阅读说明：本技术 光源装置 (Light source device ) 是由 芜木清幸 三浦雄一 于 2020-09-30 设计创作，主要内容包括：本发明提供一种光源装置,具备激光激发光源和出射包含UV区域的波长不同的光的多个LED,能够稳定地输出UV区域的光。光源装置(100)具备：激光激发光源(110),其具有激发用的半导体激光器、被该半导体激光器激发的荧光体、以及取出从该荧光体放射的荧光的光学系统；多个LED光源(120A～120D),放射具有与荧光不同的波长的光；以及合成光学系统,对来自激光激发光源(110)的荧光和来自多个LED光源(120A～120D)的光进行合成,并从光出射部出射。多个LED光源(120A～120D)包括放射紫外区域的光的LED光源,多个LED光源(120A～120D)中的放射紫外区域的光的LED光源配置在比放射其他波长的光的LED光源更远离激光激发光源(110)的位置。(The invention provides a light source device, which is provided with a laser excitation light source and a plurality of LEDs emitting light with different wavelengths including a UV region, and can stably output the light of the UV region. A light source device (100) is provided with: a laser excitation light source (110) having a semiconductor laser for excitation, a phosphor excited by the semiconductor laser, and an optical system for extracting fluorescence emitted from the phosphor; a plurality of LED light sources (120A-120D) that emit light having a wavelength different from that of the fluorescent light; and a combining optical system that combines fluorescence from the laser excitation light source (110) and light from the plurality of LED light sources (120A-120D) and emits the combined light from the light emitting section. The plurality of LED light sources (120A-120D) include LED light sources that emit light in the ultraviolet region, and of the plurality of LED light sources (120A-120D), the LED light source that emits light in the ultraviolet region is disposed at a position that is farther from the laser excitation light source (110) than the LED light sources that emit light of other wavelengths.)

1. A light source device is characterized in that a light source unit,

the disclosed device is provided with:

laser excitation light source: an optical system having a semiconductor laser for excitation, a phosphor excited by the semiconductor laser, and a light source for extracting fluorescence emitted from the phosphor;

a plurality of LED light sources that emit light having a wavelength different from the fluorescent light; and

a combining optical system that combines fluorescence from the laser excitation light source and light from the plurality of LED light sources and emits the combined light from a light emitting portion,

the plurality of LED light sources includes an LED light source emitting light in an ultraviolet region,

among the plurality of LED light sources, the LED light source that emits light in the ultraviolet region is disposed at a position that is farther from the laser excitation light source than the LED light sources that emit light of other wavelengths.

2. The light source device according to claim 1,

the plurality of LED light sources are arranged in a line along an optical axis of an optical system that takes out the fluorescent light.

3. The light source device according to claim 2,

the LED light source for emitting the light in the ultraviolet region is disposed at a position closest to the light emitting portion disposed at an end of an optical axis of the optical system for extracting the fluorescent light.

4. The light source device according to claim 2,

the plurality of LED light sources emit light from a direction orthogonal to the optical axis,

the synthesizing optical system includes dichroic mirrors that convert traveling directions of light emitted from the plurality of LED light sources into directions parallel to the optical axis, respectively.

5. The light source device according to claim 4,

the dichroic mirrors corresponding to the plurality of LED light sources are arranged on the optical axis.

6. The light source device according to claim 2,

the plurality of LED light sources are arranged in order from a light source that emits light having a long wavelength, from the laser excitation light source toward the light emitting portion.

7. The light source device according to claim 1,

the LED light source includes: an LED; a collimating lens collimating light emitted from the LED; and a first housing made of metal, which houses the LED and the collimating lens.

8. The light source device according to claim 7,

further comprising a second metal housing accommodating the laser excitation light source and the combining optical system,

the first housing is disposed outside the second housing.

9. The light source device according to claim 8,

the plurality of first cases corresponding to the plurality of LED light sources are fixed to the same surface of a case wall surface constituting the second case.

10. The light source device according to claim 2,

the LED light source includes: an LED; a collimating lens collimating light emitted from the LED; and a first housing made of metal, which houses the LED and the collimating lens.

11. The light source device according to claim 10,

further comprising a second metal housing accommodating the laser excitation light source and the combining optical system,

the first housing is disposed outside the second housing.

12. The light source device according to claim 11,

the plurality of first cases corresponding to the plurality of LED light sources are fixed to the same surface of a case wall surface constituting the second case.

Technical Field

The present invention relates to a light source device to be used in a fluorescence microscope or the like, which synthesizes and emits light of a plurality of wavelengths.

Background

Conventionally, as a light source for a fluorescence microscope, an ultrahigh pressure mercury lamp having a plurality of bright lines or a xenon lamp for maintaining continuous light has been used.

In recent years, in order to reduce environmental load and the like, Ce: light source technology for fluorescing YAG phosphors has been put to practical use. For example, patent document 1 discloses a light source device as a light source for a microscope, which synthesizes and emits emission light from a phosphor excited by an LD and emission light from 2 LEDs having different wavelengths including an ultraviolet region (UV region) by 2 pieces of Dichroic Mirrors (DM).

Documents of the prior art

Patent document

Patent document 1: U.S. patent application publication No. 2019/0121146 specification

Disclosure of Invention

Problems to be solved by the invention

In a light source device for a fluorescence microscope, a high-output laser excitation light source is used in order to obtain a sharp fluorescence image having a spectrum corresponding to a large amount of fluorescent reagents. However, the optical output of the laser excitation light source is inefficient with respect to the electrical input, and the amount of heat generated is large. Therefore, the LED disposed near the laser excitation light source is easily affected by the heat of the laser excitation light source. In particular, in a small-sized light source device, the arrangement interval between the members is narrow, and the temperature of the LED arranged in the vicinity of the laser excitation light source is easily increased.

The LED has the following characteristics: the higher the temperature, the lower the luminous efficiency, and the lower the light output. In particular, in an LED in the UV region, this tendency is strong, and a decrease in light output is likely to be caused.

As described above, the light source device for a fluorescence microscope including a laser excitation light source and a plurality of LEDs has the following problems: the laser excitation light source serves as a heat source, and the LED that emits light in the UV region is affected by heat, and the light output decreases.

Therefore, an object of the present invention is to provide a light source device including a laser excitation light source and a plurality of LEDs that emit light having different wavelengths including a UV region, and capable of stably outputting light in the UV region.

Means for solving the problems

In order to solve the above problem, one embodiment of the light source device of the present invention includes: a laser excitation light source having a semiconductor laser for excitation, a phosphor excited by the semiconductor laser, and an optical system for extracting fluorescence emitted from the phosphor; a plurality of LED light sources that emit light having a wavelength different from the fluorescent light; and a synthesizing optical system that synthesizes fluorescence from the laser excitation light source and light from the plurality of LED light sources and emits the synthesized fluorescence from the light emitting portion, wherein the plurality of LED light sources include LED light sources that emit light in an ultraviolet region, and the LED light source that emits light in the ultraviolet region among the plurality of LED light sources is disposed at a position that is farther from the laser excitation light source than the LED light sources that emit light of other wavelengths.

In this way, since the LED light source (UV-LED) that emits light in the UV region is disposed at a position distant from the laser excitation light source that is a heat source, it is possible to suppress an increase in temperature of the UV-LED and suppress a decrease in output of UV light.

In the light source device, the plurality of LED light sources may be arranged in a line along an optical axis of an optical system for extracting the fluorescent light. In this case, a plurality of LED light sources can be arranged with a narrow width, and a small-sized (narrow-width) light source device can be formed.

In the light source device, the LED light source that emits the light in the ultraviolet region may be disposed at a position closest to the light emitting portion disposed at an end of an optical axis of the optical system that extracts the fluorescent light. In this case, the light emitted from the UV-LED can be emitted from the light emitting portion without loss, and the emission intensity of the UV light can be appropriately obtained.

In the light source device, the plurality of LED light sources may emit light in a direction orthogonal to the optical axis, and the synthesizing optical system may further include dichroic mirrors that convert traveling directions of the light emitted from the plurality of LED light sources into directions parallel to the optical axis, respectively.

In this case, since the arrangement postures of the plurality of LED light sources can be matched, the plurality of LED light sources can be easily and appropriately arranged. Further, by arranging the LED light source so as to emit light from a direction orthogonal to the optical axis of the optical system for extracting fluorescent light, the traveling direction of light from the LED light source can be easily converted into a direction parallel to the optical axis.

In the light source device, the dichroic mirrors corresponding to the LED light sources may be disposed on the optical axis. In this case, the fluorescence and the light from the plurality of LED light sources can be combined on the optical axis of the optical system that takes out the fluorescence. Further, the dichroic mirror is disposed on the optical axis of the optical system for extracting fluorescent light, whereby the area occupied by the light source device can be further reduced.

In the light source device, the plurality of LED light sources may be arranged in order from a light source emitting light with a long wavelength from the laser excitation light source toward the light emitting portion. In this case, the dichroic mirror can be easily designed and manufactured, and can be configured at low cost.

In the light source device, the LED light source may include: an LED; a collimating lens collimating light emitted from the LED; and a first housing made of metal, which houses the LED and the collimating lens.

In this case, since heat generated by the LED can be conducted to the first case which is a metal case, an increase in temperature of the LED can be appropriately suppressed, and a decrease in light output can be suppressed.

In the light source device, the laser excitation light source and the combining optical system may be housed in a metal second case, and the first case may be disposed outside the second case.

In this case, since heat generated by the semiconductor laser and the fluorescent material can be conducted to the second housing, which is a metal housing, it is possible to appropriately suppress temperature increases of the semiconductor laser and the fluorescent material and suppress a decrease in fluorescence output. Further, since the housing accommodating the laser excitation light source and the housing accommodating the combining optical system are integrated, the surface area of the housing can be increased, and the heat dissipation efficiency of the heat generated by the laser excitation light source can be improved.

In the light source device, the first housings corresponding to the LED light sources may be fixed to the same surface of the housing wall surface constituting the second housing.

In this case, the arrangement accuracy of the plurality of LED light sources can be improved, and the light loss can be reduced.

The invention has the following effects:

according to the light source device of the present invention, since the UV region LED is disposed at a position farther from the laser excitation light source than the other LEDs, it is possible to suppress a temperature rise of the UV region LED. Therefore, light in the UV region can be stably output

Drawings

Fig. 1 is a diagram showing a configuration example of a fluorescence microscope including a light source device in the present embodiment.

Fig. 2 is a diagram showing a configuration example of the light source device.

Fig. 3 is a diagram showing the spectral reflectance of the interference filter (dichroic mirror).

Fig. 4 is a spectrum of light emitted from the light source device.

Fig. 5 is a graph showing a relationship between the temperature of the LED and the light output.

Description of the symbols

100 … light source device, 101 … optical fiber, 110 … laser excitation light source, 111 … LD case, 112 … cooling fin, 120A to 120D … LED light source, 121a … LED case, 122a … LED, 123a … collimator lens, 124a … collimator lens, 130 … synthetic optical system, 131 … optical system case, 132a to 132D … interference filter (dichroic mirror), 133 … condenser lens, 200 … main body portion, 201 … excitation filter, 202 … dichroic mirror, 203 … objective lens, 204 … absorption filter, 205 … eyepiece, 206 … optical adapter, 300 … sample, 1000 … fluorescence microscope system

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a diagram showing a configuration example of a fluorescence microscope system 1000 including a light source device 100 according to the present embodiment.

The fluorescence microscope system 1000 includes a light source device 100 and a main body 200. The main body 200 includes an excitation filter 201, a dichroic mirror 202, an objective lens 203, an absorption filter 204, an eyepiece 205, and an optical adapter 206. Eyepiece 205 may include an imaging optical system such as a camera.

Light emitted from the optical fiber 101 of the light source device 100 is guided to the main body portion only by appropriate light via the optical adapter 206, and is limited to light of only the excitation wavelength by the excitation filter 201. The excitation light transmitted through the excitation filter 201 is reflected by the dichroic mirror 202, and is irradiated to the sample (fluorescent sample) 300 through the objective lens 203. The sample 300 is excited by irradiation with excitation light and emits fluorescence.

The fluorescence emitted from the sample 300 enters the dichroic mirror 202 via the objective lens 203, passes through the dichroic mirror 202, and enters the absorption filter 204. Absorption filter 204 cuts off light of an excessive wavelength and causes only fluorescence generated from sample 300 to enter eyepiece 205. This enables observation of fluorescence generated from the sample 300.

Hereinafter, the light source device 100 will be specifically described.

Fig. 2 is a diagram showing a configuration example of the light source device 100. Fig. 2 shows the light source device 100 as viewed from above.

The light source device 100 includes a laser excitation light source 110, a plurality of LED light sources 120A to 120D, and a synthesis optical system 130.

The laser excitation light source 110 includes an LD case 111 and a cooling fin 112. The LD case 111 is made of a metal material having excellent heat dissipation properties, and houses a plurality of excitation semiconductor Lasers (LDs), not shown, phosphors (fluorescent plates) excited by excitation light from the excitation LDs, an optical system for extracting fluorescence (yellow) emitted from the phosphors, and the like. The heat sink 112 is fixed to the LD case 111, and dissipates heat generated by the LD and the phosphor and conducted to the LD case 111.

The LED light source 120A includes a metal LED case (first case) 121 a. The LED case 121a houses the LED122a and the collimator lenses 123a and 124 a. The light emitted from the LED122a is collimated by the 2 collimator lenses 123a and 124a, and is emitted as parallel light. The LED case 121a may be a metal case having a cylindrical shape and a plurality of grooves for providing a cooling function, for example.

Since the LED light sources 120B to 120D have the same configuration as the LED light source 120A, the description thereof is omitted.

The plurality of LED light sources 120A to 120D include LED light sources that emit light in the ultraviolet region (UV region), and emit light of different wavelengths.

In the present embodiment, the LED light source 120A is an LED light source that emits light in the UV region. In addition, light in the UV region is referred to in IEC 60050-: light having a wavelength of 400nm or less as defined in 1987.

For example, the LED light source 120A includes an LED122a having a peak wavelength of 365 nm. Further, the LED light source 120B includes an LED having a peak wavelength of 406nm, the LED light source 120C includes an LED having a peak wavelength of 436nm, and the LED light source 120D includes an LED having a peak wavelength of 470 nm.

The combining optical system 130 combines the lights emitted from the LED light sources 120A to 120D with respect to the fluorescence emitted from the laser excitation light source 110, and emits the combined light from the light emitting portion.

The composite optical system 130 includes a metal optical system housing 131. The optical system housing 131 houses the interference filters 132a to 132d and the condenser lens 133. The optical system case 131 is coupled to the LD case 111, and each of the LED cases of the plurality of LED light sources 120A to 120D is fixed to the same surface of a case wall surface constituting the optical system case 131.

The optical system case 131 may be integrally formed with the LD case 111. The LD housing 111 and the optical system housing 131 correspond to a second housing.

The interference filters 132a to 132d are formed of dielectric multilayer films. In the present embodiment, the interference filters 132a to 132d are dichroic mirrors that can reflect light in a specific wavelength range and transmit light in other wavelength ranges.

In the present embodiment, the dichroic mirrors 132a to 132d are disposed on the optical axis (optical axis L in fig. 2) of the optical system that takes out the fluorescence of the laser excitation light source 110. Specifically, each of the LED light sources 120A to 120D is arranged to emit light in a direction orthogonal to the optical axis (optical axis L in fig. 2) of the optical system that extracts fluorescence from the laser excitation light source 110. The dichroic mirrors 132a to 132d are disposed on the optical axis L at positions where light is emitted from the corresponding LED light sources.

Fig. 3 is a diagram showing the spectral reflectance of the dichroic mirrors 132a to 132 d. In fig. 3, a solid line DMa represents the characteristic of the dichroic mirror 132a, a broken line DMb represents the characteristic of the dichroic mirror 132b, a one-dot chain line DMc represents the characteristic of the dichroic mirror 132c, and a broken line DMd represents the characteristic of the dichroic mirror 132 d.

Accordingly, 365nm light emitted from the LED light source 120A is reflected by the dichroic mirror 132a and enters the condenser lens 133. Light having a wavelength of 406nm emitted from the LED light source 120B is reflected by the dichroic mirror 132B, passes through the dichroic mirror 132a, and enters the condenser lens 133.

The light having a wavelength of 436nm emitted from the LED light source 120C is reflected by the dichroic mirror 132C, passes through the dichroic mirrors 132b and 132a, and enters the condenser lens 133. The light having a wavelength of 470nm emitted from the LED light source 120D is reflected by the dichroic mirror 132D, passes through the dichroic mirrors 132c, 132b, and 132a, and enters the condenser lens 133.

The yellow fluorescence emitted from the laser excitation light source 110 passes through the dichroic mirrors 132d, 132c, 132b, and 132a, respectively, and enters the condenser lens 133.

Thus, the fluorescence extracted from the laser excitation light source 110 travels straight and enters the condenser lens 133. On the other hand, the light beams emitted from the LED light sources 120A to 120D in the direction orthogonal to the optical axis L are converted into light beams having a traveling direction parallel to the optical axis L by the dichroic mirrors 132a to 132D, respectively, and then enter the condenser lens 133.

In this way, the fluorescence emitted from the laser excitation light source 110 and the light emitted from each of the LED light sources 120A to 120D are combined on the optical axis L and emitted from the condenser lens 133. At this time, the end of the optical system housing 131 positioned on the light output side of the condenser lens 133 serves as a light output portion of the light source device 100.

In the case of using an optical fiber, a cylindrical holder is provided so that an end face of the optical fiber is arranged on the focal plane of the condenser lens 133 in order to efficiently enter the optical fiber.

With the above configuration, light having a spectrum shown in fig. 4 is emitted from the light source device 100.

However, the optical output of the laser excitation light source with respect to the electrical input is 15 to 25%, the efficiency is poor, and most of the electrical input that is not converted into light is converted into heat.

For example, in the case where the light output efficiency η 1 of the semiconductor Laser (LD) is 35% (35W is light output and 65W is heat when 100W is input) and the light output efficiency η 2 of fluorescence is 50 to 60% (19W is fluorescence output and 16W is heat when 35W is output) in the laser excitation light source, the light output efficiency η of the laser excitation light source is 18 to 24%. That is, even when the electric input is a laser excitation light source of 100W class, the amount of heat generation can be 80W class.

In this way, in the light source device for a fluorescence microscope, the LD and the phosphor included in the laser excitation light source serve as heat sources.

On the other hand, a fluorescence microscope system used for biological observation or the like is installed in a research room or the like, and therefore miniaturization is required to reduce an occupied area. Therefore, in the light source device for a fluorescence microscope, it is also required to dispose the respective components close to each other. In this case, the LED light source disposed in the vicinity of the laser excitation light source tends to increase in temperature due to the influence of heat dissipation generated in the laser excitation light source.

Fig. 5 is a graph showing a relationship between the temperature of the LED and the light output. In fig. 5, the abscissa represents the temperature (junction temperature) of the PN junction of the LED, and the ordinate represents the relative intensity when the light output at room temperature (25 ℃) is 1. The broken line a in fig. 5 shows the relationship between the temperature and the light output of the LED emitting light having a wavelength of 406nm, and the solid line b shows the relationship between the temperature and the light output of the LED emitting light having a wavelength of 365 nm.

As shown in fig. 5, the LED has a characteristic that the higher the bonding temperature, the lower the light emission efficiency and the lower the light output. The thermal characteristics vary depending on the type of LED, and particularly, an LED (UV-LED) emitting light in the UV region is susceptible to thermal influence, and as shown by the solid line b, the output tends to be lower than an LED emitting light having a wavelength of 406nm, which is shown by the broken line a.

Therefore, in the light source device 100 for a fluorescence microscope according to the present embodiment, the LED light source 120A including the UV-LED is disposed at a position farther from the laser excitation light source 110 as a heat source than the LED light sources 120B to 120D including the other LEDs.

By disposing the UV-LED at a position distant from the laser excitation light source 110 in this manner, the temperature rise of the UV-LED can be suppressed. As a result, the decrease in the light output of the UV-LED can be suppressed.

As shown in fig. 2, the LED light sources 120A to 120D are arranged in a row along the optical axis L of the optical system that extracts fluorescent light from the laser excitation light source 110. Among the plurality of LED light sources 120A to 120D, the LED light source 120A is disposed at a position farthest from the laser excitation light source 110, that is, at a position closest to the light emitting portion of the light source device 100.

Here, the plurality of LED light sources 120A to 120D are arranged to emit light from a direction orthogonal to the optical axis L. The light emitted from the LED light sources 120A to 120D is converted into light having a traveling direction parallel to the optical axis L by the dichroic mirrors 132a to 132D, respectively. The dichroic mirrors 132a to 132D are disposed on the optical axis L, and the fluorescent light emitted from the laser excitation light source 110 and the light emitted from the LED light sources 120A to 120D and having the traveling direction converted by the dichroic mirrors 132a to 132D are combined on the optical axis L.

By arranging the plurality of LED light sources 120A to 120D in a row along the optical axis L in this manner, the LED light sources 120A to 120D can be arranged in a narrow width region, and the light source device 100 can be made compact (narrow). Further, the dichroic mirrors 132a to 132d are arranged on the optical axis L, and the radiant light is synthesized on the optical axis L, whereby the occupied area can be further reduced.

Further, by disposing the UV-LED at the position closest to the light emitting portion, the light emitted from the UV-LED can be emitted from the light emitting portion without loss, and the output intensity of the UV light can be appropriately obtained.

In the arrangement shown in fig. 2, the emission light of the laser excitation light source 110 arranged farthest from the light emitting portion passes through the 4 dichroic mirrors 132a to 132d and is emitted from the light emitting portion. On the other hand, the light emitted from the UV-LED (LED light source 120A) disposed closest to the light emitting section is reflected only 1 time by the dichroic mirror 132a and emitted from the light emitting section. By disposing the LED light source 120A at the position closest to the light emitting unit as in the present embodiment, the light loss due to the UV light passing through the dichroic mirror can be eliminated, and the reflection loss can be limited to only 1-time reflection loss.

Further, the plurality of LED light sources 120A to 120D may be arranged in order from the laser excitation light source 110 toward the light emitting portion, and may be arranged in order from a light source having a long wavelength of emitted light. In this case, as shown in fig. 3, the dichroic mirrors 132a to 132d may have filter characteristics for reflecting light having a wavelength of the radiant light from the corresponding LED light sources and transmitting light having a wavelength longer than the wavelength of the radiant light. Therefore, the filter can be easily designed and manufactured, and an inexpensive structure can be provided.

The plurality of LED light sources 120A to 120D can be aligned in arrangement postures so as to emit light from a direction orthogonal to the optical axis L. Therefore, the plurality of LED light sources 120A to 120D can be easily and appropriately arranged.

Here, each of the LED light sources 120A to 120D has a structure in which an LED and a collimator lens are housed in an LED case made of metal. Each LED housing containing the LED and the collimator lens is fixed to the same surface of a common housing (in the present embodiment, the optical system housing 131) made of metal, and is fixed to the upper surface of the optical system housing 131 in the drawing in fig. 2.

In this way, by fixing the plurality of LED housings to the same surface of the common housing, the arrangement accuracy of the LED housings can be improved, and the arrangement accuracy of the optical components can be improved. Therefore, the light loss of the light emitted from the LED light sources 120A to 120D can be reduced.

Further, since the LEDs included in the LED light sources 120A to 120D are housed in the metal case together with the collimator lenses, the heat generated by the LEDs can be conducted to the metal case, and the temperature rise of the LEDs can be suppressed.

Similarly, since the LD and the phosphor included in the laser excitation light source 110 are housed together with the optical system for extracting fluorescence in the metal case, heat generated by the LD and the phosphor can be conducted to the metal case, and temperature increases of the LD and the phosphor can be suppressed. Further, by coupling the optical system case 131 and the LD case 111, the surface area of the metal case for conducting heat generated in the laser excitation light source 110 can be increased, and the heat radiation efficiency can be improved.

Further, since the LED case is disposed outside the LD case 110, heat generated from the LD or the fluorescent material can be prevented from being directly transferred to the LED, and temperature rise of the LED can be prevented.

As described above, the light source device 100 according to the present embodiment is a small-sized light source device including the laser excitation light source 110 and the plurality of LED light sources 120A to 120D that emit light having different wavelengths including the UV region, and can be a light source device capable of stably outputting light in the UV region.

(modification example)

In the above-described embodiment, the wavelength of light emitted from the LED light source and the number of LED light sources included in the light source device 100 are not limited to the above-described wavelength and number. The LED light sources included in the light source device 100 are a plurality of LED light sources that emit light having a wavelength different from the fluorescence emitted from the laser excitation light source 110, and may include an LED light source that emits light in the ultraviolet region (UV region).

In the above-described embodiment, the case where the plurality of LED light sources 120A to 120D are arranged in order from the light source having a long wavelength as viewed from the laser excitation light source 110 has been described, but the arrangement of the LED light sources 120A to 120D is not limited to the above-described arrangement.

For example, the laser excitation light source 110 may be disposed at a position farthest from the light emitting portion of the light source device 100, and the LED light source 120A may be disposed at a position closest to the light emitting portion of the light source device 100, and the order of disposing the remaining plurality of LED light sources may be determined by using thermal characteristics, a rated input current, and the like. When the arrangement order is determined according to the thermal characteristics, the LED light sources having a larger rate of output reduction due to heat are arranged at positions farther from the laser excitation light source 110. When the arrangement order is determined according to the rated input current, the LED light sources having the larger rated input current are arranged closer to the laser excitation light source 110 (at positions distant from the light emitting portion).

In the above-described embodiment, the case where the LED light sources 120A to 120D emit light in the horizontal direction has been described as shown in the plan view of the light source device 100 in fig. 2, but the direction in which light is emitted is not limited to the horizontal direction as long as it is a direction orthogonal to the optical axis L. For example, the LED light sources 120A to 120D may emit light from above and below the optical axis L.

In the above embodiment, the case where the light source device 100 is a light source device for a fluorescence microscope has been described, but the light source device 100 can be applied to devices other than a fluorescence microscope. For example, the light source device 100 can be applied to a light source device for semiconductor inspection (for example, for light resistance inspection of a semiconductor) and a light source device for material inspection.