LIGHT SOURCE DEVICE

• US 20100085758A1
• Filed: 08/14/2009
• Published: 04/08/2010
• Est. Priority Date: 10/02/2008
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Takahashi, Hidenori, Kumazawa, Noriyoshi
• Granted Patent: US 8,182,115 B2
• Time in Patent Office: Days
• US Class Current: 362/293
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: G02B 5/289 Rugate filters
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

Disclosed is a light source device that has lower costs and lower power consumption compared to a halogen lamp, and has the same spectral characteristics as the halogen lamp.

The light source device includes a white LED that emits white light having an emission peak in a blue range and an optical filter that partially reduces the quantity of light in the blue range in the white light emitted from the white LED such that the spectral characteristics of the white light emitted from the white LED are close to those of light emitted from a halogen lamp.

Claims

1. A light source device comprising:

a white LED that emits white light having an emission peak in a blue range; and

an optical filter that partially reduces the quantity of light in the blue range in the white light emitted from the white LED.

2. The light source device according to claim 1,

wherein the optical filter has spectral transmission characteristics in which transmittance is equal to or greater than 5% and equal to or less than 20% in the wavelength range of equal to or greater than 435 nm and equal to or less than 465 nm and is equal to or greater than 80% in the wavelength range of equal to or less than 405 nm and equal to or greater than 490 nm, in the wavelength range of a light source used.

3. The light source device according to claim 1,

wherein the white LED includes:

a blue LED chip that emits blue light; and

a fluorescent material that is excited by the blue light emitted from the blue LED chip and emits yellow light, and

the white LED mixes the blue light emitted from the blue LED chip and the yellow light emitted from the fluorescent material and emits the white light.