LED LIGHT- EMITTING DEVICE AND INDICATOR PROVIDED WITH THE LED LIGHT EMITTING DEVICE

• US 20130162140A1
• Filed: 02/19/2013
• Published: 06/27/2013
• Est. Priority Date: 08/18/2010
• Status: Active Grant

• Current Assignee: CMC Magnetics Corporation
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: SHAMOTO, Takeshi, Kasaukura, Akeo, Takeda, Toru
• Granted Patent: US 9,101,029 B2
• Time in Patent Office: Days
• US Class Current: 315/77
• CPC Class Codes: B60Q 3/85 for manual control of the light, e.g. of colour, orientation or intensity
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G01D 11/28 Structurally-combined illuminating devices
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/30 Driver circuits

Abstract

A first LED emits visible light of an emission color such that with respect to a CIE(1976)L*u*v* color space chromaticity diagram, the chromaticity is exterior to a prescribed white light region wherein the absolute value of a deviation duv from the blackbody radiation locus is at most 0.02 and the color temperature is within a range of from 2,500K to 10,000K, and the deviation duv from the blackbody radiation locus is larger than 0.02, and a second LED emits visible light of an emission color such that with respect to the above chromaticity diagram, the chromaticity is exterior to the prescribed white light region, and the deviation duv from the blackbody radiation locus is smaller than −0.02.

Claims

1. An LED light emitting device which radiates a combined light obtained by combining visible light emitted from first LED and visible light emitted from second LED and which comprises a drive controller unit that respectively controls a first drive current to be supplied to the first LED and a second drive current to be supplied to the second LED, wherein

the first LED emits visible light of an emission color such that with respect to a CIE (1976) L*u*v* color space chromaticity diagram, the chromaticity is exterior to a prescribed white light region wherein the absolute value of a deviation duv from the blackbody radiation locus is at most 0.02 and the color temperature is within a range of from 2,500 K to 10,000 K, and the deviation duv from the blackbody radiation locus is larger than 0.02, and

the second LED emits visible light of an emission color such that with respect to the CIE (1976) L*u*v* color space chromaticity diagram, the chromaticity is exterior to the prescribed white light region, and the deviation duv from the blackbody radiation locus is smaller than −

0.02.

2. The LED light emitting device according to claim 1, wherein the drive controller unit controls the first and second drive currents so that the chromaticity of the combined light moves on a line that connects the chromaticity of the emission color of the first LED and the chromaticity of the emission color of the second LED.

3. The LED light emitting device according to claim 2, wherein the line that connects the chromaticity of the emission color of the first LED and the chromaticity of the emission color of the second LED, passes through a chromaticity point at which X is at least 0.32 and at most 0.34, and Y is at least 0.32 and at most 0.34, in the CIE (1931) XYZ color space.

4. The LED light emitting device according to claim 1, wherein the emission color of the first LED and the emission color of the second LED are in a complementary color relation to each other.

5. The LED light emitting device according to claim 1, wherein the emission color of the first LED and the emission color of the second LED are characterized in that on the a*b* coordinate plane in the CIE (1976) L*a*b* color space chromaticity diagram, the angle between a line segment that connects the origin and coordinates representing the emission color of the first LED and a line segment that connects the origin and coordinates representing the emission color of the second LED, is an angle of at least 120°

and at most 240°

.

6. The LED light emitting device according to claim 1, wherein the emission color of the first LED and the emission color of the second LED are characterized in that on the a*b* coordinate plane in the CIE (1976) L*a*b* color space chromaticity diagram, the difference between the length of a line segment that connects the origin and coordinates representing the emission color of the first LED and the length of a line segment that connects the origin and coordinates representing the emission color of the second LED, is less than 20.

7. The LED light emitting device according to claim 1, wherein the emission color of the first LED and the emission color of the second LED are characterized in that on the a*b* coordinate plane in the CIE (1976) L*a*b* color space chromaticity diagram, as between the length of a line segment that connects the origin and coordinates representing the emission color of the first LED and the length of a line segment that connects the origin and coordinates representing the emission color of the second LED, the ratio of one of them to the other and the ratio of the other to said one of them are at most 2.0.

8. The LED light emitting device according to claim 1, wherein the emission color of the first LED and the emission color of the second LED are characterized in that on the a*b* coordinate plane in the CIE (1976) L*a*b* color space chromaticity diagram, the length of a line segment that connects the origin and coordinates representing the emission color of the first LED and the length of a line segment that connects the origin and coordinates representing the emission color of the second LED, are, respectively, at least 5.

9. The LED light emitting device according to claim 1, wherein on the a*b* coordinate plane in the CIE (1976) L*a*b* color space chromaticity diagram, the coordinates representing the emission color of the first LED are characterized in that the value of a* is smaller than −

20 and the value of b* is smaller than 20, and the coordinates representing the emission color of the second LED are characterized in that the value of a* is larger than 20 and the value of b* is larger than −

20.

10. The LED light emitting device according to claim 1, wherein the first LED comprises a first semiconductor light emitting element to be driven by the first drive current to emit light, and a first wavelength conversion member to let a part or whole of the light emitted from the first semiconductor light emitting element undergo wavelength conversion and then radiate the light, and the second LED comprises a second semiconductor light emitting element to be driven by the second drive current to emit light, and a second wavelength conversion member to let a part or whole of the light emitted from the second semiconductor light emitting element undergo wavelength conversion and then radiate the light.

11. The LED light emitting device according to claim 10, wherein the first wavelength conversion member contains a first phosphor to convert the light emitted from the first semiconductor light emitting element to light having a longer wavelength by wavelength conversion and then radiate the light, and the second wavelength conversion member contains a second phosphor to convert the light emitted from the second semiconductor light emitting element to light having a longer wavelength by wavelength conversion and then radiate the light.

12. The LED light emitting device according to claim 10, which comprises

a circuit board on which the first semiconductor light emitting element and the second semiconductor light emitting element are mounted,

a wall member formed on the circuit board to surround the first semiconductor light emitting element and the second semiconductor light emitting element, and

a partition member to divide a region inside of the wall member into a first region where the first semiconductor light emitting element is disposed and a second region where the second semiconductor light emitting element is disposed,

wherein the first wavelength conversion member is accommodated in the first region, and the second wavelength conversion member is accommodated in the second region.

13. The LED light emitting device according to claim 12, wherein in the first region, one or a plurality of the first semiconductor light emitting elements are disposed, and in the second region, one or a plurality of the second semiconductor light emitting elements are disposed.

14. The LED light emitting device according to claim 10, which comprises

a circuit board on which a plurality of the first semiconductor light emitting elements and a plurality of the second semiconductor light emitting elements are mounted,

wherein the first wavelength conversion member is provided for each of the plurality of the first semiconductor light emitting elements, and the second wavelength conversion member is provided for each of the plurality of the second semiconductor light emitting elements.

15. The LED light emitting device according to claim 14, wherein the plurality of the first semiconductor light emitting elements and the plurality of the second semiconductor light emitting elements are disposed as dispersed on the circuit board so that they are mutually mixed with each other.

16. The LED light emitting device according to claim 10, wherein the first semiconductor light emitting element and the second semiconductor light emitting element emit light having a peak wavelength in a wavelength range of from 360 nm to 420 nm.

17. An indicator employing the light radiated from the LED device as defined in claim 1 to carry out an indication depending on the degree of a physical quantity that is changeable at least over a preliminarily estimated changeable range, which comprises an indication controller unit to control the drive controller unit so that in response to a change of the physical quantity from the lower limit value to the upper limit value within the changeable range, the first drive current is decreased from a prescribed first upper limit current value to a prescribed first lower limit current value, and at the same time, the second drive current is increased from a prescribed second lower limit current value to a prescribed second upper limit current value.

18. The indicator according to claim 17, which is provided on an electronic device, wherein the physical quantity is a preset value that is set by an operation member provided to carry out setting of the electronic device.

19. The indicator according to claim 17, which is mounted on a vehicle, wherein the physical quantity is an operating condition quantity that changes in accordance with the operating condition of the vehicle.