Illumination device

Patent metadata

Field	Value
Publication number	US-9627362-B2
Application number	US-201213671804-A
Country	US
Kind code	B2
Filing date	Nov 8, 2012
Priority date	May 17, 2010
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

An illumination device includes a light-emitting device and a diffusion member. The light-emitting device has a plurality of light-emitting elements that emit light having a peak wavelength in a wavelength region of 380 to 420 nm, a first phosphor that emits visible light having a peak wavelength in a wavelength region of 560 to 600 nm, a second phosphor that is excited by ultraviolet ray or short-wavelength visible light and emits visible light in complementary color relationship with the visible light emitted by the first phosphor, and a light-transmitting member that covers the plurality of light-emitting elements and contains the first phosphor and the second phosphor dispersed therein. The diffusion member diffuses at least a part of the light emitting from the light-emitting device.

First claim

What is claimed is:

1. An illumination device comprising:
a light-emitting device having (i) a plurality of light-emitting elements that emit ultraviolet ray or short-wavelength visible light having a peak wavelength in a wavelength region of 380 to 420 nm, (ii) a substrate on which the plurality of light-emitting elements are mounted, wherein all of the light-emitting elements on the substrate are arranged in a single row, (iii) a first phosphor that is excited by the ultraviolet ray or short-wavelength visible light and emits visible light having a peak wavelength in a wavelength region of 560 to 600 nm, (iv) a second phosphor that is excited by the ultraviolet ray or short-wavelength visible light and emits visible light in complementary color relationship with the visible light emitted by the first phosphor, and (v) a light-transmitting member that covers the plurality of light-emitting elements and contains the first phosphor and the second phosphor dispersed therein, so as to obtain white color by mixing the light from each of the first and second phosphors; and
a diffusion member that has a diffusivity of 10% or more and diffuses at least a part of the light emitted from the light emitting device, said diffusion member having a plate shape and including (i) an incident surface which opposes the light-emitting surface of the light emitting device and on which light emitting from the light emitting device is incident, and (ii) a light-exiting surface from which light transmitted through the diffusion member exits and which is opposite to the incident surface,
wherein a volume concentration of the whole phosphors contained in the light-transmitting member is 0.01 vol % or more and 10 vol % or less,
wherein the light-transmitting member (i) has a shape having a thickness in a direction perpendicular to a light-exiting surface of the light-emitting elements of 0.4 mm or more and 20 mm or less and (ii) integrally seals the upper surface of the substrate on which the plurality of light-emitting elements are mounted,
wherein a relationship of Ia<0.5×Imax is satisfied, where Imax is the maximum intensity of the excitation spectrum of the first phosphor, and Ia is the intensity of the excitation spectrum of the first phosphor at the peak wavelength of the light emission spectrum of the second phosphor,
wherein the light-emitting elements are disposed so that an interval thereof to adjacent light-emitting elements is within a range of 0.4 mm to 20 mm, and
wherein the diffusion member is disposed such that a distance thereof to the light-transmitting member is at least 3 mm.

2. The illumination device according to claim 1 , wherein the first phosphor has an average particle size of 0.5 μm or more and 100 μm or less, and the second phosphor has an average particle size of 0.5 μm or more and 100 μm or less.

3. The illumination device according to claim 1 , wherein the diffusion member is disposed so that a distance thereof to the light-transmitting member is 30 mm or less.

4. The illumination device according to claim 1 , wherein the diffusion member has a transmittance within a range from 80% to 95%.

5. The illumination device according to claim 1 , wherein the diffusion member has a transmittance and a diffusivity that are set so that the variation in the brightness of a surface on the light-exiting side is 45% or less.

6. The illumination device according to claim 2 , wherein the diffusion member is disposed so that a distance thereof to the light-transmitting member is 30 mm or less.

7. The illumination device according to claim 2 , wherein the diffusion member has a transmittance within a range from 80% to 95%.

8. The illumination device according to claim 2 , wherein the diffusion member has a transmittance and a diffusivity that are set so that the variation in the brightness of a surface on the light-exiting side is 45% or less.

Assignees

• Koito Mfg Co Ltd

Inventors

• Daicho Hisayoshi

Classifications

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W90/00 Primary

  Package configurations · CPC title

• H01L33/502

  Electricity · mapped topic

• H01L2924/09701

  Electricity · mapped topic