JP7162244B2 - lighting equipment - Google Patents

Description

The present invention relates to a lighting device using laser light as a light source.

Conventionally, there is known a lighting device that emits light from a phosphor using laser light as excitation light and converts the light into a desired light color for illumination (see, for example, Patent Document 1). In such a lighting device, a laser beam output from a light source is guided to a lamp (lamp unit) via an optical fiber (optical fiber cable). The fluorescent material in the lamp is excited by the laser light that has passed through the optical fiber, so that the lamp emits illumination light of a desired color.

JP 2015-15146 A

Here, for example, during construction or maintenance, the optical fiber may be cut. may be irradiated with laser light. Therefore, it is desired to prevent the leakage of laser light from the cut portion by increasing the certainty of detecting the disconnection of the optical fiber.

SUMMARY OF THE INVENTION An object of the present invention is to provide an illumination device capable of enhancing the reliability of detecting disconnection of an optical fiber.

An illumination device according to an aspect of the present invention includes a laser light source, an optical fiber that guides light emitted by the laser light source, and a portion of the light guided by the optical fiber that is converted into detection light of a different wavelength band. a first wavelength conversion element, a light receiving unit for receiving detection light guided by the optical fiber in a direction opposite to the light, and a disconnection detection unit for detecting disconnection of the optical fiber based on the detection result of the light receiving unit. a second wavelength conversion element that converts part of the light guided by the optical fiber into illumination light of a different wavelength band; a filter for extracting light containing the emission peak wavelength of the light from the.

According to the illumination device of the present invention, it is possible to improve the reliability of detecting disconnection of an optical fiber.

FIG. 1 is a perspective view showing how a lighting device according to an embodiment is used. FIG. 2 is a schematic diagram showing the optical configuration of the illumination device according to the embodiment. FIG. 3 is a graph showing light emission characteristics of a semiconductor laser element that is a laser light source according to the embodiment. FIG. 4 is a plan view showing a schematic configuration of the first wavelength conversion element according to the embodiment. FIG. 5 is a block diagram showing the control configuration of the lighting device according to the embodiment. FIG. 6 is a schematic diagram showing an optical configuration of a lighting device according to a modification.

A lighting device according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that each of the embodiments described below is a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement of components, connection forms, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest level concept of the present invention will be described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily strictly illustrated. Moreover, in each figure, the same code|symbol is attached|subjected about the same component.

[Embodiment]
Embodiments will be described below. First, the mode of use of the lighting device according to the embodiment will be described. FIG. 1 is a perspective view showing how a lighting device 10 according to an embodiment is used. As shown in FIG. 1, the lighting device 10 is installed in a show window 301 which is one of the buildings. The illumination device 10 includes a plurality of lamps 20 , a plurality of optical fibers 30 and a light source device 40 .

The plurality of lamps 20 are attached to different locations on the ceiling of the show window 301 and function as spotlights that illuminate the mannequins 303 . A light source device 40 is provided outside the show window 301 . A laser beam emitted from the light source device 40 is transmitted to each lamp 20 through an optical fiber 30 wired outside the show window 301 .

The light source device 40 is a device that generates laser light including blue light and supplies the laser light to the plurality of lamps 20 using the optical fiber 30 . Specifically, the light source device 40 includes a plurality of laser light sources 41 (see FIG. 2, etc.) made up of semiconductor laser elements that emit laser light including blue light. By arranging the plurality of laser light sources 41 in one place in this manner, the laser light sources 41 can be arranged in a concentrated manner, and installation adjustment and maintenance can be easily performed.

The lamp 20 is a device that emits white light using laser light transmitted from the optical fiber 30 as an excitation light source.

Next, each part of the lighting device 10 will be described in detail. FIG. 2 is a schematic diagram showing the optical configuration of the illumination device 10 according to the embodiment. Note that FIG. 2 shows a set of lamps 20 and optical fibers 30 . In FIG. 2, the optical path L1 of the laser light from the laser light source 41 to the lamp 20 is indicated by a solid line, and the optical path L2 of the detection light from the lamp 20 is indicated by a chain double-dashed line. The detection light is light for detecting disconnection of the optical fiber 30 .

2, the internal structure of the light source device 40 includes a laser light source 41 corresponding to a set of lamps 20 and an optical fiber 30, a light receiving section 42, and an optical system 50 for the laser light source 41 and the light receiving section 42. Illustrated. In other words, actually, a plurality of sets of the laser light source 41 , the light receiving section 42 and the optical system 50 are provided in the light source device 40 so as to correspond to each set of the lamp 20 and the optical fiber 30 . Since the laser light source 41, light receiving section 42 and optical system 50 of each set have basically the same configuration, only one set of laser light source 41, light receiving section 42 and optical system 50 will be described below. Further, the light source device 40 is provided with a control section 49 (see FIG. 5) that controls the laser light source 41 and the light receiving section 42 of each set.

First, the optical configuration of the light source device 40 will be described. A light source device 40 is provided with a laser light source 41 composed of a semiconductor laser element having an emission peak wavelength of 455 nm. FIG. 3 is a graph showing light emission characteristics of a semiconductor laser element that is the laser light source 41 according to the embodiment. As shown in FIG. 3, the semiconductor laser element has, as its characteristics, a first emission mode that emits laser light and a second emission mode that emits only LED light with an emission intensity lower than that of the laser light. It is designed to be switched by Laser light is an example of first light, and LED light is an example of second light. That is, the light emitted by the laser light source 41 includes the laser light as the first light and the LED light as the second light.

FIG. 3 illustrates a case where the first emission mode and the second emission mode are switched at the current value I1 of the current supplied to the semiconductor laser element. That is, the laser light source 41 emits light switchably between laser light and LED light. Therefore, the LED light also travels along the optical path L1 similar to that of the laser light.

As shown in FIG. 2, the optical system 50 includes a collimator lens 51, a dichroic mirror 53, a first condenser lens 54, and a second condenser lens .

The collimating lens 51 is a lens that converts laser light or LED light emitted from the laser light source 41 into parallel light. The collimating lens 51 is arranged on the optical axis of the laser light source 41 and on the downstream side in the direction of light emission. Here, the collimating lens 51 is illustrated as being separate from the laser light source 41, but the collimating lens and the light source may be integrated.

The dichroic mirror 53 is a dichroic mirror that reflects the laser light or LED light transmitted through the collimator lens 51 and transmits the detection light. Specifically, the dichroic mirror 53 reflects light in the blue wavelength band (blue light) from 440 nm to 470 nm and transmits light in the wavelength band longer than 500 nm. The dichroic mirror 53 is arranged on the optical axis of the laser light source 41 and downstream of the collimator lens 51 . The laser light or LED light that has passed through the collimator lens 51 is reflected by the dichroic mirror 53 to be directed toward the first condenser lens 54 . Further, the detection light passes through the dichroic mirror 53 and is irradiated toward the light receiving section 42 . That is, on the side of the lamp 20 from the dichroic mirror 53, the optical path L1 of the laser light or LED light and the optical path L2 of the detection light are shared, and are branched on the opposite side of the dichroic mirror 53. Note that the dichroic mirror may be a dichroic mirror that transmits the light transmitted through the collimating lens 51 and reflects the detection light.

The first condenser lens 54 is a lens that condenses the laser light or LED light reflected by the dichroic mirror 53 and makes it incident on one end face of the optical fiber 30 . The first condenser lens 54 is arranged between the dichroic mirror 53 and one end surface of the optical fiber 30 . The first condenser lens 54 also has a function of collimating the detection light emitted from one end surface of the optical fiber 30 .

The second condenser lens 56 is a lens that condenses the detection light transmitted through the dichroic mirror 53 and causes it to enter the light receiving section 42 . The second condenser lens 56 is arranged between the dichroic mirror 53 and the light receiving section 42 on the optical path L2 of the detection light.

The light receiving unit 42 is a light receiving element that receives detection light and converts it into an electric signal. The light-receiving unit 42 photoelectrically converts the received detection light to generate an electric signal corresponding to the received amount (that is, intensity) of the detection light. The generated electrical signal is output to the control section 49 . The light receiving unit 42 is, for example, a photodiode, but is not limited to this. For example, the light receiving section 42 may be a phototransistor or an image sensor.

Next, the optical configuration of the lamp 20 will be described. In FIG. 2, as the internal structure of the lamp 20, a first wavelength conversion element 21, a second wavelength conversion element 22, a dichroic mirror 23, and an optical member 24 are illustrated.

The first wavelength conversion element 21 is an element that converts laser light or LED light emitted from the other end surface of the optical fiber 30 into detection light of a different wavelength band. Specifically, the first wavelength conversion element 21 is arranged between the other end surface of the optical fiber 30 and the dichroic mirror 23 , and arranged to face the other end surface of the optical fiber 30 .

FIG. 4 is a plan view showing a schematic configuration of the first wavelength conversion element 21 according to the embodiment. As shown in FIG. 4 , the first wavelength conversion element 21 has a substrate 211 and a fluorescent portion 212 . The substrate 211 is a plate that holds the fluorescent portion 212 . The substrate 211 is made of translucent material such as glass or sapphire. A fluorescent portion 212 is laminated on the substrate 211 .

The fluorescent portion 212 includes, in a dispersed state, a plurality of fluorescent particles that are excited by laser light or LED light emitted from the other end surface of the optical fiber 30 to emit fluorescent light. fluoresces. Specifically, the fluorescent portion 212 can be exemplified by a base material made of transparent resin or glass in which fluorescent particles are dispersed, or by hardening fluorescent particles. In this embodiment, the fluorescent portion 212 emits white light. That is, the fluorescent part 212 converts laser light or LED light into detection light with a longer wavelength band. For example, the fluorescent portion 212 contains a first fluorescent material that emits yellow light when irradiated with laser light or LED light. Part of the yellow light emitted from the first wavelength conversion element 21 enters the optical fiber 30 from the other end surface of the optical fiber 30 as detection light. This detection light reaches the light receiving section 42 by passing through the optical path L2 shown in FIG.

Although the type and characteristics of the phosphor are not particularly limited, it is preferable that the phosphor has high heat resistance and does not cause luminance saturation because relatively high output laser light serves as excitation light. For example, a yttrium-aluminum-garnet (YAG)-based phosphor is employed. A YAG-based phosphor that emits yellow fluorescence is preferable because it has excellent temperature quenching characteristics and luminance saturation characteristics compared to other phosphors. The type of substrate that holds the phosphors in a dispersed state is not particularly limited, but the higher the transparency, the higher the yellow light emission efficiency. In addition, since a laser beam of relatively high output is incident, a material having high heat resistance is preferable.

In addition, the fluorescent portion 212 has a through hole 213 through which part of the laser light or the LED light passes. A part of the laser light or LED light that has passed through the through hole 213 is emitted toward the dichroic mirror 23 without being wavelength-converted, that is, as blue light. A two-dot chain line in FIG. The through-hole 213 is arranged so as to be within the irradiation range H1. The through-hole 213 has an area equal to or more than half the area of the irradiation range H1. Because of this relationship, most of the laser light or LED light passes through the through hole 213 and is emitted toward the dichroic mirror 23 as blue light. It is converted into light and becomes detection light. In the present embodiment, by providing the through hole 213 in the fluorescent portion 212 , part of the laser light or LED light passing through the through hole 213 is not wavelength-converted, and the other part is converted by the fluorescent portion 212 . A case of wavelength conversion is illustrated. However, as long as part of the laser light or LED light is not wavelength-converted and the other part is wavelength-converted by the fluorescent portion 212, any form may be used. For example, the wavelength conversion element may be formed in a size that can be entirely accommodated with a gap in the irradiation range H1 of the laser light or the LED light. In this case, of the laser light or the LED light, the light that has passed through the gap is not wavelength-converted.

As shown in FIG. 2, the second wavelength conversion element 22 is an element that converts laser light or LED light that has passed through the dichroic mirror 23 into illumination light of a different wavelength band. Specifically, the second wavelength conversion element 22 is arranged between the dichroic mirror 23 and the optical member 24 .

The second wavelength conversion element 22 has a substrate 221 and a fluorescent portion 222 . The substrate 221 is a plate that holds the fluorescent portion 222 . The substrate 221 is made of translucent material such as glass or sapphire. A fluorescent portion 222 is laminated on the main surface of the substrate 221 on the side of the optical member 24 .

The fluorescent portion 222 includes a plurality of dispersed fluorescent particles that are excited by the laser light or LED light transmitted through the dichroic mirror 23 to emit fluorescence. emit. Specifically, the fluorescent portion 222 can be exemplified by a base material made of transparent resin or glass in which fluorescent particles are dispersed, or by hardening fluorescent particles. In this embodiment, the fluorescent portion 222 emits white light. That is, the fluorescent part 222 converts laser light or LED light into illumination light with a longer wavelength band. For example, the fluorescent portion 222 contains two types of fluorescent materials, a first fluorescent material that emits red light and a second fluorescent material that emits green light, in an appropriate ratio when irradiated with laser light or LED light. Red light emitted from the first phosphor, green light emitted from the second phosphor, and blue light formed by laser light or LED light are mixed to emit white illumination light from the fluorescent portion 222 . . Unlike the fluorescent portion 212 of the first wavelength conversion element 21, the fluorescent portion 222 does not have a through hole. Therefore, the entire irradiation range of the laser light or the LED light is superimposed on the fluorescent portion 222 .

Although the type and characteristics of the phosphor are not particularly limited, it is preferable that the phosphor has high heat resistance and does not cause luminance saturation because relatively high output laser light serves as excitation light. For example, a yttrium-aluminum-garnet (YAG)-based phosphor is employed. The type of substrate that holds the phosphors in a dispersed state is not particularly limited, but the higher the transparency, the higher the white light emission efficiency. In addition, since a laser beam of relatively high output is incident, a material having high heat resistance is preferable.

The dichroic mirror 23 is an example of a filter arranged between the first wavelength conversion element 21 and the second wavelength conversion element 22 to extract blue light from laser light or LED light. Specifically, the dichroic mirror 23 is a dichroic mirror that transmits light in the blue wavelength band of 440 nm or more and 470 nm or less and reflects light in the wavelength band of 500 nm or more.

Therefore, the blue light that has passed through the first wavelength conversion element 21 passes through the dichroic mirror 23 and travels toward the second wavelength conversion element 22 . On the other hand, the yellow light converted by the first wavelength conversion element 21 is reflected by the dichroic mirror 23 and blocked from traveling to the second wavelength conversion element 22 . Part of the yellow light reflected by the dichroic mirror 23 enters the other end surface of the optical fiber 30 as detection light. Thus, the dichroic mirror 23 can increase the intensity of the detection light entering the optical fiber 30 more than a simple filter for extracting blue light.

On the other hand, part of the illumination light emitted by the second wavelength conversion element 22 toward the dichroic mirror 23 , fluorescence in the green to red wavelength band, is reflected by the dichroic mirror 23 . In addition, external light reaching the dichroic mirror 23 through the optical member 24 is also reflected by the dichroic mirror 23 in the green to red wavelength band. In this way, the dichroic mirror 23 prevents illumination light and external light from entering the optical fiber 30 . Note that the dichroic mirror 23 reflects the illumination light, so that the intensity of the illumination light emitted from the lamp 20 can be increased more than a simple filter for extracting blue light.

Since the light in the blue wavelength band passes through the dichroic mirror 23 , for example, the light in the blue wavelength band among the external light components of sunlight enters the light source device 40 side via the optical fiber 30 , but the dichroic mirror 53 converts the light in the blue wavelength band into the light source device 40 . Since the light is reflected, it does not reach the light receiving section 42 .

Here, as a filter for extracting blue light, the dichroic mirror 23 having the characteristics of a short-pass filter was exemplified. An optical member can be employed. Other filters include a bandpass filter and the like.

The optical member 24 is an optical member for controlling the light distribution of the illumination light emitted by the second wavelength conversion element 22 . Examples of the optical member 24 include a diffusing member that diffuses the illumination light and a condensing member that converges the illumination light. Examples of the diffusing member include a milky-white translucent member and a diffusing lens. A condensing lens etc. are mentioned as a condensing member.

Next, the control configuration of the lighting device 10 will be described. FIG. 5 is a block diagram showing the control configuration of lighting device 10 according to the embodiment. As shown in FIG. 5, the illumination device 10 includes a controller 49 electrically connected to each of the laser light sources 41 and the light receivers 42 of each set. The control unit 49 is composed of a drive circuit and a microcontroller. Specifically, the control unit 49 controls the laser light source 41 based on an electrical signal caused by the detection light input from the light receiving unit 42 . The control unit 49 has a nonvolatile memory storing a control program, a volatile memory serving as a temporary storage area for executing the program, an input/output port, a processor executing the program, and the like.

The controller 49 is connected to an external power source (not shown), and controls lighting of each laser light source 41 by controlling the current supplied to each laser light source 41 . For example, the control unit 49 controls the supply current to the laser light source 41 to switch between a first light emission mode in which laser light is emitted and a second light emission mode in which only LED light having an emission intensity lower than that of the laser light is emitted. This is an example of a part. Also, the control unit 49 is an example of a disconnection detection unit that detects disconnection of the optical fiber 30 based on the detection result of the light receiving unit 42 . Specifically, the control unit 49 determines disconnection of the optical fiber 30 for each set.

For example, in a normal state where the optical fiber 30 is not disconnected, when the laser light source 41 is turned on, the laser light or the LED light passes through the optical fiber 30, and the detection light also passes through the optical fiber 30. 42 outputs an electric signal caused by the detected light to the control unit 49 . In other words, when the control unit 49 receives an electrical signal from the light receiving unit 42, it determines that the optical fiber 30 in the same set as the light receiving unit 42 is normal. Based on this determination, the control section 49 permits the light emission of the laser light source 41 of the same set as the light receiving section 42 .

On the other hand, in an abnormal state in which the optical fiber 30 is disconnected, when the laser light source 41 is turned on, the laser light or the LED light cannot pass through the optical fiber 30, so that no detection light is generated, and the light receiving unit 42 is controlled by the control unit. No electrical signal is output to 49. That is, when the control unit 49 does not receive an electrical signal from the light receiving unit 42, it determines that the optical fiber 30 in the same set as the light receiving unit 42 is broken. Based on this determination, the control unit 49 prohibits the laser light source 41 of the same set as the light receiving unit 42 from emitting light. After prohibition, the controller 49 does not turn on the laser light source 41 .

In an abnormal state, the light receiving section 42 may output an electric signal to the control section 49 due to a slight amount of scattered light or stray light within the light source device 40 . Therefore, the control section 49 may determine that the optical fiber 30 is broken even when an electrical signal significantly smaller than the electrical signal in the normal state is input from the light receiving section 42 .

In this way, when it is determined that the optical fiber 30 is disconnected, the light emission of the laser light source 41 is prohibited, but the laser light source 41 is temporarily turned on at the time of the determination. By the way, during installation or maintenance of the lighting device 10 , there is a possibility that an operator may be visually recognizing the cut portion of the optical fiber 30 . In this state, if the laser light source 41 temporarily emits a laser beam to determine whether the wire is broken, the laser beam will be emitted from the wire breakage location, which may endanger the operator. In order to prevent this, when the power is turned on, the controller 49 controls the supply current to the laser light source 41 to cause the laser light source 41 to emit light in the second emission mode. That is, when the power is turned on, the disconnection of the optical fiber 30 is detected by the LED light emitted from the laser light source 41, thereby preventing the worker from being exposed to the laser light. Further, when the disconnection of the optical fiber 30 is not detected, the control unit 49 switches from the second emission mode to the first emission mode after a predetermined time has elapsed.

It is conceivable that the optical fiber 30 may be disconnected even when the laser light source 41 is emitting laser light in the first emission mode in the normal state. A disconnection of the optical fiber 30 is determined based on the laser light. That is, in this case, the control unit 49 determines whether the wire is broken while remaining in the first light emission mode.

Here, the LED light is more susceptible to noise because the emission intensity is lower than that of the laser light. In particular, the influence of outside light is remarkable. In order to suppress the influence of the external light and improve the detection accuracy of disconnection even with LED light, in the present embodiment, the lamp 20 is provided with a dichroic mirror 23 that cuts the external light. A first wavelength conversion element 21 for emitting detection light is provided on the optical fiber 30 side of the dichroic mirror 23 in the lamp 20 . As a result, the dichroic mirror 23 blocks external light, thereby suppressing the influence of the external light on the detection light. In the case of detection light originating from LED light, the effect of blocking external light is great, but even with detection light originating from laser light, a certain degree of external light blocking effect can be obtained.

[Effects, etc.]
As described above, the illumination device 10 according to the present embodiment includes the laser light source 41, the optical fiber 30 for guiding the light (laser light or LED light) emitted by the laser light source 41, and the optical fiber 30 for guiding the light. A first wavelength conversion element 21 that converts part of the laser light or LED light into detection light in a different wavelength band, and a detection light guided by an optical fiber 30 in the opposite direction to the laser light or LED light. A light receiving unit 42 that receives light, a control unit 49 (disconnection detection unit) that detects disconnection of the optical fiber 30 based on the detection result of the light receiving unit 42, and one of laser light or LED light guided by the optical fiber 30. a second wavelength conversion element 22 that converts the portion into illumination light of a different wavelength band, and is arranged between the first wavelength conversion element 21 and the second wavelength conversion element 22 to convert the light from laser light or LED light is provided with a dichroic mirror 23 (filter) for extracting light (blue light) including an emission peak wavelength of .

According to this, since the dichroic mirror 23 for extracting blue light is arranged between the first wavelength conversion element 21 and the second wavelength conversion element 22, the dichroic mirror 23 is emitted by the second wavelength conversion element 22. Illumination light and external light are shielded. Therefore, it is possible to separate the illumination light, the external light, and the detection light. Thereby, the S/N ratio between the detection light and the outside light can be increased. Since the influence of noise on the detection light is reduced, the disconnection detection accuracy can be improved. This is particularly suitable for disconnection detection with LED light. Therefore, it is possible to provide the illumination device 10 with improved reliability in detecting disconnection of the optical fiber 30 .

Here, as an example of conventional disconnection detection, there is a method of detecting disconnection of an optical fiber by storing an electric wire along with an optical fiber in a fiber cable and detecting the disconnection of the electric wire. However, since it cannot be said that the electric wire is surely disconnected when the optical fiber is disconnected, there is a problem in detection accuracy. On the other hand, in the method according to the present embodiment, when the optical fiber 30 is broken, the detection light is surely not transmitted, so the accuracy of detecting the breakage can be improved.

As another example of conventional disconnection detection, there is a method in which the light receiving section is incorporated in the lamp instead of in the light source device. However, since the lamp requires energization, there is a problem that the reliability of the lamp, which is used in a harsh environment, tends to decrease. In the method according to the present embodiment, disconnection of the optical fiber 30 can be detected without energizing the lamp 20, so a highly reliable lamp 20 can be realized.

Further, the control unit 49 (disconnection detection unit) prohibits the light emission of the laser light source 41 when the disconnection of the optical fiber 30 is detected.

According to this, when the disconnection of the optical fiber 30 is detected, the control unit 49 prohibits the light emission of the laser light source 41, so that the laser light can be prevented from leaking from the disconnected portion. Therefore, the lighting device 10 with high safety can be provided.

In addition, the laser light source 41 emits, as the light, a laser light and an LED light having an emission intensity lower than that of the laser light in a switchable manner.

This makes it possible to detect disconnection of the optical fiber 30 caused by each of the laser light and the LED light. In particular, the influence of noise on LED light can be significantly reduced.

[Modification]
Next, a modified example according to this embodiment will be described. It should be noted that, in the following description, parts that are the same as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof may be omitted. FIG. 6 is a schematic diagram showing an optical configuration of a lighting device 10B according to a modification. As shown in FIG. 6, a plurality of optical fibers 30b and 30c are connected to one lamp 20b, which is different from the illumination device 10 according to the above embodiment.

Specifically, the illumination device 10B is provided with two laser light sources 41b and 41c and two light receiving units 42b and 42c so as to correspond to the respective optical fibers 30b and 30c. The optical system 50b of the illumination device 10B includes collimator lenses 51b and 51c, dichroic mirrors 53b and 53c, and first condenser lenses 54b and 54c so as to correspond to the laser light sources 41b and 41c. The optical system 50b also includes second condenser lenses 56b and 56c corresponding to the light receiving portions 42b and 42c.

The other ends of the optical fibers 30b and 30c are provided with connector portions 31b and 31c that are detachably attached to the lamp 20b. Specifically, the connector portions 31b and 31c are attached to the lamp 20b by being fitted into the insertion openings 29b and 29c of the lamp 20b. The connector portions 31b and 31c or the lamp 20b are provided with a lock mechanism for preventing the connector portions 31b and 31c from coming off. Examples of the locking mechanism include a mechanism including claw portions provided on the connector portions 31b and 31c and a locked portion provided on the lamp 20b side and to which the claw portions are locked. When the claw portion is released from the locked portion, the connector portions 31b and 31c can be removed from the lamp 20b.

The first wavelength conversion elements 21b, 21c and the dichroic mirrors 23b, 23c are accommodated in the connector portions 31b, 31c. The first wavelength conversion elements 21b, 21c are arranged between the other ends of the optical fibers 30b, 30c and the dichroic mirrors 23b, 23c. The first wavelength conversion elements 21b and 21c convert part of the laser light or LED light emitted from the other end surfaces of the optical fibers 30b and 30c into detection light of different wavelength bands.

The dichroic mirrors 23b, 23c are arranged on the tip surfaces of the connector portions 31b, 31c. The dichroic mirrors 23b and 23c reflect the detection light converted by the first wavelength conversion elements 21b and 21c among the laser light or the LED light, and the blue light not converted by the first wavelength conversion elements 21b and 21c. To Penetrate. That is, the connector portions 31b and 31c do not emit detection light to the outside, and only blue light is emitted to the outside.

The lamp 20b includes a second wavelength conversion element 22, an optical member 24, and reflecting members 28b and 28c.

The reflecting members 28b and 28c are mirrors that reflect blue light. The reflecting members 28b, 28c are arranged at positions corresponding to the respective insertion openings 29b, 29c. Also, the reflecting members 28b and 28c are arranged in a posture that reflects the blue light emitted from the connector portions 31b and 31c attached to the respective insertion ports 29b and 29c toward the second wavelength conversion element 22. . The blue light reflected by the reflecting members 28b and 28c is converted into illumination light by the second wavelength conversion element 22 and emitted through the optical member 24 to the outside of the lamp 20b.

Specifically, the laser light or LED light emitted from the laser light sources 41b and 41c is composed of collimator lenses 51b and 51c, dichroic mirrors 53b and 53c, first condenser lenses 54b and 54c, and optical fibers 30b and 30c. pass through the optical paths L11 and L12 to reach the first wavelength conversion elements 21b and 21c. In the first wavelength conversion elements 21b and 21c, part of the laser light or LED light is converted into detection light. Among laser light and LED light, blue light passes through the first wavelength conversion elements 21b and 21c, passes through the reflection members 28b and 28c, and is converted into illumination light by the second wavelength conversion element 22. Through the optical member 24, the light is emitted to the outside of the lamp 20b. On the other hand, the detection light passes through optical paths L21 and L22 composed of optical fibers 30b and 30c, first condenser lenses 54b and 54c, dichroic mirrors 53b and 53c, and second condenser lenses 56b and 56c, and reaches the light receiving section. 42b, 42c are reached. The control unit 49 detects disconnection of the optical fibers 30b, 30c based on the detection results of the light receiving units 42b, 42c.

Thus, the illumination device 10B includes the lamp 20b holding the second wavelength conversion element 22, and the connector portions 31b and 31c detachably attached to the lamp 20b. Fibers 30b, 30c, first wavelength conversion elements 21b, 21c, and dichroic mirrors 23b, 23c are integrally assembled.

Therefore, since the detection light is generated by the first wavelength conversion elements 21b and 21c in the connector portions 31b and 31c, disconnection of the optical fibers 30b and 30c can be detected even before the connector portions 31b and 31c are attached to the lamp 20b. It becomes possible.

Here, in the above-described embodiment, the case where the second light emission mode is switched to the first light emission mode after a predetermined time has elapsed when disconnection of the optical fiber 30 is not detected has been exemplified. In this modified example, laser light is emitted from the connector portions 31b and 31c when the second light emission mode is switched to the first light emission mode while the connector portions 31b and 31c are removed from the lamp 20b. Therefore, disconnection detection is performed with the connector portions 31b and 31c removed, and as a result, if disconnection is not detected, the control unit 49 causes switching from the second emission mode to the first emission mode. Instead, a notification unit (not shown) may be controlled to notify that the system is normal.

A plurality of pairs of the optical fibers 30b, 30c and the first wavelength conversion elements 21b, 21c are provided in a one-to-one relationship.

As a result, the detection light can be guided through the respective optical fibers 30b, 30c, so that disconnection of the respective optical fibers 30b, 30c can be determined individually.

In addition, in this modified example, one light receiving section 42b, 42c is provided for each of the first wavelength conversion elements 21b, 21c. has exemplified the case of detecting disconnection of each of the optical fibers 30b and 30c. However, it is also possible to individually detect detection light from a plurality of first wavelength conversion elements with one light receiving section. Specifically, the wavelength band of the detection light converted by each first wavelength conversion element may be set to be different, and the received light amount (intensity) of each detection light in the different wavelength band may be detected by one light receiving unit. As a result, the light receiving section can be shared, and the number of parts can be reduced.

[others]
As described above, the illumination device according to the present invention has been described based on the above-described embodiment and modifications, but the present invention is not limited to the above-described embodiment and modifications.

In the lighting device 10 according to the above-described embodiment, the case where the laser light, the LED light, and the detection light are guided by one optical fiber 30 is exemplified. However, the illumination device may be provided with a first optical fiber for laser light and LED light and a second optical fiber for detection light. In this case, the first optical fiber and the second optical fiber should be integrated as one transmission cable. This makes it possible to detect disconnection of the transmission cable (disconnection of one of the first optical fiber and the second optical fiber).

Further, an optical member for condensing the detection light may be arranged between the first wavelength conversion element 21 and the other end surface of the optical fiber 30 in the lamp 20 . Thereby, the emission intensity of the detection light incident on the optical fiber 30 can be increased. Therefore, the S/N ratio in the light receiving section 42 can be increased. Examples of the optical member for condensing the detection light include a condensing lens and a light pipe.

Further, in the above-described embodiment, the laser light source 41 that emits light whose emission peak wavelength is included in the blue wavelength band was exemplified. However, a laser light source that emits light having an emission peak wavelength in another wavelength band may also be used. Other wavelength bands include a violet wavelength band and an ultraviolet wavelength band. In this case, the dichroic mirror on the light source device side and the dichroic mirror on the lamp side are compatible with light in other wavelength bands.

Moreover, in the above-described embodiment, the case where the illumination device 10 illuminates the inside of the show window 301 has been exemplified. However, since the lamp 20 of the lighting device 10 is not provided with an electrical component, it is also possible to arrange the lamp 20 underwater and use it as an underwater illumination.

In addition, a form obtained by applying various modifications to the embodiment that a person skilled in the art can think of, and a form realized by arbitrarily combining the constituent elements and functions of each embodiment within the scope of the present invention. is also included in the present invention.

10, 10B lighting devices 20, 20b lamps 21, 21b, 21c first wavelength conversion element 22 second wavelength conversion elements 23, 23b, 23c dichroic mirror (filter)
30, 30b, 30c optical fibers 41, 41b, 41c laser light sources 42, 42b, 42c light receiving unit 49 control unit (disconnection detection unit)

Claims (5)

a laser light source;
an optical fiber that guides the light emitted by the laser light source;
a first wavelength conversion element that converts part of the light guided by the optical fiber into detection light of a different wavelength band;
a light receiving unit that receives the detection light guided by the optical fiber in a direction opposite to the light;
a disconnection detection unit that detects disconnection of the optical fiber based on the detection result of the light receiving unit;
a second wavelength conversion element that converts part of the light guided by the optical fiber into illumination light of a different wavelength band;
is arranged between the first wavelength conversion element and the second wavelength conversion element, extracts light including an emission peak wavelength of the light from the light , and converts the illumination light emitted by the second wavelength conversion element A lighting device with a shielding filter. a lighting fixture that holds the second wavelength conversion element;
a connector portion detachably attached to the lamp,
The lighting device according to claim 1, wherein the optical fiber, the first wavelength conversion element, and the filter are integrally attached to the connector portion. The lighting device according to claim 1 or 2, wherein a plurality of sets of the optical fiber and the first wavelength conversion element are provided in a one-to-one relationship. The lighting device according to any one of claims 1 to 3, wherein the disconnection detection section prohibits light emission from the laser light source when disconnection of the optical fiber is detected. The illumination device according to any one of claims 1 to 4, wherein the laser light source is switchable between a first light and a second light having an emission intensity lower than that of the first light, as the light.

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