JP2009105321A - Light source device, lighting device, image display device, and monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device that exhibits excellent heat dissipation with a small size and improves the optical utilization efficiency, and to provide a lighting device, an image display device, and a monitoring device. <P>SOLUTION: The light source device includes at least one pair of light source sections 2a, 2b each having a light source 10 having a plurality of light-emitting sections for emitting the fundamental wavelength light, a wavelength conversion element 30, a wavelength selection element 40 that functions as a resonator, a separator section 20 to guide the fundamental wavelength light emitted from the light source 10 toward the wavelength conversion element 30 and to guide the light converted into the predetermined wavelength toward the direction different from the light source 10, while guiding the fundamental wavelength light toward the light source 10, an optical waveguide section 25 to guide the light toward almost the same direction as the light transmitting through the wavelength selection element 40, and substrates 15, 16 each of which has the light source 10, the wavelength conversion element 30, and the wavelength selection element 40 on sides 15a, 15b. A pair of light source sections 2a, 2b are provided with the sides 15a, 15b on the substrates 15, 16 opposite to each other respectively across spacing members 17, 18. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light source device, an illumination device, an image display device, and a monitor device.

  In recent projection type image display apparatuses, a discharge lamp such as an ultrahigh pressure mercury lamp is generally used as a light source. However, such a discharge lamp has problems such as a relatively short life, difficulty in instantaneous lighting, a narrow color reproduction range, and ultraviolet light emitted from the lamp may deteriorate the liquid crystal light bulb. Therefore, a projection type image display apparatus using a laser light source that emits monochromatic light instead of such a discharge lamp has been proposed. In addition, it is desirable that a laser light source emits a plurality of laser beams in order to reduce the contrast for high output and speckle noise, and that the intervals between the laser beams be as narrow as possible to simplify the optical system. ing. Thus, a semiconductor laser device including a plurality of surface emitting lasers has been proposed (see, for example, Patent Document 1).

A semiconductor laser device described in Patent Document 1 includes a heat sink, a submount disposed on the heat sink, a surface emitting laser chip provided with a two-dimensional surface emitting laser disposed on the submount, and a plurality of surfaces. And a concave mirror functioning as an external reflecting mirror provided corresponding to the light emitting laser. With this configuration, light emitted from a plurality of surface-emitting lasers is reflected by the concave mirror and returned to the surface-emitting laser, and mode selection occurs and a single mode is achieved. As described above, by providing a plurality of surface emitting lasers, high output can be achieved.
Japanese Patent Laid-Open No. 2005-19804

However, in the semiconductor laser device described in Patent Document 1, although the surface emitting lasers are two-dimensionally arranged to enable high output, a plurality of surface emitting lasers dissipate heat with a single heat sink. The surface emitting laser disposed in the part has poor heat dissipation. In addition, since a plurality of surface emitting lasers are formed on one substrate, heat generated in the surface emitting laser affects other surface emitting lasers, so there is a limit to increasing the output.
By the way, in order to convert the light emitted from the light source into a predetermined wavelength, a wavelength conversion element is required. Therefore, when the wavelength conversion element is used in the semiconductor laser device described in Patent Document 1, the light converted to the predetermined conversion wavelength by passing through the wavelength conversion element passes through the concave mirror and is converted to the predetermined conversion wavelength. The light that has not been reflected is reflected by the concave mirror, and a part of the light is again transmitted through the wavelength conversion element to be converted into a predetermined conversion wavelength. Although it is necessary to provide a structure for extracting the light converted into the predetermined wavelength to the outside without returning it to the surface emitting laser, it is difficult to form such a structure in the conventional semiconductor laser device. That is, since it is difficult to extract the light converted into the predetermined conversion wavelength with the conventional technique, the utilization efficiency of the light emitted from the surface emitting laser is lowered.
Further, in the semiconductor laser device described in Patent Document 1, since a plurality of surface emitting lasers are formed on one substrate, it is difficult to reduce the interval between the individual surface emitting lasers, and it is difficult to reduce the size of the device. It is.

  The present invention has been made to solve the above-described problems, and is a light source device, an illumination device, an image display device, and a monitor that are small in size, excellent in heat dissipation, and capable of improving light utilization efficiency. An object is to provide an apparatus.

In order to achieve the above object, the present invention provides the following means.
A light source device according to the present invention includes a light source having a plurality of light emitting units that emit light having a fundamental wavelength, and a wavelength conversion element that converts at least part of the light emitted from the light source into light having a predetermined conversion wavelength. A wavelength selection element that transmits the light having the predetermined conversion wavelength among the light emitted from the light source and passed through the wavelength conversion element, reflects the light having the fundamental wavelength, and functions as a resonator; and the light source The light having the fundamental wavelength emitted from the light is guided toward the wavelength conversion element, and the light that is reflected by the wavelength selection element and passes through the wavelength conversion element is converted to the predetermined conversion wavelength. And a light guiding unit that guides light guided in a direction different from the light source in substantially the same direction as light transmitted through the wavelength selection element. And one side At least a pair of light sources having the light source, the wavelength conversion element, and the base material on which the wavelength selection element is disposed, and the pair of light source parts has one surface of each of the bases with a space member interposed therebetween. It is characterized by being provided facing each other.

In the light source device according to the present invention, the light having the fundamental wavelength emitted from the light source is reflected toward the wavelength conversion element in the separation unit. Of the light that has passed through the wavelength conversion element, light that has been converted to light of a predetermined conversion wavelength is transmitted through the wavelength selection element.
On the other hand, of the light that has passed through the wavelength conversion element, the light that has not been converted to the predetermined conversion wavelength passes through the wavelength conversion element again in the wavelength selection element. Of the return light that has passed through the wavelength conversion element, the light converted to the predetermined conversion wavelength is guided in a direction different from the light source. The light guided in a direction different from the light source is guided by the light guide unit in substantially the same direction as the light transmitted through the wavelength selection element. Moreover, the light which has not been converted into the predetermined conversion wavelength among the return light is guided to the light source by the separation unit. As described above, since the separation unit and the light guide unit are provided, light converted from the wavelength conversion element to a predetermined conversion wavelength can be extracted in the optical path emitted from the light source, reflected by the wavelength selection element, and returned to the light source. It is possible to improve the light utilization efficiency.

Further, the present invention is not a configuration in which the light sources of the pair of light source units are arranged close to each other. In other words, the pair of light source sections are provided with one surface of each base material facing each other across the space member, so that the light sources are opposed to each other, so that the optical path of the light emitted from the light source can be close to each other. It is. Therefore, as compared with the conventional case where a plurality of light sources are arranged on the same substrate, it is possible to narrow the interval between the light emitted from the plurality of light sources.
In the present invention, since the plurality of light source units are provided with one surface of each base material facing each other with the space member interposed therebetween, the other side opposite to one surface of the base material of each light source unit Can be exposed to the outside. Therefore, as a cooling device for cooling an optical member such as a light source, a wavelength conversion element, and a wavelength selection element arranged on the other surface of the base material, for example, a cooling device including air cooling fins is provided for each light source unit. Can be arranged. Furthermore, since the light source units can be individually cooled and the heat generated in the light source units can be prevented from interfering with each other, the pair of light source units can be efficiently cooled.
Therefore, since heat generated from the optical member, particularly the light source, can be efficiently radiated, high-power laser light can be emitted.
In addition, after assembling the light source units individually so that they oscillate, it is only necessary to assemble one side of the base material of the pair of light source units facing each other with a space member interposed therebetween, which simplifies manufacturing. .

In the light source device of the present invention, it is preferable that a pair of the light source units is provided.
In the light source device according to the present invention, since a pair of light source units is provided, it is only necessary to align the two light source units. Therefore, the assembly is simple, and thus the manufacturing cost can be suppressed.

In the light source device of the present invention, it is preferable that two or more pairs of the light source units are provided.
In the light source device according to the present invention, since two or more pairs of light source units are provided, the number of light emitting units in one light source unit can be reduced, and a light source device having a predetermined number of light emitting units can be configured. . Therefore, by dividing the plurality of light emitting units into several light source units, the plurality of light emitting units can be arranged separately for each light source unit, so that the heat of the light emitting units for each light source unit is less likely to interfere. Therefore, it is possible to improve the cooling efficiency.

  Further, in the light source device of the present invention, the space member has a concave portion that is subjected to reflection processing on the inner surface, and the light guided in a direction different from the light source is transmitted through the wavelength selection element by the concave portion. It is preferable that light is guided in substantially the same direction as the light, and the space member functions as the light guide.

  In the light source device according to the present invention, since the space member has a concave portion with reflection processing on the inner surface, the light guided in the direction different from the light source is substantially the same as the light transmitted through the wavelength selection element. Lead in the direction. Thus, since the space member assumes the function of the light guide unit, the number of components can be reduced as compared with the case where the space member and the light guide unit are provided as separate members. Therefore, it is possible to reduce the cost and size of the entire apparatus.

  In the light source device of the present invention, it is preferable that the pair of light source units share one light guide unit.

  In the light source device according to the present invention, since the pair of light source units share one light guide unit, the number of components can be reduced, and thus the cost of the entire device can be reduced. In addition, when a plurality of light guides are provided, it is necessary to align the individual light guides. However, by making the light guides of the plurality of light source units common, the alignment becomes easy.

  Further, in the light source device of the present invention, at least one of the plurality of separation units is a wavelength selection film formed at a position where light emitted from the light source of the light guide unit is incident, It is preferable that the light guide part functions as the separation part.

  In the light source device according to the present invention, at least one of the plurality of separation units is a wavelength selection film formed at a position where light emitted from the light source of the light guide unit is incident, and the light guide unit is separated. Since it functions as a part, the number of parts can be reduced. Therefore, the cost of the entire apparatus can be reduced. In addition, when a plurality of separation units are provided, it is necessary to align the individual separation units. However, the alignment is facilitated by forming the separation units in the light guide unit.

The illuminating device of this invention is equipped with said light source device, It is characterized by the above-mentioned.
The lighting device according to the present invention includes a light source device that is downsized, has excellent heat dissipation, and can improve light utilization efficiency. Therefore, the lighting device itself is also small and emits bright light. It becomes possible.

An image display apparatus according to the present invention includes the above-described light source device and an image forming apparatus that displays an image of a desired size on a display surface using light from the light source device.
In the image display device according to the present invention, the light emitted from the light source device enters the image forming apparatus. Then, an image having a desired size is displayed on the display surface by the image forming apparatus. At this time, since the light source device that is miniaturized, has excellent heat dissipation, and can improve the light utilization efficiency, a bright and clear image can be projected.

A monitor device according to the present invention includes the light source device described above and an imaging unit that captures an image of a subject using light emitted from the light source device.
In the monitor device according to the present invention, the light emitted from the light source device irradiates the subject, and the subject is imaged by the imaging means. At this time, since the light source device that is downsized, has excellent heat dissipation, and can improve the light utilization efficiency, the subject is irradiated with bright light. Therefore, the subject can be clearly imaged by the imaging means.

Hereinafter, embodiments of a light source device, an illumination device, an image display device, and a monitor device according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

[First Embodiment]
Next, a first embodiment of the present invention will be described with reference to FIGS.
1 is a cross-sectional view showing a light source device, FIG. 2 is a front view showing one light source portion of the light source device, and FIG. 3 is a perspective view showing the light source device. In FIG. 2, an optical path that travels inside the wavelength conversion element 30 and travels toward the external resonant mirror 40 is defined as an outbound path OW, and an optical path that travels from the external resonant mirror 40 toward the light source 10 is defined as a return path HW. Further, although the forward path OW and the return path HW are shown with an interval, they actually overlap.
As shown in FIG. 1, the light source device 1 according to the present embodiment includes a pair of a first light source unit (light source unit) 2 a and a second light source unit (light source unit) 2 b that emit laser light, and space members 17 and 18. It is comprised by.

Since the configurations of the first light source unit 2a and the second light source unit 2b are the same, the first light source unit 2a will be described.
As shown in FIG. 2, the first light source unit 2 a of the present embodiment is an external resonance type that is a method of resonating and amplifying light emitted from the light source 10 by an external resonance mirror 40 provided outside the light source 10. It is a laser device.
The first light source unit 2a includes a light source 10, a wavelength selection unit (separation unit) 20, a prism (light guide unit) 25, a wavelength conversion element 30, and an external resonance mirror (wavelength selection element) 40. These are provided on the surface 15 a of the flat substrate 15.

  As the light source 10, a surface emitting laser element in which 24 emitters (light emitting units, not shown) emitting infrared light are arranged in one direction is used. As shown in FIG. 2, the light source 10 includes a substrate 11 made of a semiconductor wafer, a mirror layer 12 formed on the substrate 11 and functioning as a reflection mirror, and a laser medium 13 stacked on the surface of the mirror layer 12. And have.

The mirror layer 12 is formed of a laminate of a high refractive index dielectric and a low refractive index dielectric formed on the substrate 11 by, for example, CVD (Chemical Vapor Deposition). The thickness of each layer constituting the mirror layer 12, the material of each layer, and the number of layers are optimized with respect to the wavelength of the light emitted from the light source 10, and are set to conditions in which reflected light interferes and strengthens.
The laser medium 13 is formed on the surface of the mirror layer 12. The laser medium 13 is connected to current supply means such as wiring (not shown), and emits light of a predetermined wavelength when a predetermined amount of current flows from the current supply means.

  The wavelength selection unit 20 transmits harmonic laser light (light having a predetermined conversion wavelength) and reflects light having a fundamental wavelength. Further, the wavelength selection unit 20 is arranged so that the light emitted from the light source 10 is incident on the optical path of the light emitted from the light source 10 at 45 °. Then, light emitted from the light source 10 and traveling in a direction substantially perpendicular to the surface 15 a of the substrate 15 is reflected by the wavelength selection unit 20. Then, the optical path of the light reflected by the wavelength selection unit 20 is converted into a direction substantially parallel to the surface 15 a of the base material 15.

The wavelength conversion element 30 (second harmonic generation element: Second Harmonic Generation) is an element that converts light of a fundamental wavelength emitted from the light source 10 into harmonic laser light, and converts incident light to almost half the wavelength. It is a nonlinear optical element. As the wavelength conversion element 30, for example, PPLN (Periodically Poled Lithium Niobate) is used. The wavelength conversion element 30 is not limited to PPLN, and may be an inorganic nonlinear optical material such as lithium niobate (LN: LiNbO ₃ ) or lithium tantalate (LT: LiTaO ₃ ).

  In the present embodiment, light emitted from the light source 10 (light having a fundamental wavelength) is converted into light having a half wavelength by passing through the wavelength conversion element 30. That is, in the case of the blue light source device, the light (920 nm) emitted from the light source 10 is converted into 460 nm blue light by the wavelength conversion element 30. Similarly, in the case of the green light source device, the light emitted from the light source 10 (1060 nm) becomes green light of 530 nm, and in the case of the red light source device, the light emitted from the light source 10 (1240 nm) becomes red light of 620 nm. Converted. However, the conversion efficiency of the wavelength conversion element 30 is about 40 to 50%. That is, not all of the light emitted from the light source 10 is converted into a laser beam having a half wavelength. Therefore, the laser light emitted from the wavelength conversion element 30 is a mixture of harmonic laser light and light having a fundamental wavelength.

  Further, the wavelength conversion element 30 is fixed to the surface 15 a of the base material 15 via the temperature adjustment unit 35 as shown in FIG. 2. Since the internal refractive index of the wavelength conversion element 30 changes as the temperature changes, the temperature adjustment unit 35 adjusts the wavelength conversion element 30 to an appropriate temperature so that the light emitted from the light source 10 has a predetermined wavelength. It becomes possible to convert it into a harmonic laser beam.

  The external resonant mirror 40 is provided to face the emission end face 30 b of the wavelength conversion element 30. The external resonant mirror 40 selectively transmits the light converted into the harmonic laser beam in the wavelength conversion element 30 (the one-dot chain line shown in FIG. 2) and reflects the other light (the two-dot chain line shown in FIG. 2). The light source 10 and the external resonant mirror 40 function as a resonator mirror. As shown in FIG. 2, the external resonant mirror 40 is only light (fundamental wavelength light) that has not been converted into harmonic laser light by the wavelength conversion element 30 in the forward path OW among the light emitted from the wavelength conversion element 30. Is reflected at a high efficiency of about 99%. That is, the harmonic laser light is amplified by the resonance of the harmonic laser light between the mirror layer 12 of the light source 10 and the external resonant mirror 40.

Specifically, the light L1 converted into the harmonic laser light (460 nm in the case of the blue light source device, 530 nm in the case of the green light source device, and 620 nm in the case of the red light source device) by the wavelength conversion element 30 in the outward path OW It passes through the mirror 40.
On the other hand, the light (920 nm in the case of the blue light source device, 1060 nm in the case of the green light source device, 1240 nm in the case of the red light source device) that has not been converted into the harmonic laser beam by the wavelength conversion element 30 in the forward path OW is transmitted by the external resonant mirror 40. Reflected. Then, the light reflected by the external resonance mirror 40 and passing through the wavelength conversion element 30 again in the return path HW and not converted into the harmonic laser light is reflected by the wavelength selection unit 20 and travels toward the light source 10.
Further, the light reflected by the external resonance mirror 40, passing through the wavelength conversion element 30 again in the return path HW, and converted into the harmonic laser light is transmitted through the wavelength selection unit 20.

A prism 25 is disposed on the optical path of the light transmitted through the wavelength selection unit 20. The prism 25 has a right-angled triangular shape, and has a first surface 25a having a long side, a second surface 25b having a short side, and a third surface 25c. The second surface 25b and the third surface 25c are mirror-finished.
The prism 25 is arranged so that light transmitted through the wavelength selection unit 20 is incident on the first surface 25a. Then, the optical path of the light transmitted through the first surface 25a is converted by 90 ° at the second surface 25b. Then, the optical path of the light reflected by the second surface 25b is further converted by 90 ° on the third surface 25c, and is guided in substantially the same direction as the light transmitted through the wavelength conversion element 30 and the external resonant mirror 40. That is, the laser light L2 emitted from the prism 25 becomes light substantially parallel to the light transmitted through the external resonant mirror 40.

  As illustrated in FIG. 1, the light source device 1 includes the first light source unit 2 a and the light source 10, the wavelength selection unit 20, the wavelength conversion element 30, and the like described above on the surface 16 a of the base material 16 in the same manner as the first light source unit 2 a. A temperature adjustment unit 35 and a second light source part 2b provided with an external resonant mirror 40, and the surfaces 15a and 16a of the base materials 15 and 16 of the first and second light source parts 2a and 2b face each other. The structure is made to face each other. Then, by providing the space member 17 on the light source 10 side of the base materials 15 and 16 and providing the space member 18 on the external resonant mirror 40 side, the distance between the first and second light source portions 2a and 2b is kept constant. . That is, as shown in FIG. 3, the overall configuration of the light source device 1 is a square tube, and four surfaces are configured by the base materials 15 and 16 and the space members 17 and 18.

As shown in FIG. 1, the thickness K of the space members 17 and 18 is such that the laser beam L2 emitted from the first light source unit 2a and the laser beam L2 emitted from the second light source unit 2b are close to each other. It has become. Accordingly, the prisms 25 of the first and second light source units 2a and 2b are arranged with almost no gap.
Further, as shown in FIG. 1, a cooling device (not shown) including air cooling fins is provided on the back surface 15b of the base material 15 of the first light source unit 2a and the back surface 16b of the base material 16 of the second light source unit 2b. ing. In particular, the cooling device cools the light source 10 and receives heat generated from the light source 10 through the base materials 15 and 16. The cooling fins are not limited to liquid cooling heat sinks, heat pipes, and Peltier elements.

At least a part of the space member 18 through which the light emitted from the light source 10 is transmitted is made of a material having optical transparency that transmits the laser light L1 transmitted through the external resonant mirror 40 and the laser light L2 reflected by the prism 25. The space member 18 has a characteristic of preventing light other than the harmonic laser light emitted from the light source 10 from being emitted to the outside.
Further, the space member 17 on the light source 10 side may be formed of a light-transmitting material similarly to the space member 18, but since the laser beam is not emitted from the space member 17, the space member 17 has a light-transmitting property. It may be formed from any material.

In the light source device 1 according to the present embodiment, the light that is emitted from the light source 10 and is not converted by the wavelength conversion element 30 in the forward path OW but is converted by the wavelength conversion element 30 in the return path HW is extracted by the wavelength selection unit 20 and the prism 25. Use. Thereby, the light inject | emitted from the light source 10 can be utilized efficiently.
In addition, the first and second light source portions 2a and 2b are provided to face each other with the space members 17 and 18 facing each other with the light sources 10 on the surfaces 15a and 16a of the base materials 15 and 16 facing each other. It is not the structure which arrange | positions the light sources 10 of the 1st, 2nd light source parts 2a and 2b adjacent. Since the light source device 1 of the present embodiment can be configured such that the laser light L2 emitted from the light source 10 is close to the light source device 1, a plurality of light sources 10 are arranged as compared with a conventional case where a plurality of light sources 10 are arranged on the same substrate. It is possible to narrow the interval between the light emitted from the light source 10.
Moreover, the back surfaces 15b and 16b of the base materials 15 and 16 can be exposed outside by facing the front surfaces 15a and 16a of the base materials 15 and 16 of the first and second light source units 2a and 2b. Thereby, since the restriction | limiting of the magnitude | size of the cooling device which cools the light source 10 can be suppressed, the cooling device which can fully cool the light source 10 can be provided.

Furthermore, the light source 10 of the first light source unit 2a is arranged away from the back surface 16b that serves as a cooling surface of the second light source unit 2b. Thereby, since it can suppress that the heat which generate | occur | produced with the light source 10 interferes, it becomes possible to cool the 1st light source part 2a efficiently. Similarly, the second light source unit 2b can be efficiently cooled.
Moreover, after assembling the light source device 1 so that the first and second light source portions 2a and 2b individually oscillate, the surfaces 15a and 16a of the base materials 15 and 16 are sandwiched between the space members 17 and 18, respectively. Since it is formed by facing each other, it can be easily manufactured.

Moreover, it becomes easy to cool all the emitters by providing a plurality of emitters separately by the two first and second light source units 2a and 2b. That is, conventionally, when a light source having a plurality of emitters on a single substrate was used, it was difficult to cool the central portion, but in this embodiment, it is possible to cool any emitter efficiently. Become.
Furthermore, in this embodiment, since it is only necessary to align the two light source parts, the first light source part 2a and the second light source part 2b, the assembly is simple. Therefore, the manufacturing cost can be suppressed.
In addition, since the light source 10 includes a plurality of emitters, it can emit high-power laser light. Therefore, bright light can be emitted from the light source device 1.

  Moreover, in this embodiment, although it was the structure provided with 1st, 2nd light source part 2a, 2b, the light source device 45 provided with 2 or more pairs may be sufficient. That is, in the light source device 45, as shown in FIG. 4, three pairs of first and second light source units 2a and 2b are provided, and the light sources 10 of the first and second light source units 2a and 2b are arranged in one direction. As shown, the side surfaces of the base materials 15 and 16 of the light source portions 2a and 2b are provided in contact with each other. A space member 47 is provided on the light source 10 side and a space member 48 is provided on the external resonance mirror 40 side between the base material 15 of the three light source units 2a and the base material 16 of the three light source units 2b. ing. The space members 47 and 48 are provided in common for the three pairs of the first and second light source units 2a and 2b. In the case of the light source device 45, the same effect as that of the light source device 1 can be obtained. Since the first and second light source units 2a and 2b are provided in three pairs, in order to obtain the same number of 24 emitters as the light source device 1, the number of emitters of the light source 10 of one light source unit is set. Eight can be used. Thus, by dividing 24 emitters into three pairs of first and second light source units 2a and 2b, eight emitters can be arranged separately for each of the first and second light source units 2a and 2b. Therefore, the cooling efficiency can be improved.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIGS. In the drawings of the respective embodiments described below, portions having the same configuration as those of the light source device 1 according to the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.
The light source device 50 according to the present embodiment is different from the first embodiment in that the space member 17 on the light source 10 side also serves as a light guide instead of the prism 25. Other configurations are the same as those in the first embodiment.

As shown in FIG. 5, the space member 17 of the light source device 50 is formed with a recess 17 b that is open on the inner surface 17 a. The recess 17b is a groove whose cross-sectional shape is a right triangle, and the inner surface of the recess 17b is subjected to reflection processing.
As a result, the optical path of the light transmitted through the wavelength selection unit 20 is reflected by the first inclined surface 17c of the recess 17b, converted by 90 °, and travels toward the second inclined surface 17d. The optical path of the light reflected by the second inclined surface 17d is converted by 90 ° and guided in substantially the same direction as the light transmitted through the wavelength conversion element 30 and the external resonant mirror 40. In other words, the laser light L2 emitted from the concave portion 17b of the space member 17 becomes light substantially parallel to the light transmitted through the external resonance mirror 40.

The light source device 50 according to the present embodiment can obtain the same effects as those of the light source device 1 of the first embodiment. Furthermore, in the light source device 50 of the present embodiment, since the recess 17b is formed in the space member 17, the space member 17 functions as the prism 25 of the first embodiment. As a result, the number of components can be reduced, so that the cost can be reduced.
As shown in FIG. 6, when the light source device 50 is assembled, even if the space member 17 is bent with respect to the surfaces 15 a and 16 a of the base materials 15 and 16, the incident light can be emitted in parallel. it can. Therefore, since it is not necessary to arrange the space member 17 with high accuracy, assembly is facilitated.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG.
In the light source device 60 according to this embodiment, the first and second light source units 2a and 2b are individually provided with the prisms 25, but the first and second light source units 2a and 2b are provided with a common prism 65. Different from the first embodiment. Other configurations are the same as those in the first embodiment.

The prism (light guide unit) 65 of the light source device 60 is a rectangular parallelepiped having a substantially square cross-sectional shape. The first surface 65a, the second surface 65b, the third surface 65c, It has four surfaces 65d. The first surface 65a and the second surface 65b are substantially perpendicular surfaces, and the prism 65 is arranged so that the first and second surfaces 65a and 65b are substantially parallel to the emission end surface 20a of the wavelength selection unit 20. Has been placed. In addition, a slight gap is provided between the first and second surfaces 65 a and 65 b and the wavelength selection unit 20. An AR (Anti-Reflection) film is applied to the first and second surfaces 65 a and 65 b of the prism 65. The AR film reflects light incident from the first and second surfaces 65 a and 65 b of the prism 65 so that it does not return to the wavelength selection unit 20 again.
The third and fourth surfaces 65c and 65d are provided with a reflection film that reflects the harmonic laser beam. Thereby, the harmonic laser light incident from the second surface 65b and reflected by the third surface 65c is reflected again by the fourth surface 65d and emitted from the second surface 65b. The harmonic laser light emitted from the second surface 65b is substantially parallel to the light transmitted through the external resonant mirror 40.
Similarly, the harmonic laser beam incident from the first surface 65a and reflected by the fourth surface 65d is reflected again by the third surface 65c and emitted from the first surface 65a.

In the light source device 60 according to the present embodiment, the same effects as those of the light source device 1 of the first embodiment can be obtained. Furthermore, in the light source device 60 of the present embodiment, the first and second light source units 2a and 2b use one prism 65 as the light guide unit, so that the number of components can be reduced compared to the first embodiment. . Therefore, the cost of the entire apparatus can be reduced. Further, when two prisms 25 are provided as in the first embodiment, alignment of the individual prisms 25 is necessary. Therefore, by replacing the two prisms 25 with one prism 65 as in the present embodiment, the alignment of the prisms 65 is facilitated.
The shape of the prism 65 is not limited to a rectangular parallelepiped.

[Fourth Embodiment]
Next, a fourth embodiment according to the present invention will be described with reference to FIG.
The light source device 70 according to the present embodiment is different from the third embodiment in that the prism 75 also serves as the wavelength selection unit 20 of the first light source unit 2a. Other configurations are the same as those of the third embodiment.

  The prism (light guide unit) 75 is a rectangular parallelepiped having a substantially square cross section, and includes a first surface 75a, a second surface 75b, a third surface 75c, and a fourth surface 75d that intersect the traveling direction of the laser beam. Have. The prism 75 is disposed such that the first surface 75a is substantially parallel to the emission end surface 20a of the wavelength selection unit 20 of the second light source unit 2b. In addition, a wavelength selection film (separation part) is formed on the second surface 75b. Similar to the wavelength selection unit 20, the wavelength selection film transmits harmonic laser light and reflects light having a fundamental wavelength. In addition, the light emitted from the light source 10 is disposed on the second surface 75b of the prism 75 at approximately 45 °. Then, the light path of light substantially perpendicular to the surface 15a of the substrate 15 emitted from the light source 10 is converted into light substantially parallel to the surface 15a by the wavelength selection film on the second surface 75b. In addition, the light reflected by the external vibrator mirror 40 and converted into the harmonic laser light by passing through the wavelength conversion element 30 again is transmitted through the wavelength selection portion film of the second surface 75b, and the third surface 75c and Reflected in the order of the fourth surface 75d. The harmonic laser light reflected from the fourth surface 65d and emitted from the second surface 65b becomes light substantially parallel to the light transmitted through the external resonant mirror 40.

In the light source device 70 according to the present embodiment, the first and second light source units 2a and 2b use one prism 75 as a light guide unit, and the prism 75 has a wavelength selection film formed on the second surface 75b. Therefore, it also serves as the wavelength selection unit 20 of the first light source unit 2a. Thereby, compared with the light source device 60 of 3rd Embodiment, it becomes possible to reduce a number of parts more. In the present embodiment, the prism 75 can be easily aligned by replacing the two prisms 25 and the wavelength selection unit 20 of the first light source unit 2a with one prism 75, as compared with the first embodiment.
The first light source unit 2a includes the wavelength selection unit 20 as in the third embodiment, does not include the wavelength selection unit 20 of the second light source unit 2b, and forms a wavelength selection film on the first surface 75a of the prism 75. May be. Further, in place of the wavelength selection unit 20 of the first and second light source units 2a and 2b, a wavelength selection film may be formed on both the first surface 75a and the second surface 75b of the prism 75.

[Fifth Embodiment: Lighting Device]
Next, a fifth embodiment will be described. In this embodiment, an example of an illumination device to which the light source device described in the above embodiment is applied will be described.
FIG. 9 is a schematic configuration diagram showing the illumination device 200 according to the present embodiment. As illustrated in FIG. 9, the illumination device 200 includes the light source device 1 described in the first embodiment and a diffusion plate 210 that diffuses light emitted from the light source device 1.
According to the illuminating device 200 configured as described above, the illuminating device 200 itself is also small because it includes the light source device 1 that is small in size, excellent in heat dissipation, and capable of improving light utilization efficiency. It is possible to irradiate bright light.

[Sixth Embodiment: Projector]
Next, a sixth embodiment will be described. In the present embodiment, an example of a projector (image display device) to which the light source device 1 described in the above embodiment is applied will be described.
As shown in FIG. 10, the projector 300 according to the present embodiment uses a reflective screen 350 and projects light including image information onto the screen 350 from the front side of the screen 350.
As shown in FIG. 10, the projector 300 includes the light source device 1, a light modulation device (image forming device) 320, a dichroic prism (color combining unit) 330, and a projection device (image forming device) 340. .
The light source device 1 includes a red light source device (light source) 1R that emits red light, a green light source device (light source) 1G according to the first embodiment that emits green light, and a blue light source according to the first embodiment that emits blue light. Device (light source) 1B.

Further, the liquid crystal light valve 320 uses, as image information, the two-dimensional red light modulation device 320R that modulates light emitted from the red light source device 1R according to image information and the light emitted from the green light source device 1G. A two-dimensional green light modulation device 320G that performs light modulation in response to this and a two-dimensional blue light modulation device 320B that modulates light emitted from the blue light source device 1B according to image information. Further, the dichroic prism (color light combining means) 330 combines the respective color lights modulated by the respective light modulation devices 320R, 320G, and 320B.
Further, in order to make the illuminance distribution of the light emitted from each light source device 1R, 1G, 1B uniform, uniform optical systems 302R, 302G, 302B are provided on the downstream side of the light path from each light source device 1R, 1G, 1B. Thus, the liquid crystal light valves 320R, 320G, and 320B are illuminated with light having a uniform illuminance distribution. For example, the uniformizing optical systems 302R, 302G, and 302B include, for example, a hologram 302a and a field lens 302b.
The projection device 340 projects the light synthesized by the dichroic prism 330 onto the screen 350.

According to the projector 300 configured as described above, since the light source devices 1R, 1G, and 1B having high light use efficiency are provided, a bright and clear image can be projected onto the screen 350.
As the red light source device 1R, a light source device that emits red light (visible light) is used as the light source 10. However, like the light source device 1 described in the first embodiment, the light source 10 that emits infrared light is used. And a light source device that converts the wavelength of light emitted from the light source 10 may be used.
Further, the light source device 1 of the first embodiment is not limited to the projector 300, and an image forming apparatus that displays an image of a desired size on the display surface by scanning a laser beam from a laser light source (light source device) on the screen. The present invention can also be applied to a light source device of a scanning type image display device having a scanning means.

[Seventh Embodiment: Monitor Device]
Next, a configuration example of the monitor device 400 to which the light source device 1 according to the first embodiment is applied will be described. FIG. 11 is a schematic diagram showing an outline of the monitor device. The monitor device 400 includes a device main body 410 and an optical transmission unit 420.

  The light transmission unit 420 includes two light guides 421 and 422 on the light sending side and the light receiving side. Each of the light guides 421 and 422 is a bundle of a large number of optical fibers, and can send laser light to a distant place. The light source device 1 is disposed on the incident side of the light guide 421 on the light transmitting side, and the diffusion plate 423 is disposed on the emission side thereof. The laser light emitted from the light source device 1 is transmitted to the diffusion plate 423 provided at the tip of the light transmission unit 420 through the light guide 421 and is diffused by the diffusion plate 423 to irradiate the subject.

  An imaging lens 424 is also provided at the tip of the light transmission unit 420, and reflected light from the subject can be received by the imaging lens 424. The received reflected light travels through the light guide 422 on the receiving side and is sent to a camera 411 as an imaging means provided in the apparatus main body 410. As a result, the camera 411 can capture an image based on the reflected light obtained by irradiating the subject with the laser light emitted from the light source device 1.

  According to the monitor device 400 configured as described above, the light source device 1 with high light use efficiency can irradiate the subject, so that the brightness of the captured image obtained by the camera 411 can be increased.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, although a cross dichroic prism is used as the color light combining means, the present invention is not limited to this. As the color light synthesizing means, for example, a dichroic mirror having a cross arrangement to synthesize color light, or a dichroic mirror arranged in parallel to synthesize color light can be used.
Moreover, in the illuminating device 200, the projector 300, and the monitor device 400, although the light source device 1 of 1st Embodiment was used, it is not restricted to this, The light source device 45, The light source device 50 of 2nd-4th Embodiment, 60 and 70 may be used.

It is sectional drawing which shows the light source device which concerns on 1st Embodiment of this invention. It is a perspective view of the light source device of FIG. It is the top view which showed one light source part of the light source device of FIG. It is a perspective view which shows the modification of the light source device which concerns on 1st Embodiment of this invention. It is a top view which shows the light source device which concerns on 2nd Embodiment of this invention. It is principal part sectional drawing which shows the modification of the light source device which concerns on 2nd Embodiment of this invention. It is a top view which shows the light source device which concerns on 3rd Embodiment of this invention. It is a top view which shows the light source device which concerns on 4th Embodiment of this invention. It is a top view which shows the illuminating device which concerns on 5th Embodiment of this invention. It is a top view which shows the image display apparatus which concerns on 6th Embodiment of this invention. It is a top view which shows the monitor apparatus which concerns on 7th Embodiment of this invention.

Explanation of symbols

1, 45, 50, 60, 70 ... light source device, 2a ... first light source unit, 2b ... second light source unit, 10 ... light source, 15, 16 ... base material, 15a, 16a ... surface (one surface), 17 , 18, 47, 48 ... space members, 20 ... wavelength selection part (separation part), 25, 65, 75 ... prism (light guide part), 30 ... wavelength conversion element, 40 ... external resonance mirror (wavelength selection element), 200 ... illumination device, 300 ... projector (image display device), 400 ... monitor device, 411 ... camera (imaging means)

Claims (9)

A light source having a plurality of light emitting portions emitting light of a fundamental wavelength;
A wavelength conversion element that converts at least a part of light emitted from the light source into light having a predetermined conversion wavelength;
Of the light emitted from the light source and passed through the wavelength conversion element, the wavelength selection element that transmits the light of the predetermined conversion wavelength, reflects the light of the fundamental wavelength, and functions as a resonator;
The light having the fundamental wavelength emitted from the light source is guided toward the wavelength conversion element, and the light reflected by the wavelength selection element and passed through the wavelength conversion element is converted into the predetermined conversion wavelength. A separation unit that guides the light of the fundamental wavelength to the light source in a different direction from the light source;
A light guide that guides light guided in a direction different from the light source in substantially the same direction as the light transmitted through the wavelength selection element;
The light source, the wavelength conversion element, the base material on which the wavelength selection element is disposed on one surface, and at least a pair of light source units,
The pair of light source units is provided with one surface of each base material facing each other with a space member interposed therebetween.   The light source device according to claim 1, wherein a pair of the light source units are provided.   The light source device according to claim 1, wherein two or more pairs of the light source units are provided. The space member is formed with a concave portion that is subjected to reflection processing on the inner surface,
2. The light guided in a direction different from the light source is guided in substantially the same direction as the light transmitted through the wavelength selection element by the concave portion, and the space member functions as the light guide unit. The light source device according to claim 3.   4. The light source device according to claim 1, wherein the pair of light source units share one light guide unit. 5. At least one separation part among the plurality of separation parts is a wavelength selection film formed at a position where light emitted from the light source of the light guide part is incident,
The light source device according to claim 5, wherein the light guide unit functions as the separation unit.   An illumination device comprising the light source device according to any one of claims 1 to 6. The light source device according to any one of claims 1 to 6,
An image display apparatus comprising: an image forming apparatus that displays light of a desired size on a display surface using light from the light source device. The light source device according to any one of claims 1 to 6,
A monitor device comprising: imaging means for imaging a subject by light emitted from the light source device.

Images