JP2016224078A - Light guide body and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light guide body capable of preventing leaked laser light from damaging human bodies and articles when laser light leaks out of a light guide member such as optical fiber due to breakage, including line breakage, of the light guide member, and to provide an illumination device.SOLUTION: A light guide body 1 comprises an optical fiber 6 and a reflective member 2 that has a reflective surface 4 for reflecting light and covers at least a part of an outer periphery of the optical fiber in an axial direction thereof. The reflective member has a light transmitting layer 5 disposed between the outer periphery of the optical fiber and the reflective surface. An illumination device comprises a laser light source, a lens for condensing light emitted from the laser light source, and the light guide body 1 that receives and guides the condensed light to an optical element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light guide provided with an optical fiber and an illumination device using the light guide.

An illumination device using a laser light source is roughly composed of a laser light source, a light guide member that guides the laser light source, such as an optical fiber, and an optical component provided at the tip of the light guide member.
Such devices may cause the optical fiber to be cut due to internal or external factors. Since the laser beam is used as the light source, the laser beam may leak from the cut surface. If your body, such as your eyes, is exposed to the leaked laser light, there is a risk of injury.

  Patent document 1 is disclosing the light-emitting device which has the reflection member which reflects the light from a light source in the output end surface of a light guide member. This light-emitting device can detect the disconnection of the light guide member with high accuracy by providing a reflective member controlled to have a predetermined reflectance.

JP 2008-26698 A

  However, although the technique of Patent Document 1 can detect disconnection of the light guide member, it cannot prevent leakage of laser light from the light guide member to the outside at the time of disconnection. In addition, breakage that does not lead to disconnection cannot be detected. Furthermore, since the reflecting member is provided on the light emitting end surface of the light guide member, for example, when used as an illuminating device, the reflecting member loses light and becomes an inefficient illuminating device.

  The present invention relates to a light guide and an illumination device that prevent damage to the body and objects of leaked laser light when laser light leaks outside the light guide member due to breakage including breakage of the light guide member such as an optical fiber. The issue is to provide.

In order to solve the above-described problems, the present invention provides a light guide including an optical fiber and a reflecting member that has a reflecting surface that reflects light and covers at least a part of the outer periphery of the optical fiber in the axial direction. . The reflecting member of the light guide includes a layer that propagates light between the outer periphery of the optical fiber and the reflecting surface.
The present invention also provides an illuminating device including a laser light source, a lens that collects the light emitted from the laser light source, and a light guide that guides the collected light to the optical element. . The light guide of this lighting device is the light guide of the present invention.

  In the present invention, the optical fiber is covered with the reflecting member, so that the laser light leaked due to the breakage or disconnection of the optical fiber is not leaked to the outside of the light guide. Thereby, the damage to the body and an object by a leaked laser beam can be prevented.

Sectional drawing of one Embodiment of the light guide of this invention (A) is a cross-sectional view of a light guide showing an example of a spacer, (b) is a cross-sectional view of AA ′ of (a), and (c) is a cross-sectional view of a light guide showing another example of a spacer. (D) is BB 'sectional drawing of (c). (A) is sectional drawing of other embodiment of the light guide of this invention, (b) is CC 'sectional drawing of (a). (A) is explanatory drawing of 1st embodiment of the illuminating device of this invention, (b) is an enlarged view of the dotted-line circle part which the arrow J of (a) shows. It is sectional drawing of the light-incidence member of 1st embodiment, Comprising: When (a) is a light detection part installed in the light source side edge part of a light guide, (b) is a light detection part of a light guide. When it is installed at the optical element side end, (c) is a case where the light detection unit 45 is installed in the middle of the light guide 1. Diagram explaining propagation of leaked laser light to light detector Functional block diagram of lighting device Flow chart of laser light source output cutoff processing (A) is explanatory drawing which shows 2nd embodiment of the illuminating device of this invention, (b) is an enlarged view of the dotted-line circle part which the arrow F of (a) shows, (c) is GG 'of (b). Cross section (A) is explanatory drawing which shows 3rd embodiment of the illuminating device of this invention, (b) is an enlarged view of the dotted-line circle | round | yen part which the arrow I of (a) shows, (c) is HH 'of (b). Cross section

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, components having the same function are given the same reference numerals, and repeated description thereof is omitted.

<Embodiment of light guide>
The light guide 1 of the present invention will be described with reference to FIG.
The light guide 1 of the present invention includes an optical fiber 6 that propagates light from a light source, and a reflection member 2 that prevents light leaked from the optical fiber 6 from leaking to the outside.

The optical fiber 6 only needs to be able to propagate light from the light source to the optical element, and includes a core that guides light from the light source, a clad that covers the outer surface of the core, and has a lower refractive index than the core, and a clad These are formed so as to extend in the longitudinal direction (not shown).
The optical fiber 6 may be a single mode fiber or a multimode fiber, but a multimode fiber is used here in order to propagate a large amount of light.
The material of the core and the clad may be any of glass, quartz glass and synthetic resin, but quartz glass is desirable for propagating a large amount of light. As a material for the coating, polyimide may be used in addition to an acrylic resin in order to improve heat resistance.
The diameter of the optical fiber 6 should just be a size which can be bent freely.

The reflecting member 2 is disposed so as to cover the entire outer periphery of the optical fiber 6.
The reflection member 2 has a three-layer structure, and includes a reflection layer (reflection surface) 4 covering the outer periphery of the optical fiber 6, a propagation layer 5 disposed between the outer periphery of the optical fiber 6 and the reflection layer 4, and a reflection A protective layer 3 for supporting the layer 4 is provided.

  The reflection layer 4 has a function of totally reflecting the laser light leaked due to the damage of the optical fiber 6. Specifically, the reflective layer 4 reflects the leaked laser light in regular reflection (specular reflection) or diffuse reflection. Due to these reflections, the leaked laser light does not leak to the outside of the optical fiber 6, but propagates in the propagation layer 5, so that damage to the human body and objects due to the leaked laser light is prevented in the middle of the propagation path. Can do. In particular, in the case of diffuse reflection, laser light is scattered and the coherency is lost, so that safety against damage to people and objects is enhanced.

The material used for the reflective layer 4 can be a material that can reflect laser light.
When regular reflection is performed, an optical thin film, metal, or the like can be used. Examples of the optical thin film include SiO ₂ , TiO ₂ , and Ta ₂ O ₅ . Examples of metals include Al, Ag, and Cr. These may be used alone or in combination of two or more.

In the case of performing diffuse reflection, particles such as alumina (Al ₂ O ₃ ) and TiO ₂ may be coated on the surface to be a reflective surface.

  A material such as an optical thin film or metal can be formed on the protective layer 3 by a method such as sputtering, vapor deposition, or plating.

  The film thickness of the reflective layer 4 may be a film thickness that can reflect the leaked laser beam, and in order to reflect efficiently, a film thickness of 30 nm or more is preferable.

  The propagation layer 5 is a material that transmits light, and has a function of propagating laser light that leaks from the optical fiber 6 and is totally reflected by the reflection layer 4. The propagation layer 5 has a thickness capable of propagating the laser light leaked from the tearing portion of the optical fiber 6. For example, it is several μm or more, and preferably several tens of μm or more.

  Specifically, the material of the propagation layer 5 may be a solid such as glass, quartz, or polymer, or a gas such as air, which is optically transparent and excellent in light resistance. Examples of the polymer include polymethyl methacrylate (PMMA), polycarbonate, fluorine resin, and polystyrene.

  As shown in FIG. 2A and FIG. 2B, when the material of the propagation layer 5 is a gas (for example, air), the protective layer 3 and the It is necessary to maintain a gap that separates the reflective layer 4 and the optical fiber 6. Therefore, the propagation layer 5 preferably includes spacers 21 (21a, 21b) at a predetermined interval between the reflective layer 4 and the optical fiber 6.

  The shape of the spacer 21 may be any shape that can provide a gap for separating the optical fiber 6 and the reflective layer 4. As an example, a cylindrical spacer 21 a (FIG. 2A) or a spherical spacer 21 b ( FIG. 2B can be used. The spacer 21a can also have other shapes such as a quadrangular prism shape or a triangular prism shape.

  The material of the spacer 21 is not particularly limited. For example, a resin or glass having excellent light resistance can be used. Examples of the resin include silicon resin, PMMA, polystyrene and the like. In view of preventing the leakage laser beam from being inhibited from propagation, it is preferably transparent to the light. When the spacer 21 is made of a material that is transparent to light, a shape of a donut ring (not shown) may be used as the shape of the spacer 21.

  The number and arrangement of the spacers 21 are not particularly limited as long as a gap for separating the optical fiber 6 and the reflective layer 4 can be secured.

  By arranging such a spacer 21 in the propagation layer 5, even if the optical fiber 6 is flexible and freely deformed, a gas layer always exists between the optical fiber 6 and the reflective layer 4 and leaks. It is possible to prevent the propagation of laser light from being inhibited.

The protective layer 3 is a support for the reflective layer 4 and has a function of protecting the optical fiber 6.
The protective layer 3 is preferably mechanically strong to prevent damage to the optical fiber 6 from external factors. For example, the protective layer 3 is preferably excellent in impact resistance and wear resistance.
Alternatively, depending on the environment in which the light guide 1 is used, the protective layer 3 preferably has weather resistance, acid resistance, or alkali resistance.

Examples of the material of the protective layer 3 include metals and resins.
Examples of the metal include stainless steel and Al. In the case of using a metal as a material, it is desirable to have a shape having flexibility that can cope with the free bending of the optical fiber 6. For example, a flexible metal protective layer can be formed by winding a metal in a thin strip shape into a spiral shape. . Even in such a shape, since the reflective layer 4 is disposed on the protective layer 3, the leaked laser light does not leak outside the light guide 1.
As the resin, an ionizing radiation curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used.

Although the thickness of the protective layer 3 is not specifically limited, For example, it is preferable that it is 0.1 mm or more.

The reflective layer 4, the propagation layer 5, and the protective layer 3 desirably have heat resistance depending on the temperature at which the light guide 1 is used.
In addition, the reflective layer 4, the propagation layer 5, and the protective layer 3 can have flexibility that can cope with free bending of the optical fiber 6.

  The light guide 1 has a configuration in which the periphery of the optical fiber 6 is covered with the propagation layer 5, the reflective layer 4, and the protective layer 3 from the inside. In addition to the propagation layer 5, the reflective layer 4, and the protective layer 3 described above, the reflective member 2 can be laminated with other layers as necessary.

In the light guide 1 of this embodiment, the optical fiber 6 is covered with the reflecting member 2, so that the laser light leaked from the optical fiber 6 is totally reflected by the reflecting layer 4 and propagates in the propagation layer 5. Leakage in the middle of the path can be prevented from leaking from the light guide 1 to the outside. Thereby, it is possible to prevent damage to the human body and objects due to the leaked laser light.
In addition, about the edge part of a light guide, it copes so that the laser beam which leaked by the use of the light guide 1 may not leak.

  In the embodiment of the light guide 1 described above, the light guide 1 having a structure in which the entire outer periphery in the axial direction of the optical fiber 6 is covered with the reflecting member 2 has been described. As shown in FIG. The reflecting member 2 may cover at least a part of the outer periphery in the axial direction of the optical fiber 6. For example, the reflecting member 2 can be applied only to a portion where the optical fiber 6 is expected to be damaged, such as a portion that bends the optical fiber 6 or a portion that is susceptible to external impact. In this case, in order not to leak the leaked laser light from the optical fiber 6, both ends of the reflecting member 2 are covered with the reflecting member 2 having a donut-shaped ring shape (see FIG. 3B).

  Next, an illumination device using the light guide 1 described in the embodiment of the light guide with reference to FIGS. 4 to 8 will be described.

<First embodiment of lighting device>
As shown in FIG. 4A and FIG. 4B, the illumination device 40 of the present embodiment includes a laser light source 41, a lens 42, a light guide 1 including an optical fiber 6 and a reflecting member 2, and The optical fiber 6 includes an incident side connector 43 and an emission side connector 44, an optical element 46, and a light detection unit 45, which are arranged around the incident side and the emission side, respectively.

As the laser light source 41, any light source that emits laser light may be used. For example, a laser diode or the like can be used. Here, a CAN type laser light source packaged including a laser diode is used.
A desired wavelength can be used as the wavelength of the laser light source 41 according to the optical element 46. For example, when the optical element 46 is a wavelength conversion member and is set so as to obtain light of a desired wavelength by being converted by the wavelength conversion member, for example, in a blue region (for example, emission wavelength is 450 nm), near ultraviolet A light source having a wavelength range (for example, an emission wavelength of 405 nm) or other wavelengths can be used.

  The lens 42 collects the emitted light 47 of the laser light source 41 (hereinafter “light source”) and makes it incident on the incident end face of the optical fiber 6. The lens 42 is disposed between the light source 41 and the optical fiber 6 (light guide 1).

The incident-side connector 43 and the emission-side connector 44 have a function of holding the optical fiber 6 by being fixed around the incident-side and emission-side tips of the optical fiber 6 extending from the light guide 1.
The optical element side end 43 a of the incident side connector 43 is bonded to the light source side end of the reflection member 2 of the light guide 1, and the light source side end 44 a of the emission side connector 44 is optical of the reflection member 2. It also has a function of preventing leakage of leaked laser light from the end of the reflecting member 2 by bonding to the end of the element side.

The incident-side connector 43 and the emission-side connector 44 can have a cylindrical shape whose inner diameter is larger than the outer diameter of the light guide 1 by a predetermined clearance, for example.
The incident side connector 43 and the emission side connector 44 may be bonded to the light guide 1 and the optical fiber 6 with an adhesive.
As a material of the entrance side connector 43 and the exit side connector 44, a metal or a ceramic is preferable from a viewpoint of heat dissipation and strength. In particular, copper has high thermal conductivity and can be suitably used. As the incident side connector 43 and the emission side connector 44, those known as ferrules can be used.

  The light source 41, the lens 42, and the incident side connector 43 are aligned so that the laser light from the light source 41 can enter the incident surface of the optical fiber 6.

  An optical element 46 is disposed on the emission side connector 44, and the optical element 46 is aligned so that the laser light guided by the optical fiber 6 can be emitted to the optical element 46.

  The optical element 46 has a function capable of condensing, mixing, dispersing, scattering, or wavelength converting the laser light guided by the optical fiber 6 in accordance with the purpose of the illumination device to be used.

For example, when the optical element 46 has a function of converting the wavelength, a wavelength conversion member that emits fluorescence when excited by light from the light source 41 can be used as the optical element 46.
Specifically, the wavelength conversion member can be made of phosphor particles dispersed in a binder, fluorescent glass, phosphor ceramics, or the like. When the phosphor in which the phosphor particles are dispersed in the wavelength conversion member 7 is used, the binder may be an inorganic substance such as glass or an organic substance such as resin.

  In addition, a light diffusing material may be dispersed in the wavelength conversion member. For example, alumina particles can be used as the light diffusing material. It is also possible to arrange a light diffusion layer for diffusing laser light between the wavelength conversion member and the end face of the optical fiber 11. For example, a diffusion layer obtained by firing alumina into a plate shape and a fluorescent plate (wavelength conversion member) obtained by firing YAG: Ce into a plate shape may be disposed on the end face of the optical fiber 6 by bonding with resin, glass, or the like. .

  When a member containing a phosphor, fluorescent glass, or phosphor ceramic is used as the wavelength conversion member, fluorescence emitted by being excited by laser light from the light source 41 and laser light from the light source 41 that has not excited fluorescence. Are selected so that light having a desired wavelength can be obtained. For example, in the case of a vehicular lamp that emits white light, when the light source 41 emits laser light in a blue region (450 nm), a phosphor that emits yellow fluorescence (for example, Ce-doped YAG) is used, and blue light is emitted. And yellow light are mixed to obtain white light. When the light source 41 emits near-ultraviolet (405 nm) laser light, for example, phosphors of three colors of red, green, and blue are used so that the three colors of fluorescence are mixed. . In this case, since near-ultraviolet light is not visible, only white light in which three colors of fluorescence are mixed is visually recognized.

  As the light guide 1, any of the light guides described in the embodiment of the light guide may be used. However, the illumination device 40 of the present embodiment uses the optical fiber 6 as the light guide 1. The entire outer periphery is covered with the reflection member 2 including the propagation layer 5, the reflection layer 4, and the protective layer 3, and a light guide of a type in which the spacer 21 is not disposed is used for the propagation layer 5.

  The optical fiber 6 has a function of propagating the laser light from the light source 41 to the optical element 46, and both end portions extending from the portion covered with the reflecting member 2 are an incident side connector 43 and an emission side connector 44, respectively. The periphery is fixed by the incident side connector 43 and the emission side connector 44. Each end face of the optical fiber 6 coincides with the end faces of the incident side connector 43 and the emission side connector 44.

  The end of the reflecting member 2 is bonded to the incident side connector 43 and the emission side connector 44, and the optical fiber 6 is located between the optical element side end 43 a of the incidence side connector 43 and the light source side end 44 a of the emission side connector 44. The entire outer periphery is covered along the axial direction. As a result, the leaked laser light propagated through the propagation layer 5 is prevented from leaking from both ends of the light guide 1 to the outside.

  The propagation layer 5 propagates the reflected leakage laser light to the light detection unit 45.

  The light detection unit 45 detects leaked laser light, and includes a light receiving element 45a that detects the laser light and a cylindrical tube 45b that propagates the leaked laser light from the propagation layer 5 to the light receiving element 45a. Prepare.

  The light detection unit 45 can be arranged at any position on the outer periphery in the axial direction of the light guide 1 as long as it can detect the leaked laser light.

The light receiving element 45a may be any element that can detect laser light, and a photodiode or the like can be used.
The light receiving element 45a can be set so as to detect the wavelength of the laser light to be used. For example, if the laser light source 41 is in the blue region (for example, the emission wavelength is 450 nm), the leaked laser light is detected using the light receiving element 45a that detects the wavelength of 450 nm.

The tube 45b causes the leaked laser light propagating through the propagation layer 5 to enter the light receiving element 45a.
The tube 45 b has one end connected to the light receiving element 45 a and the other end inserted into the reflecting member 2 and connected to the opening of the propagation layer 5 so that laser light does not leak.
As the material of the tube 45b, a material that reflects and propagates the laser light leaked to the light receiving element 45a, such as metal, can be used. When the tube 45b is made of a material that cannot reflect laser light, such as resin, a process of reflecting light from the inside of the tube 45b using a reflective material such as an optical thin film so that the laser light is incident on the light receiving element 45a. It is desirable to do.

Further, there may be a case where the light is difficult to propagate to the light receiving element 45a, such as when the leaked light is coherent. In such a case, as shown in FIGS. 5A to 5C, the light detection unit 45 includes a light incident member 61 such as a mirror or a prism in the reflection member 2 near the light detection unit 45 or in the propagation layer. 5 is desirable. Thereby, the leaked light can be easily incident on the light receiving element 45a.
The light incident member 61 may have any shape, material, and size as long as the leaked light can be incident on the light receiving element 45a.

  For example, when the light detection unit 45 is installed at the end of the light guide 1 on the light source side, the light incident member 61 is installed so that leakage light from the optical element side can enter the light receiving element 45a (FIG. 5). (A)). When the light detection unit 45 is installed at the end of the light guide 1 on the optical element side, the light incident member 61 is installed so that leakage light from the light source side can enter the light receiving element 45a (FIG. 5B). )). When the light detection unit 45 is installed in the middle of the light guide 1, the light incident member 61 is installed so that leakage light from the light source side and the optical element side can enter the light receiving element 45a (FIG. 5C). ).

  In the illuminating device 40, laser light leaked due to breakage and disconnection of the optical fiber does not leak out of the light guide 1. Thereby, the damage to the person and the thing by a laser beam is prevented.

  Next, the operation of the main part of the illumination device 40 of this embodiment will be described.

  When the optical fiber is not broken or disconnected, the laser light 47 from the light source 41 is condensed on the incident end face of the optical fiber 6 by the lens 42 and enters the optical fiber 6 as shown in FIG. The incident light propagates through the optical fiber 6, exits from the exit end face, and enters the optical element 46. Light that has been condensed, mixed, dispersed, scattered, or wavelength-converted is emitted from the optical element 46. For example, when the optical element 46 is a wavelength conversion member, part of the light incident on the wavelength conversion member is converted into fluorescence by exciting the phosphor, and the remaining light is transmitted through the wavelength conversion member. Mixed light of the fluorescence and the light transmitted through the wavelength conversion member is emitted from the wavelength conversion member.

As shown in FIG. 6, when the optical fiber 6 is broken or disconnected due to external and internal factors, and the laser light leaks from the optical fiber 6 (see the position indicated by arrow A), the leaked laser light (B Is reflected by the reflection layer 4 of the reflection member 2 and propagates in the propagation layer 5. The leaked laser light that has propagated through the propagation layer 5 reaches the light detection unit 45.
Thereby, the leaked laser beam does not leak outside the light guide 1 (reflecting member 2). Therefore, it is possible to avoid damage to the human body and objects due to the leaked laser light.

  If the reflective layer 4 uses a reflective layer that diffusely reflects, even if the leaked laser light leaks outside the light guide 1, the coherent property of the diffusely reflected laser light disappears. And safety against damage to objects is increased. Further, since the leaked laser light is diffusely reflected, even if the light incident member 61 is not installed in the reflection member 2 or the propagation layer 5, there is an advantage that the leaked laser light can easily reach the light detection unit.

  In this embodiment, when the light detection part 45 detects a leaked laser beam, the function which controls the output of a laser beam etc. can be further provided. A control unit that realizes this function will be described below.

  As shown in FIG. 7, the illumination device 40 of this embodiment includes a control unit 51 that receives a light detection notification from the light detection unit 45 and controls the output of the laser light source 41.

  The control unit 51 includes a determination unit 52, a drive control unit 53, and a notification control unit 55. Each part which comprises these control parts 51 can be constituted by CPU and memory, for example. The memory stores in advance a program for executing the function of each unit, and the CPU reads and executes the program in the memory.

  The determination unit 52 receives the detection notification of the leaked laser light from the light detection unit 45, determines that there is a leak, and notifies the drive control unit 53 and the notification control unit 55 of it.

  The drive control unit 53 receives a notification of leakage from the determination unit 52 and shuts off the power supply of the light source power supply unit 54 that supplies power to the light source. Thereby, the output of the laser beam of the light source 41 is stopped. Note that the drive control unit 53 is not limited to blocking the output of the laser light from the light source 41, and may perform control to reduce the laser light.

  The notification control unit 55 receives a notification of leakage from the determination unit 52, notifies the warning output unit 56 described later, and controls the warning output.

  The warning output unit 56 receives a notification from the notification control unit 55 and outputs a warning sound, a warning display, and the like.

With reference to FIG. 8, the flow of the laser light output blocking process will be described.
The light detection unit 45 in which the wavelength of the laser beam of the light source 41 is set in advance detects the leaked laser beam, and notifies the determination unit 52 of this (step S81). Receiving the notification, the determination unit 52 determines that the laser beam has leaked, and notifies the drive control unit 53 and the notification control unit 55 of this (step S82). Upon receiving the notification from the determination unit 52, the drive control unit 53 cuts off the power supply to the light source 41 of the light source power supply unit 54. Thereby, the output of the laser beam from the light source 41 is interrupted (step S83). On the other hand, the notification control unit 55 that has received the notification from the determination unit 52 performs warning output such as an alarm sound and a warning display of the warning output unit 56 (step S84).

According to this embodiment, the reflection layer 4 reflects the leaked laser light, and the propagation layer 5 propagates the reflected light, so that the light detection unit 45 detects the leakage, and the control unit 51 outputs the laser light. Can be cut off. Even when the leakage of the laser beam of the optical fiber 6 starts little by little, the light detection unit 45 detects the leakage, so that it is possible to detect the breakage of the optical fiber 6 that does not reach disconnection. Further, the warning output by the warning output unit 56 makes it easier to check the damage detection. Further, since the output of the light source 41 can be cut off when a leaked laser beam is detected, leakage of the leaked laser beam from the light guide 1 can be surely prevented, and safety against damage to human bodies and objects is further enhanced.
In FIG. 7, the configuration example in which the control unit 51 performs both control and notification of the light source is shown. However, in order to simplify the apparatus, a configuration in which any one of them is omitted may be used.

<Second Embodiment of Lighting Device>
In the present embodiment, the laser light leaked using the light guide 1 and the light detector 45 is the same as in the first embodiment, but the return light of the leaked laser light branched using the light branching member. The point which arrange | positions the photon detection part 45 in the position which light-receives is different.

  A configuration different from the first embodiment will be described. As shown in FIG. 9A, in the illumination device 90 of the present embodiment, the first lens 42 and the second lens 92 are disposed between the light source 41 and the incident surface of the optical fiber 6, and these lenses An optical branching member 91 is disposed therebetween. The light receiving element 45 a of the light detection unit 45 is disposed at a position for receiving the light branched by the light branching member 91. Further, as shown in FIGS. 9B and 9C, the incident-side connector 43 has an incident-side connector end 43b to an incident-side connector end 43a to guide the return light. One or more light guides 93 penetrating therethrough are provided.

In the present embodiment, the first lens 42 and the second lens 92 collect the emitted light 47 and make it incident on the incident end face of the optical fiber 6.
The second lens 92 is totally reflected by the reflective layer 4 and propagates through the propagation layer 5 and the light guide portion 93, and condenses the leaked laser light 94 emitted from the light source side end portion 43 b of the incident side connector 43. The light is made incident on the light branching member 91.

  The light branching member 91 has a function of branching the leaked laser light 94 collected by the second lens 92 to the light detection unit 45 while transmitting the laser light 47 emitted from the light source 41. Thereby, the leaked laser light 94 is detected by the light receiving element 45a without returning to the light source 41.

  As the light branching member 91, a member capable of branching the leaked laser light may be used. Specifically, a half mirror, a reflective beam splitter, or a polarizing beam splitter may be used.

  The position of the light branching member 91 can be appropriately selected depending on the purpose and application in addition to the position shown in FIG.

A specific configuration of the light guide unit 93 will be described with reference to FIG.
The light guide portion 93 has a function of propagating the leaked laser light propagated to the light source side of the propagation layer 5 and emitting it from the light source side end portion 43 b of the incident side connector 43 to the second lens 92.

  The light guide 93 is disposed on the outer periphery of the optical fiber 6. Between the light guide portion 93 and the optical fiber 6, the incident-side connector 43 has a space that can hold the optical fiber 6 (FIGS. 9B and 9C).

  In the light guide 93, the opening of the light guide 93 on the light guide side is bonded to the light source side end of the propagation layer 5 so that the laser beam does not leak (FIG. 9B).

  The diameter, number, arrangement, and shape of the light guides 93 and the distance between the adjacent light guides 93 can propagate the return light of the leaked laser light to the end 43b of the incident side connector 43, and the strength of the incident side connector 43. The size, number, arrangement, shape, and distance can be maintained.

  The light guide portion 93 is a hole that penetrates from the end portion 43b of the incident-side connector to the end portion 43a of the incident-side connector, and a material that propagates laser light is used as the material. Specifically, solids such as glass, quartz, and polymer that are optically transparent and excellent in light resistance, and gases such as air can be used, and those similar to the propagation layer 5 can be used.

  As a material of the incident side connector 43 for forming the light guide portion 93, it is preferable to use a material that reflects laser light, such as metal. Although it is possible to use a material that does not reflect the laser light, in this case, a process in which the light is reflected from the surface that contacts the light guide portion 93 of the incident side connector 43 using a material that can be reflected, such as an optical thin film. It is desirable to do.

The operation of the present embodiment that is different from the first embodiment of the main part will be described.
The laser beam 47 emitted from the light source 41 is condensed through the first lens 1 and the second lens and is incident on the incident surface of the optical fiber 6.
When laser light leaks from the optical fiber 6 due to breakage or disconnection of the optical fiber 6, the leaked laser light is totally reflected by the reflective layer 4 of the reflecting member 2 and propagates through the propagation layer 5. The propagated leakage laser light propagates through the light guide portion 93 and is emitted from the light source side end portion 43 b of the incident side connector 43 to the second lens 92. The second lens 92 collects the emitted leakage laser light 94 and emits it to the light branching member 91. The light branching member 91 branches the condensed leaked laser light 94 to the light detection unit 45 (light receiving element 45a). The light detector 45 detects the branched leaked laser light 94.
Thereby, the return light of the leaked laser light 94 can be detected by the light receiving element 45 a without returning to the light source 41.
The processing (FIG. 8) such as laser light output control by the control unit 51 that has received the notification of the leaked laser light from the light detection unit 45 is the same as in the first embodiment.

According to this embodiment, as in the first embodiment, since the light guide 1 having a structure in which the outer periphery of the optical fiber is covered with a reflecting member is used, damage to the human body and objects due to the leaked laser light is avoided. be able to. The leaked return light of the laser light is emitted to the outside of the light guide 1, but is incident on the light receiving element 45a by the light branching member 91. Therefore, the return light of the laser light is carelessly applied to a human body or an object. Will not be exposed to. Therefore, the safety for the human body and objects can be maintained.
Further, similarly to the first embodiment, since the light detection unit 45 detects leakage, the output of the laser light can be cut off, and the breakage of the optical fiber 6 before disconnection can be detected. Furthermore, the warning display ensures the recognition of damage detection. Further, by blocking the output of the light source 41, it is possible to reliably prevent external leakage of the leaked laser light from the light guide 1, thereby further improving the safety of human bodies and objects.

<Third embodiment of lighting device>
This embodiment is different from the first and second embodiments in that the light detection unit 45 is disposed on the output-side connector 44. The other points are the same, and the configuration different from the first embodiment will be described below.

  In the illuminating device 100 of this embodiment, as shown in FIG. 10, the light detection part 45 is arrange | positioned on the outer periphery of the axial direction of the output side connector 44. As shown in FIG. In addition, a light guide unit 101 that guides leaked laser light from the output side connector end 44 a to the light detection unit 45 is provided in the output side connector 44.

  The light guide unit 101 has a recess 101a formed from the light source side end 44a of the emission side connector 44 to the middle of the emission side connector toward the optical element side end 44b of the emission side connector 44, and the recess 101a. And a through-hole 101b penetrating to the opening of the tube 45b of the photodetector 45 is continuously formed.

  The recess 101 a of the light guide unit 101 is disposed on the outer periphery of the optical fiber 6. At that time, the concave portion 101a is disposed so as to have a space between the optical fiber 6 and the output side connector 44 so as to hold the optical fiber 6 (FIGS. 10B and 10C).

  The opening part of the light guide part 101 (concave part 101a) at the end part 44a of the emission side connector 44 is bonded to the optical element side end part of the propagation layer 5 so that the laser beam does not leak (FIG. 10B). )). The tube 45b is bonded to the end of the through-hole 101b continuous with the tube 45b of the photodetector 45 so that the laser beam does not leak.

As the material of the light guide unit 101, a material that propagates laser light is used. Specifically, solids such as glass, quartz, and polymer that are optically transparent and excellent in light resistance, and gases such as air can be used, and those similar to the propagation layer 5 can be used.
As a material of the emission side connector 44 for forming the light guide unit 101, it is preferable to use a material that reflects light, such as metal. A material that does not reflect light can also be used. In that case, a material that can be reflected, such as an optical thin film, is used to perform a process of reflecting light on the surface that contacts the light guide unit 101 in the output side connector 44. It is desirable.

  The diameter, number, arrangement, and shape of the light guide unit 101 and the distance between the adjacent recesses 101a are such that the opening of the recess 101a can be bonded to the propagation layer 5 and the strength of the output side connector 44 can be maintained. , Placement, shape, and distance.

  The light detection unit 45 detects the leaked laser light guided from the propagation layer 5 of the light guide 1 to the light guide unit 101.

  The position of the light detection unit 45 may be any position on the outer periphery of the emission side connector 44 in addition to the position shown in FIG. 10, and can be appropriately selected depending on the purpose and application.

An operation of the present embodiment that is different from that of the first embodiment will be described.
When laser light leaks from the optical fiber 6 due to breakage or disconnection of the optical fiber 6, the leaked laser light is totally reflected by the reflective layer 4 of the reflecting member 2 and propagates through the propagation layer 5. The propagated leakage laser light propagates through the light guide unit 101 and is emitted into the light detection unit 45. The light receiving element 45a of the light detection unit 45 detects the leaked laser light.
Note that the control processing (FIG. 8) such as laser light output by the control unit 51 that has received the detection of leakage laser light from the light detection unit 45 is the same as in the first embodiment.

The effect of this embodiment can avoid the damage to the human body and the thing by the leaked laser beam by using the light guide 1 like the first embodiment.
Further, similarly to the first embodiment, the light detection unit 45 detects leakage and blocks the output of the laser light, so that it is possible to detect the breakage of the optical fiber 6 before disconnection. Furthermore, the warning display ensures the recognition of damage detection. Further, since the output of the light source 41 can be blocked, leakage of the leaked laser light from the light guide 1 can be surely prevented, and the safety for human bodies and objects is further enhanced.

  In the present embodiment, the case where the light detection unit 45 is disposed on the outer periphery of the emission side connector 44 has been described. However, the light receiving element 45 a can be disposed on the optical element 46. In this case, it is preferable to guide the leaked laser light to the light receiving element 45 a installed in the optical element 46 by the light guide unit 101.

  As mentioned above, the illuminating device of embodiment mentioned above can be used for an indoor illuminating device, an outdoor illuminating device, a vehicle-mounted illuminating device, a projector, and a light-up illuminating device.

6 ... optical fiber, 4 ... reflective layer (reflective surface), 2 ... reflective member, 5 ... propagation layer (propagating layer), 1 ... light guide, 21 ... spacer , 41 ... laser light source, 42 ... lens, 46 ... optical element, 40, 90, 100 ... illumination device, 45 ... light detection unit, 51 ... control unit, 91. Light splitting member, 43... Incident side connector, 93, 101.

Claims (11)

An optical fiber and a reflecting member that has a reflecting surface that reflects light and covers at least a part of the outer periphery of the optical fiber in the axial direction;
The light guide body, wherein the reflection member includes a layer that propagates the light between an outer periphery of the optical fiber and the reflection surface. The light guide according to claim 1,
A light guide comprising a spacer between the reflection surface and the optical fiber. The light guide according to claim 1 or 2,
The light guide, wherein the reflection surface is a reflection surface that performs diffuse reflection. A laser light source, a lens that collects the light emitted from the laser light source, and a light guide that enters the collected light and guides it to the optical element,
The said light guide is a light guide as described in any one of Claim 1 to 3, The illuminating device characterized by the above-mentioned. The lighting device according to claim 4,
An illumination device, further comprising: a light detection unit that detects laser light leaked from the optical fiber. The lighting device according to claim 5,
The illumination device, wherein the light detection unit is disposed on an outer periphery of the light guide. The lighting device according to claim 4,
An optical branching member for branching the laser light leaked from the optical fiber;
A light detection unit for detecting the leaked laser beam branched by the light branching member,
The lighting device, wherein the light branching member is disposed between the laser light source and a light source side end of the light guide. The lighting device according to claim 7,
An incident-side connector disposed on the incident side of the optical fiber;
The said incident side connector is equipped with the light guide part penetrated from the said optical element side of the incident side connector to the said laser light source side, The illuminating device characterized by the above-mentioned. The lighting device according to claim 5,
An output side connector disposed on the output side of the optical fiber,
The lighting device, wherein the light detection unit is disposed on an outer periphery of the emission side connector. The lighting device according to claim 9,
An illumination apparatus comprising: a light guide unit configured to guide the leaked laser light from the laser light source side of the output side connector to the light detection unit in the output side connector. It is an illuminating device as described in any one of Claim 6 to 10, Comprising:
An illumination apparatus, further comprising: a control unit that controls an output of the laser light source when the light detection unit detects a leaked laser beam.

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