WO2023132162A1

WO2023132162A1 - Light source device, and anomaly determination system

Info

Publication number: WO2023132162A1
Application number: PCT/JP2022/044050
Authority: WO
Inventors: 省吾茂手木; 真太郎林; 史也八木; 俊明竹中
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-01-06
Filing date: 2022-11-29
Publication date: 2023-07-13
Also published as: JP2023100558A

Abstract

The present disclosure addresses the problem of providing: a light source device capable of improving the accuracy in determining anomaly in a wavelength conversion member; and an anomaly determination system. This light source device (4) comprises: a first light source (41); a wavelength conversion member (43); a second light source (42); and an optical sensor (44). The first light source (41) emits first light (L11). The wavelength conversion member (43) has: a first surface (431) through which the first light (L11) enters; and a second surface (432) that emits mixed light (L10) including the first light (L11) and wavelength-converted light (L12) obtained by subjecting the first light (L11) to a wavelength conversion process. The second light source (42) emits second light (L2) having a detection wavelength that is different from the excitation wavelength and fluorescent wavelength of the wavelength conversion member (43). The optical sensor (44) has a peak sensitivity at the detection wavelength. The optical sensor (44) also receives the second light (L2) reflected from the wavelength conversion member (43).

Description

Light source device and abnormality determination system

The present disclosure relates to a light source device and an abnormality determination system.

Patent Document 1 discloses a technique for detecting the presence or absence of an abnormality in each of two or more light source devices in a light source system having two or more light source devices.

Specifically, the light source system includes a first excitation light source, a second excitation light source, a first phosphor unit, a second phosphor unit, a spectroscopic sensor, and a failure detector.

The first excitation light emitted from the first excitation light source is guided to the first phosphor unit, and the first phosphor unit converts the wavelength of part of the first excitation light into first fluorescence together with the first excitation light. inject. The second excitation light emitted from the second excitation light source is guided to the second phosphor unit, and the second phosphor unit emits second fluorescence obtained by wavelength-converting part of the second excitation light together with the second excitation light. inject.

The spectroscopic sensor receives first excitation light and first fluorescence emitted from the first phosphor unit, and second excitation light and second fluorescence emitted from the second phosphor unit. The spectroscopic sensor outputs the light intensity of each of the first excitation light, the first fluorescence, the second excitation light, and the second fluorescence to the failure detector.

The failure detection unit identifies which of the first excitation light source, the second excitation light source, the first phosphor unit, and the second phosphor unit has a failure based on the input from the spectroscopic sensor.

In Patent Document 1, an abnormality in a wavelength conversion member such as a phosphor unit is determined.

JP 2013-197033 A

An object of the present disclosure is to provide a light source device and an abnormality determination system capable of improving the accuracy of abnormality determination of wavelength conversion members.

A light source device according to an aspect of the present disclosure includes a first light source, a wavelength conversion member, a second light source, and an optical sensor. The first light source emits first light. The wavelength conversion member has a first surface on which the first light is incident, and a second surface from which the first light and mixed-color light including wavelength-converted light obtained by wavelength-converting the first light are emitted. A said 2nd light source emits the 2nd light of the wavelength for a detection different from the excitation wavelength and fluorescence wavelength of the said wavelength conversion member. The photosensor has a peak sensitivity at the detection wavelength. The optical sensor receives the second light reflected by the wavelength conversion member or the second light transmitted through the wavelength conversion member.

An abnormality determination system according to an aspect of the present disclosure includes the light source device described above and an abnormality determination unit that determines an abnormality of the wavelength conversion member based on the amount of the second light received by the optical sensor.

FIG. 1 is a block diagram showing a lighting system including a light source device and an abnormality determination system according to an embodiment. FIG. 2 is a configuration diagram showing the light source device of the same. FIG. 3 is a graph showing the optical spectrum of the phosphor of the light source device; FIG. 4 is a configuration diagram showing a light source device of a first modified example of the same. FIG. 5 is a configuration diagram showing a light source device of a second modified example of the same. FIG. 6 is a configuration diagram showing a light source device according to a third modified example of the same. FIG. 7 is a configuration diagram showing a light source device according to a fourth modified example of the same. FIG. 8 is a configuration diagram showing a light source device of a fifth modified example of the same. FIG. 9 is a block diagram showing a light source device according to a sixth modification of the same. FIG. 10 is a graph showing an optical spectrum of another phosphor of the light source device;

The following embodiments generally relate to light source devices and abnormality determination systems. More specifically, the present disclosure relates to a light source device including a wavelength conversion member and an abnormality determination system.

A light source device and an abnormality determination system according to an embodiment will be described in detail below with reference to FIGS. 1 to 10. FIG. However, each drawing described in the following embodiments is a schematic drawing, and the ratio of the size and thickness of each component does not necessarily reflect the actual dimensional ratio. Note that the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications can be made according to design and the like as long as the effects of the present disclosure can be achieved.

(embodiment)
(1) Outline of Lighting System The light source device and the abnormality determination system according to the embodiment are used in a lighting system. The lighting system is used, for example, in an endoscope for observing the inside of a human body, or an industrial microscope for observing metals, cells, and the like. However, the application of the lighting system is not limited to a specific application, and may be used for applications other than endoscopes and industrial microscopes.

FIG. 1 shows a block configuration of the lighting system 1. The lighting system 1 includes a control circuit 2 , a first power supply device 31 , a second power supply device 32 , and a light source device 4 . The light source device 4 includes a first light source 41 , a second light source 42 , a wavelength conversion member 43 and an optical sensor 44 . The first light source 41 is lit by being supplied with the first lighting power from the first power supply device 31 . The second light source 42 is lit by being supplied with the second lighting power from the second power supply device 32 . The control circuit 2 controls lighting, extinguishing, and dimming of the first light source 41 and the second light source 42 by controlling the first power supply device 31 and the second power supply device 32 .

Each part of the light source device 4 is configured as shown in FIG.

The first light source 41 emits the first light L11. The wavelength conversion member 43 has a first surface 431 and a second surface 432 . The first light L11 is incident on the first surface 431 . Mixed-color light L10 is emitted from the second surface 432 . The mixed-color light L10 includes a first light L11 and a wavelength-converted light L12 obtained by subjecting the first light L11 to wavelength conversion processing.

The second light source 42 emits the second light L2. The detection wavelength λ2, which is the wavelength of the second light L2, differs from the excitation wavelength λ3 and fluorescence wavelength λ4 of the wavelength conversion member 43 .

The optical sensor 44 has a peak sensitivity at the detection wavelength λ2. Then, the optical sensor 44 receives the second light L2 reflected by the wavelength conversion member 43 or the second light L2 transmitted through the wavelength conversion member 43 (the optical sensor 44 in FIG. receive the second light L2).

The light source device 4 having the above configuration can improve the accuracy of abnormality determination of the wavelength conversion member 43 .

In addition, as shown in FIG. 1, the control circuit 2 includes an abnormality determination section 22. The light source device 4 and the abnormality determination section 22 are included in the abnormality determination system 5 . That is, the abnormality determination system 5 includes the light source device 4 and the abnormality determination section 22 . The abnormality determination system 5 having such a configuration can improve the accuracy of abnormality determination of the wavelength conversion member 43 .

(2) Details (2.1) Wavelength Conversion Member As shown in FIG. 2, the wavelength conversion member 43 is provided with a substrate 43a and a phosphor 43b. It has a laminated structure. The outer surface 430 of the wavelength conversion member 43 includes a first surface 431 and a second surface 432 facing each other in the thickness direction of the wavelength conversion member 43 . Each of the first surface 431 and the second surface 432 is a plane.

The substrate 43a has a plate shape. In the wavelength conversion member 43 of FIG. 2 , one of the pair of surfaces facing each other in the thickness direction of the substrate 43 a is the first surface 431 and the other is the second surface 432 .

The phosphor 43b is a phosphor layer positioned between the first surface 431 and the second surface 432 inside the substrate 43a. In FIG. 2, the phosphor 43b is formed in layers at a position closer to the second surface 432 than the first surface 431 is. The phosphor 43b is a YAG (Yttrium/Aluminum/Garnet) phosphor, a CASN (Cousin) phosphor, a LuAG (lutetium/Aluminum/Garnet) phosphor, or a Garnet phosphor. For example, a YAG phosphor is a yellow phosphor, a CASN phosphor is a red phosphor, and a LuAG phosphor and a garnet phosphor are green phosphors.

The excitation wavelength of the phosphor 43b is λ3, and the fluorescence wavelength of the phosphor 43b is λ4. The fluorescence wavelength λ4 is longer than the excitation wavelength λ3. That is, when the phosphor 43b is irradiated with incident light containing a component of the excitation wavelength λ3, it absorbs part of the incident light and generates wavelength-converted light with a fluorescence wavelength λ4 longer than that of the incident light. Then, the phosphor 43b emits mixed-color light in which part of the incident light not absorbed by the phosphor 43b is mixed with the wavelength-converted light.

FIG. 3 shows an optical spectrum SP1 as an example of the optical spectrum (intensity distribution) of the phosphor 43b. FIG. 3 shows an optical spectrum when the phosphor 43b is excited by incident light of the excitation wavelength λ3. In this optical spectrum SP1, the wavelength at which the intensity reaches the maximum value is the fluorescence wavelength λ4.

(2.2) First Light Source The first light source 41 includes a first laser element such as a laser diode. The number of first laser elements included in the first light source 41 is one or more. The electrical connection relationship of the plurality of first laser elements may be any of series connection, parallel connection, and combination of series connection and parallel connection.

The first light source 41 lights up when the first lighting power is supplied from the first power supply device 31, and emits laser light as the first light L11. Assuming that the wavelength of the first light L11 is an illumination wavelength λ1, the illumination wavelength λ1 is set equal to or near the excitation wavelength λ3 (see FIG. 3). The illumination wavelength λ1 is the peak wavelength in the optical spectrum of the first light L11.

As shown in FIG. 2, the first light source 41 is arranged on the side of the first surface 431 with respect to the wavelength conversion member 43 and faces the first surface 431 . The optical axis of the first light source 41 extends along the normal line of the first surface 431 . Therefore, the first light L11 emitted by the first light source 41 enters the first surface 431 from the normal direction of the first surface 431 . Hereinafter, the area on the first surface 431 where the first light L11 is incident is referred to as an incident area W1. Note that the irradiation range of the first light L11 can be adjusted by scanning the optical axis of the first light source 41 .

The first light L11 incident on the first surface 431 passes through the substrate 43a and irradiates the phosphor 43b. The phosphor 43b absorbs part of the irradiated first light L11 and generates wavelength-converted light L12 of fluorescence wavelength λ4. A part of the first light L11 that is not absorbed by the phosphor 43b and the wavelength-converted light L12 reach the second surface 432 through the substrate 43a. The second surface 432 emits mixed-color light L10 in which a portion of the first light L11 that has not been absorbed by the phosphor 43b and the wavelength-converted light L12 are mixed. For example, if the first light L11 is blue laser light and the phosphor 43b is a yellow phosphor, the mixed color light L10 is white light. Hereinafter, the area from which the mixed color light L10 is emitted on the second surface 432 will be referred to as an emission area W2.

(2.3) Second Light Source The second light source 42 includes a second laser element such as a laser diode. The number of second laser elements provided in the second light source 42 is one or plural. The electrical connection relationship of the plurality of second laser elements may be any of serial connection, parallel connection, and connection combining serial connection and parallel connection.

The second light source 42 lights up when the second lighting power is supplied from the second power supply device 32, and emits laser light as the second light L2. Assuming that the wavelength of the second light L2 is the detection wavelength λ2, the detection wavelength λ2 is different from the excitation wavelength λ3 and the fluorescence wavelength λ4. The detection wavelength λ2 is the peak wavelength in the optical spectrum of the second light L2. Further, the detection wavelength λ2 is preferably different from not only the excitation wavelength λ3 and the fluorescence wavelength λ4, but also the illumination wavelength λ1.

FIG. 3 shows a detection wavelength λ21 or a detection wavelength λ22 as a specific example of the detection wavelength λ2. The detection wavelength λ2 may be either the detection wavelength λ21 or λ22.

The detection wavelength λ21 is longer than the excitation wavelength λ3 (illumination wavelength λ1) and shorter than the fluorescence wavelength λ4. That is, the detection wavelength λ21 is the wavelength of the valley (the valley between the excitation wavelength λ3 and the fluorescence wavelength λ4) that is lower than the intensity of each of the excitation wavelength λ3 and the fluorescence wavelength λ4 in the optical spectrum SP1 of the phosphor 43b. is.

The detection wavelength λ22 is longer than the excitation wavelength λ3 (illumination wavelength λ1) and fluorescence wavelength λ4. Specifically, the detection wavelength λ22 is preferably an infrared wavelength longer than 1000 nm and shorter than 1 mm. In this case, the detection wavelength λ22 is a wavelength of infrared light that has lower intensity than the intensity of each of the excitation wavelength λ3 and the fluorescence wavelength λ4 in the optical spectrum SP1 of the phosphor 43b.

As shown in FIG. 2, the second light source 42 is arranged on the side of the first surface 431 with respect to the wavelength conversion member 43 and faces the first surface 431 . The optical axis of the second light source 42 extends in a direction intersecting the normal line of the first surface 431 so as to pass through the incident area W1 of the first surface 431 . Therefore, the second light L2 emitted by the second light source 42 obliquely enters the first surface 431 (incidence area W1). Part of the second light L2 obliquely incident on the first surface 431 (incident area W1) is reflected by the first surface 431 (incident area W1). Note that the irradiation range of the second light L2 can be adjusted by scanning the optical axis of the second light source 42 .

(2.4) Photosensor The photosensor 44 includes a light-receiving element such as a photodiode, a phototransistor, a solar cell, or a CdS cell, and has peak sensitivity at the detection wavelength λ2.

As shown in FIG. 2, the optical sensor 44 is arranged on the side of the first surface 431 with respect to the wavelength conversion member 43. Among the second light L2 reflected by the first surface 431, at least in the incident region W1 It receives the reflected second light L2. The optical sensor 44 outputs a detection signal to the control circuit 2 according to the received amount of the second light L2. In this case, the light source device 4 can determine abnormality in the vicinity of the first surface 431 (incidence region W1) of the wavelength conversion member 43 . The optical sensor 44 can minimize the amount of the second light L2 directly reaching the optical sensor 44 from the second light source 42 and can increase the amount of the second light L2 reflected by the wavelength conversion member 43 as much as possible. It should preferably be placed in a position where it can be

(2.5) Power Supply Device The first power supply device 31 can adjust lighting, extinguishing, and dimming of the first light source 41 by adjusting the first lighting power supplied to the first light source 41 . For example, the first power supply device 31 adjusts at least one of current and voltage supplied to the first light source 41 .

The second power supply device 32 can adjust the lighting, extinguishing, and dimming of the second light source 42 by adjusting the second lighting power supplied to the second light source 42 . For example, the second power supply 32 adjusts at least one of current and voltage supplied to the second light source 42 .

(2.6) Control Circuit The control circuit 2 preferably comprises a computer system. That is, in the control circuit 2, a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit) reads out and executes a program stored in a memory, thereby performing part or all of the functions of the control circuit 2. is realized. The control circuit 2 has a processor that operates according to a program as a main hardware configuration.

Any type of processor does not matter as long as it can implement functions by executing programs. The processor is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or LSI (Large Scale Integration). Here, they are called ICs and LSIs, but the names change depending on the degree of integration, and may be called system LSIs, VLSIs (Very Large Scale Integration), or ULSIs (Ultra Large Scale Integration). A field programmable gate array (FPGA), which is programmed after the LSI is manufactured, or a reconfigurable logic device capable of reconfiguring the connection relationships inside the LSI or setting up circuit partitions inside the LSI for the same purpose. can be done. A plurality of electronic circuits may be integrated on one chip or may be provided on a plurality of chips. A plurality of chips may be collectively arranged or distributed.

The control circuit 2 includes a lighting control section 21 and an abnormality determination section 22, as shown in FIG.

The lighting control unit 21 controls lighting, extinguishing, and dimming of the first light source 41 and the second light source 42 by controlling the first power supply device 31 and the second power supply device 32 .

The abnormality determination unit 22 receives the detection signal output by the optical sensor 44 . The detection signal is a signal corresponding to the amount of the second light L2 received by the optical sensor 44 , and the abnormality determination unit 22 can detect the amount of the second light L2 received by the optical sensor 44 . Then, the abnormality determination unit 22 determines abnormality of the wavelength conversion member 43 based on the amount of the second light L2 received by the optical sensor 44 .

(2.7) Abnormality determination processing Abnormality determination processing in the lighting system 1 will be described below. The light source device 4 particularly determines an abnormality on the first surface 431 side as the abnormality of the wavelength conversion member 43 .

The lighting control unit 21 turns on the first light source 41 to generate the mixed color light L10. The mixed color light L10 is applied to an illumination target. When the lighting system 1 is used in an endoscope, the illumination target is the inside of the human body. When the lighting system 1 is used in an industrial microscope, the object to be illuminated is a metal, a cell, or the like, which is an object to be observed.

Then, the lighting control unit 21 controls the second power supply device 32 to light the second light source 42 when receiving an inspection instruction from the user or periodically. When the second light source 42 is turned on, the second light source 42 emits the second light L2. The second light L2 emitted by the second light source 42 is incident on the first surface 431 (incidence area W1), and part of the second light L2 incident on the first surface 431 (incidence area W1) is the first surface 431 (incident area W1). It is reflected at the incident area W1). At this time, the amount of the second light L2 reflected by the first surface 431 (incidence area W1) varies depending on the state of the wavelength conversion member 43. FIG.

For example, if the amount of the first light L11 emitted by the first light source 41 becomes excessive, the temperature of the incident region W1 of the wavelength conversion member 43 and its periphery (hereinafter referred to as the vicinity of the incident region W1) rises excessively. As a result, stress is generated in the substrate 43a due to the thermal load in the vicinity of the incident region W1, which may cause an abnormality such as cracking or deformation of the substrate 43a. When cracking or deformation (abnormality) occurs in the vicinity of the incident region W1, the amount of reflection of the second light L2 in the incident region W1 decreases compared to normal (when the substrate 43a is neither cracked nor deformed).

Also, when the amount of the first light L11 emitted by the first light source 41 becomes excessive, the temperature near the incident region W1 of the wavelength conversion member 43 rises excessively. As a result, there is a possibility that blackening (abnormality) occurs in which the substrate 43a near the incident region W1 is discolored black. In the blackened area of the substrate 43a, the amount of reflection of the second light L2 in the incident area W1 is smaller than in the normal state (when the substrate 43a is not blackened).

Therefore, when an abnormality such as cracking, deformation, and blackening occurs in the vicinity of the incident area W1, the amount of the second light L2 received by the optical sensor 44 is reduced from that in normal times.

Therefore, the abnormality determination unit 22 monitors the amount of the second light L2 received by the optical sensor 44 based on the detection signal of the optical sensor 44, and if the amount of received light is less than the threshold value, the wavelength conversion member 43 is "abnormal". I judge. Further, the abnormality determination unit 22 determines that the wavelength conversion member 43 is “no abnormality” if the amount of received light is equal to or greater than the threshold value. In this embodiment, the abnormality determination unit 22 can particularly determine an abnormality near the incident region W1 of the wavelength conversion member 43 .

The lighting control unit 21 adjusts the first lighting power supplied to the first light source 41 by controlling the first power supply device 31 based on the determination result of the abnormality determination unit 22 . For example, the lighting control unit 21 sets the first lighting power to zero and turns off the first light source 41 if the determination result is “abnormal”. Further, if the determination result is “abnormal”, the lighting control section 21 may reduce the first lighting power to reduce the amount of the first light L11 emitted by the first light source 41 . If the determination result is "no abnormality", the lighting control unit 21 sets the first lighting power to the steady state value, and causes the first light source 41 to light steadily. The steady value of the first lighting power may be either a fixed value or a variable value according to the user's operation.

(2.8) Advantages The optical sensor 44 has peak sensitivity at the detection wavelength λ2 of the second light L2. Also, the detection wavelength λ2 is different from the excitation wavelength λ3 and the fluorescence wavelength λ4. Therefore, the optical sensor 44 can efficiently receive the second light L2 reflected by the wavelength converting member 43, and can suppress receiving other light (eg, the first light L11 and the mixed color light L10). As a result, the light source device 4 can improve the accuracy of abnormality determination of the wavelength conversion member 43 .

Further, if the detection wavelength λ2 is the detection wavelength λ22 (see FIG. 3), which is an infrared wavelength, the second light L2 received by the optical sensor 44 contains the temperature (heat) of the incident region W1 of the first surface 431. Contains information. In this case, the abnormality determination unit 22 detects the temperature of the incident area W1 based on the detection signal output from the optical sensor 44, and can determine that there is an "abnormality" when the detected temperature is higher than the upper limit temperature. Further, if the detected temperature is equal to or lower than the upper limit temperature, the abnormality determination unit 22 can determine that there is no abnormality. That is, the light source device 4 can determine temperature abnormality such as overheating of the wavelength conversion member 43 .

(3) First Modification FIG. 4 shows a light source device 4A as a first modification of the light source device. In addition, the same code|symbol is attached|subjected to the structure similar to the light source device 4 shown in FIG. 2, and description is abbreviate|omitted.

The light source device 4A is obtained by providing an incident side optical film (thin film) 43c and an emission side optical film (thin film) 43d to the light source device 4 (see FIG. 2) of the above embodiment. That is, in addition to the configuration of the light source device 4, the light source device 4A further includes an incident side optical film 43c and an exit side optical film 43d. The incident-side optical film 43c is formed on one of a pair of surfaces facing each other in the thickness direction of the substrate 43a. The exit-side optical film 43d is formed on the other of a pair of surfaces facing each other in the thickness direction of the substrate 43a. In this case, the surface of the incident-side optical film 43c constitutes the first surface 431, and the surface of the output-side optical film 43d constitutes the second surface 432. FIG.

The incident-side optical film 43c is a dielectric multilayer film such as TiO ₂ , Ta ₂ O ₃ , SiO ₂ , or MgF ₂ , and has a function of transmitting the first light L11 and reflecting the second light L2. The incident-side optical film 43c preferably has a function of reflecting light of the detection wavelength λ2, which is the peak wavelength of the second light L2.

The exit-side optical film 43d is a dielectric multilayer film such as TiO ₂ , Ta ₂ O ₃ , SiO ₂ , or MgF ₂ , and has a function of transmitting the first light L11 and reflecting the second light L2. Furthermore, the output-side optical film 43d also transmits the wavelength-converted light L12. That is, the exit-side optical film 43d transmits the mixed-color light L10. The exit-side optical film 43d preferably has a function of reflecting light of the detection wavelength λ2, which is the peak wavelength of the second light L2.

The first light L11 emitted by the first light source 41 passes through the incident-side optical film 43c and the substrate 43a, and is irradiated onto the phosphor 43b. Mixed-color light L10 generated by irradiating the phosphor 43b with the first light L11 passes through the substrate 43a and the exit-side optical film 43d and is irradiated from the second surface 432 onto the illumination target.

Also, the second light L2 emitted by the second light source 42 is reflected by the incident-side optical film 43c that constitutes the first surface 431 . The amount of second light L2 reflected by the incident-side optical film 43c is greater than the amount of reflection by the substrate 43a (see FIG. 2). That is, the amount of the second light L2 received by the optical sensor 44 of the light source device 4A is greater than the amount of the second light L2 received by the optical sensor 44 of the light source device 4 (see FIG. 2). Therefore, since the sensitivity of abnormality detection by the abnormality determination unit 22 is improved, the accuracy of abnormality determination is improved.

Also, part of the second light L2 emitted by the second light source 42 passes through the incident-side optical film 43c and enters the substrate 43a. The second light L2 that has entered the substrate 43a passes through the substrate 43a and the phosphor 43b and reaches the emission-side optical film 43d. The second light L2 that has reached the output-side optical film 43d is reflected by the output-side optical film 43d, and is less likely to be irradiated from the second surface 432 onto the illumination target. Therefore, it is possible to suppress the amount of the second light L2 that irradiates the illumination target while ensuring the amount of the mixed color light L10 that illuminates the illumination target. That is, it is possible to improve the lighting environment in the lighting target.

(4) Second Modification FIG. 5 shows a light source device 4B as a second modification of the light source device. The light source device 4B particularly determines an abnormality on the second surface 432 side as the abnormality of the wavelength conversion member 43 . In addition, the same code|symbol is attached|subjected to the structure similar to the light source device 4 shown in FIG. 2, and description is abbreviate|omitted.

In the light source device 4B, the second light source 42 is arranged on the second surface 432 side with respect to the wavelength conversion member 43 and faces the second surface 432 . The optical axis of the second light source 42 extends in a direction intersecting the normal line of the second surface 432 so as to pass through the emission region W2 of the second surface 432 . Therefore, the second light L2 emitted by the second light source 42 obliquely enters the second surface 432 (the emission area W2). Part of the second light L2 obliquely incident on the second surface 432 (the emission area W2) is reflected by the second surface 432 (the emission area W2).

The optical sensor 44 is arranged on the side of the second surface 432 with respect to the wavelength conversion member 43, and detects at least the second light L2 reflected by the emission region W2 among the second light L2 reflected by the second surface 432. receive light. The optical sensor 44 outputs a detection signal to the control circuit 2 according to the received amount of the second light L2. In this case, the light source device 4B can determine abnormality in the vicinity of the second surface 432 (the emission area W2) of the wavelength conversion member 43 . The optical sensor 44 can minimize the amount of the second light L2 directly reaching the optical sensor 44 from the second light source 42 and can increase the amount of the second light L2 reflected by the wavelength conversion member 43 as much as possible. It should preferably be placed in a position where it can be

The amount of the second light L2 reflected by the second surface 432 (the emission area W2) varies depending on the state of the wavelength conversion member 43.

For example, when the amount of the first light L11 emitted by the first light source 41 becomes excessive, the temperature of the emission region W2 of the wavelength conversion member 43 and its surroundings (hereinafter referred to as the vicinity of the emission region W2) rises excessively. As a result, stress is generated in the substrate 43a due to the thermal load in the vicinity of the emission region W2, and there is a possibility that the substrate 43a may crack or deform. When cracking or deformation (abnormality) occurs in the vicinity of the emission region W2, the amount of reflection of the second light L2 in the emission region W2 is reduced compared to normal (when the substrate 43a is neither cracked nor deformed).

Also, when the amount of the first light L11 emitted by the first light source 41 becomes excessive, the temperature in the vicinity of the emission region W2 of the wavelength conversion member 43 rises excessively. As a result, blackening (abnormality) in which the substrate 43a near the emission region W2 is discolored black may occur. In the blackened area of the substrate 43a, the amount of reflection of the second light L2 in the emission area W2 is smaller than in the normal state (when the substrate 43a is not blackened).

Therefore, when an abnormality such as cracking, deformation, and blackening occurs in the vicinity of the emission area W2, the amount of the second light L2 received by the optical sensor 44 is reduced from that in the normal state.

Therefore, the abnormality determination unit 22 monitors the amount of the second light L2 received by the optical sensor 44 based on the detection signal of the optical sensor 44, and if the amount of received light is less than the threshold value, the wavelength conversion member 43 is "abnormal". I judge. Further, the abnormality determination unit 22 determines that the wavelength conversion member 43 is "abnormal" if the amount of received light is equal to or greater than the threshold. In this embodiment, the abnormality determination unit 22 can particularly determine an abnormality near the emission region W2 of the wavelength conversion member 43 .

That is, the light source device 4 can determine whether the wavelength conversion member 43 is abnormal.

(5) Third Modification FIG. 6 shows a light source device 4C as a third modification of the light source device. In addition, the same code|symbol is attached|subjected to the structure similar to the light source device 4B shown in FIG. 5, and description is abbreviate|omitted.

A light source device 4C is obtained by providing an exit-side optical film 43d in the light source device 4B (see FIG. 5) of the second modification described above. That is, the light source device 4C further includes an exit-side optical film 43d in addition to the configuration of the light source device 4B. One of the pair of surfaces facing the thickness direction of the substrate 43a constitutes the first surface 431, and the exit-side optical film 43d is formed on the other of the pair of surfaces facing the thickness direction of the substrate 43a. In this case, the surface of the exit-side optical film 43 d forms the second surface 432 .

The first light L11 emitted by the first light source 41 passes through the substrate 43a and irradiates the phosphor 43b. Mixed-color light L10 generated by irradiating the phosphor 43b with the first light L11 passes through the substrate 43a and the exit-side optical film 43d and is irradiated from the second surface 432 onto the illumination target.

In addition, the second light L2 emitted by the second light source 42 is reflected by the output-side optical film 43d forming the second surface 432 . The amount of second light L2 reflected by the output-side optical film 43d is greater than the amount of reflection by the substrate 43a (see FIG. 5). That is, the amount of the second light L2 received by the optical sensor 44 of the light source device 4C is greater than the amount of the second light L2 received by the optical sensor 44 of the light source device 4B (see FIG. 5). Therefore, since the sensitivity of abnormality detection by the abnormality determination unit 22 is improved, the accuracy of abnormality determination is improved.

(6) Fourth Modification FIG. 7 shows a light source device 4D as a fourth modification of the light source device. The light source device 4D particularly determines an abnormality on the second surface 432 side as the abnormality of the wavelength conversion member 43 . In addition, the same code|symbol is attached|subjected to the structure similar to the light source device 4 shown in FIG. 2, and description is abbreviate|omitted.

For example, if the amount of the first light L11 emitted by the first light source 41 becomes excessive, cracking or deformation (abnormality) occurs in the vicinity of the emission region W2 of the substrate 43a, or blackening (abnormality) occurs in the vicinity of the emission region W2. ) occurs.

Therefore, in the light source device 4D, the optical sensor 44 is configured to receive the second light L2 transmitted through the region of the wavelength conversion member 43 through which the first light L11 passes. Specifically, in the light source device 4D, the second light source 42 is arranged on the second surface 432 side with respect to the wavelength conversion member 43 and faces the second surface 432 . The optical axis of the second light source 42 extends in a direction intersecting the normal line of the second surface 432 so as to pass through the emission region W2 of the second surface 432 . Therefore, the second light L2 emitted by the second light source 42 obliquely enters the second surface 432 (the emission area W2). The second light L2 obliquely incident on the second surface 432 (output region W2) enters the substrate 43a from the second surface 432 (output region W2). The second light L2 incident on the substrate 43a from the second surface 432 (the emission area W2) passes through the phosphor 43b and the substrate 43a and is emitted from the first surface 431. FIG.

The optical sensor 44 is arranged on the first surface 431 side with respect to the wavelength conversion member 43 and receives the second light L2 transmitted through the wavelength conversion member 43 . The optical sensor 44 outputs a detection signal to the control circuit 2 according to the received amount of the second light L2. In this case, the light source device 4D can determine abnormality inside the wavelength conversion member 43 as well as the second surface 432 (the emission area W2 ) of the wavelength conversion member 43 . It is preferable that the optical sensor 44 be arranged at a position where the received amount of the second light L2 transmitted through the wavelength conversion member 43 can be maximized.

Then, the lighting control unit 21 controls the second power supply device 32 to light the second light source 42 when receiving an inspection instruction from the user or periodically. When the second light source 42 is turned on, the second light source 42 emits the second light L2. The second light L2 emitted by the second light source 42 is incident on the second surface 432 (output area W2), and the second light L2 incident on the second surface 432 (output area W2) enters the substrate 43a. At this time, the amount of the second light L2 passing through the substrate 43 a and emitted from the first surface 431 varies depending on the state of the wavelength conversion member 43 .

When an abnormality (cracking, deformation, blackening, etc.) occurs in the wavelength conversion member 43, the output amount of the second light L2 from the first surface 431 is normal (when the wavelength conversion member 43 does not have an abnormality). ). Therefore, when an abnormality occurs in the wavelength conversion member 43, the amount of the second light L2 received by the optical sensor 44 is also reduced from that in the normal state.

Therefore, the abnormality determination unit 22 monitors the amount of the second light L2 received by the optical sensor 44 based on the detection signal of the optical sensor 44, and if the amount of received light is less than the threshold value, the wavelength conversion member 43 is "abnormal". I judge. Further, if the amount of received light is equal to or greater than the threshold value, the abnormality determination unit 22 determines that the wavelength conversion member 43 is “no abnormality”.

(7) Fifth Modification FIG. 8 shows a light source device 4E as a fifth modification of the light source device. In addition, the same code|symbol is attached|subjected to the structure similar to the light source device 4D shown in FIG. 7, and description is abbreviate|omitted.

The light source device 4E is obtained by providing a silicone film 43e to the light source device 4D (see FIG. 7) of the above-described fourth modification. That is, the light source device 4E further includes a silicone film (thin film) 43e in addition to the configuration of the light source device 4D. One of the pair of surfaces facing the thickness direction of the substrate 43a constitutes the first surface 431, and the silicone film 43e is formed on the other of the pair of surfaces facing the thickness direction of the substrate 43a. In this case, the surface of the silicone film 43 e constitutes the second surface 432 .

The optical transmittance of the silicone film 43e changes depending on the temperature of the silicone film 43e. Specifically, the higher the temperature of the silicone film 43e, the lower the optical transmittance of the silicone film 43e. For example, as the amount of the first light L11 emitted by the first light source 41 becomes excessive and the temperature in the vicinity of the incident region W1 rises, the optical transmittance of the silicone film 43e further decreases. Therefore, the abnormality determination unit 22 of the light source device 4E can determine temperature abnormality such as overheating near the emission region W2 of the wavelength conversion member 43 based on the detection signal of the optical sensor 44. FIG.

Note that the light source device 4E may include a liquid crystal film (thin film) instead of the silicone film 43e. As with the silicone film 43e, the optical transmittance of the liquid crystal film decreases as the temperature increases. Therefore, the abnormality determination unit 22 of the light source device 4E can determine temperature abnormality such as overheating near the emission region W2 of the wavelength conversion member 43 based on the detection signal of the optical sensor 44. FIG.

(8) Sixth Modification FIG. 9 shows a light source device 4F as a sixth modification of the light source device.

The light traveling toward the optical sensor 44 may include not only the second light L2 but also ambient light other than the second light L2 (illumination light, sunlight, first light L11, mixed color light L10, etc.). However, when the optical sensor 44 receives ambient light, there is a possibility that the accuracy of the abnormality determination by the abnormality determination unit 22 will decrease. Therefore, the light source device 4F further includes an optical filter 45 .

The optical filter 45 is arranged in the light receiving portion of the optical sensor 44 and has a function of causing the optical sensor 44 to receive light in which a specific wavelength range that does not include the detection wavelength λ2 is attenuated. In other words, the optical filter 45 has a function of transmitting the second light L2 as light to be received by the optical sensor 44 and attenuating disturbance light.

Specifically, the optical filter 45 receives light that travels toward the optical sensor 44 and emits light that has a specific wavelength attenuated from the incident light toward the optical sensor 44 . For example, the second light L2 reflected by the first surface 431 (incidence area W1) in FIG. 2 enters the optical sensor 44 after passing through the optical filter 45 . At this time, ambient light such as illumination light, sunlight, first light L11, and mixed light L10 also passes through the optical filter 45 before reaching the optical sensor 44, so the ambient light reaches the optical sensor 44. decay forward. Therefore, the light source device 4F can suppress deterioration in accuracy of abnormality determination due to ambient light.

For example, the optical filter 45 is made of glass or a dielectric multilayer film. The dielectric multilayer film is made of TiO ₂ , Ta ₂ O ₃ , SiO ₂ , MgF ₂ or the like, for example.

In FIG. 9, the optical filter 45 is added to the light source device 4 (see FIG. 1) of the above embodiment, but the optical filter 45 is added to the light source devices 4A to 4E of the above first to fifth modifications. may be added.

(9) Other Modifications The optical spectrum of the phosphor 43b may be other than the optical spectrum SP1 in FIG. The optical spectrum of the phosphor 43b may be any one of optical spectra SP2 to SP5 shown in FIG. 10, for example. In this case, the fluorescence wavelength λ4 is the wavelength at which the intensity reaches the maximum value in each of the optical spectra SP2 to SP5.

The abnormality determination unit 22 monitors the amount of the second light L2 received by the optical sensor 44 based on the detection signal of the optical sensor 44, and determines the abnormality of the wavelength conversion member 43 based on the amount of change in the amount of received light. good too. For example, the abnormality determination unit 22 determines that the wavelength conversion member 43 is “abnormal” when the amount of change in the amount of received light per unit time is equal to or more than a predetermined value or less than or equal to a predetermined value. The abnormality determination unit 22 may determine abnormality of the wavelength conversion member 43 based on parameters (parameters related to the amount of received light) other than the magnitude of the amount of received light and the amount of change in the amount of received light.

The first light source 41 is not limited to a configuration including a laser element (first laser element). The first light source 41 may have a solid-state light-emitting device such as a laser device, an LED (Light Emitting Diode), or an organic EL (Organic Electro Luminescence, OEL).

The second light source 42 is not limited to a configuration including a laser element (second laser element). The second light source 42 may be configured to include a solid light emitting device such as a laser device, LED, or organic EL.

The solid-state light-emitting elements included in the first light source 41 and the solid-state light-emitting elements included in the second light source 42 may be of the same type or of different types.

The light color of the first light L11 may be other than blue, and is not limited to a specific light color. Moreover, the light color of the mixed color light L10 may be other than white, and is not limited to a specific light color.

The circuit configuration of the first power supply device 31 is not limited to a specific circuit configuration as long as it can supply the first lighting power to the first light source 41 . The circuit configuration of the second power supply device 32 is not limited to a specific circuit configuration as long as it can supply the second lighting power to the second light source 42 .

Abnormalities of the wavelength conversion member 43 include breakage, chipping, peeling, detachment, etc. of the wavelength conversion member 43 in addition to cracking, deformation, and blackening of the substrate 43a.

It is possible to appropriately combine at least part of the respective configurations of the above-described embodiment and modifications.

(10) Summary The light source device (4, 4A to 4F) of the first aspect according to the embodiment includes a first light source (41), a wavelength conversion member (43), a second light source (42), an optical sensor (44) and A first light source (41) emits a first light (L11). The wavelength converting member (43) has a first surface (431) on which the first light (L11) is incident, the first light (L11), and the wavelength-converted light (L12 ) for emitting mixed-color light (L10). A second light source (42) emits a second light (L2) having a detection wavelength (λ2) different from the excitation wavelength (λ3) and fluorescence wavelength (λ4) of the wavelength conversion member (43). The optical sensor (44) has a peak sensitivity at the wavelength for detection (λ2). The optical sensor (44) receives the second light (L2) reflected by the wavelength conversion member (43) or the second light (L2) transmitted through the wavelength conversion member (43).

The light source devices (4, 4A to 4F) described above can improve the accuracy of abnormality determination of the wavelength conversion member (43).

In the light source device (4, 4A to 4F) of the second aspect according to the embodiment, in the first aspect, the detection wavelength (λ22) is preferably longer than 1000 nm.

The light source devices (4, 4A to 4F) described above can determine temperature abnormalities such as overheating of the wavelength conversion member (43).

In the light source device (4, 4A to 4C) of the third aspect according to the embodiment, in the first or second aspect, the optical sensor (44) reflects off the outer surface (430) of the wavelength conversion member (43) It is preferable to receive the second light (L2).

The light source devices (4, 4A to 4C) described above can determine abnormality in the vicinity of the outer surface (430) of the wavelength conversion member (43).

In the light source device (4, 4A to 4C) of the fourth aspect according to the embodiment, in the third aspect, the optical sensor (44) is configured such that the first light (L11) is incident on the first surface (431). It is preferable to receive the second light (L2) reflected by the region (W1) or the emission region (W2) from which the mixed color light (L10) is emitted on the second surface (432).

The light source devices (4, 4A to 4C) described above can determine abnormality in the vicinity of the incident region (W1) or the exit region (W2) of the wavelength conversion member (43).

In the light source device (4A, 4C) of the fifth aspect according to the embodiment, in the third or fourth aspect, the second surface (432) transmits the first light (L11) and transmits the second light (L2 ) is preferably formed of an exit-side optical film (43d) that reflects the light.

The above-described light source devices (4A, 4C) improve the sensitivity of abnormality detection, thereby improving the accuracy of abnormality determination. Furthermore, the light source devices (4A, 4C) can also improve the lighting environment in the lighting target.

In the light source device (4A) of the sixth aspect according to the embodiment, in any one of the third to fifth aspects, the optical sensor (44) detects the second light ( L2). The first surface (431) is preferably formed of an incident side optical film (43c) that transmits the first light (L11) and reflects the second light (L2).

The light source device (4A) described above improves the sensitivity of abnormality detection, thereby improving the accuracy of abnormality determination. Furthermore, the light source device (4A) can also improve the lighting environment in the lighting target.

In the light source device (4D, 4E) of the seventh aspect according to the embodiment, in the first or second aspect, the optical sensor (44) of the wavelength conversion member (43) passes the first light (L11). It is preferable to receive the second light (L2) transmitted through the region.

The light source devices (4D, 4E) described above can determine an abnormality not only on the outer surface (430) of the wavelength conversion member (43) but also on the inside of the wavelength conversion member (43).

In the light source device (4E) of the eighth aspect according to the embodiment, in the seventh aspect, the second surface (432) is preferably made of a silicone film (43e) or a liquid crystal film.

The light source device (4E) described above can determine a temperature abnormality such as overheating of the wavelength conversion member (43).

A light source device (4F) according to a ninth aspect according to the embodiment, in any one of the first to eighth aspects, emits light in which a specific wavelength range not including the detection wavelength (λ2) is attenuated. It is preferred to further comprise an optical filter (45) that allows the sensor (44) to receive light.

The light source device (4F) described above can suppress deterioration in the accuracy of abnormality determination due to ambient light.

In any one of the first to ninth aspects of the light source device (4) of the tenth aspect according to the embodiment, the first light (L11) is preferably laser light.

The light source device (4) described above has a suitable configuration for an endoscope, an industrial microscope, or the like.

An abnormality determination system (5) according to an eleventh aspect of the embodiment includes a light source device (4) according to any one of the first to tenth aspects, and an optical sensor (44) for receiving a second light (L2). and an abnormality determination unit (22) that determines abnormality of the wavelength conversion member (43) based on the quantity.

The abnormality determination system (5) described above can improve the accuracy of abnormality determination of the wavelength conversion member (43).

4, 4A to 4F light source device 41 first light source 42 second light source 43 wavelength conversion member 430 outer surface 431 first surface 432 second surface 43c incident side optical film 43d exit side optical film 43e silicone film 44 optical sensor 45 optical filter 5 abnormality Determination system 22 Abnormality determination unit L11 First light L12 Wavelength-converted light L10 Mixed color light λ2 (λ21, λ22) Wavelength for detection λ3 Excitation wavelength λ4 Fluorescence wavelength W1 Incidence area W2 Output area

Claims

a first light source that emits a first light;
a wavelength conversion member having a first surface on which the first light is incident and a second surface from which mixed color light including the first light and wavelength-converted light obtained by subjecting the first light to wavelength conversion processing is emitted;
a second light source that emits a second light having a detection wavelength different from the excitation wavelength and fluorescence wavelength of the wavelength conversion member;
an optical sensor having a peak sensitivity at the detection wavelength;
The light source device, wherein the optical sensor receives the second light reflected by the wavelength conversion member or the second light transmitted through the wavelength conversion member.
The light source device according to claim 1, wherein the detection wavelength is longer than 1000 nm.
3. The light source device according to claim 1, wherein the optical sensor receives the second light reflected by the outer surface of the wavelength conversion member.
4. The light source according to claim 3, wherein the optical sensor receives the second light reflected by an incident area where the first light is incident on the first surface or an exit area where the mixed color light is emitted on the second surface. Device.
5 . The light source device according to claim 3 , wherein the second surface is formed of an exit-side optical film that transmits the first light and reflects the second light.
The optical sensor receives the second light reflected by the first surface,
The light source device according to any one of claims 3 to 5, wherein the first surface is formed of an incident side optical film that transmits the first light and reflects the second light.
3. The light source device according to claim 1, wherein the optical sensor receives the second light transmitted through a region of the wavelength conversion member through which the first light passes.
The light source device according to Claim 7, wherein the second surface is formed of a silicone film or a liquid crystal film.
9. The light source device according to any one of claims 1 to 8, further comprising an optical filter that causes the optical sensor to receive light in which a specific wavelength range that does not include the detection wavelength is attenuated.
The light source device according to any one of claims 1 to 9, wherein the first light is laser light.
A light source device according to any one of claims 1 to 10;
An abnormality determination system, comprising: an abnormality determination unit that determines an abnormality of the wavelength conversion member based on the amount of the second light received by the optical sensor.