JP5557883B2 - Light emitting device, lighting device, vehicle headlamp - Google Patents

Description

  The present invention relates to a light emitting device that functions as a high brightness light source.

  In recent years, research on light-emitting devices using semiconductor light-emitting elements such as light-emitting diodes (LEDs) and semiconductor lasers (LDs) as excitation light sources has become active.

  As an example of a technique related to such a light emitting device, there are lamps disclosed in Patent Documents 1 and 2. In the lamps described in Patent Documents 1 and 2, in order to realize a high-intensity light source, a semiconductor laser is used as an excitation light source, and excitation light generated from the excitation light source is irradiated onto a light emitting unit including a phosphor. It is converted into incoherent fluorescence and used as illumination light.

  In general, white light used as illumination light can be realized by mixing three colors satisfying the principle of equal colors, or mixing two colors satisfying a complementary color relationship. Based on the principle of the same color or complementary color, for example, white light can be realized by mixing the color of the laser light oscillated from the semiconductor laser and the color of the light emitted from the phosphor.

  Further, by using a semiconductor laser as an excitation light source, an excitation light source that oscillates high-power excitation light can be realized.

  As an example of a technique for realizing a vehicle headlamp using a white LED, there is a vehicle headlamp disclosed in Non-Patent Document 1. However, a single white LED has a problem that luminance and luminous flux are small. is there.

JP 2005-150041 A (released on June 9, 2005) JP 2003-295319 A (published on October 15, 2003)

Masaru Sasaki, “Application of White LED to Automotive Lighting”, Journal of Applied Physics, 2005, Vol. 74, No. 11, p. 1463-1466

  In the conventional lamps disclosed in Patent Documents 1 and 2, a plurality of excitation lights are guided to the same point of the phosphor, and the power of the excitation light applied to the minute light emitting portion including the phosphor is increased. Yes.

  However, the inventor has found that when the light emitting part is excited with high power and high power density such as focused laser light, the light emitting part deteriorates severely.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a light emitting device and the like that can realize high luminance and a long life.

In order to solve the above problems, the light emitting device of the present invention
A group of laser light sources for generating a plurality of laser beams;
A light emitting unit that generates light by being irradiated with each laser beam generated from the laser light source group;
A first optical system for guiding each laser beam generated from the laser light source group to the vicinity of the light emitting unit;
A second optical system that irradiates and distributes each laser beam guided by the first optical system to a predetermined light irradiation region in the light emitting unit,
The second optical system includes a convex lens having a concave surface on at least the light irradiation region side,
The first optical system has a surrounding structure surrounded by a light reflecting side surface that reflects each laser beam incident from one end, and a cross-sectional area at the other end is smaller than a cross-sectional area at the one end. A condensing member that guides each laser beam incident from the one end to the other end by the surrounding structure,
The first optical system and the second optical system are integrated light guide members,
Each laser beam generated from the laser light source group incident from one end of the light guide member on the first optical system side is guided to the other end of the light guide member on the second optical system side,
The other end on the second optical system side is characterized in that a light dispersion portion for irradiating each of the guided laser beams by dispersing them in the light irradiation region is formed.

The light emitting device of the present invention is as described above.
A group of laser light sources for generating a plurality of laser beams;
A light emitting unit that generates light by being irradiated with each laser beam generated from the laser light source group;
A first optical system for guiding each laser beam generated from the laser light source group to the vicinity of the light emitting unit;
A second optical system that irradiates and distributes each laser beam guided by the first optical system to a predetermined light irradiation region in the light emitting unit,
The second optical system includes a convex lens having a concave surface on at least the light irradiation region side,
The first optical system has a surrounding structure surrounded by a light reflecting side surface that reflects each laser beam incident from one end, and a cross-sectional area at the other end is smaller than a cross-sectional area at the one end. A condensing member that guides each laser beam incident from the one end to the other end by the surrounding structure,
The first optical system and the second optical system are integrated light guide members,
Each laser beam generated from the laser light source group incident from one end of the light guide member on the first optical system side is guided to the other end of the light guide member on the second optical system side,
At the other end on the second optical system side, there is formed a light dispersion portion that irradiates and distributes each of the guided laser beams to the light irradiation region.

  Therefore, it is possible to provide a light emitting device and the like that can realize high luminance and a long lifetime.

It is a schematic diagram which shows schematic structure of one Embodiment of the light-emitting device in this invention. (A) is the circuit diagram of an example (LED) of the excitation light source which comprises an excitation light source group regarding the said light-emitting device, (b) is a front view which shows the general view of the said LED, (c) is It is a circuit diagram of the other example (LD) of the said excitation light source, (b) is a schematic diagram which shows the external appearance of the said LD. (A) is a schematic diagram which shows other embodiment of the light-emitting device in this invention, (b) is a schematic diagram which shows other embodiment of the light-emitting device in this invention. (A) is a figure which shows the light emission tendency of said LD, (b) is a perspective view of the light emission part in the said light-emitting device, (c) is an emitted light when a 2nd optical system does not exist. (D) is a figure which shows an example of the emitted light when a 2nd optical system exists, (e) is other than the emitted light when a 2nd optical system does not exist (F) is a figure which shows the other example of the emitted light in case a 2nd optical system exists. It is a schematic diagram which shows other embodiment (illuminating device) of the light-emitting device in this invention, (a) part shows the structure, (b) part shows an example of the ferrule which fixes a some optical fiber. . (A) is a schematic diagram of an example (substantially rectangular parallelepiped shape) of the light emission part in the said light-emitting device, (b) is a schematic diagram which shows an example of the light irradiation area | region of the said light emission part, (c) is It is a schematic diagram which shows the other example of the said light irradiation area | region. (A) is a schematic diagram which shows the light distribution pattern requested | required of the headlamp (low beam / high beam) for motor vehicles, (b) is a figure which shows the light distribution characteristic requested | required by the low beam of the headlights for motor vehicles. is there. (A) is a schematic diagram of the other example (shape of the light emission part for low beams) in the said light-emitting device, (b) is a schematic diagram which shows an example of the light irradiation area | region of the said light emission part. (C) is a schematic diagram which shows an example of the light irradiation method to the said light irradiation area | region. It is the schematic which shows the external appearance of the light emission unit with which the laser downlight which is one Embodiment of this invention is equipped, and the conventional LED downlight. It is sectional drawing of the ceiling in which the said laser downlight was installed. It is sectional drawing of the said laser downlight. It is sectional drawing which shows the example of a change of the installation method of the said laser downlight. It is sectional drawing of the ceiling in which the said LED downlight was installed. It is a figure for comparing the specifications of the laser downlight and the LED downlight. It is a figure which shows a mode that the lens diameter required for the headlamp for motor vehicles was compared with the kind of lamp. (A) is the figure which compared the performance with the kind of lamp, (b) is a figure which shows an example of the external appearance structure of the conventional automotive headlamp, (c) is the said light-emitting device (illumination) It is a figure which shows an example of an external appearance structure of the headlamp for motor vehicles at the time of using an apparatus.

  One embodiment of the present invention will be described below with reference to FIGS. Configurations other than those described in the following specific items may be omitted as necessary, but are the same as the configurations described in other items. For convenience of explanation, members having the same functions as those shown in each item are given the same reference numerals, and the explanation thereof is omitted as appropriate.

  Note that a light emitting device (lighting device, vehicle headlamp) 110, a light emitting device (lighting device, vehicle headlight) 120A, a light emitting device (lighting device, vehicle headlight) 120B, and a lighting device described below. Each form such as (light emitting device, vehicle headlamp) 140 will be described as a lighting device suitable for use in a headlamp for a vehicle or the like, or a light emitting device portion of a vehicle headlamp. Forms made into are not limited to these forms, and can be applied to lighting devices and lighting fixtures other than lighting devices or vehicle headlamps.

[1. (Outline configuration of light emitting device)
First, a schematic configuration of a light emitting device 110 according to an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a schematic diagram showing a schematic configuration of a light emitting device 110 according to an embodiment of the present invention.

  As shown in FIG. 1, the light emitting device 110 generates incoherent light (light) L3, and includes a laser diode group (excitation light source group) 10, a first light guide unit (first optical system) 20, a convex shape. A cylindrical lens (second optical system) 30 and a rectangular parallelepiped light emitter (light emitting unit) 40 are provided.

  The laser diode group 10 is an example of an excitation light source group in which a plurality of excitation light sources are gathered. In the present embodiment, the laser diode group 10 includes an LD chip (excitation light source) 11 having a total of five single light emitting ends. Each LD chip 11 generates laser light (excitation light) L0.

  1 shows a state in which the LD chip 11 shown in FIG. 1 is enclosed in a package having a diameter of 5.6 mm.

  The LD chip 11 is a semiconductor laser with one chip and one stripe, and the oscillation wavelength is 405 nm. The optical output of the LD chip 11 is 1.0 W, the operating voltage is 5 V, and the current is 0.6 A.

  The oscillation wavelength of the LD chip 11 only needs to have an oscillation wavelength in a blue-violet region or a blue region (380 nm or more and 490 nm or less).

  Moreover, although it is difficult to produce a high-quality short-wavelength laser with a wavelength of 380 nm or less with the current technology, an LD chip 11 designed to oscillate with a wavelength of 380 nm or less may be used as a light source in the future.

  As a result, the total luminous flux of a total of five LD chips 11 becomes a luminous flux of the entire light source by simple calculation, so that the luminous flux of the entire light source is increased by about 5 times compared to the case where only a single LD chip 11 is used. can do. However, the performance of the LD chip 11 is assumed to be equal.

  In the present embodiment, the number of LD chips 11 constituting the laser diode group 10 is five. However, the number of LD chips 11 is not limited to this, and may be any of 2 to 4 or 6 or more. Also good.

  As an example of the excitation light source group, a plurality of LD chips 11 (one chip and one stripe) having a single light emitting end are spatially separated as in the laser diode group 10. A plurality of excitation light sources [light emission point (excitation light source) 102] may be integrated into a single (one chip) semiconductor laser as in an LD chip 101 (one chip plural stripes) described later. A configuration in which a plurality of laser beams L0 are generated from the LD chip 101 may be employed.

  Further, each excitation light source constituting the excitation light source group may generate a coherent laser beam L0 as in the LD chip 11 of the present embodiment, or generate incoherent excitation light as in an LED. It may be what you do.

  In addition, the excitation light source group may be composed of only LD or LED, or may be a mixture of LD and LED.

  Next, the first light guide unit 20 guides each laser beam L0 incident from the light incident unit (one end of the first optical system) 201 to the light emitting unit (the other end of the first optical system) 202. The emitted light (excitation light) L1 derived from each of the guided laser beams L0 is emitted from the light emitting unit 202.

  Thereby, by adjusting the distance from the light incident part 201 to the light emitting part 202 of the first light guide part 20, the laser diode group 10 and the rectangular parallelepiped light emitter 40 are spatially separated at an arbitrary interval. Therefore, it is possible to prevent the rectangular parallelepiped light emitting body 40 from being deteriorated due to the influence of heat generated in the laser diode group 10.

  Further, since the laser light L0 oscillated from the LD chip 11 is coherent light, the directivity is strong, and the light emitting device 110 can condense and use the laser light L0 as the excitation light without waste.

  Therefore, a very small rectangular parallelepiped light emitter 40 can be formed, and as a result, a light emitting device 110 having a small size and an extremely high brightness can be realized.

  Therefore, by applying the light emitting device 110 using such an LD chip 11 as an excitation light source to a vehicle headlamp, various merits such as a reduction in the size of the headlamp for a vehicle or the like are born.

  Note that the first light guide 20 shown in FIG. 1 does not specifically describe how the laser light L0 is guided from the light incident part 201 to the light emitting part 202.

  However, specific examples of the first light guide 20 can be broadly divided into three forms.

  In the first embodiment, the first light guide unit 20 is configured with a known light collecting element (first optical system) or the like so that the cross-sectional area of the light emitting unit 202 is smaller than the cross-sectional area of the light incident unit 201. It is.

  For example, a truncated pyramid-shaped condensing part (first optical system) 21A, a Fresnel lens (first optical system), a transmission diffraction grating (first optical system), and the like described below can be exemplified.

  In the second embodiment, the cross-sectional area of the light incident part 201 and the cross-sectional area of the light emitting part 202 are substantially the same, and the first light guide part 20 is formed by a bundle of a plurality of light guide members that guide each laser beam L0. This is the case.

  For example, an optical fiber bundle (first optical system, a plurality of optical fibers) 22 described below and a bundle of waveguides (first optical system) can be exemplified.

  A 3rd form is a case where the 1st light guide part 20 is comprised by the combination of the several light guide member mentioned above and a condensing element.

  For example, for example, a combination of the optical fiber bundle 22 and the condensing element (first optical system) can be exemplified.

  A more specific form of the first light guide 20 will be described later.

  In addition to the specific form described later, the first light guide unit 20 (light condensing element) is configured by a known Fresnel lens (first optical system) and the like, and the laser light L0 is emitted from the light incident unit 201. The first light guide unit 20 may be formed of a known transmission type diffraction grating (first optical system) or the like to emit laser light L0 from the light incident unit 201. The light may be condensed on the unit 202.

  The concave-convex pattern of the Fresnel lens and the grating pattern of the transmission diffraction grating may be appropriate patterns that can focus the laser light L0 from the light incident part 201 to the light emitting part 202.

  When the light incident portion 201 is a Fresnel lens or a transmissive diffraction grating, for example, by combining an LD chip (excitation light source group) 101 having a plurality of light emitting points 102 in one chip described below, these optical systems are combined. As well as reducing the size, the mass productivity can be increased and the manufacturing cost can be reduced.

  That is, the “first optical system” including the first light guide unit 20 may be constituted by, for example, a single optical component that guides each laser beam L0 incident from one end to the other end. The first optical component that guides each laser beam L0 incident from one end to the other end and emits the guided laser beam L0 as the outgoing light L1 from the other end, and the first optical component incident from one end You may comprise with several optical components like the combination with the 2nd optical component which guides the emitted light L1 radiate | emitted from the other end to the other end. In addition, the “first optical system” may be configured by bundling a plurality of optical components as in the example of the optical fiber bundle 22 described later.

  In the present embodiment, a case where the convex cylindrical lens 30 that is a single optical component is used as an example of the “second optical system” will be described. The “second optical system” is defined by the first light guide unit 20. Any light source can be used as long as the emitted light L1 derived from each of the laser light L0 guided can be distributed and irradiated to the light irradiation region of the rectangular parallelepiped light emitting body 40 as the irradiation light L2. For example, the first light guide unit The emitted light L1 guided by the light 20 may be composed of a plurality of optical components as in the case of irradiating the light irradiation region in a distributed manner using two lenses.

  Further, as in the above-described example, the “first optical system” and the “second optical system” may be configured by two or more independent optical components, or a truncated pyramid-shaped optical member (light guide member, (1st optical system, 2nd optical system) You may comprise by one optical component integrated like 21B.

  A convex cylindrical lens (second optical system, convex lens having a convex surface having a vertical axis) 30 is a plano-convex cylindrical lens having an axis in the vertical direction, and the outgoing light L1 emitted from the light emitting unit 202 is horizontally directed. Disperse and irradiate the rectangular parallelepiped light emitter 40 (light irradiation region not shown) as irradiation light (excitation light) L2.

  In the present embodiment, a plano-convex cylindrical lens having an axis in the vertical direction is employed as an example of the “second optical system”. However, the present invention is not limited thereto, and examples thereof include a biconvex lens having an axis in the vertical direction, a plano-convex lens, A convex meniscus lens or the like may be used.

  According to the convex cylindrical lens 30, even when the horizontal spread of the emitted light L1 is larger than the horizontal width of the light irradiation region, the shape is long in the horizontal direction of the light irradiation region of the rectangular parallelepiped light emitter 40. Accordingly, the irradiation light L2 can be distributed and irradiated on the light irradiation region.

  The reason why the emitted light L1 is dispersed in the horizontal direction is to irradiate the irradiation light L2 over the entire rectangular parallelepiped light emitting body 40 that is long in the horizontal direction without being concentrated at a specific point in the light irradiation region. is there.

  In other words, the emitted light L1 is dispersed in the horizontal direction by irradiating the irradiation light L2 so as not to excite a part of the cuboid-like light emitter 40 at a pinpoint, and with the intensity that does not deteriorate the cuboid-like light emitter 40. This is because the entire region is irradiated. It should be noted that the intensity of the light intensity distribution when irradiated with the irradiation light L2 may be limited to some extent as long as the rectangular light-emitting body 40 does not deteriorate.

  In this embodiment, since it is assumed that the size of the light irradiation region is larger than the size of the light emitting unit 202, the irradiation region L is irradiated with the irradiation light L2 while the irradiation area is expanded. In addition, when the size of the light irradiation area is smaller than the size of the light emitting portion 202, the irradiation area L2 may be irradiated with the irradiation light L2 while reducing the irradiation area using a lens having a light collecting function. .

  However, when irradiating the light irradiation region with the irradiation light L2 while reducing the irradiation area using a lens having a condensing function, be careful not to concentrate the irradiation light L2 on a specific point in the light irradiation region. To do. More specifically, it is only necessary to adjust the numerical aperture, focal length, arrangement position, etc. of a lens or the like having a condensing function so as not to focus on one point on the light irradiation region.

  Further, using a collimator lens or the like, the irradiation area L may be irradiated with the irradiation light L2 with a substantially constant irradiation area.

  Next, the rectangular parallelepiped light emitter 40 generates incoherent light L3 when irradiated with the irradiation light L2. That is, the rectangular parallelepiped light-emitting body 40 includes a phosphor that generates at least the incoherent light L3 when irradiated with the irradiation light L2.

  The size of the rectangular parallelepiped light-emitting body 40 is, for example, about horizontal × vertical × height = 3 mm × 1 mm × 1 mm when used for a vehicle headlamp.

  Moreover, although the rectangular parallelepiped light-emitting body 40 contains at least a phosphor as described above, it may be composed of only a single type of phosphor, or may be composed of a plurality of types of phosphor. .

  The rectangular parallelepiped light emitter 40 may be configured by dispersing a single type or a plurality of types of phosphors in an appropriate dispersion medium. The dispersion medium is preferably a solid. However, in the case where the phosphor is sealed in a light-transmitting rectangular parallelepiped container, the dispersion medium may be a liquid.

  As the dispersion medium, a translucent resin material is preferable, and a silicone resin can be exemplified. The ratio between the silicone resin and the phosphor is about 10: 1 by weight. The dispersion medium is not limited to a silicone resin, and may be a glass material including an inorganic glass material, or an organic / inorganic hybrid material.

  As described above, since the light emitting device 110 emits the emitted light L1 derived from each laser beam L0 in the horizontal direction to the light irradiation region of the rectangular parallelepiped light emitter 40 as the irradiation light L2, the light emitting device 110 The electrons in the low energy state are efficiently excited to the high energy state over the entire phosphor contained.

  Therefore, since the incoherent light L3 is generated from the rectangular parallelepiped light emitter 40 without unevenness, it is possible to realize a higher luminous flux and higher brightness of the light emitting device 110 compared to the case where the single LD chip 11 is used.

  In addition, the emitted light L1 derived from each laser beam L0 is not irradiated in a concentrated manner on one point on the light irradiation region of the rectangular parallelepiped light emitter 40, and is applied to the light irradiation region via the first light guide 20 and the convex cylindrical lens 30. Since the irradiation is performed in a dispersed manner, it is possible to prevent the rectangular parallelepiped light-emitting body 40 from being deteriorated by irradiating each laser beam L0 in a concentrated manner at the same point.

  Based on the above, it is possible to provide the light emitting device 110 that can realize high luminous flux, high luminance, and long life.

  Note that the “phosphor” is an incoherent light that is generated when an electron in a low energy state is excited to a high energy state by irradiating the irradiation light L2, and the electron transitions from a high energy state to a low energy state. It is a substance that generates L3.

  The phosphor is preferably a sialon phosphor (oxynitride phosphor) or a III-V compound semiconductor nanoparticle phosphor, but yttrium (Y) -aluminum (Al)-activated with cerium (Ce). A garnet (YAG: Ce) phosphor or the like may be used.

Similar to silicon nitride, sialon has α-type and β-type depending on the crystal structure. In particular, alpha-sialon has the general formula _{Si 12- (m + n) Al} (m + n) O n N 16-n (m + n <12,0 <m, n <11; m, n is an integer) from 28 atom represented by There are two voids in the unit structure, and it is possible to enter various types of metal into this. It becomes a phosphor by dissolving rare earth elements. When calcium (Ca) and europium (Eu) are dissolved, a phosphor having excellent characteristics of emitting light in a yellow to orange range with a longer wavelength than YAG: Ce can be obtained.

  The sialon phosphor can be excited by light in a blue-violet region or a blue region (380 nm or more and 490 nm or less), and is suitable for a phosphor for a white LED.

Next, a procedure for synthesizing a sialon phosphor will be described. The composition of the general formula _{Ca p Si 12- (m + n} ) Al (m + n) O n N 16-n: Eu q (p, q are each Ca, solid solution amount of Eu, m + n <12,0 < m, n <11; m and n are integers). The optimum values of the solid solution amount p of Ca and the solid solution amount q of Eu are obtained in advance by experiments, and m and n are determined based on conditions for maintaining the neutrality of the charge.

Further, powders of silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), calcium carbonate (CaCO ₃ ), and europium oxide (Eu ₂ O ₃ ) are used as starting materials, and after weighing and mixing, sintering temperature 1700 Perform nitrogen gas pressure sintering at ℃. Then, if this is broken into powder, a sialon phosphor can be obtained.

  The sialon phosphor is a phosphor having a strong deterioration resistance against the laser beam L0. Therefore, theoretically, if the rectangular parallelepiped light-emitting body 40 is composed only of sialon phosphors, deterioration can be prevented more effectively.

  Moreover, as another suitable example of fluorescent substance, the semiconductor nanoparticle fluorescent substance using the nanometer-sized particle | grains of a III-V group compound semiconductor can be illustrated.

  One of the features of semiconductor nanoparticle phosphors is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the emission color is changed by the quantum size effect by changing the particle diameter to nanometer size. It is a point that can be. For example, InP emits red light when the particle size is about 3 to 4 nm (here, the particle size was evaluated with a transmission electron microscope (TEM)).

  In addition, since this semiconductor nanoparticle phosphor is semiconductor-based, it has a short fluorescence lifetime and can emit the excitation light power as fluorescence quickly, so that it is highly resistant to high-power excitation light. This is because the emission lifetime of the semiconductor nanoparticle phosphor is about 10 nanoseconds, which is five orders of magnitude smaller than that of a normal phosphor material having a rare earth as the emission center.

  Furthermore, as described above, since the emission lifetime is short, the absorption of the laser beam and the emission of the phosphor can be quickly repeated. As a result, high efficiency can be maintained with respect to strong laser light, and heat generation from the phosphor can be reduced.

  Therefore, it can suppress more that the rectangular parallelepiped light-emitting body 40 is deteriorated (discolored or deformed) by heat. Thereby, when using the light emitting element with a high light output as a light source, the lifetime of the light emitting device 110 of this embodiment, the light emitting device 120A, the light emitting device 120B, and the lighting device 140 described later is further suppressed from being shortened. be able to.

  In addition, it is thought that deterioration of the rectangular parallelepiped light emitter 40 described above is caused by deterioration of a dispersion medium (for example, silicone resin) of the phosphor included in the rectangular parallelepiped light emitter 40. That is, the sialon phosphor described above generates light with an efficiency of 60 to 80% when irradiated with laser light, but the rest is emitted as heat. It is considered that the dispersion medium deteriorates due to this heat.

  Therefore, a dispersion medium having high heat resistance is preferable as the dispersion medium. Examples of the dispersion medium having high heat resistance include glass.

  By the way, it is known that white light can be composed of a mixed color of three colors satisfying the principle of equal color as described above, or a mixed color of two colors satisfying the relationship of complementary colors. Accordingly, white light can be generated by appropriately selecting the color of the laser light L0 oscillated from the LD chip 11 and the color of the incoherent light L3 emitted from the phosphor.

  For example, in order to make the incoherent light L3 of the light emitting device 110 white, one method uses laser light having an oscillation wavelength (380 nm or more and less than 420 nm) in the blue-violet region as excitation light, and a blue phosphor as a phosphor. A combination of a green phosphor and a red phosphor may be employed.

  Another method may employ a combination of laser light having an oscillation wavelength (440 nm or more and 490 nm or less) in the blue region, yellow phosphor, or green phosphor + red phosphor as excitation light.

  Further, LED light having an oscillation wavelength (440 nm or more and 490 nm or less) in the blue region may be used as the excitation light source, and any combination of yellow phosphor or green phosphor + red phosphor may be employed as the phosphor.

  The yellow phosphor is a phosphor that emits light having a wavelength of 560 nm to 590 nm. The green phosphor is a phosphor that emits light having a wavelength of 510 nm or more and 560 nm or less. The red phosphor is a phosphor that emits light having a wavelength of 600 nm or more and 680 nm or less.

[2. Overview of the excitation light source configuration)
Next, a specific example of the excitation light source constituting the excitation light source group will be described with reference to FIGS.

  FIG. 2A is a circuit diagram of an LED lamp (excitation light source) 13 which is an example of an excitation light source constituting an excitation light source group, and FIG. 2B is a front view showing an overview of the LED lamp 13. 2C is a circuit diagram of an LD chip 11 which is another example of the excitation light source, and FIG. 2B is a schematic diagram showing an overview of the LD chip 11.

  As shown in FIG. 2B, the LED lamp 13 has a configuration in which an LED chip (excitation light source) 130 connected to the anode 14 and the cathode 15 is sealed with an epoxy resin cap 16.

  As shown in FIG. 2A, the LED chip 130 has a pn junction between a p-type semiconductor 131 and an n-type semiconductor 132, the cathode 15 is connected to the p-type electrode 133, and the anode 14 is connected to the n-type electrode 134. Is done. Note that the LD chip 101 is connected to a power source E through a resistor R.

  Further, by connecting the anode 14 and the cathode 15 to the power source E, a circuit is configured, and when power is supplied from the power source E to the LED chip 130, incoherent excitation light is generated near the pn junction.

  The material of the LED chip 130 is GaP, AlGaAs, GaAsP, etc., whose emission color is red, such as GaAsP, whose emission color is orange, GaAsP, GaP, whose emission color is yellow, GaP, whose emission color is green, and emission color. Compound semiconductors such as SiC and GaN that are blue can be exemplified.

  The LED chip 130 operates at a low voltage of about 2 V to 4 V, is small and light, has a fast response speed, has a long life, and has a low cost.

  Next, as shown in FIGS. 2C and 2D, the LD chip 11 has a cathode electrode 19, a substrate 18, a cladding layer 113, an active layer 111, a cladding layer 112, and an anode electrode 17 stacked in this order. It is a configuration.

The substrate 18 is a semiconductor substrate, and it is preferable to use GaN, sapphire, or SiC in order to obtain blue to ultraviolet excitation light for exciting the phosphor as in the present application. In general, as a substrate for a semiconductor laser, in addition, a group IV semiconductor such as Si, Ge, and SiC, GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb, and AlN are represented by III. -V group compound semiconductor, ZnTe, ZeSe, II-VI group compound such as ZnS and ZnO _{semiconductor, ZnO, Al 2 O 3,} SiO 2, TiO 2, CrO 2 and CeO ₂ or the like oxide insulator, and, SiN Any material of a nitride insulator such as is used.

  The anode electrode 17 is for injecting current into the active layer 111 through the cladding layer 112.

  The cathode electrode 19 is for injecting current into the active layer 111 from the lower part of the substrate 18 through the clad layer 113. The current is injected by applying a forward bias to the anode electrode 17 and the cathode electrode 19.

  The active layer 111 has a structure sandwiched between the clad layer 113 and the clad layer 112.

  As the material for the active layer 111 and the cladding layer, a mixed crystal semiconductor made of AlInGaN is used to obtain blue to ultraviolet excitation light. Generally, a mixed crystal semiconductor mainly composed of Al, Ga, In, As, P, N, and Sb is used as an active layer / cladding layer of a semiconductor laser, and such a configuration may be used. Moreover, you may be comprised by II-VI group compound semiconductors, such as Zn, Mg, S, Se, Te, and ZnO.

  The active layer 111 is a region where light emission is caused by the injected current, and the emitted light is confined in the active layer 111 due to a difference in refractive index between the cladding layer 112 and the cladding layer 113.

  Further, the active layer 111 is formed with a front side cleaved surface 114 and a back side cleaved surface 115 provided to face each other in order to confine light amplified by stimulated emission, and the front side cleaved surface 114 and the back side cleaved surface 115. Plays the role of a mirror.

  However, unlike a mirror that completely reflects light, a part of the light amplified by stimulated emission is obtained by cleaving the front side cleaved surface 114 and the back side cleaved surface 115 of the active layer 111 (in this embodiment, the front side cleaved surface 114 for convenience. And the laser beam L0. Note that the active layer 111 may form a multilayer quantum well structure.

  Note that a reflective film (not shown) for laser oscillation is formed on the back side cleaved surface 115 opposite to the front side cleaved surface 114, and the difference in reflectance between the front side cleaved surface 114 and the back side cleaved surface 115 is different. By providing, for example, most of the laser light L0 can be emitted from the light emitting point 103 from the cleaved surface 114 which is a low reflectance end face, for example.

  As for film formation with each semiconductor layer such as the clad layer 113, the clad layer 112, and the active layer 111, MOCVD (metal organic chemical vapor deposition) method, MBE (molecular beam epitaxy) method, CVD (chemical vapor deposition) method. The film can be formed using a general film forming method such as a laser ablation method or a sputtering method. The film formation of each metal layer can be configured using a general film forming method such as a vacuum deposition method, a plating method, a laser ablation method, or a sputtering method.

[3. Method for selecting second optical system]
Next, based on FIGS. 4A to 4F and FIG. 6A, the relationship between the irradiation range of the emitted light from the first optical system and the selection method of the second optical system will be described.

  First, as shown in FIG. 4A, when the LD chip 11 (a small rectangular parallelepiped on the large rectangular parallelepiped at the tip of the package shown in FIG. 4A) is installed horizontally, it is emitted from the LD chip 11. The laser beam L0 has a light emission tendency that is long in the vertical direction (vertical direction) and short in the horizontal direction (horizontal direction).

  That is, the laser light L0 emitted from the LD chip 11 has a very large aspect ratio (aspect ratio) (for example, 5 degrees in the horizontal direction and 30 degrees in the vertical direction).

  On the other hand, as shown in FIG. 4B, the rectangular parallelepiped light emitter 40 has a rectangular parallelepiped shape that is short in the vertical direction and long in the horizontal direction.

  Then, in order to increase the light emission efficiency of the rectangular parallelepiped light emitter 40, the optical component (second optical) that converts the laser light L0 spreading in a vertically long elliptical cone shape into irradiation light L2 that is short in the vertical direction and long in the horizontal direction. System) is required.

  Next, the light emission tendency when a truncated pyramid shaped condensing part (first optical system) 21A described later is adopted as the first optical system will be described.

  First, in the state shown in FIG. 4C, the horizontal width of the light exit surface 212A is compared as a pattern of the light exit tendency of the exit light of the truncated pyramid-shaped condensing unit 21A when the second optical system is not present. This shows a case where the horizontal spread of the outgoing light L1 is larger than the horizontal width of the light irradiation region R1 (not shown, see FIG. 6A) of the rectangular parallelepiped light emitter 40. As such a case, a case where the horizontal width of the light emitting surface 212A is larger than the horizontal width of the light irradiation region R1 is a good example.

  Even when the horizontal width of the light exit surface 212A is smaller than the horizontal width of the light irradiation region R1, depending on the shape of the truncated pyramid-shaped condensing portion 21A, the horizontal spread of the emitted light L1 may be a rectangular parallelepiped. In some cases, the light emitting region 40 may be larger than the horizontal width of the light irradiation region R1.

  For example, when the light emission surface 212A is configured as a flat surface, the emitted light L1 emitted from the light emission surface 212A cannot normally be parallel light, and is emitted with a slight spread. Even when the optical fiber bundle 22 is used as a first optical system to be described later, the optical fiber 223 uses total reflection, so that the light is emitted with a slight spread.

  Therefore, not only the magnitude relationship between the horizontal width of the light emitting surface 212A and the horizontal width of the light irradiation region R1 of the rectangular light emitter 40, but also the distance from the light emitting surface 212A to the rectangular light emitter 40 is increased. If this is done (if the rectangular parallelepiped light emitting body 40 is set apart), the horizontal spread of the emitted light L1 can be larger than the horizontal width of the light irradiation region R1.

  Next, in the state shown in FIG. 4E, the horizontal width of the light exit surface 212A is a pattern of the light exit tendency of the exit light from the truncated pyramid-shaped condensing unit 21A when the second optical system is not present. The case where the horizontal expansion of the emitted light L1 is relatively small and smaller than the width of the light irradiation region R1 (not shown, see FIG. 6A) of the rectangular parallelepiped light emitter 40 is shown.

  As such a case, a case where the horizontal width of the light emitting surface 212A is extremely smaller than the horizontal width of the light irradiation region R1 of the rectangular parallelepiped light emitter 40 is a good example.

  Further, even if the horizontal width of the light emitting surface 212A is not extremely smaller than the horizontal width of the light irradiation region R1 of the cuboid light emitter 40, the horizontal direction of the light irradiation region R1 of the cuboid light emitter 40 is not limited. When the width is about the same as the horizontal width of the light emitting surface 212A, the outgoing light L1 emitted from the light emitting surface 212A is substantially parallel by devising the optical design of the truncated pyramid-shaped condensing part 21A. Even in the case of light, the horizontal spread of the emitted light L1 can be smaller than the horizontal width of the light irradiation region R1 of the rectangular parallelepiped light emitter 40.

  Here, the convex cylindrical lens 30 shown in FIG. 4D is a plano-convex cylindrical lens having an axis in the vertical direction (front and back direction of the paper surface) and having the convex portion directed toward the light irradiation region R1 side, and the emitted light L1. This is an optical component having a function of reducing the horizontal spread with respect to the rectangular parallelepiped light emitter 40.

  Therefore, as shown in FIG. 4C, when the horizontal spread of the emitted light L1 is larger than the horizontal width of the light irradiation region R1 of the rectangular parallelepiped light emitter 40, the truncated pyramid-shaped condensing part 21A, What is necessary is just to provide the convex cylindrical lens 30 between the rectangular parallelepiped light-emitting bodies 40.

  On the other hand, the concave cylindrical lens (second optical system) 31 shown in FIG. 4 (f) is a plano-concave cylindrical lens having an axis in the vertical direction and a concave portion facing the light irradiation region R1, and a rectangular parallelepiped of the emitted light L1. This is an optical component having a function of increasing the horizontal spread with respect to the light emitter 40.

  Therefore, as shown in FIG. 4E, when the horizontal spread of the emitted light L1 is smaller than the horizontal width of the light irradiation region R1 of the rectangular parallelepiped light emitter 40, the truncated pyramid-shaped condensing unit 21A, What is necessary is just to provide the concave cylindrical lens 31 between the rectangular parallelepiped light-emitting bodies 40. FIG.

  Examples of the concave cylindrical lens 31 include a biconcave lens having an axis in the vertical direction, a plano-concave lens, and a concave meniscus lens.

  In addition to the above-described example, a combination of an independent lens having a concave surface and a convex surface having an arbitrary axis, an independent lens having a convex surface and a convex surface having an arbitrary axis, depending on the shape of the light irradiation region of the light emitting unit. A combination, a concave surface having an arbitrary axis, and an independent lens having a concave surface may be adopted.

  Thereby, the luminous efficiency of a light emission part can be improved by employ | adopting the combination of a suitable lens according to the shape of the light irradiation area | region of a light emission part.

  In addition, depending on the shape of the irradiation area of the light emitting part, a compound lens in which a lens having a concave surface and a convex surface having an arbitrary axis is integrated, a lens in which a compound lens having a convex surface and a convex surface having an arbitrary axis is integrated, any A compound lens or the like in which a concave surface having an axis and a lens having a concave surface are integrated may be employed.

  This reduces the number of parts in the entire optical system and reduces the overall size of the optical system, while adopting an appropriate compound lens according to the shape of the light irradiation area of the light emitting unit, thereby improving the light emission efficiency of the light emitting unit. Can be increased.

  Examples of other lenses include a GRIN lens (Gradient Index lens).

  The GRIN lens is a lens that produces a lens action due to a refractive index gradient inside the lens even if the lens is not convex or concave.

  Therefore, when the GRIN lens is used, for example, a lens action can be generated while the end surface of the GRIN lens is kept flat, so that the rectangular parallelepiped light emitting body 40 can be bonded to the end surface of the GRIN lens without any gap.

  Thereby, since the laser beam L0 not irradiated to the light irradiation region can be reduced, the light emission efficiency of the rectangular parallelepiped light emitter 40 can be further improved.

[4. Specific Example of Light Emitting Device (Part 1)]
Next, based on FIGS. 3A and 3B, each of the light emitting device 120 </ b> A and the light emitting device 120 </ b> B (which is embodied from the first light guide unit 20 of the light emitting device 110), which is another embodiment of the present invention. The configuration will be described.

  FIG. 3A shows a configuration of a light emitting device 120A that employs a truncated pyramid shaped condensing unit (first optical system) 21A as an example in which the first light guiding unit 20 of the light emitting device 110 is a condensing element. Yes.

  In the present embodiment, the truncated pyramid-shaped condensing unit 21A will be described as an example. However, the shape of the condensing unit is not limited to this, and various shapes such as a truncated cone shape and an elliptical truncated cone shape can be employed.

  The laser diode group 10 and the LD chip 11 are as described above.

  The truncated pyramid-shaped condensing unit 21A has a surrounding structure surrounded by a truncated pyramid side surface (light reflecting side surface, surrounding structure) 213A that reflects each laser beam L0 incident from the light incident surface (one end of the first optical system) 211A. And the cross-sectional area of the light exit surface (the other end of the first optical system) 212A is smaller than the cross-sectional area of the light incident surface 211A, and each laser light L0 incident from the light incident surface 211A is obtained. The light is guided to the light exit surface 212A by the truncated pyramid side surface 213A.

  Thereby, each laser beam L0 incident from the light incident surface 211A is guided to the light emitting surface 212A having a smaller cross-sectional area than the light incident surface 211A by the truncated pyramid side surface 213A, that is, each laser beam. L0 can be condensed on the light exit surface 212A.

  The truncated pyramid-shaped condensing part 21A is made of BK (borosilicate crown) 7, quartz glass, acrylic resin, or other transparent material.

  According to the above configuration, by reducing both the area of the light emission surface 212A and the size of the rectangular parallelepiped light emitter 40 (light irradiation region), high brightness corresponding to the number of LD chips 11 constituting the laser diode group 10 is achieved. The size of the rectangular parallelepiped light emitting body 40 that generates a high luminous flux can be reduced.

  Here, the truncated pyramid side surface 213 </ b> A is configured to surround all the optical paths of the laser beams L <b> 0 generated from the laser diode group 10.

  Each laser beam L0 is reflected once on the truncated pyramid side surface 213A and guided to the light emitting surface 212A, or is reflected multiple times on the truncated pyramid side surface 213A and guided to the light emitting surface 212A. The light is guided by any one of the optical paths in the case of being guided to the light emitting surface 212A without being reflected once on the side surface 213A of the truncated pyramid.

  The convex cylindrical lens 30 and the rectangular parallelepiped light emitter 40 are as described above.

  In the light emitting device 120 </ b> A, the emitted light L <b> 1 derived from each laser beam L <b> 0 is dispersed in the horizontal direction and irradiated as irradiation light L <b> 2 to the light irradiation region of the rectangular parallelepiped light emitting body 40. Electrons in a low energy state are efficiently excited to a high energy state throughout the body.

  Therefore, since the incoherent light L3 is generated from the rectangular parallelepiped light emitter 40 without unevenness, the light emitting device 120A can achieve higher luminous flux and higher brightness than the case where the single LD chip 11 is used.

  In addition, the irradiation light L2 derived from each laser beam L0 is not irradiated in a concentrated manner on one point on the light irradiation region of the rectangular parallelepiped light emitter 40, and the light irradiation region via the truncated pyramid condensing unit 21A and the convex cylindrical lens 30. Therefore, it is possible to prevent the rectangular parallelepiped light emitting body 40 from being deteriorated by irradiating each laser beam L0 in a concentrated manner at the same point.

  Based on the above, it is possible to provide the light emitting device 120A capable of realizing high luminous flux, high luminance, and long life.

  Note that a truncated pyramid is formed between the ferrule 70 [the emitting end (the portion where the other end of the first optical system, the other end of the optical fiber is arranged) 222] and the convex cylindrical lens 30 in the illumination device 140 described below. An optical part 21A may be provided (see part (a) in FIG. 5).

  This makes it possible to further reduce the size of the rectangular parallelepiped light emitter 40 in the illumination device 140 while increasing the number of excitation light sources.

  Next, FIG. 3B shows a truncated pyramid-shaped condensing unit (first optical system) 21 and a convex cylindrical lens (second optical system) 30 of the light emitting device 120A integrated (by the light emitting surface 212A) ( However, the size of the convex cylindrical lens 30 is adjusted as appropriate) As an example of a single optical member (light guide member), a truncated pyramid shaped optical member (light guide member, first optical system, second optical system) The structure of the light-emitting device 120B which employ | adopted 21B is shown.

  In this embodiment, the truncated pyramid shaped optical member 21B will be described as an example. However, the shape of the optical member is not limited to this, and various shapes such as a truncated cone shape and an elliptical truncated cone shape can be adopted.

  The laser diode group 10 and the LD chip 11 are as described above.

  The truncated pyramidal optical member 21B is surrounded by a truncated pyramid side surface (light reflecting side surface, surrounding structure) 213B that reflects each laser beam L0 incident from a light incident surface (one end on the first optical system side) 211B at one end thereof. Each of the laser beams L0 incident from the light incident surface 211B is guided to the other end of the truncated pyramid shaped optical member 21B.

  Further, the other end of the truncated pyramid-shaped optical member 21B has a light dispersion surface (light dispersion portion, second optical) that irradiates and distributes each of the guided laser beams L0 to a predetermined light irradiation region in the rectangular parallelepiped light emitter 40. The other end 212B on the system side is formed.

  Furthermore, the cross-sectional area of the light dispersion surface 212B is smaller than the cross-sectional area of the light incident surface 211B, and each laser light L0 incident from the light incident surface 211B is condensed on the light dispersion surface 212B by the truncated pyramid side surface 213B. It can be done.

  The truncated pyramidal optical member 21B is made of BK7, quartz glass, acrylic resin, or other transparent material.

  The light dispersion surface 212B has a structure in which a plano-convex cylindrical lens (cylindrical lens 30) having an axis in the vertical direction is integrated with the light emission surface 212A of the truncated pyramid-shaped condensing portion 21A shown in FIG. ing.

  According to the above configuration, by reducing both the area of the light dispersion surface 212B and the size of the rectangular parallelepiped light emitter 40 (light irradiation region), high brightness corresponding to the number of LD chips 11 constituting the laser diode group 10 is achieved. The size of the rectangular parallelepiped light emitting body 40 that generates a high luminous flux can be reduced.

  Here, the truncated pyramidal optical member 21 </ b> B is configured to surround all the optical paths of the laser beams L <b> 0 generated from the laser diode group 10.

  Each laser beam L0 is reflected only once on the truncated pyramid side surface 213B and guided to the light dispersion surface 212B, or is reflected multiple times on the truncated pyramid side surface 213B and guided to the light dispersion surface 212B. The light is guided by any one of the optical paths in the case of being guided to the light dispersion surface 212B without being reflected once on the side surface 213B of the truncated pyramid. The rectangular parallelepiped light emitter 40 is as described above.

  The light emitting device 120B is included in the rectangular parallelepiped illuminant 40 because the irradiation light L2 derived from each laser beam L0 is distributed in the horizontal direction from the light dispersion surface 212B to the light irradiation region of the cuboid illuminant 40. Electrons in a low energy state are efficiently excited to a high energy state over the entire phosphor.

  Therefore, since the incoherent light L3 is generated from the rectangular parallelepiped light emitter 40 without unevenness, the light emitting device 120B can achieve higher luminous flux and higher brightness than the case where the single LD chip 11 is used.

  Further, the irradiation light L2 derived from each laser light L0 is not irradiated in a concentrated manner on one point on the light irradiation region of the rectangular parallelepiped light emitter 40, but is distributed and irradiated to the light irradiation region via the truncated pyramid optical member 21B. Therefore, it is possible to prevent the rectangular parallelepiped light emitting body 40 from being deteriorated by irradiating each laser beam L0 in a concentrated manner at the same point.

  Based on the above, it is possible to provide the light emitting device 120B capable of realizing high luminous flux, high luminance, and long life.

[5. Specific Example of Light Emitting Device (Part 2)]
Next, based on the (a) part and (b) part of FIG. 5, a schematic configuration of a lighting device (light emitting device) 140 which is still another embodiment of the present invention will be described.

  FIG. 5 is a schematic diagram illustrating a configuration of an illumination device 140 that employs an optical fiber bundle (first light guide member) 22 as an example in which the first light guide unit 20 of the light emitting device 110 is configured by a plurality of light guide members. 5A shows a schematic configuration thereof, and FIG. 5B shows an example of a ferrule 70 that fixes a plurality of optical fibers.

  As shown in part (a) of FIG. 5, the illumination device 140 includes an LD chip (excitation light source group) 101, a rod-shaped lens (first optical system) 50, a fixing fixture 60, an optical fiber bundle (first optical system, A plurality of optical fibers) 22, a ferrule 70, a convex cylindrical lens (second optical system) 30, a rectangular parallelepiped light emitter 40, a reflector 80, a reflector 90, and a housing 100.

  The LD chip 101 is a single (1 chip) semiconductor laser having 5 stripes, that is, five light emitting points (excitation light sources) 102.

  The light output of each light emitting point 102 is 1 W, and the total light output emitted from one chip of the LD chip 101 is 5 W. The stripe interval is 0.4 mm.

  As described above, when the excitation light source group is configured by the LD chip 101, each light emitting point 102 generates the coherent laser light L0. Therefore, since the coherent laser beam L0 has higher directivity than the incoherent excitation light, it can be incident on the incident end (one end of the first optical system) 221 while minimizing the loss of the light beam. it can.

  In addition, according to the LD chip 101 with one chip and five stripes, the single LD chip 101 is configured to have the five light emitting points 102, so that the size of the LD chip 101 can be reduced.

  Further, mass production of a single LD chip 101 having five light emitting points 102 reduces the production cost compared to producing five one-chip, one-striped LD chips 11 having a single laser beam emitting end. be able to.

  In this embodiment, a one-chip five-stripe semiconductor laser having five light emitting points 102 is used as the excitation light source group. However, the number of light emitting points 102 is not limited to this, and 2 to 2 as necessary. There may be four, or six or more.

  In addition, as an example of the excitation light source group, a plurality of excitation light sources (light emitting points 102) may be integrated as in the LD chip 101, or a plurality of ones as in the laser diode group 10 described above. The chip 1 stripe LD chip 11 may be spatially separated.

  That is, the excitation light source group includes a plurality of LD chips 11, and each laser beam L 0 may be a laser beam L 0 generated from the corresponding LD chip 11.

  When the excitation light source group is composed of a plurality of LD chips 11, an aspheric lens (first optical system: for example, FLKN1 405 manufactured by Alps Electric, not shown) is provided for each LD chip 11, and the laser light L0 is emitted. Collimate and input from one end of the corresponding optical fiber 223. The shape and material of the aspherical lens are not particularly limited as long as the lens has the above-described function, but it is preferably a material having a high transmittance near 405 nm and good heat resistance.

  Further, each excitation light source constituting the excitation light source group may generate a coherent laser beam L0 like an LD, or may generate an incoherent excitation beam like an LED. good.

  In addition, the excitation light source group may be composed of only LD or LED, or may be a mixture of LD and LED.

  Each laser beam L0 generated from the five light emitting points 102 of the LD chip 101 is collimated by the rod-shaped lens 50 and enters the incident end 221 (one end of the optical fiber 223).

  An optical fiber bundle 22 in which five optical fibers 223 are arranged at a pitch of 0.4 mm is installed on the front side of the paper surface of the rod-shaped lens 50.

  The optical fiber 223 is a quartz optical fiber having a core diameter of 200 μm, a cladding diameter of 240 μm, and a numerical aperture NA = 0.22.

  The fixing fixture 60 has a 0.4 mm pitch groove, fixes the incident end 221 of the optical fiber bundle 22, and maintains the pitch interval of the optical fibers 223.

  In this embodiment, the optical fiber 223 having a circular cross section is used as the first optical system. However, the cross section is not limited to a circular shape, and may be a regular triangle, a parallelogram (including a square or a rectangle), or a regular hexagon. It is preferable that it is either.

  According to the above configuration, theoretically, the cross section of the emission end 222 can be spread without gaps on the cross section of the other end of the optical fiber 223 having the same shape. That is, the number of cross sections of the other end of the optical fiber 223 per area can be set to the maximum number in each cross sectional shape.

  By the way, as described above, in the lamps disclosed in Patent Documents 1 and 2, the excitation light is guided using a condensing lens provided for each excitation light source, and a hole is formed in the reflecting mirror for each excitation light. As the number of excitation light sources increases, the lamp becomes larger and the light reflection efficiency of the reflector deteriorates as the number of excitation light sources increases. There was a general problem.

  Therefore, in order to solve such a secondary problem, in the illumination device 140, the first optical system employs a configuration of an optical fiber bundle 22 that is a bundle of a plurality of optical fibers 223.

  One end of the optical fiber bundle 22 is an incident end 221 that is a collection of one ends of the optical fibers 223.

  Further, the other end of the optical fiber bundle 22 is an output end (the other end of the first optical system) in which each of the optical fibers 223 is a collection of the other ends of the optical fibers 223 inserted into five through holes formed in the ferrule 70. , A portion where the other ends of the optical fibers are arranged) 222. In addition, the material of the ferrule 70 is not specifically limited, For example, it is stainless steel.

  Further, each laser beam L0 generated from the five light emitting points 102 of the LD chip 101 is incident from one end of the corresponding optical fiber 223, and emitted from each laser beam L0 from the other end (exit end 222) of the optical fiber 223. The incident light L1 is emitted.

  Thus, each laser beam L0 is incident from one end of the corresponding optical fiber 223 and guided to the exit end 222 with a simple configuration in which the first light guide unit 20 is configured by the optical fiber bundle 22.

  Moreover, although it depends on the thickness and number of the optical fibers 223, usually, even if a plurality of optical fibers 223 are bundled, the thickness is not so large.

  Therefore, the irradiation light derived from the laser light L0 generated from the five light emitting points 102 in the light irradiation region of the small rectangular parallelepiped light emitter 40 while keeping the size of the emission end 222 and the rectangular solid light emitter 40 (light irradiation region) small. L2 can be irradiated.

  Further, for example, in the illumination device 140, a hole is formed in the center of the reflecting mirror 90, the optical fiber bundle 22 is allowed to pass through the hole, and the rectangular parallelepiped light emitter 40 is irradiated with the irradiation light L2 from the emission end 222. Even if the number of excitation light sources (light emitting points 102) increases as in the lamps disclosed in Patent Documents 1 and 2, the light reflection efficiency of the reflecting mirror 90 does not deteriorate.

  Next, the outgoing light L1 emitted from the outgoing end 222 passes through the convex cylindrical lens 30, and is irradiated as light irradiation L2 in a light irradiation region (not shown) of the rectangular parallelepiped light emitter 40. The rectangular parallelepiped light emitter 40 is as described above.

  Next, the reflecting plate 80 is a transparent resin plate bonded to the rear surface of the projection lens, and the rectangular parallelepiped light emitting unit 40 is bonded and fixed to the reflecting plate 80. The reflection plate 80 is formed of a material that blocks the laser light L0 from the LD chip 11 and transmits white light (incoherent light L3) generated by converting the laser light L0 in the rectangular parallelepiped light emitting unit 40. It is preferable to do.

  Most of the coherent laser light L0 is converted into incoherent light L3 by the rectangular parallelepiped light emitting unit 40. However, there may be a case where a part of the laser beam L0 is not converted for some reason. Even in such a case, the laser beam L0 can be prevented from leaking to the outside by blocking the laser beam L0 by the reflecting plate 80. In addition, when the rectangular parallelepiped light-emitting portion 40 is fixed by a member other than the reflecting plate 80 without expecting such an effect, the reflecting plate 80 can be omitted.

  Further, the reflecting plate 80 may be of a size that can prevent the laser light L0 from leaking to the outside. In the present embodiment, the reflecting plate 80 has a size that is slightly larger than the rectangular parallelepiped light emitting unit 40. It may be the same size as the opening surface of the light L0 reflecting mirror 90.

  The incoherent light L3 generated from the rectangular parallelepiped light emitter 40 travels in the direction opposite to the traveling direction of the irradiation light L2 by the reflecting plate 80.

  Next, the reflecting mirror 90 reflects the incoherent light L3 generated from the rectangular parallelepiped light emitter 40, thereby forming a light bundle that travels within a predetermined solid angle. The reflecting mirror 90 has a hemispherical surface facing the rectangular parallelepiped light emitter 40, and has a focal point at the position of the rectangular parallelepiped light emitter 40 at a position where the rectangular parallelepiped light emitter 40 is provided.

  The incoherent light L3 reflected by the reflecting plate 80 is reflected again by the reflecting mirror 90 and travels in front of the illumination device 140. Thus, the reflecting mirror 90 irradiates the incoherent light L3 generated from the rectangular parallelepiped light emitter 40 forward, forming a light bundle that travels within a predetermined solid angle.

  The housing 100 is a housing that houses the ferrule 70, the convex cylindrical lens 30, the rectangular parallelepiped light emitter 40, and the like.

  In addition, since the illumination device 140 irradiates the light irradiation region of the rectangular parallelepiped light emitter 40 with the emitted light L1 derived from each laser beam L0 as the irradiation light L2, the phosphor included in the rectangular parallelepiped light emitter 40 The electrons in the low energy state are efficiently excited to the high energy state throughout.

  Therefore, since the incoherent light L3 is generated from the rectangular parallelepiped light emitter 40 without any unevenness, it is possible to realize a higher luminous flux and higher luminance of the illumination device 140 as compared with the case where an excitation light source having a single light emitting point 102 is used. Can do.

  In addition, the emitted light L1 derived from each laser beam L0 is not concentrated and irradiated on one point on the light irradiation region of the rectangular parallelepiped light emitter 40, but is dispersed in the light irradiation region via the optical fiber bundle 22 and the convex cylindrical lens 30. Since it irradiates, it can prevent that the rectangular parallelepiped light-emitting body 40 deteriorates by each laser beam L0 being concentrated and irradiated to the same point.

  Based on the above, it is possible to provide the illumination device 140 that can realize high luminous flux, high luminance, and long life.

[6. (About the shape of the light emitting part and the light irradiation area)
Next, specific examples of the light emitting unit and the light irradiation region will be described with reference to FIGS. 6 (a) to 8 (c).

  First, FIG. 6A is a schematic diagram of the above-described rectangular parallelepiped light emitter 40, and FIG. 6B is a schematic diagram illustrating an example of a light irradiation region of the rectangular parallelepiped light emitter 40. FIG. c) is a schematic diagram showing another example of the light irradiation region.

  Although described in Non-Patent Document 1, as shown in FIG. 6A, the light distribution pattern of the vehicle headlamp (high beam) is narrow in the vertical direction, wide in the left and right, and the shape of the light emitting unit is Since it is desirable to be horizontally long with respect to the horizontal direction, the rectangular parallelepiped light emitter 40 has a substantially rectangular parallelepiped shape.

  As described above, the size of the rectangular parallelepiped light-emitting body 40 is approximately horizontal × vertical × height = 3 mm × 1 mm × 1 mm.

  In addition, the rectangular area shown by the oblique line on the near side is the light irradiation area R1, and is an example of the area where the area of the light irradiation area in the rectangular parallelepiped light emitter 40 is the maximum.

  In order to obtain such a light irradiation region R1, for example, a plano-convex cylindrical lens (second optical system) whose outgoing light L1 has an axis in the vertical direction and a plano-convex cylindrical lens (second optical system) having an axis in the horizontal direction are used. The irradiation light L2 collimated in the vertical direction and the vertical direction according to the light irradiation region R1 may be incident on the rectangular parallelepiped light-emitting body 40.

  As another method, the number of the optical fibers 223 may be increased so that the size of the emission end 222 is approximately the same as that of the light irradiation region, and the other ends of the optical fibers 223 may be densely laid in a matrix.

  Next, FIG. 6B shows an example of a light irradiation region in the rectangular parallelepiped light emitting body 40 in the case where the emission end 222 is formed by arranging the other ends of four optical fibers 223 (however, the diameter is slightly larger) in a horizontal row. is there.

  In this example, four light-irradiated regions (predetermined light-irradiated regions) R2 are formed by reflecting four optical fibers 223.

  FIG. 6C shows an example of a light irradiation region in the rectangular parallelepiped light emitter 40 in the case where the emission end 222 is formed by arranging the other ends of a total of eight optical fibers 223 (however, the diameter is slightly smaller) in a horizontal row.

  In the light irradiation region R3, in the circular regions arranged in a horizontal row, the number of circular regions is increased by making the central portion two vertically.

  Thereby, the brightness of the emitted light L1 directly in front (center) of the rectangular parallelepiped light emitter 40 can be increased.

  In addition to the above example, the number of circular regions may be adjusted according to the portion where the brightness of the emitted light L1 of the rectangular parallelepiped light emitter 40 is to be increased. Thereby, the brightness of the emitted light L1 at a desired position can be adjusted.

  Next, FIG. 7A is a schematic diagram showing a light distribution pattern required for an automobile headlamp (low beam / high beam), and FIG. 7B is required for an automobile headlamp low beam. It is a figure which shows a light distribution characteristic.

  As shown in FIG. 7A, there are two types of light distribution patterns required for the headlamp: a light distribution pattern required for the low beam and a light distribution pattern required for the high beam.

  The screen light distribution shown in FIG. 7A is an illuminance distribution of light irradiated on a vertical screen facing the headlamp. The brightest part in the front direction is called a hot zone, and the luminous intensity of this part determines the distance to reach far away.

  In addition, the low beam requires a large contrast between the upper and lower sides of the horizon in order to suppress glare on the oncoming vehicle.

  FIG. 7B is a diagram showing the light distribution characteristics required for the low beam of the automobile headlamp.

  Next, an example of the low-beam light emitter (light emitting unit) 41 will be described with reference to FIGS. 7B and 8A.

  As shown in FIG. 7B, cut lines are formed at the boundary between the hatched region I and the region IV, and at the boundary between the hatched region III and the region IV. In the light distribution characteristics required for this low beam, a large difference in brightness is required above and below the horizon.

  Therefore, the light distribution pattern shown in FIG. 7B is rotated by 180 degrees, and the shape of the cut line of the light distribution pattern is directly adopted as the shape of the light irradiation region R4 of the low-beam light emitter 41.

  The light distribution pattern shown in FIG. 7B is rotated 180 degrees because, as shown in FIG. 5A, the light generated from the rectangular parallelepiped light emitter 40 is reflected on the reflector plate in the illumination device 140. This is because the light reflected by 80 and then re-reflected by the reflecting mirror 90 travels in front of the illumination device 140.

  Like the low-beam light emitter 41 described above, the shape of the light emitting portion may be formed according to the shape of the cut line that defines the light / dark boundary of the light distribution pattern of the generated light.

  Thereby, the light of the light distribution pattern having various cut line shapes can be generated by forming the shape of the light emitting portion according to the shape of the cut line that defines the light / dark boundary of the light distribution pattern of the generated light. it can.

  Next, FIG. 8B is a schematic diagram showing the light irradiation region R5 of the low-beam light emitter 41, and FIG. 8C shows the irradiation of the irradiation light L2 with respect to the light irradiation region R4 of the low-beam light emitter 41. It is a schematic diagram which shows an example of a method.

  As shown in FIG. 8B, the arrangement pattern of the optical fibers 223 and the arrangement pattern of the through holes of the ferrule 70 may be determined so that the light irradiation region R4 is formed (FIG. 8B). 5 (a) and (b)).

  Thereby, even when the optical fiber bundle 22 is used as the first light guide unit 20, it is possible to form the light irradiation region R4 corresponding to the shape of the low-beam light emitter 41.

  Next, as shown in FIG. 8C, the shape of the compound cylindrical lens (second optical system) 32 may be set so that the light irradiation region R4 is formed.

  For example, in the case of a shape that is long in the horizontal direction and whose diameter in the vertical direction changes linearly with respect to the horizontal direction, such as the shape of the light irradiation region R4, the compound cylindrical lens 32 is shown in FIG. A combination of a vertical-axis cylindrical lens (convex lens having a convex surface having an axis in the vertical direction) 321 and a horizontal-axis cylindrical lens (convex lens having a convex surface having an axis in the horizontal direction) 322 shown in FIG. It is also possible to have an integrated configuration.

  As described above, the shape of the compound cylindrical lens 32 is configured by the combination of the vertical axis cylindrical lens 321 having the axis in the vertical direction and the horizontal axis cylindrical lens 322, thereby the horizontal size and the vertical size of the light irradiation region R4. Accordingly, the irradiation light L2 can be distributed and irradiated onto the light irradiation region R4.

[7. (About laser downlight)
A laser downlight (light emitting device, illumination device) 400 according to still another embodiment of the present invention will be described below with reference to FIGS.

  Here, the laser downlight 400 as an example of the illuminating device of this invention is demonstrated. The laser downlight 400 is an illumination device installed on the ceiling of a structure such as a house or a vehicle, and irradiates the rectangular light emitting unit 40 with the laser light L0 emitted from the LD chip 11 via the optical fiber 223 or the like. The fluorescence generated by this is used as illumination light.

  The aspherical lens 4 is a lens for causing the laser light L0 oscillated from the LD chip 11 to enter the incident end of the optical fiber 223. For example, as the aspheric lens 4, FLKN1 405 manufactured by Alps Electric can be used. The shape and material of the aspherical lens 4 are not particularly limited as long as the lens has the above function, but it is preferably a material having a high transmittance near 405 nm and a good heat resistance.

  When the LD chip 101 and the optical fiber bundle 22 are used in place of the LD chip 11 and the optical fiber 223, the rod-shaped lens 50 and the fixed treatment shown in FIG. The tool 60 or the like may be used.

  Further, an illuminating device having the same configuration as the laser downlight 400 may be installed on the side wall or floor of the structure, and the installation location of the illuminating device is not particularly limited.

  FIG. 9 is a schematic view showing the appearance of the light emitting unit 410 and the conventional LED downlight 500. FIG. 10 is a cross-sectional view of the ceiling where the laser downlight 400 is installed. FIG. 11 is a cross-sectional view of the laser downlight 400. As shown in FIGS. 9 to 11, the laser downlight 400 is embedded in the top plate 401 and emits illumination light, and an LD light source unit that supplies laser light to the light emitting unit 410 via an optical fiber 223. 420. The LD light source unit 420 is not installed on the ceiling, but is installed at a position where the user can easily touch it (for example, a side wall of a house). The position of the LD light source unit 420 can be freely determined in this way because the LD light source unit 420 and the light emitting unit 410 are connected by the optical fiber 223. The optical fiber 223 is disposed in a gap between the top plate 401 and the heat insulating material 402.

(Configuration of light emitting unit 410)
As shown in FIG. 11, the light emitting unit 410 includes a housing 411, an optical fiber 223, a rectangular parallelepiped light emitting unit 40, a convex cylindrical lens 30, a ferrule 70, and a light transmitting plate 413. Note that the ferrule 70 shown in FIG. 5 (b) has five through holes in accordance with the number of optical fibers 223. In the present embodiment, the ferrule 70 has one through hole. (Not shown).

  A recess 412 is formed in the housing 411, and a rectangular parallelepiped light emitting unit 40 is disposed on the bottom surface of the recess 412. A metal thin film is formed on the surface of the recess 412, and the recess 412 functions as a reflecting mirror.

  Further, a passage 414 through which the optical fiber 223 is passed is formed in the housing 411, and the optical fiber 223 extends to the rectangular parallelepiped light emitting unit 40 through the passage 414. The positional relationship between the other end of the optical fiber 223 and the rectangular parallelepiped light emitting unit 40 is the same as described above.

  The translucent plate 413 is a transparent or translucent plate disposed so as to close the opening of the recess 412. The translucent plate 413 is formed of a material that blocks the laser light L0 from the LD chip 11 and transmits the incoherent light L3 generated by converting the laser light L0 in the rectangular parallelepiped light emitting unit 40. preferable.

  Most of the coherent laser light L0 is converted into incoherent L3 by the rectangular parallelepiped light emitting unit 40. However, there may be a case where a part of the laser beam L0 is not converted for some reason. Even in such a case, the laser beam L0 can be prevented from leaking to the outside by blocking the laser beam L0 by the translucent plate 413.

  In addition, the fluorescence of the rectangular parallelepiped light emitting unit 40 is emitted as illumination light through the light transmitting plate 413. The translucent plate 413 may be removable from the housing 411 or may be omitted.

  In FIG. 9, the light emitting unit 410 has a circular outer edge, but the shape of the light emitting unit 410 (more strictly, the shape of the housing 411) is not particularly limited.

  In the downlight, unlike a headlamp, an ideal point light source is not required, and a level of one light emitting point is sufficient. Therefore, there are fewer restrictions on the shape, size, and arrangement of the rectangular parallelepiped light emitting unit 40 than in the case of a headlamp.

(Configuration of LD light source unit 420)
The LD light source unit 420 includes an LD chip 11, an aspheric lens 4, and an optical fiber 223.

  The emission end of the optical fiber 223 is connected to the LD light source unit 420, and the laser light L 0 oscillated from the LD chip 11 enters the incident end of the optical fiber 223 via the aspheric lens 4.

  Only one pair of the LD chip 11 and the aspherical lens 4 is shown inside the LD light source unit 420 shown in FIG. 11, but when there are a plurality of light emitting units 410, the optical fibers 223 extending from the light emitting units 410 respectively. The bundle may be guided to one LD light source unit 420. In this case, a pair of the LD chip 11 and the aspherical lens 4 (or a pair of the LD chip 101 and one rod-shaped lens 50) is accommodated in one LD light source unit 420. The unit 420 functions as a central power supply box.

(Example of changing the installation method of the laser downlight 400)
FIG. 12 is a cross-sectional view showing a modified example of the installation method of the laser downlight 400. As shown in the figure, as a modified example of the installation method of the laser downlight 400, only a small hole 403 through which the optical fiber 223 is passed is formed in the top plate 401, and the laser downlight body (light emitting unit) is utilized by taking advantage of the thin and light weight. 410) may be attached to the top plate 401. In this case, there are merits that restrictions on installation of the laser downlight 400 are reduced and construction costs can be significantly reduced.

(Comparison between laser downlight 400 and conventional LED downlight 500)
As shown in FIG. 9, the conventional LED downlight 500 includes a plurality of light transmitting plates 501, and illumination light is emitted from each light transmitting plate 501. That is, the LED downlight 500 has a plurality of light emitting points. The LED downlight 500 has a plurality of light emitting points because the light flux of light emitted from each light emitting point is relatively small. Therefore, if a plurality of light emitting points are not provided, light having a sufficient light flux as illumination light is provided. This is because it cannot be obtained.

  On the other hand, since the laser downlight 400 is a high-luminance illumination device, it may have one light emitting point. Therefore, it is possible to obtain an effect that the shadow caused by the illumination light is clearly displayed. Moreover, the color rendering property of illumination light can be improved by making the fluorescent substance of the rectangular parallelepiped light emitting section 40 a high color rendering fluorescent substance (for example, a combination of several kinds of oxynitride fluorescent substances).

  FIG. 13 is a cross-sectional view of the ceiling where the LED downlight 500 is installed. As shown in the figure, in the LED downlight 500, a housing 502 that houses an LED chip, a power source, and a cooling unit is embedded in the top plate 401. The housing 502 is relatively large, and a recess along the shape of the housing 502 is formed in the heat insulating material 402 where the housing 502 is disposed. A power line 523 extends from the housing 502, and the power line 523 is connected to an outlet (not shown).

  Such a configuration causes the following problems. First, since there is a light source (LED chip) and a power source that are heat sources between the top plate 401 and the heat insulating material 402, the use of the LED downlight 500 increases the ceiling temperature, and the cooling efficiency of the room. Problem arises.

  Further, the LED downlight 500 requires a power source and a cooling unit for each light source, which causes a problem that the total cost increases.

  Further, since the housing 502 is relatively large, there is a problem that it is often difficult to dispose the LED downlight 500 in the gap between the top plate 401 and the heat insulating material 402.

  On the other hand, in the laser downlight 400, since the light emitting unit 410 does not include a large heat source, the cooling efficiency of the room is not reduced. As a result, an increase in room cooling costs can be avoided.

  Further, since it is not necessary to provide a power source and a cooling unit for each light emitting unit 410, the laser downlight 400 can be made small and thin. As a result, space restrictions for installing the laser downlight 400 are reduced, and installation in an existing house is facilitated.

  Further, since the laser downlight 400 is small and thin, as described above, the light emitting unit 410 can be installed on the surface of the top plate 401, and installation restrictions are made smaller than the LED downlight 500. As well as drastically reducing construction costs.

  FIG. 14 is a diagram for comparing the specifications of the laser downlight 400 and the LED downlight 500. As shown in the figure, the laser downlight 400 has a volume reduced by 94% and a mass reduced by 86% compared to the LED downlight 500 in one example.

  In addition, since the LD light source unit 420 can be installed in a place that can be easily reached by the user, even if the LD chip 11 breaks down, the LD chip 11 can be easily replaced. Further, by guiding the optical fibers 223 extending from the plurality of light emitting units 410 to one LD light source unit 420, the plurality of LD chips 11 can be managed collectively. Therefore, even when a plurality of LD chips 11 are replaced, the replacement can be easily performed.

  In the case of a type using a high color rendering phosphor in the LED downlight 500, a light flux of about 500 lm can be emitted with a power consumption of 10 W. However, in order to realize light of the same brightness with the laser downlight 500, 3 .3W light output is required. If the LD efficiency is 35%, this light output corresponds to power consumption of 10 W, and the power consumption of the LED downlight 500 is also 10 W. Therefore, there is no significant difference in power consumption between the two. Therefore, in the laser downlight 400, the above-described various advantages can be obtained with the same power consumption as that of the LED downlight 500.

  As described above, the laser downlight 400 includes the light source unit 420 including at least one LD chip 11 that emits the laser light L0, the rectangular parallelepiped light emitting unit 40, and the at least one light emitting unit 410 including the concave portion 412 as a reflecting mirror. And an optical fiber 223 that guides the laser light L0 to each of the light emitting units 410, and a convex cylindrical that irradiates the emitted light L1 emitted from the emitting end of the optical fiber 223 as the irradiated light L2 in a distributed manner in the light irradiation region of the rectangular parallelepiped light emitter 40. A lens 30.

  Therefore, in the laser downlight 400, it is possible to reduce the possibility that the rectangular parallelepiped light emitting unit 40 is significantly deteriorated by irradiating the laser light L0 to one place of the rectangular parallelepiped light emitting unit 40 in a concentrated manner. As a result, a long-life laser downlight 400 can be realized.

[8. (Light distribution characteristics of light-emitting device)
Next, a light-emitting device (hereinafter referred to as a prototype) was prototyped using ten LD chips 11 which are one-chip, one-stripe semiconductor lasers (oscillation wavelength is 405 nm), and experiments were conducted. Each LD chip 11 has an optical output of 1.0 W, an operating voltage of 5 V, and a current of 0.6 A.

  Further, an optical fiber bundle composed of ten optical fibers 223 is used as the first optical system, a convex cylindrical lens 30 is used as the second optical system, and a rectangular parallelepiped light emitter 40 (horizontal × vertical × height = 3 mm) as the light emitting portion. × 1 mm × 1 mm) was employed.

  The optical fiber 223 is a quartz optical fiber having a core diameter of 200 μm, a cladding diameter of 240 μm, and a numerical aperture NA = 0.22.

  An aspheric lens (first optical system: for example, FLKN1 405 manufactured by Alps Electric, not shown) is provided for each LD chip 11 to collimate the laser light L0 and make it incident from one end of the corresponding optical fiber. Note that the arrangement of each of these components has been adjusted as appropriate, but it is cumbersome and will not be described.

  When the light distribution characteristics were examined in this prototype, a luminous flux of about 1500 lm (lumen) was emitted from the rectangular parallelepiped light emitter 40.

Moreover, the brightness | luminance of the rectangular parallelepiped light-emitting body 40 at this time was about 80 Mcd / m < ² > (mega candela per square meter).

  From this experimental result, the light flux per one LD chip 11 is about 150 lm by simple calculation. Therefore, for example, when 14 or more LD chips 11 are used, the rectangular parallelepiped light emitter 40 exceeds about 2000 lm. It turns out that it is possible.

Further, if 17 LD chips 11 are used, it is difficult to calculate an accurate value because light emission is not isotropic in reality, but light isotropically radiated from a light emitting point. By simple calculation, luminous intensity (light flux per unit solid angle) = 150 × 17 (lm) / 4π≈2550 (lm) /4/3.14≈203 (cd), effective aperture area of about 3 mm ² , optical Assuming that the transmittance of the system is 0.7, luminance≈203 (cd) /0.7/3 (mm ² ) = 96.6 (cd / mm ² ) ≈96.6 (Mcd / m ² ) ≈100 ( It can be seen that it is about Mcd / m ² ).

In addition, when the same experiment was performed by adjusting the number of LD chips 11, the rectangular parallelepiped light-emitting body 40 is actually capable of realizing a high luminous flux exceeding 2000 lm and a high luminance exceeding 100 Mcd / m ^2. (Such a light emitting device with high brightness and high luminous flux is hereinafter simply referred to as “laser illumination”).

[9. Comparison of light distribution characteristics between light emitting device and conventional lamp)
Next, a comparison result of the light distribution characteristics between the above-described laser illumination and the conventional lamp will be described with reference to FIGS.

  FIG. 15 is a diagram showing a state in which lens diameters necessary for automobile headlamps are compared by lamp type.

As shown in FIG. 15, the brightness of a commercially available halogen lamp is about 25 Mcd / m ² (mega candela per square meter), and the brightness of a high intensity discharge (HID) lamp is about 80 Mcd / m ² .

On the other hand, since the above-described laser illumination can achieve a high luminance of about 100 Mcd / m ² , as shown in FIG. 15, it can be seen that a high luminance exceeding the HID lamp can be realized about four times as much as the halogen lamp. .

That is, the luminance of the incoherent light L3 generated by the rectangular parallelepiped light emitter 40 is preferably 80 Mcd / m ² or more.

  In addition, halogen lamps are usually used for high beam headlamps of automobiles. However, in laser illumination, for example, by using the above-mentioned rectangular parallelepiped light emitter 40, a rectangular parallelepiped light emission having a smaller aperture size than that of the halogen lamp. Since the body 40 can achieve a brightness about four times that of the halogen lamp, the area of the lens installed in front of the high beam headlamp can be reduced to ¼.

  In addition, the size of the light emitting filament of the halogen lamp is about horizontal × vertical × height = 5 mm × 1.5 mm × 1.5 mm.

  Next, FIG. 16 (a) is a diagram comparing the performance of each type of lamp, and FIG. 16 (b) is a diagram showing an example of the external configuration of a conventional automotive headlamp. (c) is a figure which shows an example of the external appearance structure of the headlamp for motor vehicles at the time of using a laser illumination.

  First, as shown in FIG. 16A, the luminous flux of a commercially available high-power white LED (hereinafter, the description of “high power” may be omitted because it is complicated) is 400 to 500 lm (lumen) per module. The upper limit of the luminous flux is about 700 to 1500 lm (usually about 1000 lm for a halogen lamp for a passenger car), and the luminous flux of the HID lamp is about 3200 lm. However, it is difficult for the HID lamp to use all the light flux of 3200 lm for the irradiation light of the headlamp because of its structure and shape. Effectively, only a luminous flux of 2000 lm or less can be used. In addition, there is a problem that it is difficult to design an optical system.

  On the other hand, since the laser illumination of the embodiment can realize a high luminous flux exceeding 2000 lm, the luminous flux is about 4 to 5 times that of the white LED and is close to the HID lamp beyond the halogen lamp (effectively high luminous flux exceeding the HID lamp). ) Can be realized.

  That is, it is preferable that the light flux of the incoherent light L3 generated by the rectangular parallelepiped light emitter 40 is 700 lm or more and 3200 lm or less.

  Moreover, although white LED is normally used for the headlamp for low beams of a motor vehicle, according to the laser illumination of an Example, a high luminous flux for 4-5 lights of white LED is implement | achieved by one lamp, for example. Can do.

  Assuming that FIG. 16A shows the size of a conventional headlamp from the above examination results, according to the laser illumination of the embodiment, for example, as shown in FIG. Each of the headlamps for the low beam and the low beam only requires one lamp, and the area of the lens installed in front of the headlamps for the high beam and the low beam can be considerably reduced.

  Moreover, as shown to Fig.16 (a), in laser illumination, the lifetime by continuous use is about 10000 hours, and has a long lifetime comparable as white LED.

  Therefore, the light-emitting device 110, the light-emitting device 120A, the light-emitting device 120B, the lighting device 140 (laser illumination), and the like that can realize high brightness, high luminous flux, and long life can be provided.

  The present invention can also be expressed as follows.

  The light-emitting device (high-intensity light source) of the present invention has an excitation light source composed of a semiconductor laser capable of high-power laser oscillation and a light emission having a substantially rectangular shape that is long in the horizontal direction and emitted by excitation light from the excitation light source. And a light guide member for exciting the substantially rectangular light-emitting part efficiently and without unevenness (not partially biased).

  The light guide member is optically coupled to one or a plurality of excitation light sources, and the other end has one light emitting end, and is emitted from the first light guide member. You may comprise from the 2nd light guide member which consists of a substantially cylindrical lens for irradiating a light-emitting part with excitation light uniformly.

  The second light guide member may have a shape in which a plurality of substantially cylindrical lenses are combined.

  The excitation light source may be not only a semiconductor laser but also a high output light emitting diode.

  Further, not only a semiconductor laser having one laser beam emitting end in one excitation light source (one chip), but also a semiconductor laser having a plurality of laser beam emitting ends in one excitation light source (one chip). good.

  As described above, a light-emitting device suitable for a vehicle headlamp such as an automobile can be provided.

  The present invention can also be expressed as follows.

  That is, the light emitting device of the present invention includes an excitation light source group that generates a plurality of excitation light, a light emitting unit that generates light by being irradiated with each excitation light generated from the excitation light source group, and the light incident from one end. A first light guide member configured to guide each excitation light generated from the excitation light source group to a predetermined light emitting unit provided at the other end, and to output each guided excitation light from the light emitting unit; You may provide the 2nd light guide member which distributes and irradiates each excitation light radiate | emitted from the said light emission part of 1 light guide member to the predetermined light irradiation area | region in the said light emission part.

  According to the above configuration, the excitation light source group generates a plurality of excitation lights. Thereby, the light flux of the excitation light source group can be increased as compared with the case where a single excitation light source is used.

  The light emitting unit emits light by being irradiated with each excitation light generated from the excitation light source group. Therefore, the light emitting unit includes a phosphor that generates light when irradiated with at least each excitation light.

  The first light guide member guides each excitation light generated from the excitation light source group incident from one end to a predetermined light emitting portion provided at the other end, and guides each excitation light guided to the light. The light is emitted from the emission part.

  Thus, by adjusting the size from one end of the first light guide member to the other end, the excitation light source group and the light emitting unit can be spatially separated at an arbitrary interval. It is possible to prevent the light emitting portion from being deteriorated due to the influence of heat.

  Further, according to the above configuration, the second light guide member radiates each excitation light emitted from the light emitting portion of the first light guide member in a predetermined light irradiation region in the light emitting portion. It has become.

  Thereby, since each excitation light is disperse | distributed and irradiated to the light irradiation area | region of a light emission part, the electron of a low energy state excites efficiently to a high energy state over the whole fluorescent substance contained in a light emission part.

  Therefore, since incoherent light is generated from the light emitting portion without unevenness, the luminance of the light emitting device of the present invention can be increased as compared with the case where a single excitation light source is used.

  In addition, according to the above configuration, each excitation light is not radiated in a concentrated manner at one point of the light emitting unit, but is distributed and irradiated to the light irradiation region via the first light guide member and the second light guide member. It is possible to prevent the light emitting portion from being deteriorated by irradiating the excitation light concentrated on the same point.

  According to the above, it is possible to provide a light emitting device and the like that can realize high luminance and a long life.

  Here, the “excitation light source group” may be one in which a plurality of excitation light sources are spatially separated, or may be one in which a plurality of excitation light sources are integrated.

  Moreover, each excitation light source which comprises an excitation light source group may generate | occur | produce a coherent laser beam like LD, and may generate | occur | produce incoherent excitation light like LED. .

  In addition, the excitation light source group may be composed of only LD or LED, or may be a mixture of LD and LED.

  Further, as described above, the “light emitting unit” includes at least a phosphor, but may be composed of only a single type of phosphor, or may be composed of a plurality of types of phosphor. Further, the light emitting unit may be configured by dispersing a single type or a plurality of types of phosphors in an appropriate dispersion medium.

  In addition, the “phosphor” is an incoherent state in which an electron in a low energy state is excited to a high energy state by irradiating each excitation light, and this electron transitions from a high energy state to a low energy state. It is a substance that generates light.

  Further, “dispersed and irradiated” means that the excitation light is irradiated over the entire light irradiation region without being concentrated at one specific point in the light irradiation region.

  In other words, “dispersed and irradiated” means that the excitation light is irradiated over the entire light irradiation region with an intensity that does not deteriorate the light emitting part so that a part of the light emitting part is not pinpointed. That is. Note that the intensity of the light intensity distribution when the excitation light is applied may be somewhat strong as long as the light emitting portion does not deteriorate.

  “Dispersion of light” may mean that a single light is separated into a plurality of lights having a plurality of hues by a prism or the like. In this specification, the term “dispersion” is used. Terminology will not be used.

  Further, “dispersed irradiation” means that the light irradiation region may be irradiated with excitation light while expanding the irradiation area as in the case where the size of the light irradiation region is larger than the size of the light output portion. The light irradiation region may be irradiated with the excitation light while reducing the irradiation area as in the case where the size of the light irradiation region is smaller than the size.

  Further, in the light emitting device of the present invention, the first light guide member has a surrounding structure surrounded by a light reflecting side surface that reflects each excitation light incident from the one end, and the light emitting portion is cut off. The area may be smaller than the cross-sectional area of the one end of the first light guide member, and the excitation light incident from the one end may be guided to the light emitting portion by the surrounding structure.

  According to the above configuration, the surrounding light surrounded by the light reflecting side surface guides each excitation light incident from one end to the light emitting unit having a cross-sectional area smaller than the cross-sectional area of the one end. Excitation light can be condensed on a light emitting portion having a cross-sectional area smaller than the cross-sectional area of the one end.

  Therefore, by reducing both the cross-sectional area of the light emitting part and the size of the light emitting part (light irradiation region), the light emitting part that generates light of high brightness and high luminous flux according to the number of excitation light sources constituting the excitation light source group Can be reduced in size.

  Here, “go” refers to surrounding the entire optical path of each excitation light generated from the excitation light group.

  In addition, in the case of “guided to the light emitting part by the go structure”, when the light is reflected only once on the light reflecting side surface and guided to the light emitting part, it is reflected plural times on the light reflecting side surface to the light emitting part. In the case of guiding the light, any case where the light is guided to the light emitting part without being reflected on the light reflecting side surface is included.

  By the way, in the lamps disclosed in Patent Documents 1 and 2, although the viewpoint of realizing high luminance by irradiating the phosphor with excitation light generated from a plurality of excitation light sources is considered, it is provided for each excitation light source. Since the excitation light is guided using the collected condenser lens, there is a secondary problem that the lamp becomes larger as the number of excitation light sources increases.

  In addition, in this lamp, a hole is formed in the reflecting mirror for each excitation light, and the excitation light is passed through the hole to irradiate the phosphor. Therefore, as the number of excitation light sources increases, the reflection of light by the reflecting mirror increases. There is also a secondary problem that efficiency deteriorates.

  In the light emitting device of the present invention, in order to solve such a secondary problem, in addition to the above configuration, the first light guide member includes a plurality of optical fibers, and the respective excitation lights correspond to each other. The light may enter from one end of the optical fiber and exit from the other end of the optical fiber, and the light emitting unit may be configured by a portion in which the other ends of the plurality of optical fibers are arranged.

  According to the above configuration, each excitation light is incident from one end of the corresponding optical fiber and the other end of the plurality of optical fibers is arranged with a simple configuration in which the first light guide member is configured by a plurality of optical fibers. It is guided to (light emitting part).

  Further, although depending on the thickness and number of optical fibers, the thickness of the optical fibers is usually not so large even if a plurality of optical fibers are bundled.

  Therefore, it is possible to irradiate the light irradiation region of the small light emitting unit with excitation light derived from a large number of excitation light sources while keeping the size of the light emitting unit and the light irradiation region (or light emitting unit) small.

  For example, when the light-emitting device of the present invention is used for a headlamp, a hole is formed in the center of the reflecting mirror, a bundle of a plurality of optical fibers is passed through the hole, and light is emitted from a portion where the other ends of the plurality of optical fibers are arranged. Therefore, even if the number of excitation light sources constituting the excitation light source group increases, the reflection efficiency of light by the reflecting mirror as in the lamps disclosed in Patent Documents 1 and 2 can be increased. There is no deterioration.

  In the light emitting device of the present invention, in addition to the above configuration, the shape of the light irradiation region is a shape that is long in the horizontal direction, and the second light guide member is a plano-convex cylindrical lens having an axis in the vertical direction. There may be.

  If the second light guide member is composed of a plano-convex cylindrical lens having an axis in the vertical direction, the excitation light can be diffused in the horizontal direction.

  Therefore, each excitation light can be distributed and irradiated to the light irradiation region according to the shape of the light irradiation region that is long in the horizontal direction.

  In addition to the above configuration, the light emitting device of the present invention has a shape in which the shape of the light irradiation region is long in the horizontal direction and the diameter in the vertical direction changes linearly with respect to the horizontal direction. The two light guide members may be a combination of a first plano-convex cylindrical lens having an axis in the vertical direction and a second plano-convex cylindrical lens having an axis in the horizontal direction.

  By configuring the second light guide member by a combination of a first plano-convex cylindrical lens having an axis in the vertical direction and a second plano-convex cylindrical lens having an axis in the horizontal direction, the size of the light irradiation region in the horizontal direction In addition, the excitation light can be distributed and irradiated on the light irradiation region according to the size in the vertical direction.

  The light-emitting device of the present invention includes an excitation light source group that generates a plurality of excitation lights, a light-emitting unit that generates light when irradiated with each excitation light generated from the excitation light source group, and the light incident from one end. A light guide member that guides each excitation light generated from the excitation light source group to the other end is provided, and the other light guide member is irradiated with predetermined light emitted from the light emitting unit at the other end of the light guide member. A light dispersion portion that irradiates and irradiates the region may be formed.

  According to the above configuration, the excitation light source group generates a plurality of excitation lights. Thereby, the light flux of the excitation light source group can be increased as compared with the case where a single excitation light source is used.

  The light emitting unit emits light by being irradiated with each excitation light generated from the excitation light source group. Therefore, the light emitting unit includes a phosphor that generates light when irradiated with at least each excitation light.

  The light guide member guides the excitation light generated from the excitation light source group incident from one end to the other end.

  Furthermore, the other end of the light guide member is formed with a light dispersion portion that radiates and distributes each guided excitation light to a predetermined light irradiation region in the light emitting portion.

  Thus, by adjusting the size of the light guide member from one end to the other end, the excitation light source group and the light emitting unit can be spatially separated at an arbitrary interval, so the heat generated in the excitation light source group It is possible to prevent the light emitting portion from being deteriorated by the influence of the above.

  In addition, since each excitation light is dispersed and irradiated from the light dispersion part to the light irradiation region of the light emitting part, electrons in a low energy state are efficiently excited to a high energy state over the entire phosphor contained in the light emitting part. To do.

  Therefore, since incoherent light is generated from the light emitting portion without unevenness, the luminance of the light emitting device of the present invention can be increased as compared with the case where a single excitation light source is used.

  In addition, according to the above configuration, each excitation light is not concentrated on one point of the light emitting unit and irradiated on the light irradiation region via the light guide member, so that each excitation light is concentrated on the same point. It is possible to prevent the light emitting portion from being deteriorated by being irradiated.

  In the light emitting device of the present invention, the excitation light source group may be composed of a plurality of semiconductor lasers, and each of the excitation lights may be a laser beam generated from a corresponding semiconductor laser.

  Further, in the light emitting device of the present invention, the excitation light source group is composed of a single semiconductor laser having a plurality of laser light emission ends, and each excitation light is emitted from a corresponding laser light emission end. It may be light.

  In the light-emitting device of the present invention, the light-emitting portion may include an oxynitride phosphor.

In the light emitting device of the present invention, the luminance of the light generated by the light emitting unit may be 80 Mcd / m ² or more.

  In the light emitting device of the present invention, the light flux generated by the light emitting unit may be 700 lm or more and 3200 lm or less.

  In the light emitting device of the present invention, the shape of the light emitting part may be formed according to the shape of a cut line that defines a light / dark boundary of a light distribution pattern of light generated by the light emitting part.

  According to the above, it is possible to provide a light emitting device and the like that can realize high luminance and a long life.

  Moreover, the illuminating device of this invention may be provided with either of the said light-emitting devices.

  Thereby, a high-luminance and long-life lighting device can be provided.

  According to the above, it is possible to provide a light emitting device / illumination device that can achieve high brightness and a long life.

  The present invention can also be expressed as a method as follows.

  In the light generation method of the present invention, a plurality of excitation lights generated from a predetermined excitation light source group are guided to a predetermined light emitting unit, and each guided excitation light is emitted from the light emitting unit, A light generation method for generating light by irradiating a light emitting unit, wherein an excitation light generation step for generating a plurality of excitation lights from the excitation light source group, and each excitation light generated in the excitation light generation step, An excitation light guiding step for guiding light to the light emitting unit, an excitation light emitting step for emitting each excitation light guided in the excitation light guiding step from the light emitting unit, and the light emitting unit in the excitation light emitting step An excitation light dispersion irradiation step of dispersing and irradiating each excitation light emitted from the light emission portion in a predetermined light irradiation region in the light emitting unit.

  Further, the light generation method of the present invention guides a plurality of excitation lights generated from a predetermined excitation light source group to a predetermined light dispersion part, and each of the guided excitation lights from the light dispersion part to a predetermined light emission part. A light generation method for generating light by irradiating the light source with a pumping light generation step for generating a plurality of pumping light from the pumping light source group, and each pumping light generated in the pumping light generation step with the light Excitation light guiding step for guiding light to the dispersion part, and excitation light dispersion irradiation step for dispersing and irradiating each excitation light guided in the excitation light light guide step from the light dispersion part to a predetermined light irradiation region in the light emitting part May be included.

  The light generation method of the present invention guides a plurality of excitation lights generated from a predetermined excitation light source group in the vicinity of a predetermined light emitting unit, and guides each of the guided excitation lights to the predetermined light of the light emitting unit. A light generation method for generating light by irradiating an irradiation region, wherein an excitation light generation step for generating a plurality of excitation lights from the excitation light source group, and each excitation light generated in the excitation light generation step, An excitation light guiding step for guiding light in the vicinity of the light emitting unit, and an excitation light dispersion irradiating step for dispersing and irradiating each excitation light guided in the excitation light guiding step in the light irradiation region may be included. .

  The light emitting device of the present invention is generated from an excitation light source group that generates a plurality of excitation light, a light emitting unit that generates light by being irradiated with each excitation light generated from the excitation light source group, and the excitation light source group A first optical system that guides each excitation light to the vicinity of the light emitting unit, and a second optical system that irradiates each excitation light guided by the first optical system in a distributed manner in a predetermined light irradiation region in the light emitting unit. And an optical system.

  According to the above configuration, the excitation light source group generates a plurality of excitation lights. Thereby, the light flux of the excitation light source group can be increased as compared with the case where a single excitation light source is used.

  The light emitting unit emits light by being irradiated with each excitation light generated from the excitation light source group. Therefore, the light emitting unit includes a phosphor that generates light when irradiated with at least each excitation light.

  The first optical system guides each excitation light generated from the excitation light source group to the vicinity of the light emitting unit.

  Accordingly, by adjusting the distance from the side on which the respective excitation lights are incident on the first optical system to the side on which the respective excitation lights are guided, the excitation light source group and the light emitting unit are spaced at an arbitrary interval. Therefore, it is possible to prevent the light emitting portion from deteriorating due to the influence of heat generated in the excitation light source group.

  According to the above configuration, the second optical system irradiates each excitation light guided by the first optical system in a distributed manner in a predetermined light irradiation region in the light emitting unit.

  Thereby, since each excitation light is disperse | distributed and irradiated to the light irradiation area | region of a light emission part, the electron of a low energy state excites efficiently to a high energy state over the whole fluorescent substance contained in a light emission part.

  Therefore, since incoherent light is generated from the light emitting portion without unevenness, the luminance of the light emitting device of the present invention can be increased as compared with the case where a single excitation light source is used.

  In addition, according to the above configuration, each excitation light is not irradiated in a concentrated manner on one point of the light emitting unit, but is distributed and irradiated on the light irradiation region via the first optical system and the second optical system. It is possible to prevent the light emitting portion from being deteriorated by irradiating the light at the same point.

  According to the above, it is possible to provide a light emitting device and the like that can realize high luminance and a long life.

  Here, the “first optical system” may be constituted by, for example, a single optical component that guides each excitation light incident from one end to the other end, and each excitation light incident from one end is the other end. The first optical component that guides the pumped excitation light from the other end and the second optical component that guides the excitation light emitted from the other end of the first optical component incident from one end to the other end. You may comprise with several optical components like the combination with an optical component.

  In addition, the “second optical system” only needs to be capable of dispersing and irradiating each excitation light guided by the first optical system in the light irradiation region. It may be a single optical component that irradiates and irradiates the excitation light to the light irradiation region, or each excitation light guided by the first optical system is distributed and irradiated to the light irradiation region using two lenses. As in the case of, a plurality of optical components may be used.

  Further, as in the above-described example, the first optical system and the second optical system may be configured by two or more independent optical components, or one integrated as a “light guide member” described later. You may comprise with an optical component.

  In addition, the “excitation light source group” may include a plurality of excitation light sources that are spatially separated, or may be a combination of a plurality of excitation light sources.

  Moreover, each excitation light source which comprises an excitation light source group may generate | occur | produce a coherent laser beam like LD, and may generate | occur | produce incoherent excitation light like LED. .

  In addition, the excitation light source group may be composed of only LD or LED, or may be a mixture of LD and LED.

  Further, as described above, the “light emitting unit” includes at least a phosphor, but may be composed of only a single type of phosphor, or may be composed of a plurality of types of phosphor. Further, the light emitting unit may be configured by dispersing a single type or a plurality of types of phosphors in an appropriate dispersion medium.

  In addition, the “phosphor” is an incoherent state in which an electron in a low energy state is excited to a high energy state by irradiating each excitation light, and this electron transitions from a high energy state to a low energy state. It is a substance that generates light.

  Further, “dispersed and irradiated” means that the excitation light is irradiated over the entire light irradiation region without being concentrated at one specific point in the light irradiation region.

  In other words, “dispersed and irradiated” refers to irradiating excitation light over the entire light irradiation region with an intensity that does not cause deterioration of the light emitting part so as not to excite a part of the light emitting part pinpoint. is there. Note that the intensity of the light intensity distribution when the excitation light is applied may be somewhat strong as long as the light emitting portion does not deteriorate.

  “Dispersion of light” may mean that a single light is separated into a plurality of lights having a plurality of hues by a prism or the like. In this specification, the term “dispersion” is used. Terminology will not be used.

  In addition, in “dispersed irradiation”, when the irradiation area is irradiated with excitation light with the irradiation area being substantially constant, the irradiation area is reduced when the irradiation area is irradiated with excitation light while expanding the irradiation area. Any case of irradiating the light irradiation region with excitation light is included.

  In the light-emitting device of the present invention, in addition to the above configuration, the first optical system has a surrounding structure surrounded by a light reflecting side surface that reflects each excitation light incident from one end, and the other end The cross-sectional area is smaller than the cross-sectional area of the one end, and each excitation light incident from the one end may be guided to the other end by the surrounding structure.

  According to the above-described configuration, the other end of the first optical system having a cross-sectional area smaller than the cross-sectional area of the one end is allowed to cause each excitation light incident from one end of the first optical system to be surrounded by the light reflecting side surface. In other words, each excitation light can be condensed on the other end of the first optical system having a cross-sectional area smaller than the cross-sectional area of the one end.

  Therefore, by reducing both the cross-sectional area of the other end of the first optical system and the size of the light emitting part (light irradiation region), light of high brightness and high luminous flux corresponding to the number of excitation light sources constituting the excitation light source group can be obtained. The generated light emitting unit can be downsized.

  Here, “go” refers to surrounding the entire optical path of each excitation light generated from the excitation light group.

  In addition, in the case of “guided to the other end of the first optical system by the go structure”, when the light is reflected only once on the light reflection side surface and guided to the other end of the first optical system, a plurality of light is reflected on the light reflection side surface. When the light is reflected once and guided to the other end of the first optical system, both cases where the light is guided to the other end of the first optical system without being reflected once by the light reflection side surface are included.

  By the way, in the lamps disclosed in Patent Documents 1 and 2, although the viewpoint of realizing high luminance by irradiating the phosphor with excitation light generated from a plurality of excitation light sources is considered, it is provided for each excitation light source. Since the excitation light is guided using the collected condenser lens, there is a secondary problem that the lamp becomes larger as the number of excitation light sources increases.

  In addition, in this lamp, a hole is formed in the reflecting mirror for each excitation light, and the excitation light is passed through the hole to irradiate the phosphor. Therefore, as the number of excitation light sources increases, the reflection of light by the reflecting mirror increases. There is also a secondary problem that efficiency deteriorates.

  In order to solve such a secondary problem, the light emitting device of the present invention includes the first optical system including a plurality of optical fibers in addition to the above-described configuration, and each of the excitation lights includes a corresponding optical fiber. The portion of the first optical system is guided to the other end of the optical fiber, and the excitation light of the first optical system is guided by the portion where the other ends of the plurality of optical fibers are arranged. It is preferable.

  According to the above configuration, each excitation light is incident from one end of a corresponding optical fiber and the other end of the plurality of optical fibers is arranged in a simple configuration in which the first optical system is configured by a plurality of optical fibers ( The first optical system is guided to a portion where each excitation light is guided.

  Further, although depending on the thickness and number of optical fibers, the thickness of the optical fibers is usually not so large even if a plurality of optical fibers are bundled.

  Therefore, while keeping the size of the portion where the other ends of the plurality of optical fibers are arranged (the portion where each excitation light of the first optical system is guided) and the light irradiation region (or the light emitting portion) are kept small, The light irradiation region can be irradiated with excitation light derived from a large number of excitation light sources.

  For example, when the light-emitting device of the present invention is used for a headlamp, a hole is formed in the center of the reflecting mirror, a bundle of a plurality of optical fibers is passed through the hole, and light is emitted from a portion where the other ends of the plurality of optical fibers are arranged. Therefore, even if the number of excitation light sources constituting the excitation light source group increases, the reflection efficiency of light by the reflecting mirror as in the lamps disclosed in Patent Documents 1 and 2 can be increased. There is no deterioration.

  Further, in the light emitting device of the present invention, in addition to the above configuration, the shape of the light irradiation region is a shape that is long in the horizontal direction, and the second optical system includes a convex lens having a convex surface having an axis at least in the vertical direction. You may have.

  If the second optical system is constituted by a convex lens having a convex surface having an axis in the vertical direction, even if the horizontal spread of each excitation light is larger than the horizontal width of the light irradiation region, the light In accordance with the horizontal width of the irradiation region, each excitation light can be dispersed in the horizontal direction and irradiated onto the light irradiation region.

  Therefore, each excitation light can be distributed and irradiated to the light irradiation region according to the shape of the light irradiation region that is long in the horizontal direction.

  Examples of the “convex lens having a convex surface having an axis in the vertical direction” include a biconvex lens, a plano-convex lens, and a convex meniscus lens having an axis in the vertical direction.

  Further, in the light emitting device of the present invention, in addition to the above configuration, the shape of the light irradiation region is a shape in which a vertical diameter changes linearly with respect to a horizontal direction, and the second optical system includes A combination of a convex lens having a convex surface with an axis in the vertical direction and a convex lens having a convex surface with an axis in the horizontal direction may be used.

  By configuring the second optical system by a combination of a convex lens having a convex surface having an axis in the vertical direction and a convex lens having a convex surface having an axis in the horizontal direction, the shape of the light irradiation area has a horizontal diameter in the horizontal direction. Even if the shape changes linearly with respect to the direction, each excitation light is distributed and irradiated to the light irradiation region according to the horizontal size and vertical size of the light irradiation region according to the shape. Can be.

  Examples of the “convex lens having a convex surface having an axis in the horizontal direction” include a biconvex lens, a plano-convex lens, and a convex meniscus lens having an axis in the horizontal direction.

  As the “combination of convex lenses”, when the convex lens having a convex surface having an axis in the vertical direction and the convex lens having a convex surface having an axis in the horizontal direction are separate convex lenses, the optical axes of these convex lenses should be aligned. It ’s fine. Further, a convex lens having a convex surface having an axis in the vertical direction and a convex lens having a convex surface having an axis in the horizontal direction may be integrated so as not to be separated.

  In addition to the above configuration, the light emitting device of the present invention is a light guide member in which the first optical system and the second optical system are integrated, and the first light system side of the light guide member is on the first optical system side. Each excitation light generated from the excitation light source group incident from one end is guided to the other end on the second optical system side of the light guide member, and is guided to the other end on the second optical system side. A light dispersion portion that irradiates and distributes each excitation light to the light irradiation region may be formed.

  According to the above configuration, the light guide member is formed by integrating the first optical system and the second optical system. Therefore, the number of parts of the optical system can be reduced, and the size of the entire optical system can be reduced.

  Each excitation light generated from the excitation light source group incident from one end of the light guide member on the first optical system side is guided to the other end of the light guide member on the second optical system side. Yes.

  Furthermore, a light dispersion part is formed at the other end on the second optical system side to disperse and irradiate each guided excitation light to the light irradiation region.

  Thus, by adjusting the size of the light guide member from one end to the other end, the excitation light source group and the light emitting unit can be spatially separated at an arbitrary interval, so the heat generated in the excitation light source group It is possible to prevent the light emitting portion from being deteriorated by the influence of the above.

  In addition, since each excitation light is dispersed and irradiated from the light dispersion part to the light irradiation region of the light emitting part, electrons in a low energy state are efficiently excited to a high energy state over the entire phosphor contained in the light emitting part. To do.

  Therefore, since incoherent light is generated from the light emitting portion without unevenness, the luminance of the light emitting device of the present invention can be increased as compared with the case where a single excitation light source is used.

  In addition, according to the above configuration, each excitation light is not concentrated on one point of the light emitting unit and irradiated on the light irradiation region via the light guide member, so that each excitation light is concentrated on the same point. It is possible to prevent the light emitting portion from being deteriorated by being irradiated.

  According to the above, it is possible to provide a light emitting device and the like that can realize high luminance and a long life.

  Moreover, it is preferable that the illuminating device of this invention is provided with either of the said light-emitting devices in addition to the said structure.

  Thereby, a high-luminance and long-life lighting device can be provided.

  According to the above, it is possible to provide a light emitting device / illumination device that can achieve high brightness and a long life.

  In addition to the above-described configuration, the vehicle headlamp of the present invention reflects the light generated from the light emitting device and the light emitting unit, thereby forming a light beam that travels within a predetermined solid angle. And may be provided.

  According to the said structure, the light emitted from the light emission part is reflected by a reflective mirror, and the light beam which advances within the predetermined solid angle is formed. Therefore, it is possible to provide a vehicular headlamp that can achieve high brightness and a long life.

  As described above, the light-emitting device of the present invention includes a plurality of excitation light sources that generate a plurality of excitation lights, a light-emitting unit that generates light when irradiated with each excitation light generated from the excitation light sources, and the excitation A first optical system that guides each excitation light generated from the light source group to the vicinity of the light emitting unit, and each excitation light guided by the first optical system is dispersed in a predetermined light irradiation region in the light emitting unit. And a second optical system for irradiation.

  Therefore, it is possible to provide a light emitting device and the like that can realize high luminance and a long lifetime.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

  The present invention can be applied to a light-emitting device, a lighting device, a lamp, and a lighting fixture that have a high luminance and a long lifetime, particularly a headlamp for a vehicle.

10 Laser diode group (excitation light source group)
11 LD chip (excitation light source)
13 LED pilot lamp (excitation light source)
20 1st light guide part (1st optical system)
21A pyramid shaped condensing part (first optical system)
21B Pyramidal optical member (light guide member, first optical system, second optical system)
22 Optical fiber bundle (first optical system, multiple optical fibers)
30 convex cylindrical lens (second optical system, convex lens having a convex surface with an axis in the vertical direction)
31 Concave cylindrical lens (second optical system)
32 Compound cylindrical lens (second optical system)
40 Cuboid light emitter (light emitting part)
41 Light emitter for low beam (light emitting part)
50 Rod lens (first optical system)
90 reflecting mirror 101 LD chip (excitation light source group)
102 Emission point (excitation light source)
110, 120A, 120B Light emitting device (lighting device, vehicle headlamp)
130 LED chip (excitation light source)
140 Illumination device (light emitting device, vehicle headlamp)
201 Light incident part (one end of the first optical system)
202 Light emitting part (the other end of the first optical system)
211A Light incident surface (one end of the first optical system)
211B Light incident surface (one end of the first optical system, one end on the first optical system side)
212A Light exit surface (the other end of the first optical system)
212B Light dispersion surface (light dispersion part, other end on the second optical system side)
213A, 213B Side surface of truncated pyramid (light reflection side surface, go structure)
221 Incident end (one end of the first optical system)
222 Output end (the portion where the other end of the first optical system and the other end of the optical fiber are arranged)
223 Optical fiber 321 Vertical axis cylindrical lens (convex lens having a convex surface with an axis in the vertical direction)
322 Horizontal-axis cylindrical lens (convex lens having a convex surface with an axis in the horizontal direction)
400 Laser downlight (light emitting device, lighting device)
L0 laser light (excitation light)
L1 outgoing light (excitation light)
L2 irradiation light (excitation light)
L3 Incoherent light (light)
R1-R5 Light irradiation area

Claims (5)

A group of excitation light sources for generating a plurality of excitation lights;
A light emitting unit that generates light by being irradiated with each excitation light generated from the excitation light source group;
A first optical system that mixes each excitation light generated from the excitation light source group and guides it to the vicinity of the light emitting unit;
A second optical system for irradiating the light emitting unit with the excitation light mixed by the first optical system,
The area of the irradiation region of the excitation light irradiated on the light emitting unit is larger than the cross-sectional area of the exit end of the excitation light in the first optical system,
The second optical system irradiates the light emitting part with excitation light in accordance with the shape of the surface of the light emitting part on the side irradiated with excitation light ,
The light emitting device , wherein the second optical system is a convex lens .   The first optical system has a surrounding structure surrounded by a light reflecting side surface that reflects each excitation light incident from an incident end, and each excitation light incident from the incident end is The light emitting device according to claim 1, wherein the light is guided to the emission end portion by a structure.   The light emitting device according to claim 1, wherein the irradiation region has a length in a first direction that is longer than a length in a second direction perpendicular to the first direction. The light-emitting device according to any one of claims 1 to 3,
An illumination system comprising: an optical system that projects light generated from the light emitting unit as a light bundle that travels within a predetermined solid angle.   A vehicle headlamp comprising the light-emitting device according to claim 1.

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