JP2006085972A - Emitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emitter having small attenuation in luminous intensity and uniform color balance, and superior in power saving performance, portability and productivity. <P>SOLUTION: The linear emitter 1 is constructed comprising an optical fiber 4 composed of a core 2 and a cladding 3 formed in a concentric shape so as to surround the core 2 from the circumference direction, and a semiconductor laser element 5. The optical fiber 4 is a side leakage type fiber which has a function of leaking light transmitted in the core 2 from the surface of the cladding 3. A phosphor made of mixed-crystal semiconductor crystallites emitting respectively red, green, and blue light is uniformly dispersed in the cladding 3. The semiconductor laser element 5 is a group III nitride semiconductor laser element of an end-face emission type. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitter, and more particularly to a linear light emitter or a planar light emitter using an optical fiber.

  Some light emitters use light leaking from an optical fiber. In particular, such an optical fiber is referred to as a “side leakage optical fiber”. The side leakage optical fiber is an optical fiber having a basic structure of a two-core structure of a core and a clad having a refractive index lower than that of the core, and a part of light that is transmitted from the end face of the optical fiber and transmitted through the core. Is leaked to the cladding, and the leaked light is emitted from the side surface of the optical fiber. This side leakage optical fiber is also referred to as “lateral leakage optical fiber” or “leakage optical fiber”.

  As a means for leaking light from the core to the clad in the side light leakage type optical fiber, for example, Patent Documents 1 and 2 disclose a technique for forming a scratch on the side surface of the optical fiber and scattering the light transmitted through the core. . In Patent Documents 3, 4, and 5, a strain is formed on the optical fiber so that light is incident on the side surface of the core at a critical angle (incident angle satisfying the total reflection condition) or less, and the light is incident on the clad side. A technique for leaking light is disclosed.

  Further, Patent Documents 6, 7, and 8 disclose techniques for forming fine irregularities on the side surface of an optical fiber. Patent Documents 9 and 10 disclose a technique for dispersing a light diffusion center inside an optical fiber.

On the other hand, optical fibers are also widely used for illumination decoration such as illumination, and various techniques for improving the design and light emission uniformity have been proposed. For example, Patent Document 11 discloses a technique for twisting an optical fiber together with a linear reflector so that bright spots appear intermittently. Patent Document 12 discloses a technique for twisting a plurality of optical fibers with a predetermined torsional curvature around the outer periphery of a spacer linear member. Further, Patent Documents 13 and 14 propose a technique for obtaining a planar light emitter by arranging optical fibers in a planar shape. Patent Document 15 proposes a luminescent fiber product in which an optical fiber material is incorporated into a textile product such as a fabric.
Japanese Patent Laid-Open No. 50-83044 JP-A 63-253903 JP 50-83049 A Japanese Patent Laid-Open No. 2-108007 Japanese Patent Laid-Open No. 2-108008 JP 63-293505 A JP 63-318502 A JP-A-1-273007 Japanese Patent Publication No. 51-29951 JP-A-63-247705 JP-A-6-186444 JP 7-270630 A Japanese Utility Model 2-15398 Japanese Patent Laid-Open No. 7-301712 Japanese Patent Publication No. 47-42534

  The inventors of the present invention made a light emitting body (illumination device) that exhibits white light using a side leakage optical fiber with reference to the above prior art, and found that there are the following problems. First, in the side light leakage type optical fiber, the emission intensity is unavoidably attenuated as the distance from the light source increases. For this reason, it is preferable to use a laser beam with high coherency as the light source, but since a white light cannot be obtained with a semiconductor laser element, a light emitting diode element has to be used.

  However, the light emitting diode element that exhibits white light does not yet have sufficient light emission intensity. Therefore, in order to obtain linear light emission with higher light emission intensity, first, three types of light emitting diode elements of red, green, and blue that can obtain relatively high light emission intensity are prepared as light emission colors, and three or more light emitting diode elements are prepared. A light emitter entwined with an optical fiber was prepared. One of three types of light emitting diodes was placed on each end face of the optical fiber of the light emitter, and light of each color was incident from the end face to perform color mixing.

  However, in this case, since three light sources having different emission colors are required, it is disadvantageous in terms of power saving, and it is necessary to handle it more carefully in carrying, and further, to mount a light emitting diode. It has been found that productivity is lacking due to increased labor.

  In any of the above-described techniques, light incident from the end face of the optical fiber is leaked, and the leaked light is visually recognized. Therefore, the emission color is defined by the wavelength of the light source coupled to the end face of the optical fiber.

  However, when the light emitted from the light source includes a plurality of maximum wavelengths, for example, when light of three primary colors of red, green, and blue is transmitted to the optical fiber to obtain white light, each primary color light in the optical fiber medium is obtained. The attenuation rate is different. For this reason, it has been found that the color balance changes with distance from the light source, and the color rendering properties are impaired when applied to an illumination light source or the like.

  The present invention has been made in order to solve the above-described problems, and its object is to provide a light emitter that has low attenuation of light emission intensity, a uniform color balance, and excellent power saving, portability, and productivity. Is to provide.

  The inventors of the present invention achieve the above object by using a laser beam as a light source and combining the side light leakage type optical fiber and the phosphor to make the light (secondary light) emitted from the phosphor visible. The present inventors have found that a light emitting body can be realized, and have come up with the present invention.

  The light emitter according to the present invention includes an optical fiber, a laser light source, and a phosphor. The optical fiber has a core and a clad surrounding the core, and has a function of leaking light transmitted through the core from the surface of the clad. The laser light source is disposed at at least one end of the optical fiber. The phosphor is excited by light emitted from a laser light source and transmitted through the core, and emits red, green, and blue light.

  According to this structure, first, light (fluorescence) emitted from a laser light source and excited by a laser beam transmitted through an optical fiber is emitted as a light-emitting element. The laser light is stronger than the light-emitting diode element in the nature of interference light, that is, because of its high coherency, the loss of light transmitted through the core can be kept small, even if it is further away from the laser light source. The reduction in the intensity of light transmitted through the optical fiber can be minimized. As a result, the phosphor located further away from the laser light source can be excited and emitted (fluorescent) in the same manner as the phosphor located closer to the laser light source, and the average color rendering index Ra Is suppressed from decreasing. As a result, a light emitter having a uniform color balance can be obtained. The average color rendering index Ra will be described later.

  More specifically, the phosphor is preferably dispersed in the clad of the optical fiber.

  In this case, the laser beam transmitted through the core and leaked into the cladding excites the phosphor dispersed in the cladding, so that light (fluorescence) is emitted from the phosphor, and the light leaks from the side surface of the cladding. It will be visually recognized.

  In order to increase the light emitting surface area without increasing the diameter of the optical fiber, it is preferable that a plurality of optical fibers are provided and the plurality of optical fibers are twisted together.

  Alternatively, it is preferable that a linear body twisted with the optical fiber is provided, and the phosphor is dispersed in the linear body.

  In this case, laser light transmitted through the core and leaked from the cladding excites the phosphor dispersed in the linear body, so that light (fluorescence) is emitted from the phosphor, and the light is visually recognized. Become.

  The maximum wavelength of red light emitted by the phosphor is 600 to 670 nm, the maximum wavelength of blue light is 500 to 540 nm, and the maximum wavelength of green light is preferably 420 to 480 nm.

  When the maximum wavelength of the light emitted by the phosphor is within the above range, the color rendering property (average color rendering index Ra) when white light is obtained by mixing these lights can be improved. On the other hand, if even one of the maximum wavelengths of light exceeds the above range, the color balance when the colors are mixed is lost, and the color rendering is deteriorated.

  As the laser light source, the maximum wavelength of light emitted from the laser light source is preferably 380 to 420 nm.

  Thereby, the color rendering property of white light emission obtained by exciting and mixing the phosphors can be improved.

  It is preferable that such a laser light source is specifically composed of a group III nitride semiconductor.

  This is because the group III nitride semiconductor can obtain light emission with the highest external quantum efficiency at a maximum wavelength of 380 to 420 nm.

  The phosphor preferably contains a semiconductor crystal.

  In the phosphor based on the semiconductor microcrystal, the emission wavelength and the excitation efficiency can be controlled by controlling the band gap. In particular, the light emitted from the laser light source (blue) of the group III nitride semiconductor is used as the primary light. In addition, the excitation efficiency can be optimized with respect to light having a wavelength of 380 to 420 nm, and a light emitter having excellent efficiency can be obtained.

  Alternatively, it is preferable to include a resin that transmits visible light and covers the optical fiber and the phosphor.

  In this case, the optical fibers and the like that are twisted together can be kept in the most dense state by being covered with the resin. Further, even when a physical force is applied from the outside, there is no possibility that the twisting can be unwound, and a light emitting body with excellent reliability can be obtained.

  Further, it is preferable that a scattering material for scattering light is dispersed in the resin.

  By dispersing the scattering material, it is possible to uniformly mix a plurality of colors of light (fluorescence) emitted from the phosphor. In addition, the coherency of the laser beam is reduced due to the scattering, and safety is improved at the time of visual recognition.

  Alternatively, it is preferable that the optical fibers are arranged in parallel as a light emitter.

  As described above, linear light emitters have little attenuation of crest intensity and excellent color balance. By arranging such linear light emitters in a close-packed state in a planar shape, the emission intensity is in-plane. A planar light emitter with a uniform distribution is obtained.

  Furthermore, it is preferable that the optical fiber and the linear body are arranged in a plane by weaving each other from one direction and the other direction intersecting the one direction.

  In this case, by interweaving the optical fiber and the linear body, a support body for supporting the optical fiber is not necessary as compared with the case where the optical fibers are simply arranged in parallel, and the planar light emitter itself The flexibility of the shape is improved, and it can be applied to textile products such as clothing.

Embodiment 1
As a light emitter according to the first embodiment of the present invention, a linear light emitter using an optical fiber in which a phosphor is dispersed in a clad and a blue semiconductor laser element will be described.

  As shown in FIGS. 1 and 2, a linear light emitter 1 includes an optical fiber 4 including a core 2 and a clad 3 formed concentrically so as to surround the core 2 from the circumferential direction, and a semiconductor laser element. 5 is configured.

  The optical fiber 4 is a side leakage optical fiber having a function of causing light transmitted through the core 2 to leak from the surface of the clad 3. A polymethyl methacrylate resin (PMMA) is used for the core 2 of the optical fiber 4. The clad 3 is made of vinylidene fluoride-tetrafluoroethylene copolymer.

  The polymer ratio of vinylidene fluoride and tetrafluoroethylene is adjusted so that the refractive index of the cladding 3 is smaller than the refractive index of the core 2 and a part of the laser light transmitted through the core 2 leaks into the cladding 3. Yes. The core 2 has a core diameter of 0.2 mm, for example, and the clad 3 has a clad diameter of 0.5 mm, for example.

In the clad 3, phosphors emitting red, green and blue light are uniformly dispersed. In these phosphors, the fluorescence wavelength is controlled by controlling the composition ratio and particle size of the mixed crystal semiconductor microcrystal. In the first embodiment, Zn _0.1 Cd _0.9 Se having a particle size of about 8 nm is used as a phosphor emitting red light. Further, Zn _0.6 Cd _0.4 Se having a particle size of about 8 nm is used as a phosphor emitting green light. ZnSe having a particle size of about 5 nm is used as a phosphor that emits blue light.

  As shown in FIG. 3, the semiconductor laser element 5 is an edge-emitting group III nitride semiconductor laser element. In the group III nitride semiconductor laser device 5, an n-type GaN buffer layer 5b, an n-type AlGaN cladding layer 5c, an n-type GaN light guide layer 5d, an InGaN quantum well active layer 5e, and a p-type are formed on an n-type GaN substrate 5a. A GaN light guide layer 5f, a p-type AlGaN cladding layer 5g, an n-type AlGaN current blocking layer 5i, and a p-type GaN contact layer 5h are laminated. A p-type ohmic electrode 5k is formed on the surface of the p-type GaN contact layer 5h. On the other hand, an n-type ohmic electrode 5j is formed on the back side of the n-type GaN substrate 5a.

  The maximum wavelength of light emitted from the semiconductor laser element 5 is 405 nm. The semiconductor laser element 5 is disposed on at least one end face side of the optical fiber 4. A lens 6 is disposed between the semiconductor laser element 5 and the end face of the optical fiber 4. Laser light emitted from the semiconductor laser element 4 is condensed on the end face of the core 2 by the lens 6.

  Next, the operation of the linear light emitter 1 described above will be described. First, a laser beam is emitted from the semiconductor laser element 5 by passing a current through the group III nitride semiconductor laser element 5. The emitted laser light enters the core 2 of the optical fiber 4, and the laser light leaks from the core 2 to the cladding 3 while being transmitted through the core 2.

  The phosphor dispersed in the clad 3 is excited by the light leaked to the clad 3 to emit red, green, and blue light (fluorescence). The emitted red, green, and blue light are mixed (additional color mixing), and white light is emitted from the surface of the clad 3.

  Next, the evaluation performed about the linear light-emitting body 1 mentioned above is demonstrated. First, the change in emission intensity with respect to the unit length of the linear light emitter 4 was evaluated. The result is shown in FIG. As shown in FIG. 4, the light emission intensity with respect to the length of the optical fiber is expressed as a light emission intensity ratio with the light emission intensity at the incident end face of the optical fiber 4 being 100%.

  In the linear light emitter 1 according to the present embodiment, a group III nitride semiconductor laser element 5 is used as a light source. On the other hand, in the linear light emitter as a comparative example, a group III nitride light-emitting diode element having a maximum wavelength of 405 nm is used as a light source. Since the semiconductor laser element 5 has stronger properties (coherency) as interference light than the light emitting diode element, it has been found that the degree of attenuation of the emission intensity is smaller than that of the comparative example.

  Next, the change of the average color rendering index Ra with respect to the unit length of the linear light emitter 4 was evaluated. The result is shown in FIG. The average color rendering index Ra is an index indicating whether or not the color of the reference light source is faithfully reproduced. In principle, the closer the evaluation index Ra is to 100, the better the color rendering is.

  As shown in FIG. 5, in the linear light emitter 1 according to the present embodiment, the average color rendering index Ra in the vicinity of the end face of the optical fiber 4 on which the laser light is incident is Ra 90, which is relative to the length of the optical fiber. It was found that the average color rendering index Ra hardly changed from the value.

  On the other hand, in the linear light emitter as a comparative example using a white light emitting diode element as a light source, the average color rendering index Ra decreases with the length of the optical fiber as compared with the case where a semiconductor laser element is used as the light source. all right.

  This is considered as follows. First, in the comparative example, when the color of the light emitted from the light emitting diode element is composed of three primary colors, the attenuation factor of the light when transmitting through the optical fiber differs depending on the color. The color balance will change.

  On the other hand, in the linear light emitter 1 according to the present embodiment, the color balance of the fluorescence that emits light does not depend on the length of the optical fiber 4. Further, even if the intensity of light transmitted through the optical fiber 4 is attenuated, the relationship between the emission intensity ratios of red, green, and blue light emitted when the phosphor is excited remains unchanged. As a result, it is considered that the average color rendering index Ra does not decrease.

  In the linear light emitter 1 described above, a polymethyl methacrylate resin is used as the core material constituting the optical fiber 4 and a vinylidene fluoride-tetrafluoroethylene copolymer is used as an example of the cladding material. In addition, various organic resins can be used, and as the core 2, for example, a polystyrene polymer or a silicon polymer may be used.

  Further, as the clad 3, the refractive index may be adjusted by using a propylene-based polymer, a hexafluoroacetone-based polymer, a trifluoroethylene-based polymer or the like instead of the tetrafluoroethylene polymer, A homopolymer such as a methacrylic acid ester or a methacrylic acid ester may be used.

Further, the phosphor dispersed in the clad 3 is not limited to the above-described phosphors, but is a general-purpose phosphor, for example, (Y _1-xy Cd _x La _y ) ₂ O ₃ : TM, Y ₂ O ₂ S: TM, BaMgAl ₁₀ O ₁₇ : TM, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : TM (TM: transition metal element) may be used. Also in this case, similarly to the linear light emitter described above, it is possible to suppress a decrease in light emission intensity and a decrease in the average color rendering index Ra.

  By the way, these phosphors are oxide phosphors. In the oxide phosphors, the absorption maximum wavelength is in the ultraviolet region of 300 to 380 nm. Therefore, in order to perform efficient excitation, it is necessary to use a light source that emits ultraviolet light as a light source. However, since ultraviolet light deteriorates the resin that is a constituent material of the optical fiber, there is a problem that the reliability of the linear light emitter is lowered.

  In the linear light emitter 1 described above, a phosphor of semiconductor microcrystal is used as the phosphor. In semiconductor microcrystals, the absorption wavelength can be controlled by controlling the composition and particle size. Therefore, the semiconductor microcrystal of the linear light emitter 1 according to the present embodiment is adjusted so that the absorption maximum wavelength is in a blue-violet region of 380 to 420 nm.

  In addition, by using a phosphor having a two-layer structure of a core that emits light and a shell that absorbs excitation light as the phosphor, the absorption maximum wavelength and emission (fluorescence) maximum wavelength of the phosphor can be controlled independently. Is also possible.

  As a phosphor composed of such a preferable semiconductor microcrystal, a II-VI group compound semiconductor in which a group II element of Zn, Cd, Mg and a group VI element of S, Se, Te, O are arbitrarily combined can be used. . A similar phosphor can be formed using a III-V compound semiconductor. In particular, a group III nitride phosphor made of a GaN-InN mixed crystal is preferable because it can emit light having a wavelength of red to blue and is excellent in reliability.

  Regarding the wavelength of light (fluorescence) emitted by the phosphor, red has an emission maximum wavelength at 600 to 670 nm, green has an emission maximum wavelength at 500 to 540 nm, and blue has an emission maximum wavelength at 420 to 480 nm. It is preferable to have a configuration. In this case, the color rendering property (average color rendering index) is high when light in each wavelength range is mixed and is suitable as a light source for illumination.

On the other hand, if (Y, Gd) ₃ Al ₅ O ₁₂ : Se is used as the phosphor and a blue light-emitting element having an emission wavelength of about 460 nm is used as the excitation light source, white can be exhibited. However, this is not preferable because the color rendering properties are extremely low.

  Further, if a part of the light emitted from the light source is transmitted and mixed with a phosphor that emits red light and a phosphor that emits green light, the blue phosphor is not necessary. However, in the linear light emitter 1 according to the present invention, the semiconductor laser element 5 is used as a light source.

  In the semiconductor laser element 5, the energy density of the emitted light is high and the directivity is strong. For this reason, it is not preferable from the viewpoint of safety that a person visually recognizes such light. Therefore, it is preferable to increase the filling degree of the phosphor dispersed in the clad 3 so that most of the light emitted from the semiconductor laser element 5 is absorbed by the phosphor.

  The light source for the linear light emitter according to the present invention is most preferably a semiconductor laser element using a group III nitride semiconductor. In the group III nitride semiconductor laser device 5, the external quantum efficiency is maximized when the emission maximum wavelength is 380 to 420 nm.

  Therefore, the phosphor described above can be efficiently excited to emit light (fluorescence), and deterioration of the resin constituting the optical fiber 4 can be suppressed. The semiconductor laser element 5 is not limited to the above-described edge emitting type, and may be a surface emitting type semiconductor laser element, for example. Further, the light emitter according to the present invention is not limited to the linear light emitter described above.

Embodiment 2
As a light emitter according to the second embodiment of the present invention, an example of a linear light emitter in which an optical fiber in which a phosphor is dispersed in a clad is twisted will be described. As shown in FIG. 6, in the linear light emitter 10 according to the present embodiment, the optical fibers 11 a to 11 a are the same as the above-described optical fibers in which phosphors that emit red, green, and blue light are dispersed in the cladding. A composite optical fiber 12 is formed by twisting three 11c.

  A semiconductor laser element 13 is disposed on the end face side of the three optical fibers 11a to 11c. Between the end faces of the three optical fibers 11a to 11c and the semiconductor laser element 13, a beam splitter 14 and a lens 15 are disposed.

  In the linear light emitter 10 described above, the laser light emitted from the semiconductor laser element 13 is divided into three by the beam splitter 14. Each of the divided laser beams is condensed by the lens 15 on the end faces of the cores of the optical fibers 11a to 11c.

  When the diameter of the optical fiber is increased in the optical fiber, the surface area of the cladding increases, but the emission intensity per unit area decreases. In the linear light emitter 10 described above, the following effects are obtained in addition to the effects described above.

  That is, the linear light-emitting body 10 can be thickened without reducing light emission intensity by twisting relatively thin optical fibers 11a to 11c to form a thicker composite optical fiber 12. Thereby, handling of the linear light-emitting body 10 becomes easier, and portability improves.

  In the linear light emitter 10 described above, the case where the three optical fibers 11a to 11c are twisted as the composite optical fiber 12 has been described as an example. However, the number of optical fibers to be twisted is limited to three. It is not a thing.

Embodiment 3
As a light emitter according to Embodiment 3 of the present invention, another example of a linear light emitter in which an optical fiber in which a phosphor is dispersed in a clad is twisted will be described. As shown in FIG. 7, in the linear light emitter 12 according to the present embodiment, only the optical fiber 12a in which only the phosphor that emits red light is dispersed in the clad and the phosphor that emits green light in the clad are used. Three optical fibers 12a to 12c of an optical fiber 12b dispersed and an optical fiber 12c in which only a phosphor emitting blue light is dispersed in a clad are twisted to form a composite optical fiber 12. .

The phosphor emitting red light dispersed in the cladding of the optical fiber 12a is Zn _0.1 Cd _0.9 Se having a particle size of about 8 nm, and the phosphor emitting green light dispersed in the cladding of the optical fiber 12b is about particle size. The phosphor emitting blue that is 8 nm Zn _0.6 Cd _0.4 Se and dispersed in the clad of the optical fiber 12 c is ZnSe having a particle diameter of about 5 nm.

  In the linear light emitter described above, the three optical fibers 12a to 12c are twisted together, whereby red light (fluorescence) emitted from the optical fiber 12a, green light (fluorescence) emitted from the optical fiber 12b, and light. The blue light (fluorescence) emitted from the fiber 12 c is mixed and white light is emitted as the composite optical fiber 12.

  In addition, in the linear light-emitting body mentioned above, although the linear light-emitting body can be comprised thinly by twisting the three optical fibers 12a-12c as the composite optical fiber 12, the number of optical fibers to be twisted can be reduced. There is no limit.

  For example, as shown in FIG. 8, a thicker linear light emitter 12 may be configured by twisting three or more optical fibers in a close-packed state. Moreover, as shown in FIG. 9, the optical fibers 12a to 12c that emit light of each color may be twisted so that each side surface appears alternately and intermittently. In this case, the optical fibers 12a to 12c The light (fluorescence) emitted from the light can be mixed evenly and more uniform white light can be obtained.

Embodiment 4
As a light emitter according to the fourth embodiment of the present invention, a linear light emitter obtained by twisting a side leakage optical fiber in which no phosphor is dispersed in a clad and a linear body in which the phosphor is dispersed will be described. . As shown in FIG. 10, in the linear light emitter 20 according to the present embodiment, the linear body 22 in which the phosphor is dispersed is disposed around the side light leakage optical fiber 21 in which the phosphor is not dispersed in the cladding. Twisted.

  The linear body 22 is made of a single resin and does not have a core and a clad for transmitting light such as an optical fiber. In this case, a silicon resin is used as the resin constituting the linear body 22.

As the phosphor dispersed in the linear body 22, Zn _0.1 Cd _0.9 Se having a particle diameter of about 8 nm is used as a phosphor emitting red light. Further, Zn _0.6 Cd _0.4 Se having a particle size of about 8 nm is used as a phosphor emitting green light. ZnSe having a particle size of about 5 nm is used as a phosphor that emits blue light. Further, in the phosphor, the filling ratio is adjusted so that light (fluorescence) emitted by each phosphor is mixed to obtain white light emission.

  In the linear light emitter 20 described above, as in the case of the linear light emitter described above, in addition to the effect of suppressing the attenuation of the light emission intensity and suppressing the decrease in the average color rendering index Ra, the following Such an effect is obtained.

  That is, in the linear light emitter 20, the side light leakage optical fiber 21 is relatively expensive among the components constituting the linear light emitter 20, but the phosphor is dispersed in the cladding of the side light leakage optical fiber 21. Instead, it is dispersed in the resin linear body 22 separately.

  As a result, a general-purpose optical fiber can be used as the side leakage optical fiber 21, and the phosphor is dispersed in a single resin linear body rather than dispersed in the cladding of the side leakage optical fiber. Is advantageous in terms of productivity and cost. As a result, the linear light emitter 20 can be manufactured with higher productivity and lower cost than the conventional linear light emitter.

  In addition, also in the linear light-emitting body 20 mentioned above, there is no restriction | limiting in particular in the number of the side light leakage type optical fiber 21 and the linear body 22 to twist together. For example, as shown in FIG. 11, the number of the linear bodies 22 in which the phosphors twisted around the side light leakage type optical fiber 21 are dispersed may be increased. In addition, if the positional relationship is such that the phosphor dispersed in the linear body 22 is excited by the light leaking from the side light leaking optical fiber 21, the number of the side light leaking optical fibers 21 is, for example, as shown in FIG. There is no particular limitation on the positional relationship between the side light leakage optical fiber 21 and the linear body 22.

  Furthermore, as the linear body 22 for dispersing the phosphor, in addition to dispersing the phosphors emitting red, green, and blue light in one linear body, one linear body has a red color. A phosphor that disperses only a phosphor that emits light, disperses only a phosphor that emits green light in the other one linear body, and further emits blue light in another one linear body Alternatively, these may be used in such a manner that these linear bodies are twisted with a side-light leakage optical fiber to obtain white light emission.

Embodiment 5
As a light emitter according to the fifth embodiment, a linear light emitter obtained by coating a side leakage light optical fiber with a resin will be described. As shown in FIGS. 13 and 14, in the linear light emitter 30 according to the present embodiment, the seven side leakage optical fibers 31 similar to the side leakage optical fiber in which the phosphor is dispersed in the clad described above. Are twisted together, and the translucent resin 32 covers the twisted side leakage optical fiber 31 from the periphery. A silicon resin is used as the translucent resin 32.

  In the above-described linear light emitter 30, the twisted side-face leakage optical fiber 31 is covered with the light-transmitting resin 32, so that the twisted side-face leakage optical fiber 31 can be held in a close-packed state. it can. Further, even if stress is applied to the linear light emitter 30, the side leakage light optical fiber 31 is not untwisted, and the mechanical strength of the linear light emitter 30 can be increased, thereby improving portability.

  In addition, coating | covering an optical fiber with translucent resin 32 is applicable also to the linear light-emitting body comprised by twisting the some optical fiber demonstrated in Embodiment 2-4, and a linear body. it can.

  Therefore, a light emitting body in which the linear light emitting body described in Embodiment 3 is covered with a light-transmitting resin will be described as a modification. As shown in FIG. 15, in the linear light emitter 30 according to the modification, glass particles 33 having a particle diameter of about 1 μm are dispersed in a translucent resin 32 covering the light leaking optical fibers 12 a to 12 c.

  By dispersing the glass particles 33 in the translucent resin 32, the glass particles 33 serve as a diffusing material for diffusing light, and the red, green and blue light emitted from the phosphor is more uniformly mixed. It will be. When the average color rendering index Ra was evaluated for the linear light emitter 30, it was found that the average color rendering index Ra was improved to Ra95.

  As described above, in the linear light emitter 30 according to the modification, the glass particles 33 as the light diffusing material are dispersed in the translucent resin 32, thereby scattering the light emitted from the phosphor and uniformly mixing the colors. be able to. This is an effective means for uniformly mixing colors when phosphors emitting red, green, and blue light are dispersed in the clads of the different side-light-leaving optical fibers 12a to 12c.

Moreover, since the laser light used as the excitation light source of the linear light emitter 30 has a high light energy density and strong directivity, it is not preferable to directly view the laser light. In the linear light emitter 30 according to the modification, the laser light component that is not absorbed by the phosphor is also scattered by the glass particles 33 dispersed in the translucent resin 32. Thereby, coherency falls and safety can be improved. The diffusion material may be air bubbles in addition to glass (SiO ₂ ) particles, and may be metal particles if the particle size is small and the filling degree is low.

Embodiment 6
As the light emitter according to Embodiment 6, an example of a planar light emitter will be described. As shown in FIG. 16, in the planar light emitter 40 according to the present embodiment, a linear light emitter 42 similar to the linear light emitter described in Embodiment 1, for example, is provided on the upper surface of the planar support 41. They are arranged in parallel and in a close-packed state.

  A blue semiconductor laser element (not shown) is disposed on one end surface of the linear light emitter 42, and a light reflecting plate 44 is attached to the other end surface of the linear light emitter 44.

  In the planar light emitter 40 described above, an optical fiber in which a predetermined phosphor is dispersed in a clad is disposed as a linear light emitter disposed on the support plate 41, and serves as a light source for exciting the phosphor. Since the semiconductor laser element is applied, the emission intensity is less attenuated and the color balance is not lowered as described in the first embodiment.

  As a result, even if the linear light emitter is disposed on the support 41 to increase the light emission area, there is little in-plane variation (nonuniformity) in the light emission intensity, and white light emission with a high average color rendering index Ra. Can be obtained.

  Note that the linear light-emitting body 42 constituting the planar light-emitting body 40 has a feature that the attenuation of the light emission intensity is small even if the length thereof is increased. For example, as shown in FIG. Even if the long linear light emitter 42 is folded and arranged in a planar shape, the uniformity of the light emission intensity is not impaired. Therefore, in this case, the number of the linear light emitters 42 can be reduced, and as a result, the number of coupling points with the semiconductor laser element 43 is reduced, and the mounting effort can be greatly reduced.

Embodiment 7
As a light emitter according to Embodiment 7, another example of a planar light emitter will be described. As shown in FIG. 18, in the planar light-emitting body 50 according to the present embodiment, the linear light-emitting body 42 is made into a warp, and the translucent linear body 51 is made into a weft to interweave them. It is arranged in a planar shape. A blue semiconductor laser element 43 is disposed on one end face of the linear light emitter 42, and a light reflecting plate 44 is attached to the other end face of the linear light emitter 42.

  The planar light emitter 50 described above has a planar shape by weaving the linear light emitter 42 and the linear body 51 together. Thereby, it is not necessary to provide the support body 41 compared with the planar light-emitting body 40 mentioned above. For this reason, the flexibility of the shape of the planar light emitter is higher than that of a planar light emitter using a light guide plate or a light emitting element array. A light-emitting body can be applied, and great functions and added values can be given.

  The embodiment disclosed this time is an example, and the present invention is not limited to this. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is one side view of the linear light-emitting body which concerns on Embodiment 1 of this invention. FIG. 2 is a cross-sectional view of the optical fiber taken along a cross-sectional line II-II shown in FIG. 1 in the embodiment. In the same embodiment, it is a cross-sectional perspective view of the semiconductor laser element used for a linear light-emitting body. In the same embodiment, it is a graph which shows the change of the emitted light intensity of the linear light-emitting body with respect to the unit length of an optical fiber. In the same embodiment, it is a graph which shows the change of the average color rendering evaluation number of the linear light-emitting body with respect to the unit length of an optical fiber. It is a side view of the linear light-emitting body which concerns on Embodiment 2 of this invention. It is one sectional drawing of the optical fiber of the linear light-emitting body which concerns on Embodiment 3 of this invention. In the same embodiment, it is one sectional drawing of the optical fiber of another linear light-emitting body. In the same embodiment, it is a top view which shows an example of how to twist the optical fiber of a linear light-emitting body. It is one sectional drawing of the optical fiber of the linear light-emitting body which concerns on Embodiment 4 of this invention. In the same embodiment, it is one sectional drawing of the optical fiber of another linear light-emitting body. In the same embodiment, it is one sectional view of an optical fiber of still another linear light emitter. It is one sectional drawing of the optical fiber of the linear light-emitting body based on Embodiment 5 of this invention. FIG. 3 is a side view of an optical fiber of a linear light emitter in the same embodiment. In the embodiment, it is a cross-sectional view of an optical fiber of a linear light emitter according to a modification. It is a perspective view of the planar light-emitting body which concerns on Embodiment 6 of this invention. In the same embodiment, it is a top view which shows the optical fiber of the planar light-emitting body which concerns on a modification. It is a top view of the planar light-emitting body which concerns on Embodiment 7 of this invention.

Explanation of symbols

  1, 10, 20, 30, 42 Linear light emitter, 2 core, 3 clad, 4, 11a to 11c Side-light leakage optical fiber, 5, 13, 43 Semiconductor laser element, 6, 15 lens, 12 Compound optical fiber, 14 beam splitter, 21 phosphor non-dispersion optical fiber, 22, 31 phosphor dispersion optical fiber, 32 translucent resin, 41 support, 44 light reflector, 51 translucent linear body.

Claims (12)

An optical fiber having a core and a cladding surrounding the core, and having a function of leaking light transmitted through the core from the surface of the cladding;
A laser light source disposed on at least one end of the optical fiber;
And a phosphor that emits red, green, and blue light when excited by light emitted from the laser light source and transmitted through the core.   The light-emitting body according to claim 1, wherein the phosphor is dispersed in the cladding of the optical fiber. A plurality of the optical fibers,
The light emitting body according to claim 1 or 2, wherein the plurality of optical fibers are twisted together. Comprising a linear body twisted together with the optical fiber,
The light-emitting body according to claim 1, wherein the phosphor is dispersed in the linear body.   The maximum wavelength of red light emitted by the phosphor is 600 to 670 nm, the maximum wavelength of blue light is 500 to 540 nm, and the maximum wavelength of green light is 420 to 480 nm. The light emitter according to any one of the above.   The light emitting body according to claim 1, wherein a maximum wavelength of light emitted from the laser light source is 380 to 420 nm.   The light emitting body according to claim 6, wherein the laser light source is made of a group III nitride semiconductor.   The phosphor according to claim 1, wherein the phosphor includes a semiconductor crystal.   The light emitting body according to claim 4, further comprising a resin that transmits visible light and covers the optical fiber and the phosphor.   The light emitting body according to claim 9, wherein a scattering material for scattering light is dispersed in the resin.   The light emitting body according to claim 1, wherein the optical fibers are arranged in parallel and in a planar shape. A translucent linear body for holding the optical fiber;
The light emitting body according to claim 1, wherein the optical fiber and the translucent linear body are arranged in a plane by interweaving each other from one direction and another direction intersecting one direction.

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