JP6103966B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device including a light source.

Conventionally, a fiber light source in which a small solid light source and an optical fiber are combined has been proposed. Such a fiber light source is used as an illuminating device that emits light from the tip of a thin structure (for example, a thin tubular member).
Specifically, for example, Patent Document 1 discloses a light emitting device that includes a light source that emits excitation light, and a wavelength conversion member that absorbs at least a part of the excitation light and emits light having a different wavelength. It is disclosed.

  FIG. 14 is a configuration diagram of a light emitting device disclosed in Patent Document 1. As shown in the figure, the light emitting device of Patent Document 1 includes a light source 110, a light guide member 120, a wavelength conversion member 130, and a wavelength conversion member 140. The excitation light 101 emitted from the light source 110 passes through the lens 102 and is condensed on the emission unit. The condensed excitation light 101 is irradiated to the phosphor of the wavelength conversion member 140 through the light guide member 120 and the wavelength is converted.

  FIG. 15 is a diagram illustrating a structure of the wavelength conversion member 130 included in the light emitting device disclosed in Patent Document 1. A plurality of layers (a first layer 140A, a second layer 140B, and a third layer 140C) are disposed on the wavelength conversion member 140 in a cross section that intersects at least the introduction direction of the excitation light emitted from the light source. Yes. At least two of the plurality of layers are formed of materials having different resistance to excitation light. Here, each layer is formed of a mixture in which at least one selected from the group consisting of a phosphor, a diffusing agent, and a filler is mixed with a translucent material. The filler is for reflecting / scattering irradiated light. The filler improves color mixing and reduces color unevenness.

JP 2008-21973 A

  By the way, although the technique disclosed in Patent Document 1 achieves good color mixing and reduction in color unevenness, it is practically dark as illumination light. That is, when excitation light is reflected / scattered to such an extent that color unevenness is reduced and color mixing is achieved in each layer of the wavelength conversion member 140, a lot of light is reflected back and re-enters the light guide member. That is, back light that does not contribute as illumination light is generated. Furthermore, when the illumination device is used as a light source in an endoscope, it is necessary to realize a wide light distribution as well as good color mixing and color unevenness reduction.

  The present invention has been made in view of the above circumstances, and provides an illumination device that achieves good color mixing and reduction in color unevenness, maintains predetermined brightness, and realizes a wide range of light distribution. For the purpose.

In order to achieve the above object, a lighting device according to the first aspect of the present invention comprises:
A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Equipped with,
The light distribution matching unit is disposed at least around the optical axis, and has diffusion particles that expand the light distribution of the light source light passing therethrough,
When the direction in which the light source light is emitted with the strongest intensity is defined as the front and the opposite direction is defined as the rear,
The light distribution matching unit is installed in front of the wavelength conversion unit,
It is characterized by that.
In order to achieve the above object, a lighting device according to the second aspect of the present invention includes:
A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Comprising
The light distribution matching unit selectively diffuses light that passes at least around the optical axis of the light source light to expand the light distribution.
It is characterized by that.
In order to achieve the above object, a lighting device according to the third aspect of the present invention includes:
A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Comprising
The plurality of light sources are two light sources,
The wavelength conversion unit is composed of two types of wavelength conversion members that perform different wavelength conversions,
At least one wavelength conversion member of the two types of wavelength conversion members does not perform wavelength conversion of light source light emitted from any one of the two light sources.
It is characterized by that.
In order to achieve the above object, a lighting device according to the fourth aspect of the present invention includes:
A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Comprising
When the direction in which light travels along the optical axis is defined as the front, the opposite direction is defined as the rear, and the direction perpendicular to the optical axis is defined as the side,
A reflection part that reflects light is provided outside the optical path of the light source light and in a planar shape having a predetermined inclination with respect to the optical axis at the side or rear of the wavelength conversion part. ,
The reflecting unit selectively matches the light distribution of the light source light by selectively narrowing the light distribution of the wavelength-converted light.
It is characterized by that.

  According to the present invention, it is possible to provide an illuminating device that achieves good color mixing and reduction in color unevenness, maintains a predetermined brightness, and realizes a wide range of light distribution.

FIG. 1 is a diagram illustrating a configuration example of a lighting device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the concept of light distribution matching between the yellow converted light L2 and the blue transmitted light L1. FIG. 3 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the first modification. FIG. 4 is a diagram illustrating a configuration example of the tip unit of the illumination device according to the second modification. FIG. 5 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the third modification. FIG. 6 is a diagram illustrating a configuration example of the tip unit of the illumination device according to the third modification. FIG. 7 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the fourth modification. FIG. 8 is a diagram illustrating a configuration example of the tip unit of the lighting apparatus according to the fifth modification. FIG. 9 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the sixth modification. FIG. 10 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the seventh modification. FIG. 11 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the seventh modification. FIG. 12 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the seventh modification. FIG. 13 is a diagram illustrating a configuration example of the tip unit of the lighting device according to the eighth modification. FIG. 14 is a configuration diagram of a conventional light emitting device disclosed in Patent Document 1. In FIG. FIG. 15 is a diagram illustrating a structure of a wavelength conversion member included in a conventional light emitting device disclosed in Patent Document 1.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration example of a lighting device according to an embodiment of the present invention. As shown in FIG. 1, the illumination device according to the present embodiment includes a light source unit 1 and a tip unit 2.
The light source unit 1 includes a first light source 10-1, a second light source 10-2, a first light guide member 11-1, a second light guide member 11-2, an optical coupler 13, and a third light guide. It has the optical member 11-3 and a condensing lens (not shown).

  The first light source 10-1 is a light source that emits first light source light, and its light exit end is optically connected to the optical coupler 13 via the first light guide member 11-1. When the first light source 10-1 emits the first light source light, white light is emitted from the tip unit 2 to the irradiation object 90 side, and the irradiation object 90 is illuminated.

Specifically, for example, an LED light source or a laser light source is preferably used as the first light source 10-1 so that light can be incident on a light guide member having a small incident port with high efficiency.
The second light source 10-2 is a light source that emits second light source light, and its light exit end is optically connected to the optical coupler 13 via the second light guide member 11-2. When the second light source 10-2 emits the second light source light, the second light source light is diffused in the tip unit 2 and emitted toward the irradiation object 90, and the irradiation object 90 is illuminated.

Specifically, it is preferable to use, for example, an LED light source or a laser light source as the second light source 10-2, similarly to the first light source 10-1.
The first light guide member 11-1 has one end optically connected to the first light source 10-1 via a condenser lens (not shown) and the other end optically connected to the optical coupler 13. The first light source light from the first light source 10-1 is guided to the optical coupler 13. Specifically, for example, a multimode optical fiber having a core diameter of 50 μm and a numerical aperture FNA = 0.2 may be used as the first light guide member 11-1.

  The second light guide member 11-2 has one end optically connected to the second light source 10-2 via a condenser lens (not shown) and the other end optically connected to the optical coupler 13. The second light source light from the second light source 10-2 is guided to the optical coupler 13. Specifically, as the second light guide member 11-2, for example, a multimode optical fiber having a core diameter of 50 μm and a numerical aperture FNA = 0.2 may be used as in the first light guide member 11-1. .

  The optical coupler 13 is, for example, an optical coupler using a dielectric mirror or fiber, or an optical waveguide manufactured by a photolithography method or the like, and includes two light guide members (in this example, the first light guide member 11-1 and the first light guide member 11). The light emitted from the two light guide members 11-2) is mixed and incident on one light guide member (third light guide member 11-3) with high efficiency.

  The third light guide member 11-3 guides the light emitted from the optical coupler 13 and causes the light to enter the light source light incident portion 28 of the tip unit 2. Specifically, the third light guide member 11-3 has, for example, a core diameter of 50 μm and a numerical aperture FNA = 0.2, like the first light guide member 11-1 and the second light guide member 11-2. A multimode optical fiber or the like may be used.

By the way, the tip unit 2 includes a holder 20, a transparent member 21, a wavelength conversion member 23, a diffusion member 24, a reflection unit 25, a light source light incident unit 28, and an illumination light emission unit 29.
Here, for convenience of explanation, axes and directions are defined as follows. That is, the axis where the light source light that enters and travels through the through hole of the holder 20 from the center of the light source light emission end of the third light guide member 11-3 travels the tip unit with the maximum intensity is referred to as the “optical axis”. Called. The direction in which the light source light travels along this optical axis is defined as “front”, and the opposite direction is defined as “rear”. A direction perpendicular to the optical axis is defined as “lateral”.

  The holder 20 is a holder that accommodates each component of the tip unit 2, and has a tapered through-hole with the optical axis as a central axis. A reflection portion 25 that reflects light is provided on the entire inner wall of the through hole. The rear opening of the through hole is a light source light incident portion 28, and the front opening is an illumination light emitting portion 29.

  Specifically, as a material of the holder 20, in order to hold the transparent member 21, the wavelength conversion member 23, and the like without misalignment and to efficiently dissipate heat generated by the wavelength conversion of the wavelength conversion member 23, for example, metal or the like is used. It is preferable to use it.

  The transparent member 21 is a member that efficiently transmits visible light provided on the light source light incident portion 28 side in the through hole of the holder 20. Examples of the material of the transparent member 21 include an epoxy resin, a silicone resin, and inorganic glass.

  The wavelength conversion member 23 has a frustoconical shape whose side shape coincides with the inner wall of the through hole, and is bonded to the reflecting portion 25. The wavelength conversion member 23 has a function of being excited by the incident blue light and emitting yellow converted light L2 as the first wavelength converted light. Since these blue light and yellow light have a complementary color relationship, their mixed light is white light.

  That is, a part of blue light irradiated to the wavelength conversion member 23 is converted into yellow light (yellow conversion light L2 is generated), and is emitted from the wavelength conversion member 23 isotropically at 360 °. Reflecting portions 25 that reflect the yellow converted light L2 are provided on the entire surface of the inner wall of the through hole on the side and rear of the wavelength conversion member 23. Accordingly, the yellow converted light L2 is reflected forward.

On the other hand, the blue light that has not been converted into yellow light by the wavelength conversion member 23 passes through the wavelength conversion member 23 without being excited by the wavelength conversion member 23, and the first light source transmitted light (blue transmitted light L1) is converted into the wavelength conversion member. Is injected forward.
As described above, the wavelength conversion member 23 emits yellow converted light L2 and blue transmitted light L1 forward.

  As a specific material of the wavelength conversion member 23, for example, an oxide phosphor having a Ce (cerium) activated garnet crystal structure, for example, a material that fluoresces yellow when irradiated with blue light by the first light source 10-1. YAG, TAG) and the like. These materials are materials capable of absorbing yellow light from 430 nm to 470 nm and emitting yellow fluorescence. Accordingly, the wavelength conversion member 23 made of these materials is excited by the first light source light (blue light) near 450 nm, but not excited by the second light source light (purple light) near 415 nm.

  In addition, since such phosphor materials generally have a particulate form of several μm to several tens of μm, they are dispersed in a transparent material such as a resin, or the phosphor material itself is sintered. It is preferable to install ceramics. Since these materials generally have a high refractive index, a light diffusing function can be exhibited by providing a difference in refractive index from a transparent material. However, in the case of adopting a configuration in which a part of blue light is used as a part of illumination light by transmitting the wavelength conversion member 23 as in this example, the density is increased too much or the thickness is increased. It is preferable not to do. Accordingly, in this case, the light diffusion function is somewhat limited.

  The diffusing member 24 has a substantially cylindrical shape, and is provided in an area of the through hole of the holder 20 in front of the wavelength conversion member 23 and only in the vicinity of the optical axis. With this configuration, most of the blue transmitted light L1 is selectively expanded in light distribution. Here, the light distribution magnification depends on the shape and refractive index of the diffusing member 24, the particle concentration, and the like.

  Specifically, as the diffusing member 24, it is preferable to use transparent and high refractive index particles such as alumina particles and SiO2 particles. Specifically, the particle size is desirably several μm, and by using such particles as the diffusing member 24, it is easy to express Mie scattering with less wavelength dependency in the scattering characteristics, and the first light source light and the second light source light Diffusion can be matched efficiently. Since the dispersion concentration and thickness of the diffusing member 24 can be set arbitrarily, the light distribution of the two types of light emitted from the wavelength conversion member 23 is designed to match.

  The diameter of the diffusing member 24 is preferably designed according to the light distribution of the light source light emitted from the third light guide member 11-3. This is because the light source light that has been transmitted without being diffused by the wavelength conversion member 23 should be diffused, so that the diffusion member 24 has a light distribution angle that includes most of the light source light from the third light guide member 11-3. It is preferable that the beam spot diameter formed on the bottom surface (the rear surface) and the diameter of the diffusing member 24 are substantially matched.

  The diameter of the diffusing member 24 may be equal to or smaller than the beam spot diameter. When the diameter of the diffusing member 24 is equal to or smaller than the beam spot diameter, only the light source light that has traveled substantially parallel to the optical axis is diffused by the diffusing member 24 and emitted from the illumination light emitting unit 29. The inclined light is not diffused excessively, and bright illumination light can be obtained.

Here, the beam spot refers to the front side of the wavelength conversion member 23 among the light source light that enters the tip unit 2 from the light source light incident portion 28 of the holder 20 and travels forward along the optical axis through various routes. Light source light that passes through a plane including the surface of the light source, and refers to an area that is transmitted at a light amount of 1 / e ² or more with respect to the light amount at the intersection (the point where the light amount is maximum) on the optical axis and the plane. Yes.

A transparent member similar to the transparent member 21 described above may be provided between the side surface of the diffusing member 24 and the inner wall surface of the through hole of the holder 20, or nothing may be provided.
By the way, since two types of light emitted from the wavelength conversion member 23 are wavelength converted light and the other is light source light, the light distribution is remarkably different. The blue transmitted light L1 is not suitable as illumination light because the light distribution is narrow. Further, since the blue transmitted light L1 has a different light distribution from the yellow converted light L2, there is ideally uneven color in the illumination light that should be white in the entire region, which is not desirable as illumination light.

In view of such a problem, in the illuminating device according to the present embodiment, the diffusing member 24 is provided in a region of the through hole of the holder 20 in front of the wavelength conversion member 23 and only in the vicinity of the optical axis, and the blue transmitted light L1. Is configured to selectively expand the light distribution.
The reflection portion 25 is a member that reflects light and is provided on the entire inner wall of the through hole of the holder 20 (provided to exhibit a tapered shape). Specifically, it is preferable to use a material that reflects all of violet light, blue light, yellow light, and the like with high efficiency, such as silver or aluminum, for example. With this configuration, the first light source light, the second light source light, and the first wavelength converted light (yellow converted light L2) are reflected by the reflecting unit 25.

  By the way, when the reflecting portion 25 is provided in a single layer perpendicular to the optical axis, the yellow converted light L2 is reflected forward without changing the tilt angle with respect to the optical axis while the light distribution is considerably wider than the blue transmitted light L1. The

  However, like the lighting device according to the present embodiment, the yellow converted light L2 emitted rearward from the wavelength conversion member 23 is effectively reflected forward by forming the reflecting portion so as to exhibit a tapered shape, And the light distribution is reduced. Here, the degree of light distribution reduction depends on the taper angle and taper shape of the wavelength conversion member 23, or the positional relationship of the wavelength conversion member with respect to the tapered reflection surface in the optical axis direction.

  Further, as described above, since the diffusing member 24 is formed only in a part in front of the wavelength converting member 23, a large portion of the yellow converted light L2 is not irradiated on the diffusing member 24, and the surrounding space ( Or, if a transparent member is provided, it is ejected forward from the transparent member). With the above-described configuration, the mixed light formed by matching the light distribution of the yellow converted light L2 and the blue transmitted light L1 (mixed light subjected to “light distribution matching”) is irradiated forward from the illumination light emitting unit 29. White light of the same color tone is realized with respect to the illumination angle. FIG. 2 is a diagram illustrating the concept of light distribution matching between the yellow converted light L2 and the blue transmitted light L1.

In addition, the site | part which forms the reflection part 25 is not restricted to the through-hole side of the holder 20, For example, you may form in the side of the transparent member 21 or the wavelength conversion member 23.
Here, the “light distribution matching” means that the light distributions of a plurality of lights having different spreads are brought close to each other. In this light distribution matching, it is preferable that the light distribution is brought close to a level at which effective color unevenness does not occur in the light in which the plurality of lights are mixed.

Hereinafter, a series of operations by the lighting apparatus according to the present embodiment will be described in detail.
When the first light source 10-1 is turned on, blue light (light having a wavelength of around 450 nm), which is the first light source light, is emitted from the first light source 10-1, and is transmitted through a condenser lens (not shown). 1 is incident on the light guide member 11-1 with high efficiency. Thereafter, the blue light is guided through the first light guide member 11-1 having a long and narrow diameter with high efficiency and is incident on the optical coupler 13.

  Then, the light incident on the optical coupler 13 from the first light guide member 11-1 and the second light guide member 11-2 is mixed with high efficiency by the optical coupler 13 and enters the third light guide member 11-3. Is done. The blue light enters the third light guide member 11-3 through the optical coupler and is guided, and is emitted from the light emitting end of the third light guide member 11-3 to the light source light incident portion 28 of the tip unit. .

  The blue light incident on the light source light incident portion 28 of the tip unit from the third light guide member 11-3 is incident on the transparent member 21 with a light distribution close to parallel light, and then the wavelength conversion member 23 has almost all the light quantity. Incident. Part of the blue light incident on the wavelength conversion member 23 is converted into yellow converted light L2 and emitted from the wavelength conversion member 23 isotropically at 360 °. The yellow converted light L <b> 2 is reflected forward by the reflecting portion 25 installed on the side and rear of the wavelength conversion member 23.

  On the other hand, the blue light that has not been excited by the wavelength conversion member 23 passes through the wavelength conversion member 23, and the blue transmitted light L1 is emitted forward from the wavelength conversion member. That is, the yellow converted light L <b> 2 and the blue transmitted light L <b> 1 are emitted forward from the wavelength conversion member 23.

  Here, the wavelength converted light (yellow converted light L2) emitted from the wavelength converting member and the light source light (blue transmitted light L1) are light that is significantly different in light distribution, but by the configuration related to the diffusing member 24 described above, Most of the blue transmitted light L1 is selectively distributed and expanded, and the yellow converted light L2 emitted isotropically from the wavelength conversion member 23 is reflected forward by the configuration related to the reflecting section 25 and is distributed. Is emitted from the illumination light emitting unit 29, and the mixed light of the blue transmitted light L1 and the yellow converted light L2, whose light distribution is matched, is emitted as white light having the same color tone at any illumination angle. Irradiated forward from the portion 29.

  On the other hand, when the second light source 10-2 is turned on, violet light (wavelength of about 415 nm), which is the second light source light, is emitted to the second light guide member 11-2 and has a wavelength in the same optical path as the first light source 10-1. The light enters the conversion member 23. Here, the optical path is a space through which the light source light travels mainly in the tip unit 2 until it directly irradiates the diffusing member 24, and is a space denoted by a symbol V in FIG.

As described above, since the violet light that is the second light source light is not excited by the wavelength conversion member 23, almost all of the violet light passes through the wavelength conversion member 23 without being wavelength-converted and enters the diffusion member 24.
Here, the diffusion degree of the blue light and the diffusion degree of the violet light are substantially matched by the diffusion member 24, and the light distribution of the blue transmitted light L1 and the purple transmitted light is substantially matched with the light distribution of the yellow converted light L2. The

Then, the mixed light (white light) of the first light source light (blue light) and the yellow converted light L2 when the first light source 10-1 is turned on, and the first light when the second light source 10-2 is turned on. The light distribution of the two light source lights (purple light) coincides with each other.
That is, two types of uniformly switchable illumination light (white illumination light and purple illumination light) have the same light distribution, and the observation area in observation using both illumination lights, the brightness distribution and contrast in the observation screen, and so on. , The two observation modes agree.

As described above, according to the present embodiment, it is possible to provide an illuminating device that achieves good color mixing and reduction in color unevenness, maintains predetermined brightness, and realizes wide light distribution. . Specifically, the lighting device according to the present embodiment has the following effects, for example.
Since the diffusing member 24 as the light distribution expanding portion is arranged on the optical path of the light source light, it is possible to selectively diffuse a plurality of types of light source light and maintain white light while maintaining a predetermined brightness. The respective white light distribution colors (blue light and yellow light) are made to coincide with each other to reduce the color unevenness of the white illumination light. Also, since the white light distribution during white observation and the special light distribution during special light illumination match each other, the observable areas of both in the observation mode using both lights match, The brightness distribution and contrast of the same.

  Since the diffusing member 24 is installed only around the optical axis, the diffusing member 24 selectively diffuses light in the light source light that passes through the optical axis and is substantially parallel to the optical axis. Loss of light due to excessive diffusion without diffusing wavelength-converted light with a wide angle of light more than necessary (the light that has been directed forward is diffused sideways or rearward, thereby reflecting part 25, transparent member 21, 3) is absorbed by the light guide member 11-3 and the like.

Since the diffusing member 24 is installed in front of the wavelength converting member 23, the distance from the light source light incident portion 28 is large, and the light scattered backward is incident on the third light guide member 11-3 and lost. This contributes to maintaining a predetermined brightness.
Since the diffusing member 24 is installed with a small diameter equal to or smaller than the beam spot drawn by the light source light, only the light source light is selectively distributed by selectively diffusing the light source light mainly transmitted around the optical axis. The light can be enlarged, and the wavelength-converted light having a wide light distribution angle is not diffused more than necessary, and light loss due to excessive diffusion can be minimized.

Since the emission point of the light source light irradiating the wavelength conversion member 23 and the diffusing member 24 is matched by the optical coupler described above, the illumination position is matched in addition to the matching of the illumination light distribution, and color unevenness is reduced. Realization of good color mixing is further promoted.
Since both the first light source 10-1 and the second light source 10-2 can be configured as laser light sources, bright light source light can be efficiently guided to the tip unit 2 (a predetermined brightness has been realized). Lighting device can be provided). The configuration in which energy is efficiently transmitted to the tip unit by the laser light and the illumination light is obtained by the processing by the tip unit 2 (light is diffused) contributes to the realization of good efficiency and power saving.

  The reflection part 25 formed in the taper shape is installed on the side and rear of the wavelength conversion member 23 of the tip unit 2 and outside the optical path of the two light source lights. Thereby, compared with the case where the reflection part perpendicular | vertical to an optical axis is formed in the back of the wavelength conversion member 23, the light inject | emitted from the wavelength conversion member 23 is reflected ahead, narrowing a light distribution angle. Is done. Therefore, the wavelength-converted light L2 having a wide light distribution can be brought close to the light distribution of the light source light L1 having a narrow light distribution, and the ratio of transmitting through the refractive index interface with air existing in the illumination light emitting unit 29 is increased. More light can be used as illumination light. That is, a brighter illumination device is realized.

  As the diffusion member 24, particles having a low light absorption rate and a high refractive index are used, and the diffusion member 24 is configured such that the concentration and thickness can be arbitrarily set, so that the illumination light is not lost. Light distribution can be expanded with high efficiency. In addition, color unevenness in white light is reduced, and observation areas, brightness, and contrast in a plurality of observation modes match.

The present invention has been described based on one embodiment. However, the present invention is not limited to the above-described embodiment, and it is needless to say that modifications / applications are possible within the scope of the gist of the present invention. Hereinafter, a modified example of the above-described embodiment will be described.
<< First Modification >>
Hereinafter, the lighting device according to the first modification of the embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation.

  FIG. 3 is a diagram illustrating a configuration example of the tip unit 2 of the lighting device according to the first modification. In the first modification, the tapered through hole in the holder 20 is formed not in a conical shape but in a dome shape (for example, a paraboloid shape). In detail, it is preferable to form the through-hole in the holder 20 in a paraboloid shape so that the yellow converted light L2 has a light distribution close to parallel light parallel to the optical axis.

  By configuring in this way, the light source light can also be light close to parallel light. Therefore, when the diameter of the emission portion of the third light guide member 11-3 is small, the optical axis and the rear side of the wavelength conversion member 23 Light is concentrated in the vicinity of one point where the surface intersects. With this configuration, the yellow converted light L2 emitted backward from the wavelength conversion member 23 becomes a point light source from the one point, and it becomes easy to bring the reflected light close to the light distribution close to parallel light again.

  The first modified example is reflected by the yellow converted light L2 emitted isotropically forward from the wavelength converting member 23 and the reflecting portion 25 formed on the front surface of the inner wall of the parabolic through hole of the holder 20. The light distribution of the mixed light with the yellow converted light L2 is particularly effective when the blue transmitted light L1 close to the parallel light is similar to the light distribution of the diffused light diffused by the diffusing member 24.

As described above, according to the first modification, the same effect as that of the illumination device according to the above-described embodiment can be obtained, and the reflected light can be easily brought close to the light distribution close to parallel light again. An apparatus can be provided.
<< Second Modification >>
Hereinafter, the lighting device according to the second modification of the embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation.

FIG. 4 is a diagram illustrating a configuration example of the tip unit 2 of the illumination device according to the second modification. In the second modification, the diffusion member 24 is not provided inside the holder 20 but is provided separately from the holder 20 and on the front side of the holder 20.
More specifically, for example, a substantially cylindrical glass 31 provided with a diffusion member 24 near the center in the longitudinal direction is installed as a cover glass for the holder 20.

As described above, according to the second modification, in addition to achieving the same effect as the lighting device according to the above-described embodiment, the diffusion member 24 can be manufactured as a separate body from the holder 20, It is possible to provide a lighting device that can be expected to reduce yield.
<< Third Modification >>
Hereinafter, the lighting device according to the third modification of the embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation.

  FIG. 5 is a diagram illustrating a configuration example of the tip unit 2 of the illumination device according to the third modification. In the third modified example, instead of providing the diffusing member 24 (instead of providing the scattering particles), the wavelength conversion member 23 is provided up to the illumination light emitting unit 29, and the portion related to the air interface of the illumination light emitting unit 29 is A diffusion region 24-1 having a minute uneven shape is provided. The light that has entered the diffusion portion 24-1 is diffused and emitted. Specifically, for example, only a portion of the illumination light emitting unit 29 that is irradiated with the light source light may be formed with a minute uneven shape that diffuses and emits the light source light.

  Instead of forming the minute uneven shape as shown in FIG. 5, a lens-shaped diffusion part 24-2 may be formed at a part related to the air interface of the illumination light emitting part 29 as shown in FIG. . FIG. 6 is a diagram illustrating a configuration example of the tip unit 2 of the illumination device according to the third modification.

As described above, according to the third modification example, the same effect as that of the lighting device according to the above-described embodiment can be obtained, and in addition to the structure in which the diffusing member including the diffusing particles is provided, it is perpendicular to the refractive index interface. As a result, it is possible to provide a proving device that can emit more light efficiently forward.
<< 4th modification >>
Hereinafter, a lighting device according to a fourth modification of an embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation. FIG. 7 is a diagram illustrating a configuration example of the tip unit 2 of the illumination device according to the fourth modification.

In the fourth modified example, instead of providing the diffusing member 24 (instead of providing the scattering particles), the wavelength converting member 23 is provided up to the illumination light emitting unit 29, and “means for selectively diffusing the light source light, which will be described later”. ".
That is, as shown in FIG. 7, for example, in the vicinity of the center in the longitudinal direction, a substantially cylindrical glass 31 provided with a diffusion member 24 is used as a cover glass for the holder 20 (separate from the holder 20) on the front side of the holder 20. Provide.

Furthermore, the reflection part 41 which reflects visible light is formed only in the vicinity of the optical axis in front of the wavelength conversion member 23 in the substantially cylindrical glass 31.
As described above, according to the fourth modification example, the same effect as that of the illumination device according to the above-described embodiment is obtained, and only the light source light is selectively reflected to the rear side, and the wavelength conversion member 23 is obtained. Thus, it is possible to provide a lighting device in which the yellow converted light L2 is diffused (the light distribution angle is expanded) and emitted from the front side.
<< 5th modification >>
Hereinafter, a lighting device according to a fifth modification of the embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation.

FIG. 8 is a diagram illustrating a configuration example of the tip unit 2 of the lighting device according to the fifth modification.
In the fifth modification, the diffusion particle diameter, the refractive index, the refractive index of the dispersion resin, etc. are adjusted so that only the violet light or blue light, which is the light source light, is preferentially diffused. A member 24-3 is provided.

  Specifically, for example, when the diffusion member 24-3 is configured using small diffusion particles from the μm order to the submicron order, scattering based on the Rayleigh scattering principle is given priority in diffusion by the diffusion member 24-3. The wavelength dependence of the scattering degree occurs. Utilizing this fact, the diffusion member 24-adjusts the diameter, refractive index, and refractive index of the dispersion resin of the diffusing particles, and preferentially diffuses only violet light and blue light as the light source light. 3 is configured.

  In addition, when comprising the diffusing member 24-3 in this way, it is not necessary to limit the position where the diffusing member 24-3 is provided to the position where the light source light is irradiated. Therefore, as shown in FIG. 8, the diffusing member 24-3 can be provided over the entire illumination light emitting portion 29 (over the entire front side of the wavelength conversion member 23).

As described above, according to the fifth modification, in addition to the same effect as the illumination device according to the above-described embodiment, only the light source light has priority due to the diffusion wavelength dependency of the diffusion member 24-3. It is possible to provide an illuminating device that realizes bright illumination light that is selectively selectively expanded in light distribution and yellow wavelength converted light is not significantly expanded in light distribution.
<< Sixth Modification >>
Hereinafter, an illuminating device according to a sixth modification of one embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation.

FIG. 9 is a diagram illustrating a configuration example of the tip unit 2 of the illumination device according to the sixth modification. In the sixth modified example, by providing a plurality of diffusion members 24-4 and 24-5 with a concentration gradient introduced (with a gradient in the diffusivity), two types of light source light can be emitted uniformly. To do.
For example, if the beam spot diameter of the violet light that is the light source light is narrower than the beam spot diameter of the blue light that is the light source light, the violet light irradiated with the narrow beam spot should be diffused with a larger diffusivity. is there.

Therefore, in the sixth modified example, the density at which the violet light efficiently expands the distribution of light in the area on the beam spot diameter of the violet light or smaller than the beam spot diameter (light distribution expansion degree suitable for violet light). ) Diffusion member 24-4.
Similarly, in the area corresponding to the beam spot diameter of blue light, a diffusing member 24-5 having a light distribution magnification smaller than that of the diffusing member 24-4 is installed. In other words, the diffusion member 24-5 on the blue light beam spot diameter has a lower dispersion concentration of the diffusion particles than the diffusion member 24-4 on the purple light beam spot diameter. 24-4 and 24-5 are installed.

As described above, according to the seventh modified example, the same effects as those of the lighting device according to the above-described embodiment can be obtained, and the beam spot diameters of the plurality of light source lights applied to the diffusing member can be mutually different. When different (for example, when the NA of the third light guide member 11-3 has wavelength dependency, when the refractive index of the transparent member and the diffusion member has wavelength dependency, the diffusion degree of the diffusion member has wavelength dependency) Even in such a case, it is possible to provide a lighting device capable of uniform light emission of the plurality of types of light source light.
<< Seventh Modification >>
Hereinafter, an illuminating device according to a seventh modification of the embodiment will be described. Note that differences from the embodiment will be described in order to avoid duplication of explanation.

10, 11, and 12 are diagrams showing a configuration example of the tip unit 2 of the lighting device according to the seventh modification. In the seventh modified example, similarly to the sixth modified example described above, a diffusion member in which a concentration gradient is introduced (a gradient is provided in the diffusivity) is provided.
That is, in the example shown in FIG. 10, the diffusion member 24-6 formed in a tapered shape is provided. In the example shown in FIG. 11, a diffusing member 24-7 formed in a dome shape is provided. In the example shown in FIG. 12, a diffusion member 24-8 formed in a step shape is provided.

  As shown in FIGS. 10 to 12, by providing diffusion members 24-6 to 24-8 whose diffusivity is adjusted by a physical structure, a plurality of types having different diffusivities as in the sixth modification example are provided. Therefore, a desired diffusivity distribution can be realized in a relatively simple manner without using any diffusion member.

As described above, according to the seventh modification, it is possible to provide an illumination device that has the same effect as the illumination device according to the sixth modification.
<< Eighth Modification >>
Hereinafter, a lighting apparatus according to an eighth modification of the embodiment will be described. In order to avoid duplication of explanation, differences from the sixth modification will be described.

FIG. 13 is a diagram illustrating a configuration example of the tip unit 2 of the illumination device according to the eighth modification. In the eighth modification, a plurality of wavelength conversion members are provided. That is, for example, as shown in the figure, the first wavelength conversion member 23-1 and the second wavelength conversion member 23-2 are installed.
The first wavelength conversion member 23-1 emits the first wavelength converted light by efficiently absorbing the light of the first light source 10-1. The second wavelength conversion member 23-2 emits the second wavelength converted light by efficiently absorbing the light from the second light source 10-2. The second wavelength conversion member 23-2 hardly absorbs and emits light from the first light source 10-1.

  With this configuration, when the first light source 10-1 is caused to emit light, the first light source transmitted light and the first wavelength converted light are emitted from the illumination light emitting unit 29. When the second light source 10-2 is caused to emit light, the second light source transmitted light, the second wavelength converted light, and the first wavelength converted light by excitation of the second light source light depending on the material type of the first wavelength converting member 23-1. Is injected in the same way.

Here, the first light source transmitted light, the first wavelength converted light, the second light source transmitted light, the second wavelength converted light, and all the light distributions of the first wavelength converted light by excitation of the second light source light are substantially the same. It is preferable.
Therefore, in the eighth modification, the light having the narrower light distribution out of the first light source transmitted light and the second light source transmitted light is selectively enlarged by the above-described configuration, and the wider light distribution is selected. As for the transmitted light, the straight light is diffused to some extent. Therefore, similarly to the above-described sixth modification, the light distribution is matched by the diffusion members 24-4 and 24-5 in which the concentration gradient is introduced (the diffusion degree is provided with the gradient).

  As described above, according to the eighth modification example, the same effect as that of the illumination device according to the fifth modification example described above is obtained, and the illumination light emission unit 29 is more uniform by the light emission of the first light source 10-1. It is possible to provide an illuminating device that can illuminate a special white color and can observe special light using illumination light of two colors by the light emitted from the second light source 10-2.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

    DESCRIPTION OF SYMBOLS 1 ... Light source part, 2 ... Tip unit, 10-1 ... 1st light source, 10-2 ... 2nd light source, 11-1 ... 1st light guide member, 11-2 ... 2nd light guide member, 11-3 ... 3rd light guide member, 13 ... Optical coupler, 20 ... Holder, 21 ... Transparent member, 23 ... Wavelength conversion member, 24, 24-3, 24-4, 24-5, 24-6, 24-7, 24- DESCRIPTION OF SYMBOLS 8 ... Diffusing member, 24-1, 24-2 ... Diffusion part, 25 ... Reflection part, 28 ... Light source light incident part, 29 ... Illumination light emission part, 31 ... Substantially cylindrical glass, 40 ... Wavelength conversion member, 90 ... Irradiation object.

Claims (15)

A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Equipped with,
The light distribution matching unit is disposed at least around the optical axis, and has diffusion particles that expand the light distribution of the light source light passing therethrough,
When the direction in which the light source light is emitted with the strongest intensity is defined as the front and the opposite direction is defined as the rear,
The light distribution matching unit is installed in front of the wavelength conversion unit,
A lighting device characterized by that. A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Comprising
The light distribution matching unit includes an illumination device, characterized in that to enlarge the selectively diffused by the light distribution of the light passing through the at least around the optical axis of the source light. Wherein the plurality of light sources, the lighting device according to claim 1 or 2, characterized in that it comprises an LED or laser light source. Lighting device according to any one of claims 1 to 3, characterized in that it comprises a light source optical multiplexing unit to be incident on a common waveguide multiplexes the light source light emitted from the plurality of light sources. Including a light source light combining unit for combining light sources emitted from the plurality of light sources to enter a common waveguide;
When the direction in which the light source light emitted from the emission end of the common waveguide is emitted with the strongest intensity is defined as the front, and the opposite direction is defined as the rear,
The lighting device according to claim 2 , wherein the light distribution matching unit is installed in front of the wavelength conversion unit. The light distribution matching unit is:
When projected onto a plane perpendicular to the optical axis, it has a circular shape, and is equal to or smaller than the beam spot diameter irradiated to the light distribution matching portion by the light source light emitted from the emission end of the common waveguide. The illumination device according to claim 4 , wherein the illumination device has a diameter of The illumination device according to any one of claims 1 to 6 , wherein the light distribution matching unit is formed of an internal diffusion member formed by mixing a group of materials having different refractive indexes. The lighting device according to claim 7, wherein the light distribution matching unit has a dome shape, a stepped shape, or a tapered shape having a height difference in the optical axis direction. The light distribution matching unit is provided with a concentration distribution in which the concentration on the optical axis is the highest and the concentration gradually decreases in a concentric manner in a direction perpendicular to the optical axis. The lighting device according to claim 7. The lighting device according to claim 6, wherein the light distribution matching unit is a concave portion and / or a convex portion formed on an air interface at an illumination light emitting end of the lighting device. When the direction in which the light source light emitted from the emission end of the common waveguide is emitted with the strongest intensity is defined as the front, and the opposite direction is defined as the rear,
The illumination device according to claim 6, wherein the light distribution matching unit includes a reflection unit that is installed in front of the wavelength conversion unit and that regularly or scatter-reflects the light source light. The light diffusivity, which is the degree of diffusion by the diffusing particles in the light distribution matching portion, has a dependency on the wavelength of incident light,
The lighting device according to claim 1, wherein the light distribution matching unit selectively and strongly diffuses light having a narrower light distribution among the light source light and the wavelength converted light. A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Comprising
The plurality of light sources are two light sources,
The wavelength conversion unit is composed of two types of wavelength conversion members that perform different wavelength conversions,
The two least one wavelength conversion member of the wavelength conversion member, the illuminating device, characterized in that not the source light emitted by the one light source of the two light sources and a wavelength conversion. A plurality of light sources emitting light sources having different wavelengths from each other;
A wavelength conversion unit that emits wavelength-converted light that has different absorptance with respect to the center wavelength of each light source light emitted from the plurality of light sources and is excited by incident light of a specific wavelength, and wavelength-converted the incident light;
A light distribution matching unit that matches and emits the light distribution of the light source light and the light distribution of the wavelength-converted light; and
Comprising
When the direction in which light travels along the optical axis is defined as the front, the opposite direction is defined as the rear, and the direction perpendicular to the optical axis is defined as the side,
A reflection part that reflects light is provided outside the optical path of the light source light and in a planar shape having a predetermined inclination with respect to the optical axis at the side or rear of the wavelength conversion part. ,
The reflective portion, by narrowing selectively the light distribution of the wavelength converted light, the illumination device characterized by aligning the light distribution of the light source light. The lighting device according to claim 14, wherein the reflecting portion is provided so as to exhibit a parabolic shape.

Images