness of emitted light produced by the first light emitting diode, the second light emitting diode, and the third light emitting diode; and
the driving circuit generates a first drive current supplied to the first light emitting diode, a second drive current supplied to the second light emitting diode, and a third drive current supplied to the third light emitting diode as the drive current based on the characteristic information, and the driving circuit supplies the first drive current, the second drive current, and the third drive current to respectively drive the first light emitting diode, the second light emitting diode, and the third light emitting diode.

4. The LED driving circuit according to claim 1 , wherein:
the light emitting diode includes a first light emitting diode that emits red light, a second light emitting diode that emits green light, and a third light emitting diode that emits blue light;
the characteristic information includes at least one of information related to a combination of a color rank of emitted light of the first light emitting diode, a color rank of emitted light of the second light emitting diode, and a color rank of emitted light of the third light emitting diode and information related to a combination of a brightness of emitted light of the first light emitting diode, a brightness of emitted light of the second light emitting diode, and a brightness of emitted light of the third light emitting diode; and
the driving circuit generates a first drive current supplied to the first light emitting diode, a second drive current supplied to the second light emitting diode, and a third drive current supplied to the third light emitting diode as the drive current based on the characteristic information, and the driving circuit supplies the first drive current, the second drive current, and the third drive current to respectively drive the first light emitting diode, the second light emitting diode, and the third light emitting diode.

5. An LED driving device comprising:
an LED module including a light emitting diode; and
an LED driving circuit that drives the light emitting diode, wherein
the LED module includes an identification unit having characteristic information related to light emission characteristics of the light emitting diode,
the LED driving circuit includes
a detector that detects the characteristic information and generates a detection signal corresponding to the characteristic information, and
a driving circuit that generates a drive current with a drive signal provided in accordance with the characteristic information based on the detection signal and supplies the drive current to drive the light emitting diode,
the identification unit includes a resistance element having a resistance value corresponding to the characteristic information,
the detector detects the characteristic information from a voltage value when current flows to the resistance element, and
the detector includes:
a detection circuit that generates a voltage corresponding to the resistance element; and
a conversion circuit that converts the voltage into the characteristic information.

6. The LED driving device according to claim 5 , wherein the resistance value of the resistance element is greater than or equal to 100Ω and less than or equal to 10 kΩ.

7. The LED driving device according to claim 5 , wherein the LED module is a package of the light emitting diode and the identification unit.

8. The LED driving device according to claim 5 , wherein
the LED module includes a plurality of the light emitting diodes,
the characteristic information includes at least one of information related to a color rank of emitted light produced by the plurality of light emitting diodes and information related to a brightness of emitted light produced by the plurality of light emitting diodes, and
the driving circuit generates the drive current based on the characteristic information for each of the plurality of light emitting diodes and supplies the drive current to drive each of the plurality of light emitting diodes.

9. The LED driving device according to claim 5 , wherein:
the light emitting diode includes a first light emitting diode that emits red light, a second light emitting diode that emits green light, and a third light emitting diode that emits blue light;
the characteristic information includes at least one of information related to a color rank of emitted light produced by the first light emitting diode, the second light emitting diode, and the third light emitting diode and information related to a brightness of emitted light produced by the first light emitting diode, the second light emitting diode, and the third light emitting diode; and
the driving circuit generates a first drive current supplied to the first light emitting diode, a second drive current supplied to the second light emitting diode, and a third drive current supplied to the third light emitting diode as the drive current based on the characteristic information, and the driving circuit supplies the first drive current, the second drive current, and the third drive current to respectively drive the first light emitting diode, the second light emitting diode, and the third light emitting diode.

10. The LED driving device according to claim 5 , wherein:
the light emitting diode includes a first light emitting diode that emits red light, a second light emitting diode that emits green light, and a third light emitt

Assignees

• Rohm Co Ltd

Inventors

• Fukumoto Kenichi
• Katsura Koji
• Kanemitsu Ryosuke
• Itai Junichi
• Matsui Nobuaki
• Nakashima Seiji
• Miyamoto Kouji

Classifications

• H10H20/85

  Packages · CPC title

• H10H20/80

  Constructional details · CPC title

• H05B45/395

  Linear regulators · CPC title

• H05B45/20

  Controlling the colour of the light · CPC title

• H05B47/135 Primary

  by determining the type of light source being controlled (electrical parameters of light source being controlled H05B47/14) · CPC title