JP2009038067A - Light source device, lighting device, monitor device, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device capable of emitting light with high efficiency and high wavelength conversion efficiency when using an array light source, and to provide a lighting device, a monitor device and an image display device using the light source device. <P>SOLUTION: The light source device includes a semiconductor element 11 as an array light source having a plurality of light emission portions 12 emitting light, a wavelength conversion unit which has a polarization inversion layer 17 formed along a plane nearly orthogonal to a specified direction and in parallel to the specified direction and having polarization inverted, and converts the wavelength of the light from the array light source, and a first surface 18 as an adjustment unit which adjusts travel directions of a plurality of light beams emitted from the plurality of light emission portions, where the adjustment unit transmits the plurality of light beams to the wavelength conversion unit while uniformly adjusting the travel directions thereof almost to the specified direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light source device, an illumination device, a monitor device, and an image display device, and more particularly to a technology of a light source device using a wavelength conversion element.

  In recent years, a technique using a laser light source as a light source device of a projector has been proposed. Laser light sources have been developed as light sources for projectors with higher output and more colors. Compared with UHP lamps conventionally used as projector light sources, laser light sources have advantages such as high color reproducibility, instant lighting, and long life. By using an external resonator that resonates the light, the laser light source can narrow the wavelength of the laser light and increase the output of the laser light. A technique of a light source device having an external resonator is proposed in Patent Document 1, for example.

JP 2001-284718 A

  As the laser light source, there is known a laser light source that emits the fundamental wave light from the light source with the same wavelength, and a laser light source that converts the wavelength of the fundamental wave light and emits it. As a wavelength conversion element that converts the wavelength of fundamental light, for example, a second-harmonic generation (SHG) element is known. By using the SHG element, it is possible to supply laser light having a desired wavelength and a sufficient amount of light using a general-purpose light source that can be easily obtained. As the SHG element, a polarization inversion crystal of a nonlinear optical material can be used. In order to increase the output of the light source device, an array light source in which a plurality of light emitting units emitting laser light are arranged in parallel can be used. In general, the array light source is bonded to the submount using AuSn solder or the like. The array light source and the submount are usually made of materials having different linear expansion coefficients. Since the amount of contraction due to a temperature change from the temperature at the time of soldering to room temperature differs between the array light source and the submount, the joined body of the array light source and the submount may be warped. When such an array light source is combined with a domain-inverted crystal, there will be a component of light that is transmitted obliquely with respect to the domain-inverted structure. Usually, the phase matching condition is determined for the light that passes through the wavelength conversion element perpendicular to the domain-inverted structure. For this reason, the wavelength conversion efficiency will fall, so that the light which transmits diagonally with respect to a polarization inversion structure increases. For simple displacement of the array light source, the traveling direction of the light transmitted through the wavelength conversion element can be easily corrected by adjusting the position of the wavelength conversion element. On the other hand, when the array light source is curved, it is difficult to correct the traveling direction of light transmitted through the wavelength conversion element. As described above, according to the conventional technique, there is a problem that it may be difficult to emit light with high efficiency in the configuration using the array light source. The present invention has been made in view of the above-described problems. When an array light source is used, a light source device capable of emitting light with high efficiency due to high wavelength conversion efficiency, an illumination device using the light source device, An object is to provide a monitor device and an image display device.

  In order to solve the above-described problems and achieve the object, a light source device according to the present invention is formed along an array light source including a plurality of light emitting units that emit light and a plane substantially orthogonal to a specific direction. A polarization reversal layer that reverses polarization and is parallel to the direction, converts the wavelength of light from the array light source, and adjusts the traveling direction of multiple light emitted from multiple light emitters And an adjustment unit that adjusts the traveling directions of the plurality of lights so as to be close to a specific direction and transmits the light to the wavelength conversion unit.

  The wavelength conversion unit can obtain high wavelength conversion efficiency by transmitting light along a direction orthogonal to the domain-inverted layer constituting the domain-inverted structure. By aligning the traveling directions of a plurality of lights so as to be close to a specific direction, high wavelength conversion efficiency can be obtained even when a warped array light source is used. Thereby, when an array light source is used, a light source device capable of emitting light with high efficiency due to high wavelength conversion efficiency can be obtained.

  Moreover, as a preferable aspect of the present invention, when the direction in which a plurality of lights from the array light source are arranged in parallel is an array direction, the adjustment unit desirably adjusts the traveling direction of the plurality of lights with respect to the array direction. When the array light source is warped, the traveling direction of the plurality of lights changes in the array direction. Thereby, the advancing direction of the some light from an array light source can be arrange | equalized so that it may become close to a specific direction.

  Moreover, as a preferable aspect of the present invention, it is desirable that the adjustment unit includes a refracting unit that parallelizes a plurality of lights from the array light source by refraction. Thereby, the advancing direction of the some light from an array light source can be adjusted.

  Moreover, as a preferable aspect of the present invention, it is desirable that the refracting section is provided on the surface of the wavelength conversion section on the array light source side. Thereby, the several light by which the advancing direction was adjusted can be permeate | transmitted to a wavelength conversion part.

  Moreover, as a preferable aspect of the present invention, it is preferable that the optical element is provided in the optical path between the array light source and the wavelength conversion unit, and the refraction unit is provided in the optical element. Thereby, the several light by which the advancing direction was adjusted can be permeate | transmitted to a wavelength conversion part.

  Moreover, as a preferable aspect of the present invention, it is preferable that the optical element has a light source housing that houses the array light source, and the optical element is an emission unit that emits light from the array light source to the outside of the light source housing. A high wavelength conversion efficiency and a dustproof effect can be obtained with a simple configuration by providing a refractive action to the emitting portion.

  In a preferred aspect of the present invention, the optical element is preferably a prism that bends the optical path of light from the array light source. By providing the prism with a refractive action, high wavelength conversion efficiency can be obtained with a simple configuration, and the optical path can be bent.

  Moreover, as a preferable aspect of the present invention, it is desirable that the refracting portion has a concave concave surface. Thereby, a some light can be made parallel with respect to the array light source which converges a some light.

  Moreover, as a preferable aspect of the present invention, it is desirable that the refracting portion has a convex surface. Thereby, several light can be made parallel with respect to the array light source which diverges several light.

  As a preferred aspect of the present invention, it is desirable that the refracting section includes a hologram element that diffracts light from the array light source. Thereby, a plurality of lights can be collimated by appropriately refracting the light by diffraction.

  Moreover, as a preferable aspect of the present invention, it is desirable that the adjustment portion is composed of a plurality of refraction portions. The number of refracting portions can be the same as the maximum number of rays from the array light source. As the number of refracting portions increases, it becomes possible to refract light accurately in the direction orthogonal to the polarization inversion layer. Thereby, higher wavelength conversion efficiency can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable that the refracting section reduces the beam diameter of light from the array light source. It is known that the wavelength conversion element generally improves the wavelength conversion efficiency substantially in proportion to the energy density of light transmitted through the wavelength conversion element. By narrowing the beam diameter at the refracting portion, it is possible to increase the energy density of the light transmitted through the wavelength conversion element. Thereby, higher wavelength conversion efficiency can be obtained.

  Furthermore, an illumination device according to the present invention includes the light source device described above, and illuminates an object to be irradiated using light from the light source device. By using the above light source device, light can be emitted with high efficiency. Thereby, the illuminating device which can supply light with high efficiency can be obtained.

  Furthermore, a monitor device according to the present invention includes the above-described illumination device and an imaging unit that captures an image of a subject illuminated by the illumination device. By using the lighting device, light can be supplied with high efficiency. Thereby, a monitor device capable of monitoring a bright image using light supplied with high efficiency can be obtained.

  Furthermore, an image display device according to the present invention includes the light source device described above, and displays an image using light from the light source device. By using the above light source device, light can be emitted with high efficiency. Thereby, an image display apparatus capable of displaying a bright image using light supplied with high efficiency can be obtained.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a light source device 10 according to Embodiment 1 of the present invention. The light source device 10 is a laser array that emits a plurality of laser beams. The semiconductor element 11, the SHG element 14, and the external resonator 15 are arranged along the Z-axis direction that is a specific direction. The X axis is an axis perpendicular to the Z axis. The Y axis is an axis perpendicular to the Z axis and the X axis.

  FIG. 2 shows a perspective configuration of the semiconductor element 11 and the submount 12. The semiconductor element 11 is a surface-emitting array light source that includes a plurality of light emitting units (not shown) that emit fundamental light having a first wavelength. The first wavelength is, for example, 1064 nm. The semiconductor element 11 is configured using, for example, a GaAs-based material. The semiconductor element 11 has a plurality of light emitting units arranged in parallel in the X-axis direction. The semiconductor element 11 has a mirror layer (not shown) that reflects light of the first wavelength.

  The semiconductor element 11 is mounted on the submount 12. The submount 12 is a heat dissipation board that dissipates heat generated in the semiconductor element 11. The submount 12 is configured using, for example, an aluminum nitride (AlN) material. The semiconductor element 11 and the submount 12 are bonded to each other using, for example, AuSn solder.

  The temperature at the time of bonding of AuSn solder is, for example, about 280 degrees. Even if a solder having a relatively low melting point is used in place of the AuSn solder, the temperature at the time of joining the solder is about 170 degrees. Since the semiconductor element 11 and the submount 12 are made of different materials, the amount of contraction with respect to a temperature change from the temperature at the time of soldering to room temperature differs. The joined body of the semiconductor element 11 and the submount 12 is warped due to a significant difference in shrinkage between the semiconductor element 11 and the submount 12. The semiconductor element 11 is curved so that the central portion is convex toward the opposite side to the direction in which light is emitted. In addition, the semiconductor element 11 and the submount 12 are not limited to those causing warping to the extent illustrated in the present embodiment. When the length of the semiconductor element 11 in the array direction is 10 mm, the emission surface of the semiconductor element 11 has an inclination of, for example, about 1 mrad when expressed in terms of an angle with respect to the horizontal plane.

  Returning to FIG. 1, the joined body of the semiconductor element 11 and the submount 12 is disposed on the package base 13. The SHG element 14 emits harmonic light of the second wavelength by making the fundamental wave light of the first wavelength from the semiconductor element 11 incident. The SHG element 14 is a wavelength conversion element that converts the wavelength of light from the semiconductor element 11. The SHG element 14 is provided in the optical path between the semiconductor element 11 and the external resonator 15. The second wavelength is half the first wavelength and is, for example, 532 nm. The SHG element 14 is arranged with the first surface 18 facing the semiconductor element 11 side and the second surface 19 facing the external resonator 15 side.

The external resonator 15 resonates light from the semiconductor element 11 with the mirror layer of the semiconductor element 11. The external resonator 15 selectively reflects light having the first wavelength and transmits light having a wavelength (including the second wavelength) different from the first wavelength. As the external resonator 15, for example, VHG (Volume Holographic Grating) can be used. VHG can be formed using a photorefractive crystal such as LiNbO ₃ or BGO, a polymer, or the like.

  Interference fringes generated by incident light incident from two directions are recorded on the VHG. The interference fringes are recorded as a periodic structure in which a high refractive index portion and a low refractive index portion are periodically arranged. The VHG selectively reflects only light that satisfies such interference fringes and Bragg conditions by diffraction. The external resonator 15 has a rectangular parallelepiped shape. The external resonator 15 is obtained by cutting a plate-shaped material. The external resonator 15 only needs to have wavelength selectivity, and is not limited to VHG. As the external resonator 15, for example, a band pass filter or a dichroic mirror may be used.

The SHG element 14 is, for example, a polarization inversion crystal (Periodically Poled Lithium Niobate; PPLN) of lithium niobate (LiNbO ₃ ) which is a nonlinear optical crystal. The SHG element 14 has a polarization inversion structure in which the spontaneous polarization layers 16 and the polarization inversion layers 17 are alternately arranged in parallel. The spontaneous polarization layer 16 and the polarization inversion layer 17 constitute a wavelength conversion unit that converts the wavelength of light from the semiconductor element 11. The spontaneous polarization layer 16 and the polarization inversion layer 17 are arranged in parallel in the Z-axis direction, which is a specific direction. The spontaneous polarization layer 16 and the polarization inversion layer 17 constitute a polarization inversion structure having a pitch corresponding to the first wavelength of the fundamental light. The spontaneous polarization layer 16 and the polarization inversion layer 17 are formed along the XY plane substantially orthogonal to the Z-axis direction. The illustrated spontaneous polarization layer 16 and polarization inversion layer 17 are schematically shown.

  The polarization inversion structure is configured by inverting the sign of the nonlinear optical constant for each coherent length. For the formation of the domain-inverted structure, a method of applying a voltage to a nonlinear optical crystal having spontaneous polarization is often used. The polarization inversion layer 17 is a layered region in which the spontaneous polarization of the nonlinear optical crystal is inverted. The spontaneous polarization layer 16 is a layered region in which the spontaneous polarization of the nonlinear optical crystal is left. The domain-inverted structure can be obtained, for example, by forming a fine pattern of an insulating layer on a lithium niobate (LN) substrate and applying a voltage via an electrode or an electrolytic solution. The domain-inverted structure can be formed, for example, by applying a pulse voltage after cutting a material substrate on which an insulating layer pattern and electrodes are formed. Further, the SHG element 14 is completed through the polishing of the first surface 18 and the second surface 19 and the formation of an antireflection film (AR coating). The SHG element 14 is a so-called bulk type wavelength conversion element that enables wavelength conversion of light in the entire element. The SHG element 14 may have a configuration having a waveguide that transmits light.

  FIG. 3 shows a perspective configuration of the SHG element 14. The first surface 18 of the SHG element 14 is a concave concave surface. The first surface 18 has a curvature in the X-axis direction. The first surface 18 functions as a refraction part that refracts a plurality of lights from the semiconductor element 11. The first surface 18 has a shape obtained by inverting the shape of the semiconductor element 11. The second surface 19 has a planar shape parallel to the X axis and the Y axis.

  Returning to FIG. 1, the plurality of lights from the semiconductor element 11 are arranged in parallel in the X-axis direction that is the array direction. The plurality of lights from the semiconductor element 11 travel while converging with each other. The first surface 18 functions as an adjustment unit that adjusts the traveling direction of the plurality of lights from the semiconductor element 11 in the X-axis direction. The traveling directions of the plurality of lights from the semiconductor element 11 are converted in the Z-axis direction on the first surface 18 of the SHG element 14. The first surface 18 collimates a plurality of lights from the semiconductor element 11 by refraction. The first surface 18 is transmitted through the spontaneous polarization layer 16 and the polarization inversion layer 17 with the traveling directions of the plurality of lights aligned in the Z-axis direction. The light transmitted through the SHG element 14 enters the external resonator 15.

  The harmonic light generated by the SHG element 14 passes through the external resonator 15. The harmonic light transmitted through the external resonator 15 is emitted outside the light source device 10. The fundamental light transmitted through the SHG element 14 from the first surface 18 side is reflected by the external resonator 15. The fundamental light incident perpendicularly to the external resonator 15 is reflected by the external resonator 15, and then follows the same optical path as that when entering the external resonator 15.

  The light transmitted through the SHG element 14 from the second surface 19 toward the first surface 18 side enters the semiconductor element 11. The fundamental light incident on the semiconductor element 11 is reflected by the mirror layer of the semiconductor element 11 and is emitted from the semiconductor element 11. The fundamental light reflected by the semiconductor element 11 and the external resonator 15 resonates with the fundamental light newly emitted by the semiconductor element 11 and is amplified.

  FIG. 4 illustrates the traveling direction of light when the rectangular parallelepiped SHG element 20 and the semiconductor element 11 are combined. The first surface 21 of the SHG element 20 has a planar shape parallel to the X axis and the Y axis. The plurality of lights that have traveled from the semiconductor element 11 so as to converge with each other also travel within the SHG element 20 so as to converge with each other. For this reason, the light emitted from the light emitting portion near the end of the semiconductor element 11 travels obliquely with respect to the spontaneous polarization layer 16 and the polarization inversion layer 17 in the SHG element 20. The more light that is transmitted obliquely with respect to the domain-inverted structure having the pitch corresponding to the first wavelength of the fundamental wave light, the more the phase matching condition is broken and the wavelength conversion efficiency is lowered.

  Returning to FIG. 1, the present invention can obtain high wavelength conversion efficiency by using the SHG element 14 that transmits light along the Z-axis direction orthogonal to the spontaneous polarization layer 16 and the polarization inversion layer 17. Become. By aligning the traveling directions of a plurality of lights in the Z-axis direction, high wavelength conversion efficiency can be obtained even when the warped semiconductor element 11 is used. Thereby, when using an array light source, there exists an effect that light can be inject | emitted with high efficiency by high wavelength conversion efficiency.

  As the SHG element 14 is longer in the direction of transmitting light, the wavelength conversion efficiency can be increased. If the wavelength conversion element is made small in order to arrange another optical element for aligning the traveling directions of a plurality of lights, the wavelength conversion efficiency is lowered. Since the light source device 10 of the present embodiment controls the traveling direction of light using the first surface 18 of the SHG element 14, the length of the SHG element 14 can be sufficiently secured, and high wavelength conversion efficiency can be realized.

  The shape of the first surface 18 of the SHG element 14 can be determined based on the measurement result obtained by measuring the shape of the semiconductor element 11. By forming the first surface 18 having substantially the same shape as the shape of the semiconductor element 11, the traveling direction of all the light from the semiconductor element 11 can be aligned with the Z-axis direction. However, the SHG element 14 is not limited to the case where the shape of the first surface 18 is the same as the shape of the semiconductor element 11. The first surface 18 may have a shape close to the shape of the semiconductor element 11 as long as at least the traveling direction of a plurality of lights can be adjusted to be close to the Z-axis direction. If the traveling direction of the plurality of lights from the semiconductor element 11 can be made closer to the Z-axis direction, an effect of improving the wavelength conversion efficiency can be obtained. For example, when individual differences occur in the shape of the semiconductor element 11 in the manufacturing process of the light source device 10, the shape of the first surface 18 may be determined based on the average shape of the semiconductor element 11.

  FIG. 5 shows a schematic configuration of a light source device 30 according to a modification of the present embodiment. The light source device 30 of the present embodiment includes a semiconductor element 31 that is curved opposite to the semiconductor element 11 (see FIG. 1) of the light source device 10 described above. The semiconductor element 31 and the submount 32 are curved so that the central portion is convex toward the light emitting side. The semiconductor element 31 has the same configuration as the semiconductor element 11 described above except that the way of bending is reversed.

  FIG. 6 shows a perspective configuration of the SHG element 33. The first surface 34 of the SHG element 33 is a convex convex surface. The first surface 34 has a curvature in the X-axis direction. The first surface 34 functions as a refraction part that refracts a plurality of lights from the semiconductor element 31. The first surface 34 has a shape that is the reverse of the shape of the semiconductor element 31. The SHG element 33 has the same configuration as the SHG element 14 (see FIG. 3) except that the shape of the first surface 34 is different.

  Returning to FIG. 5, the plurality of lights from the semiconductor element 31 travel so as to diverge from each other. The traveling directions of the plurality of lights from the semiconductor element 31 are converted in the Z-axis direction on the first surface 34 of the SHG element 33. The first surface 34 functions as an adjustment unit that adjusts the traveling direction of the plurality of lights from the semiconductor element 31 in the X-axis direction. The first surface 34 collimates a plurality of lights from the semiconductor element 31 by refraction. The first surface 34 is transmitted through the spontaneous polarization layer 16 and the polarization inversion layer 17 with a plurality of light traveling directions aligned in the Z-axis direction. Also in this modification, light can be emitted with high efficiency due to high wavelength conversion efficiency.

  The SHG elements 14 and 33 of the present embodiment can be formed, for example, by cutting a plate-like PPLN into a desired shape. The first surfaces 18 and 34 are not limited to the case where the shapes of the semiconductor elements 11 and 31 are accurately inverted. For the semiconductor elements 11 and 31 having a complicated shape, the first surfaces 18 and 34 may be formed based on a simple shape that approximates the complicated shape. For example, the first surfaces 18 and 34 having a certain curvature may be applied to the semiconductor elements 11 and 31 having a combination of portions having different curvatures.

  The first surfaces 18 and 34 may have curvatures in the X-axis direction and the Y-axis direction in addition to the case where the first surfaces 18 and 34 have curvature in the X-axis direction. The first surfaces 18 and 34 are not limited to curved surfaces having a constant curvature, and may be free-form surfaces having no constant curvature. The first surfaces 18 and 34 are not limited to curved surfaces, and may be a combination of a plurality of planes or a combination of a plane and a curved surface. The light source devices 10 and 30 may use an array light source in which a plurality of light emitting units are arranged in parallel in the X axis direction and the Y axis direction, instead of an array light source including a plurality of light emitting units arranged in parallel in the X axis direction. For an array light source that is curved in two directions, the X-axis direction and the Y-axis direction, an SHG element having a curvature on the first surface in the X-axis direction and the Y-axis direction may be used.

  FIG. 7 shows a schematic configuration of a light source device 40 according to Embodiment 2 of the present invention. The light source device 40 of the present embodiment has an emission unit 42 that collimates a plurality of lights. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. The light source casing 41 houses the semiconductor element 11, the submount 12, and the package base 13. The emission unit 42 is provided on the surface of the light source casing 41 on the SHG element 20 side. The emitting unit 42 emits light from the semiconductor element 11 to the outside of the light source casing 41. The emission unit 42 is an optical element provided in the optical path between the semiconductor element 11 and the SHG element 20. The emission part 42 is a transparent member having two concave surfaces. The emission part 42 functions as a concave lens. The emitting unit 42 functions as a refracting unit that refracts a plurality of lights from the semiconductor element 11. Further, the emission unit 42 also functions as a dust-proof cover for the light source casing 41. Due to the dust-proofing action by the emission part 42, the performance degradation of the light source device 40 can be reduced. The SHG element 20 has a rectangular parallelepiped shape.

  The plurality of lights from the semiconductor element 11 travel so as to converge with each other. The emission unit 42 functions as an adjustment unit that adjusts the traveling direction of the plurality of lights from the semiconductor element 11 in the X-axis direction. The traveling directions of the plurality of lights from the semiconductor element 11 are converted in the Z-axis direction at the emission unit 42. The emitting unit 42 collimates a plurality of lights from the semiconductor element 11 by refraction. The emitting unit 42 transmits the light in the spontaneous polarization layer 16 and the polarization inversion layer 17 with the traveling direction of the plurality of lights aligned in the Z-axis direction. Also in the case of the present embodiment, light can be emitted with high efficiency due to high wavelength conversion efficiency. In addition, since the light traveling direction is controlled using the emitting unit 42, the light source device can be made simpler than the case where another optical element for aligning the traveling directions of a plurality of lights is separately provided.

  FIG. 8 shows a schematic configuration of a light source device 45 according to a modification of the present embodiment. The light source device 45 of the present embodiment includes the semiconductor element 31 and the submount 32 that are curved so that the central portion is convex toward the light emitting side. The exit portion 46, which is a refracting portion, is a transparent member having two convex surfaces. The emission unit 46 functions as a convex lens. The injection section 46 is configured in the same manner as the above-described injection section 42 (see FIG. 7) except that the shape is different.

  The plurality of lights from the semiconductor element 31 travel so as to diverge from each other. A plurality of lights from the semiconductor element 31 are converted in the traveling direction in the Z-axis direction at the emission portion 46. The emitting unit 46 collimates a plurality of lights from the semiconductor element 31 by refraction. Also in the case of the present embodiment, light can be emitted with high efficiency due to high wavelength conversion efficiency.

  FIG. 9 shows a schematic configuration of a light source device 50 according to Embodiment 3 of the present invention. The light source device 50 of this embodiment includes a prism 51. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. The prism 51, the SHG element 20, and the external resonator 15 are arranged in parallel in the Z-axis direction. The semiconductor element 11 and the submount 12 are disposed in the recess 53 of the substrate 52. The semiconductor element 11 emits light in the Y-axis direction.

  The prism 51 is provided at a position where light from the semiconductor element 11 enters. The prism 51 is disposed with the bottom surface 55 facing the semiconductor element 11. The prism 51 bends the optical path of light from the semiconductor element 11 by total reflection at the inclined surface 54. The prism 51 is an optical element provided in the optical path between the semiconductor element 11 and the SHG element 20. The SHG element 20 has a rectangular parallelepiped shape. The prism 51, the SHG element 20, and the external resonator 15 are disposed on the substrate 52. The substrate 52 is a plate-like member provided with a recess 53. The recess 53 is formed on a part of the upper surface of the substrate 52.

  FIG. 10 shows a perspective configuration of the prism 51. The prism 51 has a shape in which a bottom surface 55 is deformed into a concave shape among triangular prisms having a right-angled triangular cross section. The bottom surface 55 is a concave concave surface. The bottom surface 55 functions as a concave lens. The prism 51 functions as a refracting unit that collimates a plurality of lights from the semiconductor element 11 by refraction at the bottom surface 55. The bottom surface 55 has a curvature in the X-axis direction. As shown in FIG. 11, the bottom surface 55 has a shape obtained by inverting the shape of the semiconductor element 11.

  The plurality of lights from the semiconductor element 11 travel so as to converge with each other. The prism 51 functions as an adjustment unit that adjusts the traveling direction of the plurality of lights from the semiconductor element 11 in the X-axis direction. The traveling directions of the plurality of lights from the semiconductor element 11 are converted in the Y-axis direction on the bottom surface 55 of the prism 51. Returning to FIG. 9, the light transmitted through the bottom surface 55 of the prism 51 is bent in the Z-axis direction by total reflection at the inclined surface 54. The prism 51 transmits the light in the spontaneous polarization layer 16 and the polarization inversion layer 17 with the traveling directions of the plurality of lights aligned in the Z-axis direction. Also in the case of the present embodiment, light can be emitted with high efficiency due to high wavelength conversion efficiency. Further, since the light traveling direction is controlled using the prism 51, the light source device can be made simpler than the case where another optical element for aligning the traveling directions of a plurality of lights is separately provided.

  FIG. 12 shows a schematic configuration of a main part of a light source device according to a modification of the present embodiment. The light source device of this modification includes a semiconductor element 31 and a submount 32 that are curved so that the central portion is convex toward the light emitting side. The prism 57 has a shape obtained by deforming the bottom surface 58 into a convex shape out of a triangular prism having a right triangular section. The bottom surface 58 is a convex surface having a convex shape. The bottom surface 58 functions as a convex lens. The prism 57 is configured in the same manner as the prism 51 (see FIG. 10) except that the shape of the bottom surface 58 is different.

  The plurality of lights from the semiconductor element 31 travel so as to diverge from each other. The traveling directions of the plurality of lights from the semiconductor element 31 are converted in the Y-axis direction on the bottom surface 58 of the prism 57. Also in this modification, light can be emitted with high efficiency due to high wavelength conversion efficiency. The prisms 51 and 57 are not limited to the case where a plurality of lights are collimated by refraction at the bottom surfaces 55 and 58. The light can be collimated on any surface of the prisms 51 and 57 where the light reaches.

  The optical element provided with the refracting portion is not limited to the emitting portion of the third embodiment and the prism of the present embodiment, and may have other configurations. For example, a mirror that bends the optical path of light from the array light source may have a curved surface shape so that it functions in the same manner as the prism of this embodiment.

  FIG. 13 shows a schematic configuration of the SHG element 60 according to the fourth embodiment of the present invention. The SHG element 60 of the present embodiment can be applied to the light source device 10 (see FIG. 1) of the first embodiment. The SHG element 60 according to the present embodiment includes a plurality of microlenses 62. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. The SHG element 60 of the present embodiment can be used in combination with the semiconductor element 11 that is curved so that the central part is convex toward the side opposite to the light emitting side. The plurality of microlenses 62 are arranged in parallel in the X-axis direction on the first surface 61. In the SHG element 60, the same number of microlenses 62 as the light rays from the semiconductor element 11 are formed. The microlens 62 has a concave concave surface. Each micro lens 62 has a curvature in the X-axis direction and the Y-axis direction.

  FIG. 14 shows a cross-sectional configuration of the microlens 62. The microlens 62 refracts light from the semiconductor element 11 in the Z-axis direction. The inclination of light from the semiconductor element 11 differs for each microlens 62. The shape of each microlens 62 is set according to the inclination of light from the semiconductor element 11. The microlens 62 functions as a refracting unit that collimates a plurality of lights from the semiconductor element 11 by refraction. By using the same number of microlenses 62 as the light rays from the semiconductor element 11, light can be refracted accurately in the Z-axis direction. Thereby, higher wavelength conversion efficiency can be obtained.

  In addition, it is known that the wavelength conversion element usually improves the wavelength conversion efficiency substantially in proportion to the energy density of light transmitted through the wavelength conversion element. In addition to refracting light, the microlens 62 may have a function of reducing the beam diameter in at least one of the X-axis direction and the Y-axis direction. By narrowing the beam diameter with the micro lens 62, the energy density of the light transmitted through the SHG element 60 can be increased. Thereby, higher wavelength conversion efficiency can be obtained.

  For the light source device 30 shown in FIG. 5, as shown in FIG. 15, a microlens 63 having a convex surface can be used. The SHG element provided with the microlens 63 can be used in combination with the semiconductor element 31 that is curved so that the central portion is convex toward the light emitting side. The microlens 63 can use the light from the semiconductor element 31 in the Z-axis direction. Refract to. The shape of each microlens 63 is set according to the inclination of light from the semiconductor element 31. Also in this case, high wavelength conversion efficiency can be obtained. Note that the microlenses 62 and 63 of the present embodiment need only be able to refract light so as to be at least close to the Z-axis direction, and may have a shape having a curvature only in the X-axis direction. The microlenses 62 and 63 can be formed using, for example, a nanoimprint technique.

  As the SHG element, a hologram element may be used instead of the microlenses 62 and 63. As shown in FIG. 16, the plurality of hologram elements 65 can be arranged in parallel in the X-axis direction on the first surface 61. The hologram element 65 includes a plurality of projections and depressions formed with a minute rectangular area as a unit. The hologram element 65 changes the phase of light for each rectangular area. The hologram element 65 diffracts the light from the semiconductor element by spatially changing the phase of the light. By optimizing the surface conditions including the pitch of the rectangular area and the height of the unevenness, the light can be refracted in a desired direction. Also in this case, high wavelength conversion efficiency can be obtained. The hologram element 65 may also have a function of reducing the beam diameter. The hologram element 65 can be formed using, for example, a nanoimprint technique.

  The light source device of each of the above embodiments may be configured to use a microlens or a hologram element. In the present embodiment, the microlens and the hologram element which are the refracting parts are not limited to the case where one light is refracted, and a plurality of lights may be refracted. When light having different inclinations is incident on the refracting portion, the refracting portion may be configured so that at least the traveling direction of each light can be close to the Z-axis direction. By using a refracting portion that refracts a plurality of lights, a configuration in which a number of refracting portions smaller than the number of light rays from the semiconductor element can be provided. The smaller the number of refracting parts, the easier the forming of the refracting parts. The closer the number of refracting parts is to the number of light beams, the more accurately each light can be refracted in the Z-axis direction.

  The light source device of each of the above embodiments is not limited to the configuration described in this embodiment, and the configuration may be changed as appropriate. For example, a semiconductor laser pumped solid state (DPSS) laser or the like may be used as the light source unit. The light source device may be provided with optical elements such as a polarization selection filter and a wavelength selection filter as necessary.

  FIG. 17 shows a schematic configuration of a monitor device 70 according to the fifth embodiment of the present invention. The monitor device 70 includes a device main body 71 and an optical transmission unit 72. The apparatus main body 71 includes the light source apparatus 10 (see FIG. 1) of the first embodiment. The light transmission unit 72 includes two light guides 74 and 75. A diffusion plate 76 and an imaging lens 77 are provided at the end of the light transmission unit 72 on the subject (not shown) side. The first light guide 74 transmits light from the light source device 10 to the subject. The diffusion plate 76 is provided on the emission side of the first light guide 74. The light propagating through the first light guide 74 is diffused on the subject side by passing through the diffusion plate 76. Each part in the optical path from the light source device 10 to the diffusion plate 76 constitutes an illumination device that illuminates the subject.

  The second light guide 75 transmits light from the subject to the camera 73. The imaging lens 77 is provided on the incident side of the second light guide 75. The imaging lens 77 collects light from the subject onto the incident surface of the second light guide 75. Light from the subject enters the second light guide 75 through the imaging lens 77, then propagates through the second light guide 75 and enters the camera 73.

  As the first light guide 74 and the second light guide 75, a bundle of many optical fibers can be used. By using an optical fiber, light can be transmitted far away. The camera 73 is provided in the apparatus main body 71. The camera 73 is an imaging unit that captures an image of a subject illuminated by light from the light source device 10. By making the light incident from the second light guide 75 enter the camera 73, the subject can be imaged by the camera 73. By using the light source device 10 of the first embodiment, light can be emitted with high efficiency. As a result, a bright image can be monitored using light supplied with high efficiency. Note that any of the light source devices described in the above embodiments may be applied to the monitor device 70.

  FIG. 18 shows a schematic configuration of a projector 80 according to Embodiment 6 of the present invention. The projector 80 is a front projection type projector that views light by supplying light to the screen 89 and observing light reflected by the screen 89. The projector 80 includes a red (R) light source device 81R, a green (G) light source device 81G, and a blue (B) light source device 81B. Each of the color light source devices 81R, 81G, 81B has the same configuration as the light source device 10 (see FIG. 1) of the first embodiment. The projector 80 is an image display device that displays an image using light from each color light source device 81R, 81G, 81B.

  The light source device for R light 81R is a light source device that supplies R light. The diffusing element 82 shapes and enlarges the illumination area, and uniformizes the light amount distribution in the illumination area. As the diffusing element 82, for example, a computer generated hologram (CGH) which is a diffractive optical element can be used. The field lens 83 collimates the light from the R light source device 81R and makes it incident on the R light spatial light modulator 84R. The R light source device 81R, the diffusing element 82, and the field lens 83 constitute an illumination device that illuminates the R light spatial light modulator 84R. The R light spatial light modulator 84R is a spatial light modulator that modulates R light from the illumination device in accordance with an image signal, and is a transmissive liquid crystal display device. The R light modulated by the R light spatial light modulator 84R enters the cross dichroic prism 85 which is a color synthesis optical system.

  The G light source device 81G is a light source device that supplies G light. The light that has passed through the diffusing element 82 and the field lens 83 enters the G spatial light modulator 84G. The G light source device 81G, the diffusing element 82, and the field lens 83 constitute an illumination device that illuminates the G light spatial light modulator 84G. The G light spatial light modulator 84G is a spatial light modulator that modulates the G light from the illumination device according to an image signal, and is a transmissive liquid crystal display device. The G light modulated by the G light spatial light modulator 84G is incident on a different surface of the cross dichroic prism 85 from the surface on which the R light is incident.

  The light source device 81B for B light is a light source device that supplies B light. The light that has passed through the diffusing element 82 and the field lens 83 enters the B light spatial light modulator 84B. The light source device 81B for B light, the diffusing element 82, and the field lens 83 constitute an illumination device that illuminates the spatial light modulation device 84B for B light. The B light spatial light modulator 84B is a spatial light modulator that modulates the B light from the illumination device in accordance with an image signal, and is a transmissive liquid crystal display device. The B light modulated by the B light spatial light modulator 84B is incident on a surface of the cross dichroic prism 85 that is different from the surface on which the R light is incident and the surface on which the G light is incident. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used.

  The cross dichroic prism 85 has two dichroic films 86 and 87 arranged substantially orthogonal to each other. The first dichroic film 86 reflects R light and transmits G light and B light. The second dichroic film 87 reflects B light and transmits R light and G light. The cross dichroic prism 85 combines R light, G light, and B light incident from different directions and emits the light toward the projection lens 88. The projection lens 88 projects the light combined by the cross dichroic prism 85 toward the screen 89.

  By using each color light source device 81R, 81G, 81B having the same configuration as the light source device 10 described above, light can be emitted with high efficiency. As a result, a bright image can be displayed using light supplied with high efficiency. Note that any light source device described in the above embodiments may be applied to the light source devices for color light 81R, 81G, and 81B. In the projector 80, for example, the R light source device 81R does not use an SHG element and emits the fundamental wave light from the light source unit as it is, and the G light source device 81G and the B light source device 81B have the above-described embodiments. It is good also as a structure similar to any one of these light source devices.

  The projector is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector is not limited to a configuration including a spatial light modulator for each color light. The projector may be configured to modulate two or three or more color lights with one spatial light modulator. The projector is not limited to the case where the spatial light modulator is used. The projector may be a laser scanning projector that scans the laser light from the light source device by scanning means such as a galvanometer mirror and displays an image on the irradiated surface. The projector may be a slide projector that uses a slide having image information. The projector may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen.

  The light source device of the present invention may be applied to a liquid crystal display that is an image display device. By combining the light source device of the present invention and the light guide plate, it can be used as an illumination device for illuminating the liquid crystal panel. Also in this case, a bright image can be displayed. The light source device of the present invention is not limited to being applied to a monitor device or an image display device. The light source device of the present invention may be used, for example, in an optical system such as an exposure device for laser beam exposure or a laser processing device.

  As described above, the light source device according to the present invention is suitable for use in a monitor device or an image display device.

The figure which shows schematic structure of the light source device which concerns on Example 1 of this invention. The figure which shows the perspective structure of a semiconductor element and a submount. The figure which shows the perspective structure of a SHG element. The figure explaining the advancing direction of light in the case of using a rectangular parallelepiped-shaped SHG element. FIG. 6 is a diagram illustrating a schematic configuration of a light source device according to a modification of the first embodiment. The figure which shows the perspective structure of a SHG element. The figure which shows schematic structure of the light source device which concerns on Example 2 of this invention. FIG. 10 is a diagram illustrating a schematic configuration of a light source device according to a modification of the second embodiment. The figure which shows schematic structure of the light source device which concerns on Example 3 of this invention. The figure which shows the perspective structure of a prism. The figure explaining the advancing direction of the light which passed the bottom face of the prism. FIG. 10 is a diagram illustrating a schematic configuration of a main part of a light source device according to a modification of Example 3; FIG. 6 is a diagram showing a schematic configuration of an SHG element according to Example 4 of the invention. The figure which shows the cross-sectional structure of a micro lens. The figure which shows the cross-sectional structure of a micro lens provided with a convex surface. The figure explaining the structure using a some hologram element. The figure which shows schematic structure of the monitor apparatus which concerns on Example 5 of this invention. FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a sixth embodiment of the invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Light source device, 11 Semiconductor element, 12 Submount, 13 Package base, 14 SHG element, 15 External resonator, 16 Spontaneous polarization layer, 17 Polarization inversion layer, 18 1st surface, 19 2nd surface, 20 SHG element, 21 First surface, 30 Light source device, 31 Semiconductor element, 32 Submount, 33 SHG element, 34 First surface, 40 Light source device, 41 Light source housing, 42 Ejection unit, 45 Light source device, 46 Ejection unit, 50 Light source device , 51 prism, 52 substrate, 53 concave portion, 54 slope, 55 bottom surface, 57 prism, 58 bottom surface, 60 SHG element, 61 first surface, 62 micro lens, 63 micro lens, 65 hologram element, 70 monitor device, 71 device main body 72 light transmission unit 73 camera 74 first light guide 75 second light guide 7 6 diffuser plate, 77 imaging lens, 80 projector, light source device for 81R R light, light source device for 81G G light, light source device for 81B B light, 82 diffusing element, 83 field lens, spatial light modulator for 84R R light, 84G G light spatial light modulator, 84BB light spatial light modulator, 85 cross dichroic prism, 86 first dichroic film, 87 second dichroic film, 88 projection lens, 89 screen

Claims (15)

An array light source comprising a plurality of light emitting units for emitting light;
A wavelength conversion unit that is formed along a plane substantially orthogonal to a specific direction and has a polarization reversal layer that reverses polarization, and is parallel to the specific direction, and converts the wavelength of light from the array light source;
An adjustment unit that adjusts a traveling direction of a plurality of lights emitted from the plurality of light emitting units,
The adjusting unit aligns the traveling directions of the plurality of lights so as to be close to the specific direction and transmits the light to the wavelength conversion unit. When the direction in which a plurality of lights from the array light source are aligned is the array direction,
The light source device according to claim 1, wherein the adjustment unit adjusts a traveling direction of the plurality of lights in the array direction.   3. The light source device according to claim 1, wherein the adjustment unit includes a refraction unit that parallelizes a plurality of lights from the array light source by refraction.   The light source device according to claim 3, wherein the refraction unit is provided on a surface of the wavelength conversion unit on the array light source side. An optical element provided in an optical path between the array light source and the wavelength converter;
The light source device according to claim 3, wherein the refracting unit is provided in the optical element. A light source housing for housing the array light source;
The light source device according to claim 5, wherein the optical element is an emission unit that emits light from the array light source to the outside of the light source casing.   The light source device according to claim 5, wherein the optical element is a prism that bends an optical path of light from the array light source.   The light source device according to claim 3, wherein the refracting portion includes a concave concave surface.   The light source device according to claim 3, wherein the refracting portion includes a convex surface having a convex shape.   The light source device according to claim 3, wherein the refraction unit includes a hologram element that diffracts light from the array light source.   The light source apparatus according to claim 3, wherein the adjustment unit includes a plurality of the refraction units.   The light source device according to claim 3, wherein the refracting unit reduces a beam diameter of light from the array light source.   An illumination device comprising the light source device according to any one of claims 1 to 12 and illuminating an object to be irradiated using light from the light source device. A lighting device according to claim 13;
An image pickup unit for picking up an image of a subject illuminated by the illumination device.   An image display device comprising the light source device according to claim 1 and displaying an image using light from the light source device.

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