JP2000021223A - Optical fiber tip light diffusion device and chandelier using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decrease of brightness from a light source and to efficiently illuminate a decorated body of a chandelier. SOLUTION: An optical fiber front end light diffusion device 6 which diffuses the light passing through the optical fiber and emitted from the front end is fitted to the front end of the optical fiber introducing the light from a light source to a base end. The light diffusion device 6 is made of an optical wave- guide material having a refractive index higher than that of air. A conical recess 13 which is recessed toward the optical fiber front end side and being concentric with the optical axis is formed to the light diffusion device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip of an optical fiber used in a lighting device for transmitting light from a light source to a place to be illuminated by an optical fiber and using the transmitted light as illumination of a chandelier. The present invention relates to a light diffusion device and a chandelier using the same.

[0002]

2. Description of the Related Art A device using an optical fiber as a light source for a chandelier is conventionally known (for example, Japanese Patent Application Laid-Open No. 6-203615). In this type of chandelier, the place where the light source is placed can be set separately from the decorative body,
This has the advantage that maintenance of the light source is easy.
In this type of chandelier, the tip light from the optical fiber is diffused in all directions to enhance the visibility of the brightness from all directions.

[0003]

However, in a chandelier using a conventional optical fiber, light is attenuated inside the optical fiber, and light emitted from the tip of the optical fiber is diffused in all directions. Therefore, there is a problem that the luminance for illuminating the decorative body tends to be insufficient.

The present invention has been made in view of the above points, and an optical fiber tip light diffusion device capable of efficiently illuminating a decorative chandelier while suppressing a decrease in luminance from a light source, and a chandelier using the same. The purpose is to provide.

[0005]

An optical fiber tip light diffusion device according to the present invention is attached to a tip of an optical fiber for introducing light from a light source to a base end, propagates through the optical fiber, and emits light from the tip. An optical fiber tip light diffusing device for diffusing the light to be emitted, which is formed of an optical waveguide material having a higher refractive index than air, and has a conical shape coaxial with an optical axis which is depressed toward the tip side of the optical fiber. It is characterized by forming a recess.

A chandelier according to the present invention comprises a light source, an optical fiber for introducing light from the light source to a base end,
The above-described optical fiber tip light diffusion device attached to the tip of the optical fiber and propagating through the optical fiber and diffusing light emitted from the tip, and a plurality of light diffusion devices arranged around the optical fiber tip light diffusion device. And a decorative body.

According to the present invention, the optical fiber tip light diffusion device forms a conical concave portion coaxial with the optical axis which is recessed toward the distal end side of the optical fiber, so that light emitted from the optical fiber distal end portion is formed. Is reflected by the conical recess, and most of the light is radially diffused in a certain range, angle, and direction in the radial direction with respect to the optical axis. For this reason, if a decorative body made of glass or the like is arranged around the diffusion device, most of the light emitted from the optical fiber can be applied to the surrounding decorative body, and the decorative body can be provided with high luminance. Can shine. Further, since the diffusion of light up and down the optical fiber tip light diffusion device is suppressed, there is no useless light not used as irradiation light to the decorative body, and the power of the light source is also suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a main part of a chandelier according to one embodiment of the present invention. A fiber guide 2 is suspended from a ceiling 1, and an optical fiber cable 3 is housed inside the fiber guide 2. The optical fiber cable 3 penetrates the ceiling 1, and has a base end optically coupled to the light source 4. Further, a light diffusing device 6 is connected to a distal end of the optical fiber cable 3 via a connector 5. Further, a plurality of glass rod-shaped decorative bodies 7 are suspended from the ceiling 1 so as to surround the light diffusing device 6.

FIG. 2 is a side view showing a part of the light diffusion device 6 in cross section. The light diffusing device 6 includes a screw portion 11 connected to the connector 5 and a main body portion 12 having a hemispherical outer peripheral surface. A conical recess 13 is formed on the lower surface of the main body portion 12. . The conical concave portion 13 is disposed coaxially with the optical axis indicated by a dashed line in the figure, with its apex facing the light emitting end face side (upper side in the figure) of the optical fiber cable 3. Further, the side surface 14 of the conical recess 13 forms a curved surface projecting toward the bottom surface with a predetermined radius of curvature.

The light diffusion device 6 is formed of an optical waveguide material such as glass or transparent resin. As the light diffusing device 6, for example, a methacrylic resin having a refractive index of n = 1.49 is used. Is set, for example, from the tip of the optical fiber cable 3 to the emission angle 60
The light emitted in degrees can be diffused in the radial direction at an angle of 66 to 67 degrees. In the case of this type of chandelier illumination, the axial diffusion angle in the radial direction is preferably 45 to 70 °, more preferably 66 to 6 °.
The range of 7 ° has been confirmed by experiments by the present inventors.

As described above, since the range (angle) of light diffusion is limited, the brightness of the range to be illuminated can be increased as compared with the conventional type in which light is diffused in all directions. For example, when considering a spherical surface with a unit distance as a radius,
The area Ap of the spherical surface is

[0012]

## EQU1 ## Ap = 4πD ² = 4π = 12.566

When the range of diffusion is limited to 66.5 °, the area of the partial spherical surface is approximated by a cylinder,

[0014]

As = 2πDH = 2π · 2 · tan (66.5 ° / 2) = 8.2386

Since the luminance ratio is the ratio between the two areas,
When the light diffusion device 6 of the present invention is used, 12.566 / 8.2386 = approximately 1.5 in comparison with the type that diffuses in all directions.
Double brightness is obtained.

In the above embodiment, as shown in FIG. 2, the side surface 14 of the conical recess 13 of the light diffusion device 6 is a curved surface projecting toward the bottom surface, and this side surface 14 is concave with respect to light. Since it functions as a reflecting mirror, it is possible to concentrate light on a portion emitted from the main body 12. For this reason, when the decorative body 7 is particularly arranged in the vicinity, the decorative body can be illuminated with high luminance.

[0017]

As described above, according to the present invention, the optical fiber tip light diffusing device forms a conical recess coaxial with the optical axis which is recessed toward the tip end of the optical fiber. The light emitted from the tip is reflected by the conical recess, and most of the light is radially diffused in a certain range, angle and direction in the radial direction with respect to the optical axis, and is emitted from the optical fiber. Most of the applied light can be applied to the surrounding decorations, so that the decorations can be illuminated with high luminance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of a chandelier according to an embodiment of the present invention.

FIG. 2 is a side view showing a cross section of a part of an optical fiber tip light diffusion device used in the chandelier.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ceiling, 2 ... Fiber guide, 3 ... Optical fiber cable, 4 ... Light source, 5 ... Connector, 6 ... Light diffusing device, 7 ... Decorative body, 11 ... Screw part, 12 ... Body part, 13 ... Conical concave part, 14 ... Side.

Claims (3)

[Claims] 1. An optical fiber distal end light diffusion device attached to a distal end of an optical fiber for introducing light from a light source to a base end and diffusing light propagating in the optical fiber and emitted from the distal end, A light guide member having a refractive index higher than that of air, and a conical recess coaxial with an optical axis which is recessed toward the distal end side of the optical fiber; apparatus. 2. The conical concave portion has a curved surface having a side surface protruding at a predetermined curvature to a bottom surface side so as to reflect most of incident light in a radial direction and in a predetermined angle range in an optical axis direction and reflect the light. 2. The optical fiber tip light diffusion device according to claim 1, wherein the light diffusion device is formed by: 3. A light source, an optical fiber for introducing light from the light source to a base end, and a light attached to a distal end of the optical fiber for diffusing light that propagates in the optical fiber and is emitted from the distal end. In a chandelier including a fiber tip light diffusion device and a plurality of decorations arranged around the optical fiber tip light diffusion device, the optical fiber tip light diffusion device has an optical waveguide material having a refractive index higher than air. A chandelier formed by forming a conical concave portion coaxial with an optical axis, the concave portion being formed toward the distal end side of the optical fiber.