US 12,764,839 B2 · Illumination device

Abstract

An illumination device is an illumination device that illuminates an object containing a fluorescent brightener and includes a light emitter that emits white light including violet light whose light emission peak wavelength that excites the fluorescent brightener is less than or equal to 405 nm. A spectral reflectance ρ(λ) is expressed by an intensity EA(λ)/an intensity E(λ), where the intensity EA(λ) is an intensity of reflected light at a wavelength λ and the intensity E(λ) is an intensity of emitted light at a wavelength λ. The reflected light is light reflected off a surface of the object, and the emitted light is light emitted onto the surface of the object containing the fluorescent brightener. The maximum value of the spectral reflectance ρ(λ) at a wavelength λ ranging from 460 nm to 500 nm falls between 0.9 and 1.05, both inclusive.

Claims15

Dependent claims

An illumination device that illuminates an object containing a fluorescent brightener, the illumination device comprising:

a light emitter that emits white light including violet light whose light emission peak wavelength that excites the fluorescent brightener is less than or equal to 405 nm;
and
a controller, wherein
a spectral reflectance ρ(λ) is expressed by an intensity EA(λ)/an intensity E(λ), where the intensity EA(λ) is an intensity of reflected light at a wavelength λ and the intensity E(λ) is an intensity of emitted light at a wavelength λ, the reflected light being reflected off a surface of the object, the emitted light being emitted onto the surface of the object containing the fluorescent brightener, and
the controller controls:
an output of the light emitter to cause a maximum value of the spectral reflectance ρ(λ) at a wavelength ranging from 460 nm to 500 nm to fall between 0.9 and 1.05, both inclusive, and
the light emitter to cause the spectral reflectance ρ(λ) to fall within a predetermined range, the spectral reflectance ρ(λ) being calculated based on the intensity EA(λ) and the intensity E(λ).

4 more elements

Dependencies are inferred from the claim text.

Illumination device

Life of this patent

Illumination device

Life of this patent

Abstract

Claims15