JP2016119139A - Linear luminous body and solid light-emitting device - Google Patents

Abstract

A linear light emitter capable of emitting light in the radial direction of a quartz optical fiber and a solid state light emitting device are provided. A linear light emitter includes a quartz optical fiber, a translucent coating layer, a phosphor layer, and a translucent protective tube. The optical fiber has a core and a clad provided around the core, and laser light having a wavelength of ultraviolet light to blue light introduced into the core end surface of one end is an interface between the core and the clad. Is reflected and guided toward the other end, and scattered light at the interface passes through the cladding and is emitted outward. The coating layer is provided around the cladding. The phosphor layer is provided around the coating layer. The protective tube protects the quartz optical fiber and the phosphor layer so that the inner edge is separated from the outer edge of the phosphor layer. [Selection] Figure 1

Description

  Embodiments described herein relate generally to a linear light emitter and a solid state light emitting device.

  When a phosphor layer or the like is irradiated with ultraviolet light to blue light through a narrow light guide made of resin or glass, a linear light emitter capable of emitting white light can be obtained.

  However, it is difficult to lengthen the resin and the glass light guide, and the shape of the light emitting device is limited.

  On the other hand, the optical fiber has a thin light guide path and is flexible. However, in order to perform long-distance optical transmission, the amount of incident light that is totally reflected at the interface between the core and the clad and emitted from the clad in the radial direction is suppressed as much as possible. For this reason, it was difficult to use as a linear light guide.

Special table 2010-514108 gazette

  Provided are a linear light emitter and a solid state light emitting device capable of emitting light in a radial direction of a quartz optical fiber.

  The linear light emitter of the embodiment includes a quartz optical fiber, a translucent coating layer, a phosphor layer, and a translucent protective tube. The optical fiber has a core and a clad provided around the core, and laser light having a wavelength of ultraviolet light to blue light introduced into the core end surface of one end is an interface between the core and the clad. Is reflected and guided toward the other end, and scattered light at the interface passes through the cladding and is emitted outward. The coating layer is provided around the cladding. The phosphor layer is provided around the coating layer. The protective tube protects the quartz optical fiber and the phosphor layer so that the inner edge is separated from the outer edge of the phosphor layer.

  ADVANTAGE OF THE INVENTION According to this invention, the linear light-emitting body and solid-state light-emitting device which can discharge | release light to the radial direction of a quartz optical fiber are attained.

FIG. 1A is a schematic cross-sectional view of the linear light emitter according to the first embodiment, and FIG. 1B is a schematic cross-sectional view of the linear light emitter. 1 is a schematic perspective view of a solid state light emitting device using a linear light emitter according to a first embodiment. FIG. 3A is a schematic cross-sectional view of the linear light emitter according to the second embodiment, and FIG. 3B is a schematic cross-sectional view of the linear light emitter. It is a schematic cross section of the modification of a linear light-emitting body. It is a model perspective view showing an example of the illuminating device using a solid light-emitting device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic cross-sectional view of the linear light emitter according to the first embodiment, and FIG. 1B is a schematic cross-sectional view of the linear light emitter.
The linear light emitter 20 includes a quartz optical fiber 30, a translucent coating layer 31, a phosphor layer 40, and a translucent protective tube 50.

  The quartz optical fiber 30 includes a core 30a and a clad 30b provided around the core. The quartz optical fiber 30 reflects the laser beam G1 introduced into the core end surface of one end of the quartz optical fiber 30 at the interface 30c between the core 30a and the clad 30b and guides it toward the other end. The covering layer 31 is provided around the cladding 30b. The coating layer 31 is a material that transmits at least the wavelength band of the laser beam G1, and for example, the transmittance is preferably 50% or more. The covering layer 31 may have a light diffusing function. The quartz optical fiber 30 emits the scattered light G2 at the interface 30c outward through the cladding 30b and the coating layer 31.

  The phosphor layer 40 is provided around the coating layer 31. The quartz optical fiber 30, the coating layer 31, and the phosphor layer 40 are inserted into the translucent protective tube 50. The protective tube 50 is a material that transmits at least visible light. For example, the transmittance is preferably 60% or more. Further, the protective tube 50 may have a light diffusion function.

  The diameter D1 of the core 30a of the quartz optical fiber 30 may be 100 μm, the outer diameter D2 of the clad 30b may be 150 μm, and so on. The covering layer 31 is made of an acrylic resin or the like, and the outer diameter thereof can be 250 μm or the like. The thickness of the phosphor layer 40 can be 50 μm or the like. The protective tube 50 can be made of Teflon or the like.

  The inner edge 50a of the protective tube 50 and the outer edge 40a of the phosphor layer 40 are separated from each other. When the length of the linear light emitter 20 is short, the separation distance K may be short. In addition, the center of the protective tube 50 and the center of the core 30a do not need to correspond. When the linear light emitter 20 is long, for example, 100 m, assembly is easier when the separation distance K is longer. The outer diameter of the linear light emitter 20 can be set to 1 to 3 mm, for example.

  The inventors have found that when the wavelength of the laser beam is 490 nm or less, the amount of light leaking in the radial direction of the cladding is not confined in the core of the step index type multimode fiber. For this reason, it turned out that the light-emitting device using the light emitted from the quartz optical fiber 30 in the radial direction is possible.

  If the wavelength of the propagating light is 800 nm or more, the quartz optical fiber 30 has a sufficient amount of the incident laser light G1 confined and emitted outward from the clad 30b due to the refractive index difference between the core 30a and the clad 30b. Can be made smaller. In this case, it is difficult to construct a light emitting device that uses light emitted in the radial direction from the cladding of the quartz optical fiber.

  Leakage of light with a wavelength of 490 nm or less is related to an increase in Rayleigh scattering. That is, light scattering by particles having a size smaller than the wavelength of light is called Rayleigh scattering, and also occurs in a transparent liquid or solid. The scattering coefficient ks of Rayleigh scattering with respect to the wavelength of light can be expressed by equation (1).

  As expressed in Expression (1), the amount of scattered light depends on the particle diameter d and the wavelength λ. The scattering coefficient ks is inversely proportional to the fourth power of the wavelength λ. For example, when the wavelength is 1 in 2 minutes, the scattering coefficient ks becomes 16 times. That is, short wavelength light such as blue laser light causes Rayleigh scattering due to minute irregularities at the interface 30c between the core 30a and the clad 30b. For this reason, the blue laser light turns into the blue scattered light G2, passes through the coating layer 31 and enters the phosphor layer 40 from the clad 30b.

  When laser light G1 is introduced into the quartz optical fiber 30, there is little loss due to absorption or the like. For this reason, the transmission loss of the quartz optical fiber 30 is about 20 to 30 dB / km. Therefore, it is possible to emit light at a higher light guide distance and higher efficiency than the plus-chip optical fiber (transmission loss / approximately 100 dB / km). Further, since the outer diameter of the outer edge 40a of the phosphor layer 40 is in the range of 0.35 to 0.5 mm, etc., very thin linear light emission is possible.

FIG. 2 is a schematic perspective view of the solid-state light emitting device using the linear light emitter according to the first embodiment.
The solid state light emitting device 5 includes a light source 10, a linear light emitter 20 according to the first embodiment, and a framework 60. The light source 10 is a nitride semiconductor laser or the like that can emit laser light having a wavelength of ultraviolet light (380 nm) to blue light (490 nm). By using a semiconductor laser having a small beam divergence angle, the laser beam can be efficiently incident on the core of the quartz optical fiber.

  The skeleton 60 can be configured by combining linear bodies made of metal, insulator, resin, or the like. In this case, there is a gap between the linear bodies, allowing light to pass freely. Alternatively, the skeleton 60 may be a transparent body. Light passes freely through the transparent body. Furthermore, the outer frame of the framework 60 can be freely selected from a sphere, an ellipsoid, a cuboid, a cube, a cylinder, a cone, and the like.

  The linear light emitter 20 is three-dimensionally wound around the outer frame of the framework 60. Since light can pass through the inside of the skeleton 60, the mixed light GT emitted from the linear light emitter 20 can be spread over a wide angle range such as the inside of the skeleton 60 or on the opposite side.

  When the phosphor layer 40 contains a yellow phosphor made of YAG (Yttrium-Aluminum-Garnet) or the like, the quartz optical fiber 30 emits white light. If the quartz optical fiber 30 is lengthened and wound tightly around the surface of the framework 60, the linear light emitter 20 can emit light uniformly. In addition, the surface of the skeleton 60 can be loosely wound. Further, for example, the irradiated body can be provided inside the framework 60 without winding the linear light emitter 20 on the upper surface side of the framework 60.

  When the framework 60 is a sphere, when the sphere diameter is 50 cm, the length of the linear light emitter 20 can be 20 to 100 m or the like. In this case, the number of windings is 7 to 30 times. If the sphere diameter is too small, the bending radius of the quartz optical fiber 30 becomes small, and the chromaticity changes partially. For example, the light emission at the bend may be yellowish. For this reason, it is preferable to wind the quartz optical fiber 20 so that the bending radius is larger than the minimum bending radius of the quartz optical fiber.

  If the core is made of plastic, the transmission loss is too large, and it is difficult to guide the length of 100 m. Plastics are deteriorated by light having a wavelength of ultraviolet light to blue light. On the other hand, the solid-state lighting device of the present embodiment has a simple structure, for example, guides 1 W laser light emitted from one semiconductor laser in a quartz optical fiber 30 having a length of 100 m, for example. White light can be emitted while shining. In addition, quartz glass is less deteriorated by light having a wavelength of ultraviolet light to blue light.

FIG. 3A is a schematic cross-sectional view of the linear light emitter according to the second embodiment, and FIG. 3B is a schematic cross-sectional view of the linear light emitter.
A light scattering layer 36 in which a scattering agent is dispersed can be further provided between the clad 30 b of the quartz optical fiber 30 and the coating layer 31. In this way, the scattered light G2 generated by the interface 30c between the core 30a and the clad 30b is further scattered by the light scattering layer 36 to become the scattered light G5, thereby reducing coherence and uniform light emission. Safety can be further improved by reducing coherence.

FIG. 4 is a schematic cross-sectional view of a modification of the linear light emitter.
In the modified example, the guide portion 50c provided by the outer edge 40a of the protective tube 50 that is separated from the outer edge 40a of the phosphor layer 40 by a distance K1 and the outer edge 40a of the phosphor layer 40 is along the length direction of the quartz optical fiber 30. Are provided. For example, as shown in the figure, the protective tube 50 is fixed to the outer edge 40a of the phosphor layer 40 from the outside. In this way, the phosphor layer 40, the quartz optical fiber 30 and the like can be reliably fixed. When the linear light emitter 20 is fixed to the framework 60, the protective tube 50 protects the phosphor layer 40 and the like.

FIG. 5 is a schematic perspective view illustrating an example of a lighting device using a solid-state light emitting device.
The solid state light emitting device 5 of the present embodiment is irradiated from the outside using a projector 70 or the like. For example, the linear light emitter 20 wound around the framework 60 becomes a bowl-shaped light emitter. That is, the bowl-shaped light emitter can be used as a projection mapping screen, and the illumination light and the projection light RL can be overlapped. In addition, when a plurality of types of phosphor layers 40 such as red, green, yellow, and blue are provided on the linear light emitter 20, the color tone of the illumination light can be further enriched.

  In the first embodiment, the configuration in which the translucent coating layer 31 that covers the quartz optical fiber 30 is provided, but the configuration in which the coating layer 31 is omitted and the phosphor layer 40 is provided around the quartz optical fiber 30 is shown. But you can. In this case, for example, the phosphor layer 40 may have a configuration in which phosphor particles are mixed in a material constituting the coating layer 31 so that the coating layer 31 and the phosphor layer 40 are integrally formed. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 light source, 20 linear light emitter, 30 quartz optical fiber, 30a core, 30b cladding, 30c interface, 31 coating layer, 40 phosphor layer, 50 protective tube, 60 framework, G1 laser light, G2 scattered light, G3 wavelength converted light , GT mixed light

Claims (6)

A core and a clad provided around the core, and reflects laser light having a wavelength of ultraviolet light to blue light introduced at one end of the core at an interface between the core and the clad. A silica optical fiber that guides light toward the end of the optical fiber and emits scattered light at the interface through the cladding and outwards;
A light-transmitting coating layer provided around the cladding;
A phosphor layer provided around the coating layer;
A translucent protective tube that protects the quartz optical fiber and the phosphor layer so that the inner edge is separated from the outer edge of the phosphor layer;
A linear light emitter comprising: A core and a clad provided around the core, and reflects laser light having a wavelength of ultraviolet light to blue light introduced at one end of the core at an interface between the core and the clad. A silica optical fiber that guides light toward the end of the optical fiber and emits scattered light at the interface through the cladding and outwards;
A phosphor layer provided around the quartz optical fiber;
A translucent protective tube that protects the quartz optical fiber and the phosphor layer so that the inner edge is separated from the outer edge of the phosphor layer;
A linear light emitter comprising: The linear light emitter according to claim 1 or 2,
A light source that emits the laser light;
A framework around which the linear light emitter is wound;
With
The phosphor layer that has absorbed the irradiated scattered light emits wavelength-converted light,
A solid-state light emitting device that emits mixed light of scattered light that has not been absorbed by the phosphor layer and is emitted outward and the wavelength-converted light from an outer edge of the linear light emitter.   The solid light-emitting device according to claim 3, wherein the mixed light passes through the inside of the framework.   5. The solid state light emitting device according to claim 3, wherein the outer frame of the frame is any one of a sphere, an ellipsoid, a rectangular parallelepiped, a cube, a cylinder, and a cone.   The solid-state light-emitting device according to claim 3, wherein the phosphor layer includes at least one of a yellow phosphor and a red phosphor.

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