JP2024075530A - Light source - Google Patents

Abstract

[Problem] To provide a light source device that excites a phosphor with excitation light from a solid-state light-emitting element such as an LED and emits fluorescence from the phosphor, and covers a wide band from the near ultraviolet to infrared ranges while suppressing spike-like excitation light contained in the emitted light. [Solution] The light source device comprises at least one first light-emitting element that emits excitation light in a first wavelength band, a phosphor that is arranged in the optical path of the first light-emitting element and excited by the excitation light to emit fluorescence in a second wavelength band having a longer wavelength than the first wavelength band, and an optical filter that is arranged to partially cover the first light-emitting element and cuts out a portion of the excitation light that passes through the phosphor, and is characterized in that the relative position of the optical filter with respect to the first light-emitting element is adjusted based on the intensity of the fluorescence and the intensity of the excitation light. [Selected Figure] Figure 2

Description

The present invention relates to a light source device used in biochemical analyzers, etc.

Conventionally, in biochemical analyzers that use samples of body fluids such as blood or urine to measure various components such as sugar, cholesterol, protein, and enzymes, a spectrophotometer measures the absorbance in the wavelength range from 340 nm to 800 nm to quantify each component, and a light source device capable of emitting light in this wavelength range is used.

Conventionally, such light source devices have used halogen lamps as the light source, but because the emission intensity in the near-ultraviolet region of 300 to 400 nm is extremely weak, there has been a demand for increased intensity in this wavelength region from the standpoint of reliability and measurement speed. In recent years, LEDs (Light Emitting Diodes) that emit near-ultraviolet light have been developed, and light sources using phosphors that are excited by near-ultraviolet light and emit light up to the near-infrared wavelength region have been proposed as alternatives to halogen lamps.

For example, Patent Document 1 describes a light-emitting device (light source device) that includes a solid-state light source (LED) that emits ultraviolet light with a peak wavelength at 365 nm and a fluorescent film that covers the solid-state light source and contains at least one type of phosphor, in which the fluorescent film is excited by the ultraviolet light from the LED and emits light in the wavelength range from 350 nm to 1200 nm.

Patent document 2 also describes a light source device that excites a resin layer in which multiple phosphors are dispersed in a transparent resin with ultraviolet light of 340 nm wavelength from an LED, and emits light in a wide wavelength range.

International Publication No. 2019/240150 JP 2020-87974 A

According to the light source devices of Patent Documents 1 and 2, it is possible to obtain emitted light having a continuous emission spectrum in a wide wavelength range (for example, in the range of 350 to 1200 nm).
However, in the configuration of a light source device that excites such a fluorescent film with excitation light to emit fluorescence, a part of the excitation light that is incident on the fluorescent film and is not converted into fluorescence is mixed with the fluorescence generated in the fluorescent film and emitted from the emission surface of the fluorescent layer, so that the intensity of the excitation light that passes through the fluorescent film and the intensity of the fluorescence emitted from the fluorescent film are affected by the amount of phosphor filled in the fluorescent film and the thickness of the fluorescent film. Therefore, the spectral distribution of the emitted light tends to be spike-shaped near the central wavelength of the excitation light, and the intensity tends to be significantly increased compared to the surrounding wavelength ranges. And since this spike-shaped emitted light is light with relatively high energy in the near ultraviolet range, it may have a chemical effect on the reagents used in biochemical analysis.
As a means for suppressing such spike-like excitation light, it is conceivable to increase the loading amount or film thickness of the phosphor contained in the phosphor film and absorb and diffuse the excitation light within the phosphor film, but if the excitation light is suppressed by the absorption and diffusion of the phosphor, the fluorescence generated within the phosphor film will also be affected by the absorption and diffusion of the phosphor between the position where the fluorescence is generated and the emission surface of the phosphor layer, just like the excitation light, and the intensity will be suppressed. If the intensity of the fluorescence is suppressed, the problem of not being able to obtain the desired intensity (intensity required for analysis) will arise.

The present invention was made in consideration of the above circumstances, and aims to provide a light source device that excites a phosphor with excitation light from a solid-state light-emitting element such as an LED and emits fluorescent light from the phosphor, and that covers a wide band from the near ultraviolet to infrared range while suppressing spike-like excitation light contained in the emitted light.

To achieve the above object, the light source device of the present invention comprises at least one first light-emitting element that emits excitation light in a first wavelength band, a phosphor that is arranged in the optical path of the first light-emitting element and is excited by the excitation light to emit fluorescence in a second wavelength band that has a longer wavelength than the first wavelength band, and an optical filter that is arranged to partially cover the first light-emitting element and cuts a portion of the excitation light that passes through the phosphor, and is characterized in that the relative position of the optical filter with respect to the first light-emitting element is adjusted based on the intensity of the fluorescence and the intensity of the excitation light.

With this configuration, the intensity of unnecessary excitation light is adjusted by the optical filter, suppressing spikes of excitation light contained in the emitted light and providing emitted light that covers a wide band from the near ultraviolet to infrared range.

It is also preferable that the excitation light is composed of multiple lights with different peak wavelengths. In this case, it is also preferable that the multiple lights include light with a peak wavelength of 370 to 390 nm and light with a peak wavelength of 400 to 420 nm.

It is also desirable that the fluorescence is composed of multiple lights with different peak wavelengths. In this case, it is also desirable that the multiple lights include light with a peak wavelength of 440 to 480 nm, light with a peak wavelength of 480 to 525 nm, light with a peak wavelength of 525 to 560 nm, light with a peak wavelength of 560 to 630 nm, and light with a peak wavelength of 630 to 750 nm.

It is also preferable that the device further includes at least one second light-emitting element that emits light in a third wavelength band, and that the second light-emitting element is arranged so that the emitted light in the third wavelength band does not interfere with the optical filter. In this case, it is also preferable that the third wavelength band has a shorter wavelength than the first wavelength band. It is also preferable that the emitted light in the third wavelength band includes light with a peak wavelength of 330 to 350 nm.

It is also desirable that the relative position of the optical filter with respect to the first light-emitting element is adjusted so that the ratio of the peak intensity of the excitation light to the peak intensity of the fluorescence is 20 to 100%.

It is also preferable to further include a light guide section that mixes and guides the light from the light source device.

It is also desirable that the spectrum of light emitted from the light source device be continuous in the wavelength range of 340 to 800 nm.

As described above, the light source device of the present invention suppresses the spike-like excitation light contained in the emitted light, and realizes a light source device that can obtain the desired spectral characteristics over a wide band from the near ultraviolet to infrared region.

FIG. 1 is a diagram showing a configuration of a light source device according to an embodiment of the present invention. FIG. 2 is a plan view illustrating the configuration of a light source unit provided in the light source device according to the embodiment of the invention. FIG. 3 is a diagram showing the light intensity distribution (emission spectrum) of five types of phosphors used in the phosphor layer provided in the light source device according to the embodiment of the present invention. FIG. 4 is a diagram showing the spectral transmittance of an optical filter provided in the light source device according to the embodiment of the present invention. FIG. 5 is a diagram showing a spectrum of light emitted from the exit end surface of the light guide portion included in the light source device according to the embodiment of the present invention. FIG. 6 is a diagram showing a modified example of the light source unit included in the light source device according to the embodiment of the present invention.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated.

First Embodiment
1A and 1B are diagrams showing the configuration of a light source device 1 according to a first embodiment of the present invention, in which FIG. 1A is a perspective view of the light source device 1, and FIG. 1B is a cross-sectional view of the light source device 1 cut along the YZ plane. The light source device 1 of this embodiment is a device that emits light in a wide wavelength range and is used in biochemical analysis devices and the like. In this specification, as shown in the coordinates of FIG. 1, the emission direction of the light-emitting elements (first LEDs 22 and 23, second LED 24, and third LED 26) described later is defined as the Z-axis direction, and the directions defining the substrate 21 are defined as the X-axis direction and the Y-axis direction.

As shown in FIG. 1, the light source device 1 of this embodiment includes a case 10, a light source unit 20, a heat sink 30, and a light guide section 40.

The case 10 is a box-shaped metallic member that accommodates the light source unit 20, the heat sink 30, a cooling fan (not shown), and the like therein.
The heat sink 30 is a so-called air-cooled heat sink that is disposed so as to be in close contact with the rear surface of the substrate 21 of the light source unit 20 and dissipates heat generated by the light source unit 20. The heat sink 30 is made of a material with good thermal conductivity such as aluminum or copper, and is provided with a plurality of heat dissipation fins 32 on the surface opposite to the surface that contacts the substrate 21. Each heat dissipation fin 32 has a thin plate shape parallel to the YZ plane, and is provided at a predetermined interval in the X-axis direction and the Y-axis direction. In this embodiment, the plurality of heat dissipation fins 32 are uniformly cooled by cooling air generated by a cooling fan (not shown).
Rectangular exhaust ports 11 and 12 are formed on the upper surface (the surface on the + side in the Y-axis direction) and the lower surface (the surface on the - side in the Y-axis direction) of the case 10, respectively, to exhaust air from inside the case 10, and air that flows between the heat dissipation fins 32 is discharged from the exhaust ports 11 and 12.
A light guiding unit 40 is attached to the front surface (the surface on the positive side in the Z-axis direction) of the case 10. The light guiding unit 40 in this embodiment has a mixing rod 41 and an optical fiber bundle 42, and mixes the light from the light source unit 20 in the mixing rod 41 and guides the light through the optical fiber bundle 42 for emission. The mixing rod 41 may be a polygonal columnar rod made of quartz, or a polygonal tubular member whose inner surface is a reflective surface.

The light source unit 20 is disposed along the front surface of the case 10, and is a member that emits output light toward the light guide portion 40. Fig. 2 is a plan view illustrating the configuration of the light source unit 20 of this embodiment.
As shown in FIG. 2, the light source unit 20 has a substrate 21, first LEDs 22 and 23 (first light-emitting elements), a second LED 24 (first light-emitting element), a third LED 26 (second light-emitting element), a dam material 27, a phosphor layer 28 (phosphor), and an optical filter 29 (gray portion).

The substrate 21 is a rectangular wiring board made of a material with high thermal conductivity (e.g., aluminum nitride), and first LEDs 22, 23, a second LED 24, and a third LED 26 are mounted on the surface of the substrate 21 by COB (Chip On Board).
An anode pattern (not shown) and a cathode pattern (not shown) for supplying power to the first LED 22, 23, the second LED 24, and the third LED 26 are formed on the substrate 21, and the first LED 22, 23, the second LED 24, and the third LED 26 are soldered to the anode pattern and the cathode pattern, respectively, and are electrically connected. The substrate 21 is also electrically connected to a driver circuit (not shown) by a wiring cable (not shown), and a drive current is supplied from the driver circuit to the first LED 22, 23, the second LED 24, and the third LED 26 via the anode pattern and the cathode pattern.

The first LEDs 22 and 23 are light-emitting elements that emit light having a peak wavelength at a first wavelength (e.g., 405 nm). When a drive current is supplied to the first LEDs 22 and 23 via the anode pattern and cathode pattern of the substrate 21, light with an intensity according to the drive current is emitted. In addition, a phosphor layer 28 (shaded area in FIG. 1) described below is formed on the emission surface (i.e., on the optical path) of the first LEDs 22 and 23 in this embodiment. In addition, the entire first LED 22 and a part of the first LED 23 are covered by an optical filter 29 described below.

The second LED 24 is a light-emitting element that emits light having a peak wavelength at a second wavelength (e.g., 385 nm). When a drive current is supplied to the second LED 24 via the anode pattern and cathode pattern of the substrate 21, light with an intensity according to the drive current is emitted. In addition, a phosphor layer 28 (shaded area in FIG. 1) described below is formed on the emission surface (i.e., on the optical path) of the second LED 24 in this embodiment. In addition, a portion of the second LED 24 is covered by an optical filter 29 described below.

The third LED 26 is a light-emitting element that emits emitted light having a peak wavelength at a third wavelength (e.g., 340 nm). When a drive current is supplied to the third LED 26 via the anode pattern and cathode pattern of the substrate 21, emitted light of an intensity according to the drive current is emitted. Unlike the first LEDs 22, 23 and the second LED 24, the phosphor layer 28 is not formed on the emission surface (i.e., on the optical path) of the third LED 26 of this embodiment, and the third LED 26 is not covered by the optical filter 29. In other words, the third LED 26 is positioned so that the emitted light does not interfere with the optical filter 29.

The dam material 27 is a frame-shaped member formed on the substrate 21 to surround the first LED 22, 23, the second LED 24, and the third LED 26, and is provided to form a space in the Z-axis direction between the first LED 22, 23, the second LED 24, and the optical filter 29. In this embodiment, the dam material 27 is formed, for example, from a silicone resin having ultraviolet light resistance.

The phosphor layer 28 is a thin film having a thickness of approximately 100 μm that is formed on the emission surfaces of the first LEDs 22, 23 and the second LED 24 and emits fluorescence using the emitted light from the first LEDs 22, 23 and the second LED 24 as excitation light. The phosphor layer 28 of this embodiment is formed by dispersing powder obtained by mixing five types of phosphors at a predetermined ratio in silicone resin (e.g., S111 manufactured by Mitsubishi Chemical Corporation), applying the powder directly to the emission surfaces of the first LEDs 22, 23 and the second LED 24, and curing the powder by heating.
3 is a diagram showing the light intensity distribution (emission spectrum) of five types of phosphors used in phosphor layer 28 of the present embodiment. Figures 3(a) to (e) show normalized emission spectra of a blue phosphor (Figure 3(a)), a blue-green phosphor (Figure 3(b)), a β-sialon phosphor (Figure 3(c)), an α-sialon phosphor (Figure 3(d)), and a red phosphor (Figure 3(e)) used in phosphor layer 28 of the present embodiment.
As shown in FIG. 3A, the blue phosphor of the phosphor layer 28 uses the emitted light from the first LEDs 22 and 23 and the second LED 24 as excitation light to emit fluorescent light with a peak wavelength of 466.2 nm.
As shown in FIG. 3B, the blue-green phosphor of the phosphor layer 28 uses the emitted light from the first LEDs 22 and 23 and the second LED 24 as excitation light to emit fluorescent light with a peak wavelength of 504.00 nm.
As shown in FIG. 3C, the β-sialon phosphor of the phosphor layer 28 uses the emitted light from the first LEDs 22 and 23 and the second LED 24 as excitation light to emit fluorescent light with a peak wavelength of 541.52 nm.
As shown in FIG. 3D, the α-sialon phosphor of the phosphor layer 28 uses the emitted light from the first LEDs 22 and 23 and the second LED 24 as excitation light to emit fluorescent light with a peak wavelength of 593.21 nm.
As shown in FIG. 3E, the red phosphor of the phosphor layer 28 uses the emitted light from the first LEDs 22 and 23 and the second LED 24 as excitation light to emit fluorescent light with a peak wavelength of 674.20 nm.
In this way, when the emitted light (excitation light) from the first LED 22, 23 and the second LED 24 is incident on the phosphor layer 28, fluorescence is emitted according to the emission spectra of the blue phosphor, blue-green phosphor, β-sialon phosphor, α-sialon phosphor, and red phosphor. Note that the intensity of the fluorescence emitted from the phosphor layer 28 is affected by the intensity of the excitation light from the first LED 22, 23 and the second LED 24, the filling amount of each phosphor in the phosphor layer 28, and the film thickness of the phosphor layer 28, but in this embodiment, the intensity of the emitted light from the first LED 22, 23 and the second LED 24 (i.e., the drive current) is adjusted so that the spectrum of each fluorescence overlaps with the spectrum of the adjacent fluorescence and the combined spectrum is approximately equal to the emission spectrum of the halogen lamp in the visible range.
In addition, of the excitation light incident on the phosphor layer 28 (i.e., the light emitted from the first LED 22, 23 and the second LED 24), a portion of the excitation light that is not converted into fluorescence is mixed with the fluorescence generated within the phosphor layer 28 and emitted from the exit surface of the phosphor layer 28.

Returning to Fig. 2, the optical filter 29 is a sector-shaped light-absorbing filter made of glass and arranged so as to cover the entire first LED 22, part of the first LED 23, and part of the second LED 24 (i.e., arranged so as to partially cover the first light-emitting element), which have a phosphor layer 28 and emit fluorescence. Fig. 4 is a diagram showing the spectral transmittance of the optical filter 29.
As shown in FIG. 4, in this embodiment, a sharp cut filter (sharp cut filter: Y44 manufactured by HOYA CORPORATION) that transmits light with a wavelength of 440 nm or more and cuts (absorbs) light with a wavelength of less than 440 nm was used as the optical filter 29 after being processed to a thickness of 0.5 mm.
In addition, the optical filter 29 of this embodiment is arranged so as to cover the entire first LED 22, a part of the first LED 23, and a part of the second LED 24, and is finally fixed on the dam material 27 by an adhesive, but before fixing, the relative position of the optical filter 29 with respect to the first LED 22, 23, and the second LED 24 is adjusted. Specifically, while monitoring the intensity of the excitation light that does not pass through the optical filter 29 (i.e., the light emitted from the first LED 23 and the second LED 24 that has not been converted into fluorescence by the phosphor layer 28 and does not pass through the optical filter 29) and the intensity of the fluorescence that passes through the optical filter 29 (light converted into fluorescence by the phosphor layer 28), the optical filter 29 is moved parallel to the substrate 21 (i.e., in the X-axis direction and the Y-axis direction), and the area covering the first LED 23 and the area covering the second LED 24 are finely adjusted, thereby adjusting the emission intensity of the first wavelength (e.g., 405 nm) and the emission intensity of the second wavelength (e.g., 385 nm). In this embodiment, the ratio of the peak intensity of the light of the first wavelength (eg, 405 nm) to the peak intensity of the fluorescent light is adjusted to a predetermined value (eg, 20 to 100%).
In this manner, in this embodiment, an optical filter 29 is provided to prevent excitation light with an intensity higher than necessary from being emitted from the light source device 1, and the relative position of the optical filter 29 with respect to the first LEDs 22, 23 and the second LED 24 is adjusted.
The fluorescence that has passed through the optical filter 29, the excitation light that has not passed through the optical filter 29, and the emitted light from the third LED 26 are incident on the incident end surface of a mixing rod 41 of a light guiding unit 40 attached to the front surface of the case 10, guided by an optical fiber bundle 42, and emitted from the exit end surface of the light guiding unit 40 (optical fiber bundle 42).

Fig. 5 is a diagram showing the intensity distribution (spectrum) of the outgoing light emitted from the exit end face of the light guide 40. The solid line in Fig. 5 is the emission spectrum of the light source device 1 of the present embodiment having the optical filter 29 (Fig. 5: "with filter"), and the dashed line in Fig. 5 is the emission spectrum of the light source device of the comparative example not having the optical filter 29 (Fig. 5: "without filter").
As shown in FIG. 5, in the comparative example ( FIG. 5 : "without filter"), the emitted light contains a spike-like light of a first wavelength (e.g., 405 nm) with a very high light intensity, whereas in the light source device 1 of this embodiment ( FIG. 5 : "with filter"), the spike-like light of the first wavelength (e.g., 405 nm) is suppressed, and it can be seen that the ratio of the peak intensity of light of the first wavelength (e.g., 405 nm) (approximately 0.2) to the peak intensity of the fluorescence (approximately 0.3) is approximately 67%.
It can also be seen that the emission spectrum of the light source device 1 of this embodiment is continuous in the wavelength range of 340 to 800 nm (that is, it covers a wide band from the near ultraviolet to the infrared region).
It should be noted that the spike-shaped light at approximately 340 nm in FIG. 5 is light emitted from the third LED 26. However, the light emitted from the third LED 26 does not pass through the phosphor layer 28 and the optical filter 29, but enters the light-guiding section 40 directly and is then emitted. Therefore, by changing the drive current supplied to the third LED 26, the emission intensity peak can be freely changed.

The above is a description of this embodiment, but the present invention is not limited to the above configuration, and various modifications are possible within the scope of the technical concept of the present invention.

For example, the light source device 1 of this embodiment is described as a device used in a biochemical analysis device, but the use is not necessarily limited to this, and it can also be used for other purposes that require light in a wide wavelength range.

In addition, the optical filter 29 in this embodiment is a light absorption filter that transmits light with a wavelength of 440 nm or more (i.e., fluorescence emitted from the phosphor layer 28) and cuts light with a wavelength of less than 440 nm (i.e., excitation light that transmits through the phosphor layer 28), but is not necessarily limited to this configuration, and a multilayer interference filter having equivalent spectral characteristics can also be applied.
Furthermore, the cutoff wavelength of the optical filter 29 is not necessarily limited to 440 nm, but may be appropriately selected based on the relationship between the excitation light and the fluorescent light.

In addition, in this embodiment, the emitted light of the first LED 22, 23 has a peak wavelength of 405 nm (first wavelength), the emitted light of the second LED 24 has a peak wavelength of 385 nm (second wavelength), and the emitted light of the third LED 26 has a peak wavelength of 340 nm (third wavelength), but this is not necessarily limited to this. For example, the emitted light of the first LED 22, 23 can have a peak wavelength of 400 to 420 nm, the emitted light of the second LED 24 can have a peak wavelength of 370 to 390 nm, and the emitted light of the third LED 26 can have a peak wavelength of 330 to 350 nm.

In addition, in this embodiment, the peak wavelengths of the five types of fluorescence emitted from the phosphor layer 28 are 466.2 nm, 504.00 nm, 541.52 nm, 593.21 nm, and 674.20 nm, but are not necessarily limited to these and can be changed within the ranges of, for example, 440 to 480 nm, 480 to 525 nm, 525 to 555 nm, 580 to 610 nm, and 660 to 690 nm, respectively.

In addition, in the phosphor layer 28 of this embodiment, five types of phosphors are used, but as long as the desired spectral characteristics (emission spectrum) are obtained, it is also possible to configure it with four, six or more types of phosphors by appropriately selecting and combining the phosphors.

In addition, in this embodiment, the emitted light from the first LED 22, 23 and the second LED 24 (i.e., light of two wavelengths) is used as excitation light to obtain fluorescence from the phosphor layer 28, but as long as the desired spectral characteristics (emission spectrum) are obtained, light of one type or three or more wavelengths may be used as excitation light (i.e., one or more LEDs that emit one type or three or more types of excitation light may be provided).

In addition, in this embodiment, one optical filter 29 is used and the optical filter 29 is arranged to cover the entire first LED 22, part of the first LED 23, and part of the second LED 24, but this configuration is not necessarily limited to this. For example, multiple optical filters 29 may be used and each optical filter 29 may be arranged to correspond to each of the first LED 22, the first LED 23, and the second LED 24. In this case, each optical filter 29 is arranged to cover all or part of the first LED 22, the first LED 23, and the second LED 24, respectively.

(Modifications of the Light Source Unit 20)
Fig. 6 is a diagram showing a light source unit 20A according to a modified example of the light source unit 20 of the present embodiment. As shown in Fig. 6, the light source unit 20A according to this modified example has two second LEDs 24 and 25 arranged in parallel with the first LEDs 22 and 23, and the optical filter 29 is rectangular and is arranged so as to cover a part of the first LED 22, the whole of the first LED 23, a part of the second LED 24, and the whole of the second LED 25, which are different from the light source unit 20 of the present embodiment.

As with the light source unit 20 of this embodiment, the relative position of the optical filter 29 of the light source unit 20A with respect to the first LEDs 22 and 23 and the second LEDs 24 and 25 is adjusted before fixing. Specifically, while monitoring the intensity of the excitation light that does not pass through the optical filter 29 (that is, the light emitted from the first LED 22 and the second LED 24 that is not converted into fluorescence by the phosphor layer 28 and does not pass through the optical filter 29) and the intensity of the fluorescence that passes through the optical filter 29 (the light converted into fluorescence by the phosphor layer 28), the optical filter 29 is moved in the Y-axis direction to finely adjust the area covering the first LED 22 and the area covering the second LED 24, thereby adjusting the emission intensity of the first wavelength (e.g., 405 nm) and the emission intensity of the second wavelength (e.g., 385 nm).
In this manner, in the light source unit 20A of this modified example, the output intensity of the first wavelength (e.g., 405 nm) and the output intensity of the second wavelength (e.g., 385 nm) can be adjusted by moving the optical filter 29 only in the Y-axis direction, making adjustment easier than in the light source unit 20 of the present embodiment.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

1: Light source device 10: Case 11: Exhaust port 12: Exhaust port 20: Light source unit 20A: Light source unit 21: Substrate 22: First LED
23: First LED
24: Second LED
25: Second LED
26: Third LED
27: Dam material 28: Phosphor layer 29: Optical filter 30: Heat sink 32: Heat dissipation fin 40: Light guide section 41: Mixing rod 42: Optical fiber bundle

Claims (11)

At least one first light-emitting element that emits excitation light in a first wavelength band;
a phosphor that is disposed in an optical path of the first light-emitting element, is excited by the excitation light, and emits fluorescence in a second wavelength band that is longer than the first wavelength band;
an optical filter disposed so as to partially cover the first light-emitting element and configured to cut a portion of the excitation light passing through the phosphor;
Equipped with
A light source device, characterized in that a relative position of said optical filter with respect to said first light emitting element is adjusted based on an intensity of said fluorescent light and an intensity of said excitation light. The light source device according to claim 1, characterized in that the excitation light is composed of multiple lights with different peak wavelengths. The light source device according to claim 2, characterized in that the multiple lights include light with a peak wavelength of 370 to 390 nm and light with a peak wavelength of 400 to 420 nm. The light source device according to claim 1, characterized in that the fluorescent light is composed of multiple lights with different peak wavelengths. The light source device according to claim 4, characterized in that the multiple lights include light with a peak wavelength of 440 to 480 nm, light with a peak wavelength of 480 to 525 nm, light with a peak wavelength of 525 to 560 nm, light with a peak wavelength of 560 to 630 nm, and light with a peak wavelength of 630 to 750 nm. Further comprising at least one second light emitting element that emits light in a third wavelength band;
2 . The light source device according to claim 1 , wherein the second light emitting element is disposed so that emitted light in the third wavelength band does not interfere with the optical filter. The light source device according to claim 6, characterized in that the third wavelength band has a shorter wavelength than the first wavelength band. The light source device according to claim 7, characterized in that the emitted light in the third wavelength band includes light with a peak wavelength of 330 to 350 nm. The light source device according to claim 1, characterized in that the relative position of the optical filter with respect to the first light-emitting element is adjusted so that the ratio of the peak intensity of the excitation light to the peak intensity of the fluorescence is 20 to 100%. The light source device according to claim 1, further comprising a light guide section that mixes and guides the light from the light source device. A light source device according to any one of claims 1 to 10, characterized in that the spectrum of light emitted from the light source device is continuous in the wavelength range of 340 to 800 nm.

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