JP2016225448A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device provided with optical elements having high light resistance with respect to incident light and being capable of enhancing a degree of freedom in material selection.SOLUTION: A light source device 100 includes: a substrate 10; semiconductor light-emitting elements 20 mounted onto a first surface 11a of the substrate 10 and emitting light in an in-plane direction of the first surface 11a; window portions 32 to which the light emitted from the semiconductor light-emitting elements 20 is incident; prisms 34 to which light transmitted through the window portions 32 is incident, the prisms deflecting the light transmitted through the window portions 32 in a direction separating from the first surface 11a; and condensing sections 40 condensing the light deflected by the prisms 34. The window portions 32 are formed of a material having higher light resistance with respect to wave lengths of the light emitted by the semiconductor light-emitting elements 20 than that of a material of the prisms 34.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light source device and a projector.

  The projector modulates light emitted from the light source device according to image information with a light modulation device, and enlarges and projects the obtained image with a projection device. In recent years, attention has been paid to a light source device used in such a projector using a semiconductor light emitting element such as a semiconductor laser (LD).

  Since the light output of a single semiconductor light emitting element is not sufficient for a projector that requires a high light quantity, such a light source device uses a plurality of semiconductor light emitting elements in an array.

  For example, in Patent Document 1, a plurality of semiconductor lasers formed on the main surface of the substrate and emitting light in a direction parallel to the in-plane direction of the main surface of the substrate were emitted from each of the plurality of semiconductor lasers. There is disclosed a light source device including an optical element that reflects light in a direction away from a main surface of a substrate. The optical element also includes a prism that reflects light incident on the optical element in a direction away from the main surface of the substrate, and a lens that reduces an emission angle of the light reflected by the prism. And the lens are integrally formed.

JP 2010-45274 A

  However, in the light source device of Patent Document 1, since the light incident surface of the prism is provided near the light emitting surface of the semiconductor laser, it is necessary to give the prism light resistance depending on the intensity of the emitted light of the semiconductor laser. There is a limit to the freedom of choice of materials. For this reason, it has been difficult to improve the shape accuracy of both the lens and the prism depending on the material.

  One of the objects according to some embodiments of the present invention is to provide a light source device including an optical element that has high light resistance to incident light and can increase the degree of freedom of material selection. . Another object of some aspects of the present invention is to provide a projector including the light source device.

The light source device according to the present invention includes:
A substrate,
A semiconductor light emitting device mounted on the first surface of the substrate and emitting light in an in-plane direction of the first surface;
A window part into which light emitted from the semiconductor light emitting element is incident;
A prism that receives light transmitted through the window and bends the light transmitted through the window in a direction away from the first surface;
A light collecting unit for collecting the light bent by the prism;
Including
The window portion is formed of a material having higher light resistance to the wavelength of light emitted from the semiconductor light emitting element than the material of the prism.

  In such a light source device, since the window portion is formed of a material having higher light resistance to the wavelength of light emitted from the semiconductor light emitting element than the material of the prism, the window portion can improve light resistance to incident light. In addition, the degree of freedom in selecting the prism material can be increased. Therefore, it is possible to realize a light source device including an optical element that has high light resistance to incident light and can increase the degree of freedom of material selection.

In the light source device according to the present invention,
A lens surface for condensing light emitted from the semiconductor light emitting element may be formed on the light incident surface of the window portion.

  In such a light source device, since the lens surface is formed on the light incident surface of the window portion, the light emitted from the semiconductor light emitting element can be collected in the vicinity of the light emitting surface of the semiconductor light emitting element. Therefore, it is possible to reduce the size of the optical element and improve the light utilization efficiency.

In the light source device according to the present invention,
A diffractive optical element that condenses the light emitted from the semiconductor light emitting element may be formed on the light incident surface of the window portion.

  In such a light source device, since the diffractive optical element is formed on the light incident surface of the window portion, the light emitted from the semiconductor light emitting element can be collected in the vicinity of the light emitting surface of the semiconductor light emitting element. Therefore, it is possible to reduce the size of the optical element and improve the light utilization efficiency.

In the light source device according to the present invention,
The reflecting surface of the prism may be a concave surface.

  In such a light source device, light can be condensed on the reflecting surface of the prism.

In the light source device according to the present invention,
The condensing unit may be a diffractive optical element.

  In such a light source device, it is possible to realize a light source device including an optical element that can improve light resistance against incident light and can increase the degree of freedom of material selection.

In the light source device according to the present invention,
The prism and the light condensing unit may be integrally formed.

  In such a light source device, since the prism and the condensing part are integrally formed, the number of parts can be reduced as compared with the case where the prism and the condensing part are provided as independent optical parts. Therefore, alignment between components is easy and manufacturing cost can be reduced.

In the light source device according to the present invention,
The normal of the light incident surface of the window portion may be inclined with respect to the normal of the light emitting surface of the semiconductor light emitting element when viewed from the normal direction of the first surface.

In the light source device according to the present invention,
The semiconductor light emitting element is
An active layer in which current is injected to generate light;
A first cladding layer and a second cladding layer sandwiching the active layer;
Have
The active layer constitutes an optical waveguide for guiding light,
The optical waveguide is provided to be inclined with respect to a normal to the light emission surface of the semiconductor light emitting device as seen from the stacking direction of the active layer and the first cladding layer,
The light emitted from the semiconductor light emitting element may be refracted on the light incident surface of the window portion and travel along a perpendicular line of the light emitting surface of the semiconductor light emitting element.

  In such a light source device, light emitted from the light emitting surface of the semiconductor light emitting element in a direction inclined with respect to the normal of the light emitting surface is refracted by the light incident surface of the window portion to emit light from the semiconductor light emitting element. It can proceed along the normal of the surface. For this reason, for example, the light utilization efficiency in the optical system at the subsequent stage can be improved as compared with the case where the perpendicular of the light incident surface of the window portion is parallel to the perpendicular of the light emitting surface of the semiconductor light emitting element.

In the light source device according to the present invention,
The semiconductor light emitting element is
An active layer in which current is injected to generate light;
A first cladding layer and a second cladding layer sandwiching the active layer;
Have
The active layer constitutes an optical waveguide for guiding light,
The optical waveguide may be provided in parallel to a perpendicular line of the light emitting surface of the semiconductor light emitting device when viewed from the stacking direction of the active layer and the first cladding layer.

  In such a light source device, instability of laser oscillation caused by light emitted from the semiconductor light emitting element, reflected by the light incident surface of the window portion, and returning to the semiconductor light emitting element can be reduced.

In the light source device according to the present invention,
The window portion may be made of an inorganic material.

  In such a light source device, the light resistance of the window portion can be improved.

In the light source device according to the present invention,
The material of the prism may be a resin material.

  In such a light source device, the prism can be manufactured easily and inexpensively.

The light source device according to the present invention includes:
A substrate,
A semiconductor light emitting device mounted on the first surface of the substrate and emitting light in an in-plane direction of the first surface;
A prism that bends light emitted from the semiconductor light emitting element in a direction away from the first surface;
A light collecting unit for collecting the light bent by the prism;
Including
The prism is formed of a material having higher light resistance with respect to the wavelength of light emitted from the semiconductor light emitting element than the material of the light collecting portion.

In such a light source device, since the prism is formed of a material having higher light resistance to the wavelength of light emitted from the semiconductor light emitting element than the material of the light collecting portion, the light resistance to incident light can be improved by the prism. At the same time, the degree of freedom in selecting the material for the light collecting portion can be increased. Therefore, it is possible to realize a light source device including an optical element that has high light resistance to incident light and can increase the degree of freedom of material selection.

In the light source device according to the present invention,
The condensing unit may be a diffractive optical element.

  In such a light source device, it is possible to realize a light source device including an optical element that can improve light resistance against incident light and can increase the degree of freedom of material selection.

In the light source device according to the present invention,
A lens surface for condensing light emitted from the semiconductor light emitting element may be formed on the light incident surface of the prism.

  In such a light source device, since the lens surface is formed on the light incident surface of the prism, the light emitted from the semiconductor light emitting element can be condensed near the light emitting surface of the semiconductor light emitting element. Therefore, it is possible to reduce the size of the optical element and improve the light utilization efficiency.

In the light source device according to the present invention,
A diffractive optical element that condenses light emitted from the semiconductor light emitting element may be formed on the light incident surface of the prism.

  In such a light source device, since the diffractive optical element is formed on the light incident surface of the prism, the light emitted from the semiconductor light emitting element can be condensed in the vicinity of the light emitting surface of the semiconductor light emitting element. Therefore, it is possible to reduce the size of the optical element and improve the light utilization efficiency.

In the light source device according to the present invention,
The reflecting surface of the prism may be a concave surface.

  In such a light source device, light can be condensed on the reflecting surface of the prism.

In the light source device according to the present invention,
The material of the prism may be an inorganic material.

  In such a light source device, the light resistance of the prism can be improved.

In the light source device according to the present invention,
The material of the condensing part may be a resin material.

  In such a light source device, the condensing part can be manufactured easily and inexpensively.

The projector according to the present invention is
A light source device according to the present invention;
A light modulation device that modulates light emitted from the light source device according to image information;
A projection device for projecting an image formed by the light modulation device;
including.

  Since such a projector includes the light source device according to the present invention, the light use efficiency can be improved.

The top view which shows typically the light source device which concerns on 1st Embodiment. Sectional drawing which shows typically the light source device which concerns on 1st Embodiment. Sectional drawing which shows a semiconductor light-emitting device, a bending part, and a condensing part typically. Sectional drawing which shows typically the optical element of the light source device which concerns on a 1st modification. Sectional drawing which shows typically the optical element of the light source device which concerns on a 2nd modification. Sectional drawing which shows typically the optical element of the light source device which concerns on a 3rd modification. Sectional drawing which shows typically the optical element of the light source device which concerns on a 4th modification. The top view which shows typically a part of light source device which concerns on a 5th modification. The top view which shows typically a part of light source device which concerns on a 5th modification. The top view which shows typically the light source device which concerns on 2nd Embodiment. Sectional drawing which shows typically the light source device which concerns on 2nd Embodiment. Sectional drawing which shows typically the optical element of the light source device which concerns on 2nd Embodiment. Sectional drawing which shows typically the optical element of the light source device which concerns on a 1st modification. Sectional drawing which shows typically the optical element of the light source device which concerns on a 2nd modification. Sectional drawing which shows typically the optical element of the light source device which concerns on a 3rd modification. Sectional drawing which shows typically the optical element of the light source device which concerns on a 4th modification. The top view which shows typically the light source device which concerns on 3rd Embodiment. Sectional drawing which shows typically the light source device which concerns on 3rd Embodiment. The top view which shows typically a part of light source device which concerns on the modification of 3rd Embodiment. The top view which shows typically a part of light source device which concerns on the modification of 3rd Embodiment. FIG. 10 is a diagram schematically illustrating a projector according to a fourth embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. 1. First embodiment 1.1. First, a light source device according to a first embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing the light source device 100 according to the first embodiment. 2 is a cross-sectional view taken along line II-II in FIG. 1 schematically showing the light source device 100 according to the first embodiment. 1 and 2 and FIGS. 3 to 20 shown below, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other.

  As shown in FIGS. 1 and 2, the light source device 100 includes a light source substrate (an example of a substrate) 10, a plurality of semiconductor light emitting elements 20, a plurality of bent portions 30, and a plurality of light collecting portions 40. .

  The light source substrate 10 is a semiconductor substrate such as silicon. A plurality of semiconductor light emitting elements 20 are mounted on the main surface (first surface) 11a of the light source substrate 10 (the surface facing the + Z-axis direction). On the main surface 11b of the light source substrate 10 (a main surface opposite to the main surface 11a, a surface facing the −Z axis direction), a heat radiating plate 12 is provided. The material of the heat sink 12 is a material having excellent thermal conductivity such as copper, and the heat sink 12 can release heat during operation of the semiconductor light emitting element 20. Thereby, the fall of the luminous efficiency of the semiconductor light-emitting device 20 can be suppressed.

The plurality of semiconductor light emitting elements 20 are mounted on the main surface 11 a of the light source substrate 10. The plurality of semiconductor light emitting elements 20 are arranged in a plurality of rows and a plurality of columns (matrix shape). That is, the plurality of semiconductor light emitting elements 20 are arranged in a two-dimensional array. In the illustrated example, two rows of four semiconductor light emitting elements 20 arranged in the Y-axis direction are arranged in the X-axis direction. As described above, in the light source device 100, eight semiconductor light emitting elements 20 arranged in four rows and two columns are arrayed to form one array light source unit. The semiconductor light emitting device 20
The number of is not particularly limited.

  The semiconductor light emitting element 20 emits light in the in-plane direction of the main surface 11 a of the light source substrate 10. In the illustrated example, the semiconductor light emitting element 20 emits light in the + X axis direction.

  FIG. 3 is a cross-sectional view schematically showing the semiconductor light emitting element 20 and the bent part 30 and the light collecting part 40 corresponding to the semiconductor light emitting element 20. Hereinafter, a case where the semiconductor light emitting element 20 is an InGaAlP-based (red) edge emitting semiconductor laser will be described.

  As shown in FIG. 3, the semiconductor light emitting element 20 includes a stacked body 101 including an active layer 106, a first electrode 110, and a second electrode 112.

  The stacked body 101 includes a base layer 102, a first cladding layer 104, an active layer 106, and a second cladding layer 108. The stacked body 101 is formed by epitaxially growing a first cladding layer 104, an active layer 106, and a second cladding layer 108 in this order on a base layer (substrate) 102.

  The base layer 102 includes, for example, a substrate and a buffer layer. As the substrate, for example, a first conductivity type (for example, n-type) GaAs substrate or the like can be used. The buffer layer is, for example, an n-type GaAs layer, an AlGaAs layer, an InGaP layer, or the like. When the buffer layer is epitaxially grown, the crystallinity of the layer formed thereabove can be improved.

  The first cladding layer 104 is formed on the base layer 102. The first cladding layer 104 is, for example, an n-type InGaAlP layer.

  The active layer 106 is formed on the first cladding layer 104. The active layer 106 is sandwiched between the first cladding layer 104 and the second cladding layer 108. The active layer 106 has, for example, a multiple quantum well (MQW) structure in which three quantum well structures each composed of an InGaP well layer and an InGaAlP barrier layer are stacked.

  The active layer 106 is a layer that can generate light by being injected with current. A part of the active layer 106 constitutes an optical waveguide 22 that guides light generated in the active layer 106.

  The optical waveguide 22 connects the side surface of the active layer 106 on the −X axis direction side and the side surface of the active layer 106 on the + X axis direction side. The optical waveguide 22 is linearly provided between the two side surfaces of the active layer 106 when viewed from the Z-axis direction (the stacking direction of the active layer 106 and the first cladding layer 104), and is perpendicular to the normal of the light exit surface. Are provided in parallel. The light generated in the active layer 106 is multiple-reflected between the two side surfaces of the active layer 106 and oscillates. The light generated in the active layer 106 is emitted in the + X-axis direction from the light emission surface provided on one side surface (the side surface on the + X-axis direction side) of the active layer 106.

  The second cladding layer 108 is formed on the active layer 106. The second cladding layer 108 is, for example, a second conductivity type (for example, p-type) InGaAlP layer.

The first electrode 110 is formed under the base layer 102. The second electrode 112 is formed on the second cladding layer 108. A contact layer (not shown) may be provided between the second electrode 112 and the second cladding layer 108. For example, the current path between the electrodes 110 and 112 is determined by the planar shape (the shape viewed from the Z-axis direction) of the contact surface between the second electrode 112 and the layer in ohmic contact with the second electrode 112, and as a result, The planar shape of the optical waveguide 22 is determined.

  The semiconductor light emitting element 20 may be a so-called refractive index waveguide type in which light is confined by providing a refractive index difference in the active layer, or an optical waveguide generated by injecting a current becomes a waveguide region as it is. A so-called gain waveguide type may be used.

  Since the semiconductor light emitting device 20 is an edge-emitting light emitting device in which light traveling along the in-plane direction of the active layer 106 resonates, for example, light traveling in a direction orthogonal to the in-plane direction of the active layer resonates. Compared with a surface-emitting light-emitting element, the output of light obtained from one element can be increased.

  Further, since the semiconductor light emitting element 20 is an edge-emitting light emitting element, the light emitted from the semiconductor light emitting element 20 has greatly different divergence angles in two directions orthogonal to the optical axis of the light. In the illustrated example, the light emitted from the semiconductor light emitting element 20 (the light traveling in the X-axis direction) has a larger spread angle in the Z-axis direction than the spread angle in the Y-axis direction. That is, the cross-sectional shape of the light emitted from the semiconductor light emitting element 20 is elliptical (or substantially elliptical) having a major axis along the Z axis.

  The bending unit 30 bends the light emitted from the semiconductor light emitting element 20 in a direction away from the main surface 11 a of the light source substrate 10. In the illustrated example, the bending unit 30 bends the light emitted from the semiconductor light emitting element 20 and traveling in the + X-axis direction in the + Z-axis direction. The bent portion 30 includes a window portion 32 and a prism 34.

  The light L emitted from the semiconductor light emitting element 20 enters the window 32. The window portion 32 is disposed in the vicinity of the light emission surface of the semiconductor light emitting element 20. The window portion 32 is disposed at a position closer to the light emission surface of the semiconductor light emitting element 20 than the prism 34 on the optical path of the light L emitted from the semiconductor light emitting element 20.

  The shape of the window part 32 is a rectangular parallelepiped as shown in FIGS. 1-3, for example. In the illustrated example, the window portion 32 has a rectangular cross-sectional shape on the XZ plane, and has a flat plate shape elongated in the Y direction (having a longitudinal direction). Optically, one window portion 32 is provided corresponding to one semiconductor light emitting element 20 (one light emission surface), but structurally, a plurality of windows 32 are arranged along the Y axis. One window 32 is provided corresponding to (four) semiconductor light emitting elements 20. In the illustrated example, two window portions 32 are provided corresponding to two columns of the semiconductor light emitting elements 20. Thereby, joining of the window part 32 and the prism 34 becomes easy, and the precision of alignment can be improved. Furthermore, the manufacturing cost of the optical substrate 50 can be reduced.

  The window 32 has a light incident surface 31a and a light exit surface 31b parallel to the YZ plane. The light incident surface 31 a is orthogonal to the optical axis of the light L emitted from the semiconductor light emitting element 20. That is, the perpendicular of the light incident surface 31a is parallel to the optical axis of the light L. Although not shown, an antireflection film is formed on the light incident surface 31a.

  The window 32 is made of a material having higher light resistance to the wavelength of the light L emitted from the semiconductor light emitting element 20 than the material of the prism 34. As the material of the window portion 32, for example, an inorganic material such as glass or inorganic crystal can be used, and glass (for example, BK7, refractive index = about 1.52) is particularly suitable. This is because glass is easy to mold and polish, and glass is amorphous (amorphous), and it is not necessary to consider the influence of crystals on light. Moreover, the material of the window part 32 is not limited to an inorganic material, For example, a composite organic material may be sufficient. The composite organic material is a resin material in which ultrafine particles made of nanometer-sized inorganic material are uniformly dispersed to improve various physical properties. For example, a composite organic material in which an organic component and an inorganic component are hybridized at a molecular level to improve light resistance can be used.

  The window part 32 is produced by, for example, cutting a glass base material into a predetermined size and optically polishing the two surfaces that are the light incident surface 31a and the light emitting surface 31b that are in parallel with each other. Since the window portion 32 has a relatively simple flat plate shape, it can be easily and inexpensively manufactured by a general processing method.

  Light L that has passed through the window 32 is incident on the prism 34. The prism 34 includes a light incident surface 33a that is opposed to (in contact with, in the illustrated example) the light exit surface 31b of the window 32, and a reflective surface 33b that reflects the light L incident from the light incident surface 33a. Have. The light incident surface 33a of the prism 34 and the light emitting surface 31b of the window portion 32 are joined by an adhesive or the like. It is desirable to use an adhesive with high light resistance. The reflection surface 33 b is inclined 45 degrees with respect to the main surface 11 a of the light source substrate 10. That is, the reflecting surface 33 b is inclined 45 degrees with respect to the optical axis of the light L emitted from the semiconductor light emitting element 20. A reflective film (not shown) is provided on the reflective surface 33b. The light emitted from the semiconductor light emitting element 20 is reflected by the reflecting surface 33 b and bent in a direction away from the main surface 11 a of the light source substrate 10. Note that the inclination of the reflection surface 33b with respect to the optical axis of the light is not limited to 45 degrees, and the light L traveling in the in-plane direction of the main surface 11a can be bent in a direction away from the main surface 11a (+ Z axis direction side). Any tilt is acceptable.

  The condensing part 40 condenses the light L bent by the bending part 30. Here, condensing light means that the divergence angle (emission angle) of light emitted from the condensing unit 40 is smaller than the divergence angle of light incident on the condensing unit 40. For example, the condensing unit 40 condenses and collimates the light L. Thereby, the light L is emitted as parallel light (or substantially parallel light). The condensing part 40 is comprised with the lens (lens surface 41).

  In the light source device 100, the prism 34 and the light collecting unit 40 are provided integrally. The light source device 100 includes an optical substrate 50 on which the prism 34 and the light collecting unit 40 are integrally provided. In the light source device 100, the window portion 32 and the optical substrate 50 are joined to constitute one optical element 2.

  The optical substrate 50 is formed using a resin substrate such as plastic or a transparent substrate made of glass as a base material. The optical substrate 50 has a support portion 54, and the support portion 54 is bonded to the main surface 11 a of the light source substrate 10 with an adhesive or the like. A concave portion 52 is provided on the side of the optical substrate 50 facing the main surface 11a of the light source substrate 10 (on the −Z axis direction side). In a state where the light source substrate 10 and the optical substrate 50 are connected, the semiconductor light emitting element 20 is accommodated in the recess 52. That is, the semiconductor light emitting element 20 is accommodated in a space surrounded by the light source substrate 10 and the optical substrate 50.

  In the optical substrate 50, the prism-shaped portion that protrudes from the surface that defines the bottom surface of the recess 52 (the surface on the −Z axis direction side) to the semiconductor light emitting element 20 side (the −Z axis direction side) constitutes the prism 34. Yes. The cross-sectional shape of the prism 34 on the ZX plane is, for example, a triangle (isosceles triangle), and is a prism shape elongated in the Y-axis direction (having a longitudinal direction). As shown in FIG. 1, the prisms 34 corresponding to a plurality (four) of the semiconductor light emitting elements 20 arranged along the Y axis are continuous.

  On the surface of the optical substrate 50 opposite to the surface that defines the bottom surface of the recess 52 (the surface on the + Z-axis direction side), a lens surface 41 that constitutes the light condensing unit 40 is provided. One lens surface 41 is provided for one semiconductor light emitting element 20. The lens surface 41 is arranged in a plurality of rows and a plurality of columns (array) corresponding to the semiconductor light emitting elements 20 arranged in a plurality of rows and a plurality of columns (array). The lens surface 41 is provided with an antireflection film (not shown).

  Each of the light source substrate 10, the plurality of semiconductor light emitting elements 20, and the optical substrate 50 is formed with alignment marks (not shown), and a plurality of semiconductors are formed using these alignment marks. The relative positions of the light emitting element 20 and the optical substrate 50 can be matched. Thereby, the light emitted from the semiconductor light emitting element 20 can be accurately incident on the bent portions 30 and the predetermined positions of the light collecting portion 40.

  The optical substrate 50 is integrally provided with a plurality of prisms 34 and a plurality of condensing portions 40 corresponding to the plurality of semiconductor light emitting elements 20. Therefore, the optical substrate 50 has a complicated shape as compared with the window portion 32, for example.

  The material of the optical substrate 50 is a resin material such as plastic (synthetic resin, for example, PMMA, refractive index = 1.49). Since the resin material is excellent in moldability and mass productivity, the optical substrate 50 having a complicated shape can be easily and inexpensively formed by injection molding, molding method, or the like. Further, since the material of the optical substrate 50 is a resin material, the optical substrate 50 having a complicated shape can be formed with high accuracy.

  In addition, since the window part 32 and the optical board | substrate 50 are joined using an adhesive agent as mentioned above, it is preferable to use a material with a refractive index close to the window part 32, the optical board | substrate 50, and an adhesive agent mutually. preferable. Thereby, light reflection at the bonding interface between the window portion 32 and the optical substrate 50 (prism 34) can be reduced, and the optical element 2 with high light utilization efficiency can be realized.

  As described above, since the light L emitted from the semiconductor light emitting element 20 has a large emission angle (expansion angle), the material of the window portion 32 and the material of the optical substrate 50 are preferably materials having a high refractive index. The light L incident on the window portion 32 and the optical substrate 50 has an exit angle narrowed by refraction, so that the window portion 32 and the optical substrate 50 can be downsized.

  In the light source device 100, as shown in FIG. 3, the light L emitted from the semiconductor light emitting element 20 and traveling in the + X-axis direction is incident on the light incident surface 31a of the window 32 and is emitted from the light emitting surface 31b. . The light L emitted from the light exit surface 31b of the window portion 32 enters the light incident surface 33a of the prism 34, and is reflected in the + Z-axis direction by the reflection surface 33b. The reflected light L is condensed by the condensing unit 40 (lens surface 41) and emitted in the + Z-axis direction. In the light source device 100, as shown in FIG. 1, a plurality of semiconductor light emitting elements 20 are arranged in a two-dimensional array on the main surface 11a of the light source substrate 10, and a bent portion 30 and a corresponding one of the plurality of semiconductor light emitting elements 20 are provided. Since the condensing unit 40 is provided, the light source device 100 can emit an array light beam composed of light arranged in a two-dimensional array.

  Although the InGaAlP light emitting element has been described above, any material system capable of forming an optical waveguide can be used as the semiconductor light emitting element 20. For example, semiconductor materials such as AlGaN, GaN, InGaN, GaAs, AlGaAs, InGaAs, InGaAsP, InP, GaP, AlGaP, and ZnCdSe can be used.

  The light source device 100 has the following features, for example.

In the light source device 100, the light emitted from the semiconductor light emitting element 20 that emits light in the in-plane direction of the light source substrate 10 can be bent in a direction away from the main surface 11 a of the light source substrate 10 by the bending portion 30. That is, in the light source device 100, the edge-emitting semiconductor light emitting element 20 can be used. Therefore, in the light source device 100, the light output obtained from one semiconductor light emitting element can be increased as compared with the case where a surface light emitting type semiconductor light emitting element is used, for example. Furthermore, in the light source device 100, it is possible to highly integrate edge-emitting semiconductor light-emitting elements. As described above, since the light source device 100 can be highly integrated while increasing the light output obtained from one semiconductor light emitting element, the output of the light source device 100 can be increased.

  Here, the light emitted from the edge-emitting semiconductor light-emitting element is emitted from a very narrow active layer, so that the light intensity (light density) is very high in the vicinity of the light-emitting surface of the semiconductor light-emitting element. . However, since the emission angle (expansion angle) of light emitted from the semiconductor light emitting device is very wide (particularly in the thickness direction of the active layer), the light intensity is inversely proportional to the square of the distance as the distance from the light emission surface increases. Then drop rapidly. As an example, the distance between the light emitting surface of the semiconductor light emitting element 20 shown in FIG. 3 and the light incident surface 31a of the window 32 is 0.05 mm, and the thickness of the window 32 (light incident surface 31a and light emitting surface 31b). Is 0.2 mm, the light intensity at the light incident surface 33 a of the prism 34 is reduced to about 1/14 with respect to the light intensity at the light incident surface 31 a of the window 32.

  Therefore, in the light source device 100, the window portion 32 is formed of a material having higher light resistance to the wavelength of light emitted from the semiconductor light emitting element 20 than the material of the prism 34, and thus the window portion 32 has light resistance to incident light. Since the prism 34 does not require the light resistance as much as that of the window portion 32, the degree of freedom in selecting the material of the prism 34 (optical substrate 50) can be increased. Therefore, in the light source device 100, the optical element 2 (window portion 32) can be disposed in the immediate vicinity of the light emission surface of the semiconductor light emitting element 20. Thereby, since light can be incident on the optical element 2 in a state where the light emission angle (expansion angle) is small, the optical element 2 can be reduced in size, and even when the output of the semiconductor light emitting element 20 is increased, In the optical element 2, high light use efficiency can be obtained stably. Further, for example, in the light source device 100, the window 32 is not suitable for processing a complicated shape, but is a material with high light resistance (for example, an inorganic material), while the prism 34 (optical substrate 50) has high light resistance. It can be formed of a material (for example, a resin material) that is not complicated but can be easily processed. Therefore, in the light source device 100, the optical element 2 including the window portion 32 and the prism 34 (optical substrate 50) can be manufactured easily and inexpensively. Therefore, the light source device 100 can achieve high output, long-term reliability, reduction in manufacturing cost, and the like.

  Further, in the optical element 2, the light incident surface 31a on which the antireflection film is formed and the reflection surface 33b on which the reflection film is formed are in a close positional relationship. Therefore, if the optical element 2 is composed of a single element (the window portion and the prism are integrally formed), and optical films having different characteristics are formed on two adjacent surfaces, the film is formed on a surface other than the target surface. There is a problem that the wraparound of the substance is likely to occur and the optical characteristics of each optical film are likely to be deteriorated. Masking other than the target surface can prevent wraparound, but if the shape of the optical element is complicated, it takes time to mask.

  On the other hand, in the light source device 100, by forming the optical element 2 using the window part 32 and the prism 34 manufactured separately, a predetermined optical film is made to wrap around the light incident surface 31a and the reflecting surface 33b. It is possible to form without suppressing the occurrence and deteriorating the optical characteristics.

  In the light source device 100, since the prism 34 and the light collecting unit 40 are integrally formed, the number of components can be reduced as compared with the case where the prism 34 and the light collecting unit 40 are provided as independent optical components. Therefore, alignment between components is easy and manufacturing cost can be reduced.

Further, in the light source device 100, since the prism 34 and the light condensing unit 40 are integrally formed, the light L emitted from the semiconductor light emitting element 20 enters the prism 34 and is reflected by the reflecting surface 33b of the prism 34. After that, the light is condensed (parallelized) by the light collecting unit 40 and emitted. That is, since the light L emitted from the semiconductor light emitting element 20 enters the prism 34 and is reflected by the reflecting surface 33b, the light emission angle (expansion angle) is larger than when reflected in the air. Is reflected in a small state. Therefore, the prism 34 can be made small. Therefore, the optical element 2 can be made optical. Thereby, for example, the interval between adjacent semiconductor light emitting elements 20 can be reduced, and the light emission intensity per unit area can be increased as viewed from the normal direction of the main surface 11a of the light source substrate 10.

  In the present embodiment, the light resistance evaluation (determination of whether the light resistance of a specific material (for example, material A) is higher than that of another specific material (for example, material B)) is, for example, The following experiment can be performed.

First, the material A and the material B are made to have the same shape (for example, a plate shape having the same thickness), and have the same wavelength as the light L emitted from the semiconductor light emitting element 20 in the same environment (for example, in the atmosphere at a temperature of 25 degrees). Irradiate light (laser light). At this time, the light irradiation conditions (the beam diameter (area of the light irradiation region) and the energy density (mW / cm ² )) for the material A and the material B are the same. Then, for each of the material A and the material B, the light transmittance of the light irradiation region is measured with a spectrophotometer, and the temporal change of the light transmittance is examined. From this result, the irradiation time until the light transmittance of the material A and the material B falls below a predetermined value (for example, 0.5% reduction) is compared. A material having a longer irradiation time until the light transmittance falls below a predetermined value is assumed to have higher light resistance.

1.2. Next, a modification of the light source device according to the first embodiment will be described. Hereinafter, in the light source device according to each modification, members having the same functions as those of the constituent members of the light source device 100 according to the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

(1) First Modification First, a first modification will be described. FIG. 4 is a cross-sectional view schematically showing the optical element 2 of the light source device 200 according to the first modification. FIG. 4 corresponds to FIG.

  In the light source device 100 described above, the light incident surface 31a of the window 32 is a plane orthogonal to the optical axis of the light L emitted from the semiconductor light emitting element 20, as shown in FIG.

  On the other hand, in the light source device 200 according to the present modification, a lens surface (lens shape) 210 that collects the light L emitted from the semiconductor light emitting element 20 is formed on the light incident surface 31a of the window portion 32. ing.

  When forming the lens surface 210 in the window part 32, it is preferable that the material of the window part 32 is a low melting glass. Thereby, a highly accurate lens shape can be easily produced.

  The light L emitted from the semiconductor light emitting element 20 is divergent light having a large emission angle as described above. When converging such diverging light, it is desirable to arrange an action surface (for example, a refracting surface) that changes the traveling direction of light at a position as close as possible to the light emitting surface of the semiconductor light emitting element 20. In the light source device 200, the lens surface 210 is formed on the light incident surface 31 a of the window portion 32 so as to have a condensing function. The light can be condensed, and the optical element 2 can be downsized and the light utilization efficiency can be improved.

Moreover, in the light source device 200, since it can condense in two places, the lens surface 210 provided in the light-incidence surface 31a of the window part 32, and the condensing part 40, for example compared with the case where it condenses in one place. The radius of curvature of the lens surface can be increased, and the lens surface (lens shape) can be easily produced. When the light L emitted from the semiconductor light emitting element 20 is condensed on the lens surface 210, when the light has a desired divergence angle (emission angle) (including substantially parallel light), the condensing unit 40 is used. It is not necessary to provide the (lens surface 41), and the optical element 2 can be downsized and the manufacturing cost can be reduced.

(2) Second Modification Next, a second modification will be described. FIG. 5 is a cross-sectional view schematically showing the optical element 2 of the light source device 300 according to the second modification. FIG. 5 corresponds to FIG.

  In the light source device 100 described above, the light incident surface 31a of the window 32 is a plane orthogonal to the optical axis of the light L emitted from the semiconductor light emitting element 20, as shown in FIG.

  On the other hand, in the light source device 200 according to this modification, a diffractive optical element (DOE element) that condenses the light L emitted from the semiconductor light emitting element 20 is formed on the light incident surface 31a of the window 32. ) 310 is formed.

  The diffractive optical element 310 is an element for changing the traveling direction of light using light diffraction. The diffractive optical element 310 diffracts light with a fine structure, for example. The diffractive optical element 310 includes a hologram element and the like.

  The diffractive optical element 310 can be formed, for example, by pressing a mold or the like against the glass base material that becomes the window portion 32 and performing transfer molding. When the diffractive optical element 310 is provided in the window portion 32, the material of the window portion 32 is preferably low-melting glass. Thereby, a highly accurate diffractive optical element can be easily manufactured.

  In the light source device 300, since the diffractive optical element 310 is formed on the light incident surface 31a of the window portion 32 to provide a light collecting function, the light emitting surface of the semiconductor light emitting element 20 is similar to the light source device 200 described above. The divergent light (light L) can be collected in the vicinity of the pole, and the optical element 2 can be downsized and the light use efficiency can be improved. Moreover, in the light source device 300, since it can condense in two places, the diffractive optical element 310 provided in the light-incidence surface 31a of the window part 32, and the condensing part 40, for example compared with the case where it condenses in one place. Thus, the radius of curvature of the lens surface constituting the light condensing unit 40 can be increased, and the lens surface (lens shape) can be easily manufactured. Note that when the light L emitted from the semiconductor light emitting element 20 is collected by the diffractive optical element 310, light having a desired divergence angle (emission angle) (including substantially parallel light) is obtained. 40 (lens surface 41) is not required, and the optical element 2 can be reduced in size and the manufacturing cost can be reduced.

(3) Third Modification Next, a third modification will be described. FIG. 6 is a cross-sectional view schematically showing the optical element 2 of the light source device 400 according to the third modification. 6 corresponds to FIG.

  In the light source device 100 described above, the reflecting surface 33b of the prism 34 is a plane inclined by 45 degrees with respect to the optical axis of the light L as shown in FIG.

  On the other hand, in the light source device 400, the reflecting surface 33b of the prism 34 is a concave surface for the light L incident on the reflecting surface 33b. The reflecting surface 33b constitutes a concave mirror. Thereby, the light L can be bent and condensed at the reflecting surface 33b. The reflecting surface 33b is a curved concave surface in the illustrated example. As for the outer shape of the prism 34, the reflective surface 33 b is a convex surface that protrudes outside the prism 34.

  In the light source device 400, since the light can be condensed at two places, that is, the reflecting surface 33 b of the prism 34 and the light collecting part 40, for example, the lens constituting the light collecting part 40 compared to the case where light is condensed at one place. The radius of curvature of the surface 41 can be increased, and the lens surface (lens shape) can be easily manufactured.

  Note that the reflecting surface 33b is a parabolic surface with the light emitting surface of the semiconductor light emitting element 20 as a focal point, so that the light L can be converted into parallel light (or substantially parallel light) by the reflecting surface 33b. Therefore, for example, the lens surface 41 formed on the optical substrate 50 can be omitted, and the optical element 2 can be downsized and the manufacturing cost can be reduced.

(4) Fourth Modification Next, a fourth modification will be described. FIG. 7 is a cross-sectional view schematically showing the optical element 2 of the light source device 500 according to the fourth modification. FIG. 7 corresponds to FIG.

  In the light source device 100 described above, the condensing unit 40 is configured by a lens surface 41 (lens shape) provided on the optical substrate 50 as shown in FIG.

  On the other hand, in the light source device 500, the condensing part 40 is comprised with the diffractive optical element 510, as shown in FIG.

  The diffractive optical element 510 is formed on the surface of the optical substrate 50 facing the + Z-axis direction. The diffractive optical element 510 can be formed by forming a structure such as minute irregularities on the surface of the optical substrate 50 facing the + Z-axis direction. For example, when the optical substrate 50 is manufactured, the diffractive optical element 510 can be easily transferred by transferring the optical substrate 50 when the optical substrate 50 is formed by forming a minute uneven shape on a corresponding part of a mold used when molding the resin material. Can be produced. Thereby, for example, the optical element 2 can be downsized and the manufacturing cost can be reduced.

(5) Fifth Modification Next, a fifth modification will be described. FIG. 8 is a plan view schematically showing a part of the light source device 600 according to the fifth modification.

  In the light source device 100 described above, the light incident surface 31a of the window 32 is a surface perpendicular to the optical axis of the light L as shown in FIG. That is, the perpendicular line of the light incident surface 31 a of the window portion 32 was parallel to the perpendicular line of the light emitting surface of the semiconductor light emitting element 20.

  On the other hand, in the light source device 600, as shown in FIG. 8, the perpendicular P1 of the light incident surface 31a of the window 32 is from the perpendicular direction of the main surface 11a of the light source substrate 10 (Z-axis direction in the illustrated example). As seen, the semiconductor light emitting element 20 is inclined with respect to the normal P2 of the light emission surface. That is, the perpendicular line P1 of the light incident surface 31a of the window portion 32 is inclined with respect to the optical axis of the light L emitted from the semiconductor light emitting element 20 when viewed from the Z-axis direction. Therefore, for example, compared with the case where the perpendicular line P1 and the perpendicular line P2 are parallel (that is, compared with the case where the light incident surface 31a and the light emission surface of the semiconductor light emitting element 20 are parallel), the light is emitted from the semiconductor light emitting element 20. Thus, instability of laser oscillation caused by light reflected by the light incident surface 31a of the window 32 and returning to the semiconductor light emitting element 20 can be reduced. For example, when the light incident surface 31a and the light emitting surface of the semiconductor light emitting element 20 are parallel, the light reflected by the light incident surface 31a may enter the semiconductor light emitting element 20 and laser oscillation may become unstable. .

  As shown in FIG. 9, in the light source device 600, a lens surface 610 (lens shape) may be formed on the light incident surface 31 a of the window portion 32. Even in such a configuration, it is possible to reduce instability of laser oscillation due to incidence of return light.

2. Second Embodiment 2.1. Next, a light source device according to a second embodiment will be described with reference to the drawings. FIG.
It is a top view which shows typically the light source device 700 which concerns on 2nd Embodiment. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 10 schematically showing the light source device 100 according to the second embodiment. FIG. 12 is a cross-sectional view schematically showing the optical element 2 of the light source device 700 according to the second embodiment. Hereinafter, in the light source device according to the second embodiment, members having the same functions as those of the constituent members of the light source device 100 according to the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In the light source device 100 described above, as shown in FIG. 1 to FIG. 3, the bent portion 30 includes a window portion 32 and a prism 34, and the window portion 32 includes the semiconductor light emitting element 20 rather than the material of the prism 34. It was formed of a material having high light resistance to the wavelength of the emitted light L.

  On the other hand, in the light source device 700, as shown in FIGS. 10 to 12, the bent portion 30 has a prism 34, and the prism 34 emits the semiconductor light emitting element 20 rather than the material of the light collecting portion 40. It is made of a material having high light resistance to the wavelength of the light L. Specifically, the material exemplified for the material of the window portion 32 described above can be used as the material of the prism 34. In the light source device 700, the window portion 32 is not provided.

  The shape of the prism 34 is a triangular prism shape whose ZX cross-sectional shape is a triangular shape. Therefore, the prism 34 can be easily formed even if an inorganic material having high light resistance is used. An antireflection film (not shown) is formed on the light incident surface 33a of the prism 34, and a reflection film is formed on the reflection surface 33b. However, since the prism 34 has a simple triangular prism shape, It is easy to perform a mask process for preventing the film-forming substance from entering outside the target surface during film formation. Therefore, it is possible to reduce the deterioration of the characteristics of the optical film caused by the wraparound of the film forming material to other than the target surface. The prism 34 is joined to the surface of the optical substrate 50 where the light exit surface 33c faces the −Z-axis direction with an adhesive or the like. The optical element 2 includes a prism 34 and an optical substrate 50 (condenser 40).

  The light collecting unit 40 is provided on the optical substrate 50. In the light source device 700, the optical substrate 50 is provided with only the light collecting unit 40, and the light collecting unit 40 and the prism 34 are not integrally formed.

  In the light source device 700, as shown in FIG. 12, the light L traveling in the + X-axis direction emitted from the semiconductor light emitting element 20 mounted on the main surface 11a of the light source substrate 10 enters the light incident surface 33a of the prism 34. Then, it is reflected in the + Z-axis direction by the reflecting surface 33b. The reflected light L is condensed by the condensing unit 40 (lens surface 41) and becomes light (including substantially parallel light) having a desired divergence angle (emission angle) and emitted in the + Z-axis direction.

  In the light source device 700, since the bent portion 30 is formed of a material having higher light resistance to the wavelength of the light L emitted from the semiconductor light emitting element 20 than the material of the light collecting portion 40, similarly to the light source device 100 described above, The optical element 2 which can improve the light resistance with respect to incident light, and can raise the freedom degree of material selection of the condensing part 40 can be provided.

2.2. Next, a modification of the light source device according to the second embodiment will be described. Hereinafter, in the light source device according to each modification, members having the same functions as the constituent members of the light source devices 100 and 700 according to the first and second embodiments described above are denoted by the same reference numerals, and the description thereof is omitted. To do.

(1) First Modification First, a first modification will be described. FIG. 13 is a cross-sectional view schematically showing the optical element 2 of the light source device 800 according to the first modification. FIG. 13 corresponds to FIG.

  In the light source device 700 described above, the light incident surface 33a of the prism 34 is a plane orthogonal to the optical axis of the light L emitted from the semiconductor light emitting element 20, as shown in FIG.

  In contrast, in the light source device 800 according to the present modification, the light incident surface 33a of the prism 34 is provided with a lens surface (lens shape) 810 that condenses the light L emitted from the semiconductor light emitting element 20. Yes.

  When the lens surface 810 is formed on the prism 34, the material of the prism 34 is preferably low-melting glass. Thereby, a highly accurate lens shape can be easily produced.

  In the light source device 800, since the lens surface 810 is formed on the light incident surface 33a of the prism 34 to provide a light condensing function, divergent light (light L) is collected in the vicinity of the light emitting surface of the semiconductor light emitting element 20. The optical element 2 can be reduced in size and light utilization efficiency can be improved.

  Moreover, in the light source device 800, since it can condense in two places, the lens surface 810 provided in the light-incidence surface 33a of the prism 34, and the condensing part 40, compared with the case where it condenses, for example in one place, The radius of curvature of each lens surface can be increased, and the lens surface (lens shape) can be easily manufactured. When the light L emitted from the semiconductor light emitting element 20 is collected by the lens surface 810, the light having a desired divergence angle (emission angle) (including substantially parallel light) is obtained. It is not necessary to provide the (lens surface 41), and the optical element 2 can be downsized and the manufacturing cost can be reduced.

(2) Second Modification Next, a second modification will be described. FIG. 14 is a cross-sectional view schematically showing the optical element 2 of the light source device 900 according to the second modification. FIG. 14 corresponds to FIG.

  In the light source device 700 described above, the light incident surface 33a of the prism 34 is a plane orthogonal to the optical axis of the light L emitted from the semiconductor light emitting element 20, as shown in FIG.

  On the other hand, in the light source device 900 according to this modification, a diffractive optical element 910 that condenses the light L emitted from the semiconductor light emitting element 20 is formed on the light incident surface 33 a of the prism 34.

  In the light source device 900, since the diffractive optical element 910 is formed on the light incident surface 33a of the prism 34 to provide a condensing function, the pole of the light emission surface of the semiconductor light emitting device 20 is the same as the light source device 800 described above. The divergent light (light L) can be collected in the vicinity, and the optical element 2 can be downsized and the light utilization efficiency can be improved. Moreover, in the light source device 900, since it can condense in two places, the diffractive optical element 910 provided in the light-incidence surface 33a of the prism 34, and the condensing part 40, for example compared with the case where it condenses in one place. The radius of curvature of the lens surface constituting the light condensing unit 40 can be increased, and the lens surface (lens shape) can be easily manufactured. Note that when the light L emitted from the semiconductor light emitting element 20 is collected by the diffractive optical element 910, light having a desired divergence angle (emission angle) (including substantially parallel light) is obtained. 40 (lens surface 41) is not required, and the optical element 2 can be reduced in size and the manufacturing cost can be reduced.

(3) Third Modification Next, a third modification will be described. FIG. 15 is a cross-sectional view schematically showing the optical element 2 of the light source device 1000 according to the third modification. FIG. 15 corresponds to FIG.

In the light source device 700 described above, the reflecting surface 33b of the prism 34 is, as shown in FIG.
The plane was inclined at 45 degrees with respect to the optical axis of the light L.

  On the other hand, in the light source device 1000, the reflecting surface 33b of the prism 34 is a concave surface for light incident on the reflecting surface 33b. Thereby, the light L can be bent and condensed at the reflecting surface 33b. As for the outer shape of the prism 34, the reflective surface 33 b is a convex surface that protrudes outside the prism 34.

  In the light source device 1000, since the light can be condensed at two places, that is, the reflecting surface 33b of the prism 34 and the light collecting part 40, for example, a lens constituting the light collecting part 40 as compared with the case where light is condensed at one place. The radius of curvature of the surface can be increased, and the lens surface (lens shape) can be easily manufactured.

  Note that the reflecting surface 33b is a parabolic surface with the light emitting surface of the semiconductor light emitting element 20 as a focal point, so that the light L can be converted into parallel light (or substantially parallel light) by the reflecting surface 33b. Therefore, for example, the lens surface 41 formed on the optical substrate 50 can be omitted, and the optical element 2 can be downsized and the manufacturing cost can be reduced.

(4) Fourth Modification Next, a fourth modification will be described. FIG. 16 is a cross-sectional view schematically showing the optical element 2 of the light source device 1100 according to the fourth modification. FIG. 16 corresponds to FIG.

  In the light source device 700 described above, the condensing unit 40 is configured by a lens surface 41 (lens shape) provided on the optical substrate 50 as shown in FIG.

  On the other hand, in the light source device 1100, the condensing part 40 is comprised with the diffractive optical element 1110, as shown in FIG.

  The diffractive optical element 1110 is formed on the surface of the optical substrate 50 that faces the + Z-axis direction. The diffractive optical element 1110 can be formed by forming a structure such as minute irregularities on the surface of the optical substrate 50 facing the + Z-axis direction. For example, when the optical substrate 50 is manufactured, the diffractive optical element 1110 can be easily formed by transfer at the time of molding the optical substrate 50 by forming a minute uneven shape on a corresponding part of a mold used when molding the resin material. Can be produced. Therefore, for example, the optical element 2 can be downsized and the manufacturing cost can be reduced.

3. Third Embodiment 3.1. Light Source Device Next, a light source device according to a third embodiment will be described with reference to the drawings. FIG. 17 is a plan view schematically showing a light source device 1200 according to the third embodiment. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 17 schematically showing a light source device 1100 according to the third embodiment. Hereinafter, in the light source device according to the third embodiment, members having the same functions as those of the constituent members of the light source device 100 according to the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In the light source device 100 described above, as shown in FIGS. 1 and 2, the semiconductor light emitting element 20 is a semiconductor laser.

  On the other hand, in the light source device 1200, as shown in FIGS. 17 and 18, the semiconductor light emitting element 20 is a super luminescent diode (SLD). The SLD has a similar element structure to that of a semiconductor laser, but is a light emitting element in which laser oscillation is suppressed by not having a resonator structure.

  The semiconductor light emitting element 20 emits light L from both sides of the optical waveguide 22 when viewed from the Z-axis direction. In the illustrated example, the semiconductor light emitting element 20 emits light L in the + X axis direction and the −X axis direction, respectively. Since the SLD can emit light that is less likely to cause speckle noise than a semiconductor laser and can achieve higher output than an LED, for example, the light source device 100 is used as a light source such as a projector. It is suitable for the case.

  In the semiconductor light emitting device 20, in order to suppress laser oscillation, the optical waveguide 22 is provided to be inclined with respect to the normal of the light emitting surface when viewed from the Z-axis direction (stacking direction of the active layer 106 and the first cladding layer 104). It has been. For example, the optical waveguide 22 is provided to be inclined so as to form an angle of about 0.5 degrees to 10 degrees with respect to the normal of the light exit surface. For this reason, the light L emitted from the semiconductor light emitting element 20 is emitted in a direction inclined with respect to the normal of the emission end face.

  The bent portions 30 are provided on the + X axis direction side and the −X axis direction side of the semiconductor light emitting element 20 corresponding to the two light emission surfaces of the semiconductor light emitting element 20, respectively. Similarly, the light converging units 40 are provided on the + X axis direction side and the −X axis direction side of the semiconductor light emitting element 20, respectively, corresponding to the two light emission surfaces of the semiconductor light emitting element 20. Therefore, in the light source device 1200, each of the light L emitted from the two light emitting surfaces of the semiconductor light emitting element 20 and traveling in the in-plane direction of the main surface 11a of the light source substrate 10 is separated from the main surface 11a by the bent portion 30. The light L bent in the direction can be condensed by the condensing unit 40 and emitted.

  In the light source device 1200, since the semiconductor light emitting element 20 is an SLD, as described above, speckle noise can be reduced as compared with the semiconductor laser, and higher output can be achieved compared with the LED.

  In the light source device 1200, the semiconductor light emitting element 20 emits light L from both sides of the optical waveguide 22, and each of the emitted light L is bent in a direction away from the main surface 11 a of the light source substrate 10 by the bending portion 30. The emitted light per unit area in the light source device can be increased. Therefore, for example, when the light source device 1200 is used in an illumination device (for example, a light source of a projector), illumination light having a uniform intensity distribution can be obtained.

3.2. Next, a modification of the light source device according to the third embodiment will be described. FIG. 19 is a plan view schematically showing a part of a light source device 1300 according to a modification of the third embodiment. Hereinafter, in the light source device 1300 according to the present modification, members having the same functions as the constituent members of the light source device 1200 according to the third embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the light source device 1200 described above, the light incident surface 31a of the window portion 32 is a surface perpendicular to the optical axis of the light L as shown in FIG. That is, the perpendicular line of the light incident surface 31 a of the window portion 32 was parallel to the perpendicular line of the light emitting surface of the semiconductor light emitting element 20.

  On the other hand, in the light source device 1300, as shown in FIG. 19, the perpendicular P1 of the light incident surface 31a of the window 32 is from the perpendicular direction of the main surface 11a of the light source substrate 10 (Z-axis direction in the illustrated example). As seen, the semiconductor light emitting element 20 is inclined with respect to the normal P2 of the light emission surface. That is, the perpendicular line P1 of the light incident surface 31a of the window portion 32 is inclined with respect to the optical axis of the light L emitted from the semiconductor light emitting element 20 when viewed from the Z-axis direction. The inclination of the perpendicular line P2 with respect to the perpendicular line P1 is, for example, an angle such that the light L emitted from the semiconductor light emitting element 20 is refracted by the light incident surface 31a of the window portion 32 and travels along the perpendicular line P2.

Here, since the light emitted from the SLD is emitted in a direction inclined with respect to the normal of the light emission surface in plan view, for example, the light incident surface of the window portion is relative to the optical axis of the light emitted from the SLD. In the case of a vertical surface (see, for example, FIG. 17), the optical axis of the light that is reflected by the reflecting surface of the prism and travels toward the condensing unit is not parallel to the Z axis but tilted with respect to the Z axis (FIG. 17). In the example of FIG. Thereby, the parallelism of the light inject | emitted from a light source device falls, and the light utilization efficiency in an optical system of a back | latter stage falls.

  On the other hand, in the light source device 1300, the perpendicular P1 of the light incident surface 31a of the window 32 is relative to the perpendicular P2 of the light emitting surface of the semiconductor light emitting element 20 when viewed from the perpendicular direction of the main surface 11a of the light source substrate 10. Therefore, the light L emitted from the semiconductor light emitting element 20 can travel along the perpendicular line P2 on the light incident surface 31a of the window portion 32. Thereby, the optical axis of the light L reflected by the reflecting surface 33b of the prism 34 can be made parallel to the Z axis. Therefore, each of the light L emitted from the light source device is parallel (or substantially parallel), for example, as compared with the case where the light incident surface of the window 32 is parallel to the perpendicular of the light emitting surface of the semiconductor light emitting element 20. Thus, it is possible to improve the light use efficiency in the subsequent optical system. In addition, the lens surface 41 of the condensing part 40 is arrange | positioned so that the optical axis and the center of the light L may correspond.

  As shown in FIG. 20, in the light source device 1300, a lens surface 1310 (lens shape) may be formed on the light incident surface 31 a of the window portion 32. Also in such a form, the light utilization efficiency can be improved similarly.

4). Fourth Embodiment Next, a projector according to a fourth embodiment will be described with reference to the drawings. FIG. 21 is a diagram schematically showing a projector 1400 according to the fourth embodiment.

  As shown in FIG. 21, the projector 1400 includes a red light source 100R that emits red light, green light, and blue light, a green light source 100G, and a blue light source 100B. The red light source 100R, the green light source 100G, and the blue light source 100B are light source devices according to the present invention. Hereinafter, an example in which the light source device 100 is used as the light source device according to the present invention will be described. For the sake of convenience, in FIG. 21, the casing that configures the projector 1400 is omitted, and the light source device 100 is illustrated in a simplified manner.

  The projector 1400 further includes a uniformizing optical system 1402R, 1402G, 1402B, transmissive liquid crystal light valves (light modulation devices) 1404R, 1404G, 1404B, and a projection lens (projection device) 1408.

  Light emitted from the light sources 100R, 100G, and 100B enters the uniformizing optical systems 1402R, 1402G, and 1402B. The light emitted from the light sources 100R, 100G, and 100B becomes light whose light intensity distribution is made uniform by the uniformizing optical systems 1402R, 1402G, and 1402B. The uniformizing optical systems 1402R, 1402G, and 1402B include, for example, a lens array, a condenser lens, and a parallelizing lens. The lens array, the condensing lens, and the collimating lens constitute an integrator optical system that uniformizes the light emitted from the light sources 100R, 100G, and 100B.

  Light emitted from each of the uniformizing optical systems 1402R, 1402G, and 1402B is incident on the liquid crystal light valves 1404R, 1404G, and 1404B. Each of the liquid crystal light valves 1404R, 1404G, and 1404B modulates incident light according to image information.

  In addition, the projector 1400 can include a cross dichroic prism (color light combining unit) 1406 that combines light emitted from the liquid crystal light valves 1404R, 1404G, and 1404B and guides the light to the projection lens 1408.

  The three color lights modulated by the liquid crystal light valves 1404R, 1404G, and 1404B are incident on the cross dichroic prism 1406. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The combined light is projected onto the screen 1410 by the projection lens 1408 which is a projection optical system, and the images (images) formed by the liquid crystal light valves 1404R, 1404G and 1404B are enlarged and displayed.

  Since the projector 1400 includes the light source device 100 including an optical element that has high light resistance to incident light and can increase the degree of freedom of material selection, high light utilization efficiency can be realized.

  In the above example, a transmissive liquid crystal light valve is used as the light modulation device. However, a transmissive light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such a light valve include a reflection type liquid crystal light valve and a digital micromirror device (Digital Micromirror Device). Further, the configuration of the projection optical system is appropriately changed depending on the type of light valve used.

  Further, the light source device 100 can be applied to a light source of a scanning image display device (projector) that displays an image of a desired size on a screen by scanning light from the light source. .

  The light source device 100 can also be applied to a backlight of a liquid crystal display.

  The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 2 ... Optical element, 10 ... Light source board | substrate, 11a ... Main surface, 11b ... Main surface, 12 ... Heat sink, 20 ... Semiconductor light emitting element, 22 ... Optical waveguide, 30 ... Bending part, 31a ... Light incident surface, 31b ... Light Emission surface, 32 ... window portion, 33a ... light incident surface, 33b ... reflection surface, 34 ... prism, 40 ... condensing portion, 41 ... lens surface, 50 ... optical substrate, 52 ... concave portion, 54 ... support portion, 100 ... Light source device, 100B ... blue light source, 100G ... green light source, 100R ... red light source, 101 ... laminated body, 102 ... base layer, 104 ... first cladding layer, 106 ... active layer, 108 ... second cladding layer, 110 ... first DESCRIPTION OF SYMBOLS 1 electrode, 112 ... 2nd electrode, 200 ... Light source device, 210 ... Lens surface, 300 ... Light source device, 310 ... Diffractive optical element, 400 ... Light source device, 500 ... Light source device, 510 ... Diffractive optical element, 600 ... Light source device 61 ... lens surface, 700 ... light source device, 800 ... light source device, 810 ... lens surface, 900 ... light source device, 910 ... diffractive optical element, 1000 ... light source device, 1100 ... light source device, 1110 ... diffractive optical element, 1200 ... light source device DESCRIPTION OF SYMBOLS 1300 ... Light source device, 1310 ... Lens surface, 1400 ... Projector, 1402B ... Uniformation optical system, 1402G
... homogenizing optical system, 1402R ... homogenizing optical system, 1404B ... liquid crystal light valve, 1404G ... liquid crystal light valve, 1404R ... liquid crystal light valve, 1406 ... cross dichroic prism, 1408 ... projection lens, 1410 ... screen

Claims (19)

A substrate,
A semiconductor light emitting device mounted on the first surface of the substrate and emitting light in an in-plane direction of the first surface;
A window part into which light emitted from the semiconductor light emitting element is incident;
A prism that receives light transmitted through the window and bends the light transmitted through the window in a direction away from the first surface;
A light collecting unit for collecting the light bent by the prism;
Including
The light source device, wherein the window portion is formed of a material having higher light resistance to a wavelength of light emitted from the semiconductor light emitting element than a material of the prism.   The light source device according to claim 1, wherein a lens surface that collects light emitted from the semiconductor light emitting element is formed on a light incident surface of the window portion.   The light source device according to claim 1, wherein a diffractive optical element that condenses light emitted from the semiconductor light emitting element is formed on a light incident surface of the window portion.   The light source device according to claim 1, wherein the reflecting surface of the prism is a concave surface.   The light source device according to claim 1, wherein the light collecting unit is a diffractive optical element.   The light source device according to claim 1, wherein the prism and the light collecting unit are integrally formed.   7. The normal of the light incident surface of the window portion is inclined with respect to the normal of the light emitting surface of the semiconductor light emitting element when viewed from the normal direction of the first surface. The light source device according to any one of the above. The semiconductor light emitting element is
An active layer in which current is injected to generate light;
A first cladding layer and a second cladding layer sandwiching the active layer;
Have
The active layer constitutes an optical waveguide for guiding light,
The optical waveguide is provided to be inclined with respect to a normal to the light emission surface of the semiconductor light emitting device as seen from the stacking direction of the active layer and the first cladding layer,
The light emitted from the semiconductor light emitting device is refracted on a light incident surface of the window portion and travels along a perpendicular line of the light emitting surface of the semiconductor light emitting device. Light source device. The semiconductor light emitting element is
An active layer in which current is injected to generate light;
A first cladding layer and a second cladding layer sandwiching the active layer;
Have
The active layer constitutes an optical waveguide for guiding light,
The said optical waveguide is provided in parallel with the perpendicular of the light emission surface of the said semiconductor light-emitting device seeing from the lamination direction of the said active layer and the said 1st clad layer, The said light guide is characterized by the above-mentioned. Light source device.   The light source device according to claim 1, wherein a material of the window portion is an inorganic material.   The light source device according to claim 1, wherein a material of the prism is a resin material. A substrate,
A semiconductor light emitting device mounted on the first surface of the substrate and emitting light in an in-plane direction of the first surface;
A prism that bends light emitted from the semiconductor light emitting element in a direction away from the first surface;
A light collecting unit for collecting the light bent by the prism;
Including
The light source device, wherein the prism is formed of a material having higher light resistance to a wavelength of light emitted from the semiconductor light emitting element than a material of the light collecting unit.   The light source device according to claim 12, wherein the condensing unit is a diffractive optical element.   14. The light source device according to claim 12, wherein a lens surface for condensing light emitted from the semiconductor light emitting element is formed on a light incident surface of the prism.   The light source device according to claim 12, wherein a diffractive optical element that collects light emitted from the semiconductor light emitting element is formed on a light incident surface of the prism.   The light source device according to claim 12, wherein the reflecting surface of the prism is a concave surface.   The light source device according to claim 12, wherein a material of the prism is an inorganic material.   The light source device according to any one of claims 12 to 17, wherein a material of the light collecting unit is a resin material. A light source device according to any one of claims 1 to 18,
A light modulation device that modulates light emitted from the light source device according to image information;
A projection device for projecting an image formed by the light modulation device;
Including a projector.

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