Illumination device, display apparatus, and timepiece

Patent metadata

Field	Value
Publication number	US-9523960-B2
Application number	US-201414323150-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 8, 2013
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

There is provided an illumination device including: a light guide plate in which a light diffusion pattern of diffusing incident light is formed to have density that is coarse on one side and gets denser toward the other side; a first light source which is provided on a side corresponding to the one side of the light diffusion pattern in the light guide plate; and a second light source which is provided on a side corresponding to the other side of the light diffusion pattern in the light guide plate.

First claim

What is claimed is:

1. An illumination device comprising:
a light guide plate in which a light diffusion pattern of diffusing incident light is formed to have density that is coarse on one side and gets denser toward the other side;
a first light source configured to be provided on a side corresponding to the one side of the light diffusion pattern in the light guide plate;
a second light source configured to be provided on a side corresponding to the other side of the light diffusion pattern in the light guide plate; and
a fluorescent layer configured to be provided to correspond to the side where the density of the light diffusion pattern in the light guide plate is dense, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source.

2. The illumination device according to claim 1 , further comprising:
a first incident unit configured to be provided on the one side of the light guide plate and take in light from the first light source to the light guide plate along a surface direction of the plate; and
a second incident unit configured to be provided on the other side of the light guide plate and take in light from the second light source to the light guide plate along a surface direction of the plate.

3. The illumination device according to claim 1 , further comprising:
a first incident unit configured to be provided on the one side of the light guide plate and take in light from the first light source to the light guide plate along a surface direction of the plate; and
a second incident unit configured to be provided on the other side of the light guide plate and take in light emitted from the second light source to the light guide plate from a direction orthogonal to a surface direction of the plate.

4. The illumination device according to claim 1 , further comprising:
a first incident unit configured to be provided on the one side of the light guide plate and take in light from the first light source to the light guide plate along a surface direction of the plate;
a second incident unit configured to be provided on the other side of the light guide plate and take in light from the second light source to the light guide plate along a surface direction of the plate; and
a fluorescent layer configured to be provided to correspond to at least a part of a surface of the light guide plate from which the incident light is emitted, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source.

5. The illumination device according to claim 1 , further comprising:
a first incident unit configured to be provided on the one side of the light guide plate and take in light from the first light source to the light guide plate along a surface direction of the plate;
a second incident unit configured to be provided on the other side of the light guide plate and take in light emitted from the second light source to the light guide plate from a direction orthogonal to a surface direction of the plate; and
a fluorescent layer configured to be provided to correspond to at least a part of a surface of the light guide plate from which the incident light is emitted, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source.

6. The illumination device according to claim 1 , wherein the first light source is configured to emit light in a visible spectral range, while the second light source is configured to emit light in an ultraviolet spectral range.

7. The illumination device according to claim 1 , further comprising:
a first incident unit configured to be provided on the one side of the light guide plate and take in light from the first light source to the light guide plate along a surface direction of the plate; and
a second incident unit configured to be provided on the other side of the light guide plate and take in light from the second light source to the light guide plate along a surface direction of the plate, wherein
the first light source is configured to emit light in a visible spectral range, while the second light source is configured to emit light in an ultraviolet spectral range.

8. The illumination device according to claim 1 , further comprising:
a first incident unit configured to be provided on the one side of the light guide plate and take in light from the first light source to the light guide plate along a surface direction of the plate; and
a second incident unit configured to be provided on the other side of the light guide plate and take in light emitted from the second light source to the light guide plate from a direction orthogonal to a surface direction of the plate, wherein
the first light source is configured to emit light in a visible spectral range, while the second light source is configured to emit light in an ultraviolet spectral range.

9. The illumination device according to claim 1 , further comprising a fluorescent layer configured to be provided to correspond to at least a part of a surface of the light guide plate from which the incident light is emitted, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source, wherein
the first light source is configured to emit light in a visible spectral range, while the second light source is configured to emit light in an ultraviolet spectral range.

10. The illumination device according to claim 1 , further comprising a fluorescent layer configured to be provided to correspond to at least a part of a surface of the light guide plate from which the incident light is emitted, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source, wherein
the fluorescent layer is provided to correspond to the other side of a surface of the light guide plate.

11. The illumination device according to claim 1 , further comprising:
a fluorescent layer configured to be provided to correspond to at least a part of a surface of the light guide plate from which the incident light is emitted, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source; and
a reflection plate configured to be provided with the fluorescent layer, wherein
the fluorescent layer is provided in a region covering roughly half the reflection plate which is located on a side corresponding to the other side of a surface of the light guide plate.

12. The illumination device according to claim 1 , further comprising:
a fluorescent layer configured to be provided to correspond to at least a part of a surface of the light guide plate from which the incident light is emitted, the fluorescent layer emitting light in a visible spectral range of a wavelength longer than that of light from the second light source once an electron is excited by irradiation with the light from the second light source; and
a reflection plate configured to be provided with the fluorescent layer, wherei

Assignees

• Casio Computer Co Ltd

Inventors

• Hanzawa Kei
• Yamakawa Eiji

Classifications

• G04B19/30 Primary

  Illumination of dials or hands {(dials in general G04B19/06; moving indicating means with numbers or hands, in general G04B19/20; arrangements for indicating different local apparent times by means of a globe illuminated from inside G04B19/22; continuous indication of the time by non-electric light sources G04B25/00, e.g. by electric lamps G04C17/02; illumination by electric lamps which function at fixed times or periodically G04C19/02; illuminated panels G09F13/00)} · CPC title

• G04B19/32

  by luminescent substances {(disc or drum shaped indicating means with marks or windows G04B19/04; with numbers or number-marks G04B19/20; cases for housing the electrical parts G04G17/00; projection of hands and/or scales on weighing apparatus G01G19/00; on measuring instruments G01D5/262; for advertising G09F19/18)} · CPC title

• G02B6/0036

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0018

  Redirecting means on the surface of the light guide · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title