Light source device and projection-type video display device

Abstract

A light source device according to the present disclosure comprises: a first light source unit and a second light source unit that are disposed apart from each other in a first direction and each include a light source element row in which a plurality of laser light source elements are arrayed in the first direction; and a light guide optical system that is disposed facing the first light source element row and disposed so as to span across the first light source unit and the second light source unit. The second light source unit includes at least two light source element rows disposed apart from each other in a second direction orthogonal to the first direction. The light source element row of the first light source unit is disposed between the two light source element rows of the second light source unit adjacent to each other as viewed from the first direction. The light guide optical system guides light from the first light source unit and emits the light so as to overlap light of the second light source unit as viewed from the second direction.

Description

Light source device and projection-type image display device

[0001] The present disclosure relates to a light source device and a projection-type image display device, and more specifically to a light source device that collects and outputs light emitted from a plurality of laser light sources at a high density, and a projection-type image display device including such a light source device.

[0002] As the output of projection-type video display devices has become larger, there have been known illumination devices that emit high-brightness illumination light by densely concentrating light emitted from multiple light sources such as LEDs and laser elements. Examples of such illumination devices include those disclosed in Patent Documents 1 and 2.

[0003] International Publication WO2018 / 211886 JP 2022-53290

[0004] Patent Document 1 proposes a light source optical system that uses a composite mirror provided with multiple reflective regions and multiple transmissive regions to converge light emitted from multiple laser light sources composed of multiple laser elements. However, in the light source optical system of Patent Document 1, the composite mirror is positioned at an angle to the laser light source. Because ineffective regions created during coating exist near the peripheries of the multiple reflective regions and multiple transmissive regions formed on the composite mirror, the multiple laser elements that make up the laser light source are positioned at a certain distance from each other. This limits the convergence of light emitted from the laser light sources.

[0005] Patent Document 2 proposes an illumination device that uses a prism or a mirror to bring light emitted from a plurality of light source units, each of which is made up of laser light source elements arranged in an array, into close proximity and output the light. However, in the illumination device of Patent Document 2, the arrangement pitch of the laser light source elements remains in each light source unit, and therefore the light emitted from the laser light source elements does not become a high-density collection.

[0006] Therefore, there is still room for improvement in the configuration of the conventional light source device in terms of realizing high-intensity irradiation by concentrating the emitted light from a plurality of laser light sources at a high density.

[0007] Therefore, the present disclosure aims to provide a light source device that includes a plurality of light source units, each of which includes a light source element array in which a plurality of laser light source elements are arranged, and that concentrates the emitted light from each light source element array at a high density.

[0008] In order to achieve the above object, a light source device according to one aspect of the present disclosure includes: a first light source unit including a first light source element row formed by a plurality of light source elements arranged in a first direction and emitting a first laser beam; a second light source unit including a second light source element row formed by the plurality of light source elements arranged in the first direction and spaced apart in the first direction from the first light source unit and emitting a second laser beam; and a light guiding optical system arranged opposite the first light source element row and extending across the first light source unit and the second light source unit, wherein the second light source unit emits a second laser beam in a second direction perpendicular to the first direction. the first light source element row is arranged between two adjacent second light source element rows when viewed from the first direction, the first laser light and the second laser light are emitted in a third direction substantially perpendicular to the first direction and the second direction, and the light-guiding optical system includes a first reflecting surface that reflects the incident first laser light toward the second light source unit in the first direction, and a second reflecting surface that is parallel to the first reflecting surface and further reflects the first laser light reflected by the first reflecting surface and emits the first laser light so as to overlap with the second laser light when viewed from the second direction.

[0009] According to the present disclosure, a light source device can be provided that includes a plurality of light source units, each of which includes a light source element row in which a plurality of laser light source elements are arranged, and that concentrates the emitted light from each light source element row at a high density.

[0010] 1 is a schematic configuration diagram of a projection type image display device according to a first embodiment of the present disclosure; FIG. 2 is a schematic configuration diagram of an illumination device of the projection type image display device of FIG. 1; FIG. 3 is a perspective view of a light source device according to the first embodiment; FIG. 4 is a perspective view of the light source device of FIG. 3A, showing the configuration of the light source device excluding the prism element; FIG. 5 is a top view of the light source device of FIG. 3A; FIG. 6 is a perspective view of a light source unit of the light source device according to the first embodiment; 3 is a perspective view of a light source unit of the light source device; 4 is a plan view showing the configuration of the light source unit of the light source device of embodiment 2; 5 is a top view showing the arrangement of light source elements in the light source device of embodiment 2; 6 is a top view showing the arrangement of emitted light from the light source device of embodiment 2; 7 is a perspective view of the light source device of embodiment 3; 8 is a side view of the light source device of embodiment 3; 9 is another side view of the light source device of embodiment 3; 10 is a top view of the light source device of embodiment 3; 11 is a side view showing the optical path of emitted light from the light source device of embodiment 3; 12 is a top view showing the arrangement of emitted light from the light source device of embodiment 3;

[0011] According to a first aspect of the present disclosure, there is provided a first light source unit including a first light source element row formed by a plurality of light source elements arranged in a first direction and emitting a first laser beam, a second light source unit including a second light source element row formed by a plurality of light source elements arranged in the first direction and arranged spaced apart in the first direction from the first light source unit and emitting a second laser beam, and a light guiding optical system arranged opposite the first light source element row and disposed across the first light source unit and the second light source unit, wherein the second light source units are arranged spaced apart from each other in a second direction perpendicular to the first direction. the first light source element row is disposed between two adjacent second light source element rows when viewed from a first direction, the first laser light and the second laser light are emitted in a third direction substantially perpendicular to the first direction and the second direction, and the light-guiding optical system includes a first reflecting surface that reflects the incident first laser light toward the second light source unit in the first direction, and a second reflecting surface that is parallel to the first reflecting surface and further reflects the first laser light reflected by the first reflecting surface, and emits the first laser light so as to overlap with the second laser light when viewed from the second direction.

[0012] According to this aspect, it is possible to provide a light source device including a plurality of light source units each including an array of laser elements, in which light emitted from each of the laser element rows is concentrated at a high density.

[0013] According to a second aspect of the present disclosure, there is provided the light source device described in the first aspect, wherein the light-guiding optical system is composed of a prism element, and the prism element includes a first prism surface onto which the first laser light is incident, a second prism surface which is a first reflecting surface, and a third prism surface which is a second reflecting surface.

[0014] According to a third aspect of the present disclosure, there is provided a light source device as described in the second aspect, wherein the first light source unit includes at least two first light source element rows arranged at a distance from each other in the second direction, and at least two prism elements arranged opposite each of the first light source element rows and extending across the first light source unit and the second light source unit, the first light source element rows and the second light source element rows being arranged alternately when viewed from the first direction, each prism element having a surface parallel to the third direction and a pair of fourth prism surfaces extending along the first direction, and a second laser light is emitted between the opposing fourth prism surfaces of adjacent prism elements.

[0015] According to a fourth aspect of the present disclosure, there is provided a light source device as described in the third aspect, in which the width between a pair of fourth prism surfaces of the prism element is substantially equal to the spacing between adjacent side ends of two adjacent second light source element rows.

[0016] According to a fifth aspect of the present disclosure, there is provided a light source device as described in the third or fourth aspect, in which the light source elements constituting the first light source element row include semiconductor laser elements and collimating lenses provided for the semiconductor laser elements, and the collimating lens has a lens width in the second direction that is substantially equal to the width between a pair of fourth prism surfaces.

[0017] According to a sixth aspect of the present disclosure, there is provided the light source device according to the fifth aspect, wherein a distance between the first prism surface and the collimating lens is equal to or less than three times the lens width.

[0018] According to a seventh aspect of the present disclosure, there is provided a light source device as described in any one of the second to sixth aspects, further comprising a support member for supporting the prism element, the support member abutting the first prism surface between the first light source unit and the second light source unit.

[0019] According to an eighth aspect of the present disclosure, there is provided a light source device as set forth in any one of the first to seventh aspects, comprising: a first light source device that emits a first irradiation light and a second light source device that emits a second irradiation light, the first and second light source devices being arranged a first distance apart in a first direction, the first and second light source devices being arranged between the first and second light source devices, wherein the light guiding optical system includes a third reflecting surface that reflects the incident second irradiation light toward the first light source device in the first direction, and a fourth reflecting surface that is parallel to the third reflecting surface and further reflects the second irradiation light reflected by the third reflecting surface, and emits the second irradiation light along the optical axis in the first direction at a second distance from the first irradiation light that is smaller than the first distance.

[0020] According to a ninth aspect of the present disclosure, there is provided a light source device as described in the eighth aspect, in which the light-guiding optical system is composed of a prism, and the prism includes a fifth prism surface onto which the second irradiation light is incident, a sixth prism surface which is a third reflecting surface, and a seventh prism surface which is a fourth reflecting surface.

[0021] According to a tenth aspect of the present disclosure, there is provided a light source device as defined in any one of the first to seventh aspects, comprising: a first light source device that emits a first irradiation light; a third light source unit that includes a third light source element row formed by a plurality of light source elements arranged in a second direction and that emits a third laser light in the third direction; and a light guiding optical system that is arranged opposite the third light source element row and is arranged across the third light source unit and the first light source device, wherein the third light source element row does not intersect with the second light source element row when viewed from the second direction and is arranged apart from the second light source element row when viewed from the first direction, and the light guiding optical system includes: a fifth reflecting surface that reflects the incident third laser light toward the first light source device in the second direction; and a sixth reflecting surface that is parallel to the fifth reflecting surface and further reflects the third laser light reflected by the fifth reflecting surface and emits the third laser light so as to overlap with the first irradiation light when viewed from the first direction.

[0022] According to an eleventh aspect of the present disclosure, there is provided a light source device as described in the tenth aspect, wherein the light-guiding optical system is composed of a prism, and the prism includes an eighth prism surface onto which the third laser light is incident, a ninth prism surface which is a fifth reflecting surface, and a tenth prism surface which is a sixth reflecting surface.

[0023] According to a twelfth aspect of the present disclosure, there is provided an illumination device including at least one light source device according to any one of the first to eleventh aspects.

[0024] According to a thirteenth aspect of the present disclosure, there is provided a projection-type image display device comprising: the lighting device according to the twelfth aspect; an image display element that modulates the illumination light emitted from the lighting device and emits it as projection light; and a projection optical system that enlarges and projects the projection light to display an image.

[0025] Any of the above-described various embodiments may be combined appropriately to achieve the effects of each of them.

[0026] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0027] Hereinafter, a light source device according to an embodiment of the present disclosure, as well as an illumination device and a projection-type image display device including the same, will be described with reference to Figures 1 to 19. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. Also, in each figure, each element is shown exaggerated for ease of explanation.

[0028] First Embodiment <Projection-Type Image Display Device> FIG. 1 is a schematic diagram of a projection-type image display device 100 according to a first embodiment of the present disclosure.

[0029] As shown in FIG. 1, the projection-type image display device 100 according to the first embodiment is a so-called DLP-type projector, in which at least a portion of illumination light from an illumination device 200 is modulated by DMDs (Digital Micromirror Devices) 117R, 117G, and 117B as image display elements and emitted as projection light, and a projection optical system 118 enlarges and projects the emitted projection light to display an image.

[0030] The configuration of illumination device 200 will be described in detail later. Illumination light from illumination device 200 is condensed onto rod integrator 101, and the light emitted from rod integrator 101 passes through relay lenses 102 and 103, is reflected by folding mirror 104, passes through field lens 105, and enters total reflection prism unit 106.

[0031] Total reflection prism unit 106 is configured by fixing first prism 107 and second prism 108 with a small gap (air gap) maintained between them. Light incident on total reflection prism unit 106 is totally reflected by prism surface 109, then passes through prism surface 110 and enters color prism unit 111.

[0032] The color prism unit 111 includes a first prism 113, a second prism 115, and a third prism 116, with a gap (air gap) provided between the first prism 113 and the second prism 115, and the second prism 115 and the third prism 116 being adhesively fixed together.

[0033] Of the light incident on the first prism 113 from the total internal reflection prism unit 106, the red and green light is transmitted, and the blue light is reflected by the dichroic mirror surface 112, which has the property of reflecting blue light, changes its direction of travel, travels toward the total internal reflection prism unit 106, and re-enters the entrance surface of the first prism 113 at a large angle of incidence, where it is totally reflected and enters the DMD 117B for modulating blue light.

[0034] Subsequently, of the red and green light beams that pass through the air gap between first prism 113 and second prism 115, the red light beam is reflected by dichroic mirror surface 114, which has spectral characteristics that reflect red light beams and transmit green light beams, and changes its traveling direction toward first prism 113. The red light beam that has changed its traveling direction is totally reflected by the air gap between first prism 113 and second prism 115, and enters DMD 117R for modulating red light beams.

[0035] Of the red and green light that passes through the air gap between the first prism 113 and the second prism 115, the green light further passes through the dichroic mirror surface 114 and proceeds directly to the third prism 116. After passing through the third prism 116, the green light enters the DMD 117G for modulating the green light.

[0036] DMDs 117R, 117G, and 117B are devices including micromirrors arranged in a matrix, each with a tilt angle that can be selected from two options. The tilt angle of the micromirrors is controlled in two directions based on an external video signal. For example, the micromirrors are selectively tilted at a first tilt angle at which the reflected light from the micromirrors is incident on color prism unit 111 at an angle of zero degrees, and at a second tilt angle at which the reflected light is incident on color prism unit 111 at an angle greater than zero degrees. With this configuration, DMD 117R outputs at least partially modulated red light (red projection light), and DMDs 117G and 117B similarly output green and blue projection light.

[0037] The red projection light, green projection light, and blue projection light from DMDs 117R, 117G, and 117B are combined by color prism unit 111, and the combined projection light (color projection light) is emitted toward total reflection prism 46. The color image light passes through total reflection prism unit 116 and is enlarged and projected onto a projection target such as a screen via projection optical system 118, which includes a projection lens and the like.

[0038] <Illumination Device> Next, the configuration of an illumination device of a projection-type image display device and the configuration of a light source device according to embodiment 1 will be described with reference to FIGS. 2 to 3C. FIG. 2 is a schematic diagram of the illumination device 200 of the projection-type image display device 100 of FIG. 1. FIG. 3A is a perspective view of a light source device 210 according to embodiment 1. FIG. 3B is a perspective view of the light source device 210 of FIG. 3A with the prism element removed. FIG. 3C is a top view of the light source device 210 of FIG. 3A. Note that the X-Y-Z Cartesian coordinate system shown in the figures is intended to facilitate understanding of the present disclosure and does not limit the present disclosure. Furthermore, in this specification, the Z-axis direction indicates the irradiation direction of the light source device.

[0039] 2 includes light source device 210R that emits red light, light source device 210G that emits green light, and light source device 210B that emits blue light. The blue light emitted from light source device 210B that emits blue light is incident on dichroic mirror 205 that transmits blue light and reflects green light, and is transmitted through dichroic mirror 205. The green light emitted from light source device 210G that emits green light is incident on and reflected by dichroic mirror 205 that reflects green light, and is coaxially combined with the blue light that transmitted through dichroic mirror 205. The combined green light then enters dichroic mirror 206 that transmits blue and green light and reflects red light, and is transmitted through dichroic mirror 206. The red light emitted from light source device 210R that emits red light is incident on and reflected by dichroic mirror 206 that reflects red light, and is coaxially combined with the blue light and green light that have passed through dichroic mirror 206 to form illumination light. The illumination light combined from the red light, green light, and blue light passes through condenser lens 207, folding mirror 208, and condenser lens 209 in this order, and then exits illumination device 200 along the Z axis in the drawing and enters rod integrator 101 shown in FIG.

[0040] Taking into consideration differences in the light-emitting efficiency of light source elements depending on the wavelength range of the emitted light and the desired color balance of the projection-type video display device, the illumination device 200 of Figure 2 can be configured so that light source device 210R emitting red light includes two light source units, light source device 210G emitting green light includes two light source units, and light source device 210B emitting blue light includes one light source unit. The red light and green light emitted from the light source device are light obtained by combining the emitted light from the two light source units constituting light source devices 210R and 210G. The light source units included in each light source device can have substantially the same configuration.

[0041] 2 can be configured with substantially similar light source units, except that the wavelength ranges of the emitted light are different. Therefore, in the following, light source devices 210R, 210G, and 210B will be described as light source device 210.

[0042] 3A-3C includes two light source units 210a and 210b having substantially the same configuration, two prism elements 211a and 211b having substantially the same configuration, and a support member 311. Prism elements 211a and 211b collect light emitted from light source units 210a and 210b, and support member 311 supports prism elements 211a and 211b.

[0043] The light source units 210a and 210b are spaced apart from each other in the X direction. The light source unit 210a includes light source element rows 202a1 and 202a2 in which a plurality of light source elements that emit laser light toward the irradiation side in the Z direction are arranged in the X direction. Similarly, the light source unit 210b includes light source element rows 202b1 and 202b2 in which a plurality of light source elements that emit laser light toward the irradiation side in the Z direction are arranged in the X direction. The configurations of the light source units 210a and 210b will be described in more detail later.

[0044] Prism elements 211a and 211b are disposed on the irradiation side and extend parallel to each other in the X direction across light source unit 210a and light source unit 210b. As shown in Fig. 3C, prism elements 211a and 211b are disposed opposite light source element rows 202a1 and 202a2, respectively. Light source element rows 202a1 and 202a2 of light source unit 210a are disposed alternately with light source element rows 202b1 and 202b2 of light source unit 210b, respectively, when viewed from the X direction.

[0045] Support member 311 is used to support prism elements 211a and 211b, and in this embodiment, is disposed between prism elements 211a and 211b when viewed from the Z direction. As shown in FIG. 3B, support member 311 has surfaces 312 and 313 in the X-Z plane, surface 314 in the X-Y plane, and surface 315 in the Y-Z plane. These surfaces can abut against and fix prism surfaces of prism elements 211a and 211b, including prism surfaces 211a2 and 211b1 shown in FIG. 3C, to support the prism elements. Furthermore, recesses 316 are provided between surfaces 312 and 313 that abut against the prisms to allow adhesive used to fix the prism elements to escape.

[0046] In this embodiment, surfaces 312, 313, 314, and 315 of the support member 311 that contact the prisms are arranged in areas that do not allow light emitted from the light source elements of the light source units 210a and 210b to pass through. This allows the prism elements to be supported without affecting the output of the light source device. The optical path of light emitted from the light source elements will be described in detail later. Note that the configuration of the support member 311 shown in Figures 3A-3C is an example, and the present disclosure is not limited thereto. The prism elements can also be supported using support members with other configurations.

[0047] <Light Source Unit> The configuration of the light source unit that constitutes the light source device 210 according to embodiment 1 will be described with reference to Fig. 4 to Fig. 6. Fig. 4 is a perspective view of light source unit 210a of light source device 210 according to embodiment 1. Fig. 5 is a plan view showing the configuration of light source units 210a and 210b of light source device 210 according to embodiment 1. Fig. 6 is a top view showing the arrangement of light source elements in light source device 210 according to embodiment 1.

[0048] As shown in FIG. 4 , the light source unit 210a includes light source element arrays 202a1 and 202a2 arranged along the X direction, a substrate 203, and an electrode 204. Each of the light source element arrays 202a1 and 202a2 includes an array of multiple light source elements 202m that emit laser light along parallel optical axes. While not limited thereto, in this embodiment, for example, the light source element arrays 202a1 and 202a2 may each include the same number of similar light source elements 202m, which may be arranged in a matrix. In this embodiment, the light source unit 210a includes eight light source elements 202m arranged in a 2×4 matrix, but the present disclosure is not limited to this number of light source elements. The light source unit or light source element array may include any number of light source elements greater than or equal to two.

[0049] Each light source element 202m is configured, for example, with a semiconductor laser element and a collimating lens that converts the laser light from the semiconductor laser element into substantially parallel light, and is attached so as to emit laser light approximately parallel to each other. The light source element rows 202a1 and 202a2 are mounted on a substrate 203 with excellent thermal conductivity, and are supplied with power by electrodes 204 connected to a power source.

[0050] The light source unit 210b has substantially the same configuration as the light source unit 210a, and the light source units 210a and 210b are housed in a package with excellent thermal conductivity to form the light source device 210 shown in FIGS. 3A-3C.

[0051] 5A and 5B, the light source units 210a and 210b are arranged such that their substrates are substantially on the same plane and spaced apart from each other in the X direction. Furthermore, the light source element rows 202a1 and 202a2 of the light source unit 210a and the light source element rows 202b1 and 202b2 of the light source unit 210b are alternately arranged when viewed in the X direction. Therefore, as shown in the figure, the light source element rows 202a1 and 202a2 of the light source unit 210a and the light source element rows 202b1 and 202b2 of the light source unit 210b are at different positions in both the X and Y directions. Furthermore, the light source element rows 202a1 and 202a2 of the light source unit 210a are arranged at a pitch P1, and the light source element rows 202b1 and 202b2 of the light source unit 210b are arranged at a pitch P2. Here, the pitches P1 and P2 are the distance between the centers of the collimating lenses of the light source elements 202m that constitute adjacent light source element rows. In this embodiment, for example, the light source units 210a and 210b can be configured with substantially equal pitches P1 and P2.

[0052] On the irradiation side of the light source device 210, the prism elements 211a and 211b extending across the light source units 210a and 210b are arranged parallel to each other, facing the light source element rows 202a1 and 202a2, respectively. In this embodiment, the prism elements 211a and 211b are arranged in positions where they overlap each other when viewed from the Y direction.

[0053] In this specification, "overlap" means that at least a portion of the object has substantially the same coordinate position in a certain direction. It should be understood that in this specification, "overlap" includes not only a complete overlap, but also a partial overlap.

[0054] In this embodiment, prism elements 211a and 211b can be configured to have substantially the same shape and dimensions, and are rectangular in the X-Y plan view shown in Fig. 5(b) and are approximately parallelograms in the X-Z view shown in Fig. 5(c). Also, as shown in Fig. 5(c), prism elements 211a and 211b have prism surface 212 onto which light emitted from light source unit 210a is incident and light exit surface 213 which is the opposing surface. Prism surfaces 212 and 213 can be coated with an anti-reflection coating corresponding to the wavelength range of light emitted from light source unit 210a.

[0055] 5(c), in the prism elements 211a and 211b, the portion 212a of the prism surface 212 between the light source units 210a and 210b and the end portion 212b on the light source unit 210a side can abut against the surfaces 314 and 315 of the support member 311, respectively. Because the light emitted from the light source unit 210a does not pass through the portion 212a and the end portion 212b of the prism surface 212, the support member 311 can support the prism elements without affecting the output of the light source device.

[0056] 6, in this embodiment, prism element 211a and prism element 211b have prism surfaces 211a1 and 211a2 and prism surfaces 211b1 and 211b2, respectively, that extend parallel to the X direction. As shown in the figure, prism elements 211a and 211b, which are arranged opposite light source element arrays 202a1 and 202a2, are arranged alternately with light source element arrays 202b1 and 202b2 when viewed from the X direction. Desirably, width W between prism surfaces 211a1 and 211a2 and between prism surfaces 211b1 and 211b2 is configured to be as wide as possible without blocking the light emitted from light source element arrays 202b1 and 202b2.

[0057] The light source units 210a and 210b may have substantially the same dimensional configuration, or may have different dimensional configurations. In this embodiment, the light source element rows 202a1 and 202a2 of the light source unit 210a are arranged with a separation distance d between adjacent side edges, and the light source elements 202m1 constituting the light source element rows 202a1 and 202a2 have a uniform condenser lens width m in the Y direction. The light source unit 210b has substantially the same dimensional configuration as the light source unit 210a, i.e., the light source element rows 202b1 and 202b2 are arranged with a separation distance d, and the light source elements 202m2 have a uniform condenser lens width m in the Y direction.

[0058] Preferably, the width W of the prism elements 211a and 211b is substantially equal to the separation distance between the light source element arrays 202b1 and 202b2 (in this embodiment, the separation distance d between the light source element arrays of the light source units 210a and 210b). Also, the lens width m of the condenser lens of the light source element 202m1 (in this embodiment, the lens width m of the condenser lens of the light source elements 202m1 and 202m2) is substantially equal to the width W of the prism elements 211a and 211b. This minimizes the gap between the light emitted from the light source element arrays 202a1 and 202a2 and the light emitted from the light source element arrays 202b1 and 202b2, allowing the light emitted by the light source device 210 to be concentrated at a high density.

[0059] In this specification, "substantially equal" does not mean a completely identical value, but rather takes into consideration actual processing tolerances, and may include an error within a range of, for example, ±10%, and preferably, an error within a range of, for example, ±5%.

[0060] (Optical Path and Arrangement of Emitted Light of Light Source Device) In the present embodiment, prism elements 211a and 211b are used as a light-guiding optical system for the emitted light of light source unit 210a. The optical path and arrangement of the emitted light in the light source device of the present embodiment will be described with reference to FIGS. 7A to 8. FIG. 7A is a side view of the X-Z plane showing the optical path of the emitted light of light source device 210 of embodiment 1. FIG. 7B is a side view of the Y-Z plane showing the optical path of the emitted light of light source device 210 of embodiment 1. FIG. 8 is a top view showing the arrangement of the emitted light of light source device 210 of embodiment 1.

[0061] In the X-Z plane shown in FIG. 7A , light emitted from light source elements 202m1 of light source element rows 202a1 and 202a2 of light source unit 210a is incident along parallel optical axes (not shown) on prism surfaces 212 of prism elements 211a and 211b on the illumination side of the light source device, and the incident light travels within the prism elements and reaches prism surface 214. Because the optical glass constituting prism elements 211a and 211b has a high refractive index relative to external air, prism surface 214 can be configured to totally reflect the incident light. The totally reflected light is guided within prism elements 211a and 211b toward light source unit 210b and reaches prism surface 215 on the opposite side, which is parallel to prism surface 214. After further total reflection at prism surface 215, the light is emitted from prism surface 213 as output light Lm1 parallel to the optical axis Oa.

[0062] On the other hand, light emitted from light source elements 202m2 of light source element rows 202b1 and 202b2 of light source unit 210b is emitted along parallel optical axes (not shown), does not enter prism elements 211a and 211b, and is emitted from the light source device as emitted light Lm2. In light source device 210, light source units 210a and 210b are arranged as close as possible, but due to constraints such as their size and shape, the two light source units are arranged in parallel with a distance D between their adjacent side edges. As shown in the figure, at least some of the multiple light source elements 202m1 of light source unit 210a can emit light via prism elements 211a and 211b from coordinate positions within the range of coordinate positions in the X direction from which the multiple light source elements 202m2 of light source unit 210b emit light. In other words, the light beams Lm1 and Lm2 emitted from the light source units 210a and 210b are emitted from the light source device 210 so as to overlap when viewed from the Y direction. Note that in FIG. 7A , the light source element 202m1 is shown emitting light from substantially the same coordinate position in the X direction as the light source element 202m2, i.e., the emitted light beams Lm1 and Lm2 are shown almost completely overlapping when viewed from the Y direction, but the present disclosure is not limited to this. At least some of the multiple light source elements 202m1 may be configured to emit light from coordinate positions within the range of coordinate positions in the X direction from which the multiple light source elements 202m2 emit light, i.e., the emitted light beams Lm1 and Lm2 may be configured to partially overlap when viewed from the Y direction.

[0063] 7A shows prism surface 214 reflecting incident light in the X direction perpendicular to the incident direction (Z direction), the present disclosure is not limited to this configuration, and prism surface 214 can also be configured to reflect incident light in other directions.

[0064] 7B, prism elements 211a and 211b are preferably arranged such that prism surfaces 211a1 and 211a2 and prism surfaces 211b1 and 211b2 extend parallel to optical axes Oa1 and Oa2 and optical axes Ob2 and Ob1. At this time, emitted light beams Lm11 and Lm12 from light source element 202m1 are incident on prism surfaces 212 of prism elements 211a and 211b along parallel optical axes Oa1 and Oa2, propagate within the prism elements, and then are emitted. On the other hand, the light beams Lm22 and Lm21 emitted from the light source element 202m2 of the light source unit 210ba are emitted along parallel optical axes Ob2 and Ob1, and are emitted from the side of the prism surface 211b2 and between the opposing prism surfaces 211b1 and 211a2 without passing through the prism elements 211a and 211b.

[0065] Preferably, prism surface 212, through which the emitted light from light source element 202m1 enters prism elements 211a and 211b, is installed close to the condenser lens of light source element 202m1. In this embodiment, prism elements 211a and 211b are installed so that the distance h between prism surface 212 and the condenser lens of light source element 202m1 is three times or less the lens width m in the Y direction of the condenser lens. This allows the emitted light to be taken in by prism surface 212 even if there is misalignment or tilt due to installation errors of prism elements 211a and 211b, or if there is diffusion or misalignment of the emitted light rays due to configuration errors of the light source.

[0066] In this embodiment, the prism surfaces 211a1, 211a2 and prism surfaces 211b1, 211b2 of the prism elements 211a, 211b can be configured as surfaces parallel to the output optical axes of the light source elements 202m1, 202m2. Preferably, the prism surfaces 211a1, 211a2 and prism surfaces 211b1, 211b2 are configured as smooth surfaces parallel to the output optical axes of the light source elements 202m1, 202m2. In this specification, the term "smooth surface" refers to a smooth surface without any irregularities, but also includes a surface with some irregularities within the processing tolerance range. For example, the prism surfaces 211a1, 211a2 and prism surfaces 211b1, 211b2 may be configured to a general mirror finish level. A typical mirror surface is a smooth surface with little scattering due to unevenness, for example, a surface with surface roughness that substantially reflects incident light without substantially scattering it. More specifically, for example, the surface roughness of the mirror surface may be such that the arithmetic mean height Ra and / or the maximum height Rz and / or the ten-point mean height RzJIS, as defined in the JIS standard, are smaller than the wavelength of the incident light. By configuring the prism surfaces 211a1, 211a2 and the prism surfaces 211b1, 211b2 as smooth surfaces parallel to the output optical axes of the light source elements, for example, in the light emitted from the light source element 202m2, the light rays Li2a, Li2b, and Li2c that are incident on the prism surfaces 211a2, 211b1, and 211b2 at large angles of incidence can be prevented from being diffusely reflected by the prism surfaces 211a2, 211b1, and 211b2. This allows the light rays Lm2a, Lm2b, and Lm2c reflected at a reflection angle substantially equal to the angle of incidence to be emitted in the irradiation direction (Z direction) of the light source device, thereby reducing the loss of light emitted from the light source element 202m2.

[0067] 8, in the XY plane, light source element arrays 202a1 and 202a2 of light source unit 210a are arranged in area 216a, and light source element arrays 202b1 and 202b2 of light source unit 210b are arranged in area 216b. Prism elements 211a and 211b guide the light emitted from light source element arrays 202a1 and 202a2 from area 216a onto light source unit 210b, and the light is emitted from area 216a1, which overlaps with arrangement area 216b of light source element arrays 202b1 and 202b2 when viewed from the Y direction. This allows light source device 210 to emit irradiation light from light-emitting area 217 where the emitted light from light source units 210a and 210b is concentrated at a high density, and can output high-brightness irradiation light.

[0068] In addition, in this embodiment, the prism elements 211a and 211b as the light-guiding optical system totally reflect incident light on the prism surfaces 214 and 215 (FIG. 7A), thereby suppressing a decrease in brightness due to scattering and absorption during light reflection. Furthermore, the prism elements can achieve high-precision parallelism of the prism surfaces 214 and 215 during manufacturing, and do not require chamfering, thereby avoiding invalid areas that can occur when forming a reflective surface on a mirror. This allows prism elements to be inserted between the light source element arrays 210b of the light source unit, and the emitted light from the light source element arrays 202a1 and 202a2 and the light source element arrays 202b1 and 202b2 can be concentrated at a high density.

[0069] Furthermore, the present disclosure is not limited to light-guiding optical systems configured with prism elements. For example, the light-guiding optical system may be configured with mirrors. The light source device 210 of the present embodiment may include a light-guiding optical system including, for example, reflecting surfaces 214 and 215 configured with mirrors, instead of the prism elements 211a and 211b shown in FIG. 7A . In this case, the light emitted from the light source element 202m1 can be reflected in turn by the reflecting surfaces 214 and 215 and then emitted as emitted light Lm1.

[0070] According to the first embodiment as described above, in a light source device having a plurality of light source units each including a light source element row in which a plurality of laser light source elements are arranged, the light emitted from each light source element row can be concentrated at a high density to output high-brightness irradiation light.

[0071] (Embodiment 2) The configuration of a light source device according to Embodiment 2 will be described with reference to Figures 9 to 12. The light source device according to Embodiment 2 differs from the above-described Embodiment 1 in that a different light source unit is included. Therefore, Embodiment 2 will be described focusing on this difference. Note that components of Embodiment 2 that are substantially the same as those of Embodiment 1 above are assigned the same reference numerals.

[0072] Fig. 9 is a perspective view of light source unit 220a of the light source device according to embodiment 2. Fig. 10 is a plan view showing the configuration of light source units 220a and 220b of light source device 220 according to embodiment 2. Fig. 11 is a top view showing the arrangement of light source elements in light source device 220 according to embodiment 2. Fig. 12 is a top view showing the arrangement of emitted light from light source device 220 according to embodiment 2.

[0073] As shown in Fig. 10 , light source device 220 of embodiment 2 includes light source units 220a and 220b and a prism element 221 arranged across light source units 220a and 220b on the irradiation side. Although a support member for supporting prism element 221 is omitted in Fig. 10 , light source device 220 may include a support member similar to support member 311 of light source device 210 described above. Prism element 221 has a configuration similar to prism elements 211a and 211b described above, and light source unit 220b has a configuration similar to light source units 210a and 210b described above. Light source unit 220a differs from light source unit 210a shown in Fig. 4 in that it includes one light source element row 202, as shown in Fig. 9 .

[0074] The light source unit 220a includes a light source element array 202 arranged along the X direction, a substrate 203, and an electrode 204. The light source element array 202c is configured by arranging a plurality of light source elements 202m in an array, each of which emits laser light along optical axes parallel to one another. In the present embodiment, the light source unit 220a is configured by a light source element array 202c in which four light source elements 202m are arranged, but the present disclosure is not limited to this. The light source element array constituting the light source unit 220a may include any number of light source elements.

[0075] Each light source element 202m is configured, for example, with a semiconductor laser element and a collimating lens that converts the laser light from the semiconductor laser element into substantially parallel light, and is attached so as to emit laser light approximately parallel to each other. The light source element rows 202a1 and 202a2 are mounted on a substrate 203 with excellent thermal conductivity, and are supplied with power by electrodes 204 connected to a power source.

[0076] As shown in FIG. 10 , the light source units 220a and 220b are arranged such that their substrates are substantially flush with each other and spaced apart in the X direction. Furthermore, the light source element array 202c of the light source unit 220a is disposed between the light source element arrays 202d1 and 202d2 of the light source unit 220b when viewed in the X direction. Therefore, as shown in the figure, the light source element array 202c of the light source unit 220a and the light source element arrays 202d1 and 202d2 of the light source unit 220b are located at different positions in both the X and Y directions. The light source element arrays 202d1 and 202d2 of the light source unit 220b can be arranged at a pitch P2. Here, the pitch P2 is the center-to-center distance between the collimating lenses of the light source elements 202m constituting adjacent light source element arrays.

[0077] 11 , in this embodiment, prism element 221 has prism surfaces 221a and 221b extending parallel to each other along the X direction. As shown in the figure, prism element 221 arranged opposite light source element array 202c is located on the plane between light source element arrays 202d1 and 202d2. Desirably, width W between prism surfaces 221a and 221b is maximized without blocking the light emitted from light source element arrays 202d1 and 202d2.

[0078] In this embodiment, the light source element rows 202d1 and 202d2 of the light source unit 220b are arranged with a separation distance d between adjacent side ends, and the light source element 202m1 that constitutes the light source element row 202c and the light source element 202m2 that constitutes the light source element rows 202d1 and 202d2 have a uniform condenser lens width m in the Y direction.

[0079] Preferably, the width W of the prism element 221 is substantially equal to the separation distance d between the light source element arrays 202d1 and 202d2. Furthermore, the lens width m of the condenser lenses of the light source elements 202m1 and 202m2 is substantially equal to the width W of the prism element 221. This minimizes the gap between the light emitted from the light source element array 202c and the light emitted from the light source element arrays 202d1 and 202d2, allowing the light emitted by the light source device 220 to be concentrated at a high density.

[0080] A prism element 221 extending across light source units 220a and 220b on the irradiation side of light source device 220 is disposed opposite light source element row 202c of light source unit 220a and is used as a light-guiding optical system for light emitted from light source unit 220a. Light emitted from light source unit 220a enters prism element 221 and is guided within prism element 221 toward light source unit 220b before being emitted. On the other hand, light emitted from light source unit 220b can be emitted without passing through prism element 221. The optical paths of light emitted from light source units 220a and 220b are similar to the optical paths shown in Figures 7A and 7B, and therefore detailed description thereof will be omitted here.

[0081] As shown in FIG. 12 , in the XY plane, light source element array 202c of light source unit 220a is arranged in area 226a, and light source element arrays 202d1 and 202d2 of light source unit 220b are arranged in area 226b. Prism element 221 guides light emitted from light source element array 202c from area 226a to area 226b, and the light is emitted from area 226a1, which overlaps with area 226b where light source element arrays 202d1 and 202d2 are arranged, as viewed from the Y direction. At this time, at least some of the light source elements of light source unit 220a can emit light, via prism element 221, from coordinate positions within the range of coordinate positions in the X direction from which the light of the light source elements of light source unit 220b is emitted. In other words, the light emitted from light source units 220a and 220b is emitted from light source device 220 so as to overlap as viewed from the Y direction. Here, "emitted so as to overlap" may refer to emitted light that is almost completely overlapping or emitted light that is partially overlapping. This allows the light source device 220 to emit irradiation light from the light-emitting area 227 where the emitted light from the light source units 220a and 220b is concentrated at high density, thereby outputting high-brightness irradiation light. As described above, in this embodiment, the prism element 221 can be inserted between the rows of the light source element row 220b of the light source unit, and the emitted light from the light source element row 202c and the light source element rows 202d1 and 202d2 can be concentrated at high density.

[0082] The light source device 220 of this embodiment may include a light guide optical system including reflecting surfaces 224 and 225 made of mirrors, instead of the prism element 221 shown in FIG.

[0083] According to the second embodiment described above, in a light source device having a plurality of light source units each including a light source element row in which a plurality of laser light source elements are arranged, the light emitted from each light source element row can be concentrated at a high density to output high-brightness irradiation light.

[0084] 13 to 16, the configuration of a light source device according to the third embodiment will be described. The light source device according to the third embodiment includes a light source device unit configured with the light source device according to the first or second embodiment described above. Components that are substantially the same as those in the first or second embodiment described above are assigned the same reference numerals, and detailed description thereof will be omitted.

[0085] FIG. 13 is a perspective view of light source device 230 of embodiment 3. FIG. 14A is a side view of light source device 230 of embodiment 3, showing the configuration in the XZ plane. FIG. 14B is another side view of light source device 230 of embodiment 3, showing the configuration in the YZ plane. FIG. 14C is a top view of light source device 230 of embodiment 3. FIG. 15 is a side view showing the optical path of emitted light from light source device 230 of embodiment 3. FIG. 16 is a top view showing the arrangement of emitted light from light source device 230 of embodiment 3.

[0086] 13 , the light source device 230 of this embodiment includes light source device units 230A and 230B and a prism 232. The light source device unit 230A is configured with light source units 230a and 230b and prism elements 231a and 231b extending across the light source units 230a and 230b. The light source device unit 230B is configured with light source units 230c and 230d and prism elements 231c and 231d extending across the light source units 230c and 230d. The prism 232 is disposed on the irradiation side of the light source device 230 across the light source device units 230A and 230B.

[0087] The light source device units 230A and 230B may each have a configuration similar to that of the light source device 210 according to the above-described embodiment 1 or the light source device 220 according to the above-described embodiment 2. Note that although Figures 13 to 14C show the light source device units 230A and 230B as having a configuration similar to that of the light source device 210 according to embodiment 1, the present disclosure is not limited thereto. One or both of the light source device units 230A and 230B may be configured similarly to the light source device 220 according to embodiment 2.

[0088] As shown in Figures 14A to 14C, the light source device units 230A and 230B are positioned as close as possible, but due to constraints such as their size and shape, adjacent side edges are spaced apart by a distance D1. Although not limited to this, in this embodiment, each light source unit of the light source device units 230A and 230B can be configured with similar light source elements 202m. As shown, the rightmost light source element 202m of the light source unit 230b and the leftmost light source element 202m of the light source unit 230c are spaced apart by a distance D2. The prism 232 arranged on the irradiation side has a substantially parallelogram shape in the X-Z plane view, extends across the light source device units 230A and 230B in the X direction, and has a width in the Y direction sufficient to cover the light source unit 230c and the prism elements 231c and 231d.

[0089] 15, the light emitted from light source units 230a and 230b of light source device unit 230A is concentrated at high density by prism elements 231a and 231b and emitted as emitted light LmA without passing through prism 232. The light emitted from light source units 230c and 230d of light source device unit 230B is concentrated at high density by prism elements 231c and 231d and then enters prism surface 234 of prism 232 as emitted light LmB.

[0090] In this embodiment, the prism 232 is used as a light-guiding optical system for the light emitted from the light source device unit 230B. The light emitted from the light source device unit 230B enters the prism 232 via the prism surface 234 and travels within the prism 232 to reach the prism surface 235. Because the optical glass constituting the prism 232 has a high refractive index relative to the external air, the prism surface 235 can be configured to totally reflect the incident light. The totally reflected light is guided within the prism 232 toward the light source device unit 230A and reaches the prism surface 236 on the opposite side, parallel to the prism surface 235. After further total reflection by the prism surface 236, the light is emitted from the prism surface 237 as the emitted light LmC. The prism surfaces 234 and 237 can be coated with an anti-reflection coating corresponding to the wavelength range of the light emitted from the light source device unit 230B.

[0091] On the other hand, as shown in FIG. 15 , the light emitted from the light source device unit 230A can be emitted without passing through the prism 232. In this embodiment, in the light source units 230a, 230b, 230c, and 230d, the light source elements 202m can be arranged at pitches PC1, PC2, PC3, and PC4 in the X direction shown in the figure. Although not limited thereto, in this embodiment, PC1, PC2, PC3, and PC4 can be configured to have the same value PC. In this case, the luminous flux of the emitted light LmA from the light source device unit 230A can be emitted along optical axes parallel to each other at a pitch PC in the X direction.

[0092] The light beams of the emitted light LmB from the light source device unit 230B are incident on the prism 232 at a pitch PC in the X direction and are guided by the prism 232 toward and emitted from the light source device unit 230A. The light beams of the emitted light LmC are emitted along parallel optical axes at a pitch PC in the X direction. The leftmost light beam of the emitted light LmC can be emitted at a distance d1 from the rightmost light beam of the emitted light LmA. The distance d1 is smaller than the distance D1 between the light source device units 230A and 230B and can be, for example, but is not limited to, equal to the pitch PC. In this way, in the light source device 230 of this embodiment, the emitted lights LmA and LmC from the light source device units 230A and 230B can be emitted close to each other at a distance d1 that is smaller than the distance D1 between the light source device units 230A and 230B.

[0093] 16, in the XY plane, the light source element array of light source unit 230a is arranged in area 236a, and the light source element array of light source unit 230b is arranged in area 236b. Prism elements 231a and 231b allow light source device unit 230A to emit irradiation light from light-emitting area 237a where the emitted light from light source units 236a and 220b is concentrated. Light source element array of light source unit 230c is arranged in area 236c, and light source element array of light source unit 230d is arranged in area 236d. Prism elements 231c and 231c allow light source device unit 230B to emit irradiation light from light-emitting area 237b where the emitted light from light source units 236c and 220d is concentrated. Furthermore, the prism 232 guides the illumination light from the light source device unit 230B from the area 237b toward the light source unit 230A, so that the illumination light can be emitted from the light-emitting area 237b1 that is close to the light-emitting area 237a of the light source device unit 230A in the X direction. This allows the light source device 230 to emit illumination light from the light-emitting area 238 where the illumination light from the light source device units 230A and 230B is concentrated at a high density, and can output illumination light with high brightness.

[0094] The light source device 230 of this embodiment may include a light guide optical system including reflecting surfaces 235 and 236 made of mirrors, instead of the prism 232 shown in FIG.

[0095] According to the third embodiment as described above, in a light source device having a plurality of light source units each including a light source element row in which a plurality of laser light source elements are arranged, the light emitted from each light source element row can be concentrated at a high density to output high-brightness irradiation light.

[0096] (Fourth Embodiment) The configuration according to the present disclosure for collecting light emitted from a light source element array at a high density can be applied without being limited by the arrangement of the light source unit including the light source element array. In this regard, the configuration of a light source device according to the fourth embodiment will be described with reference to FIGS. 17 to 19 . The light source device according to the fourth embodiment includes the light source device according to the first or second embodiment described above, and further includes a light source unit having a light source element array with a different orientation. Components that are substantially the same as those in the first or second embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

[0097] Fig. 17 is a top view of light source device 240 according to embodiment 4. Fig. 18 is a top view showing the arrangement of light source elements in light source device 240 according to embodiment 4. Fig. 19 is a top view showing the arrangement of emitted light from light source device 240 according to embodiment 4.

[0098] 17 , the light source device 240 of this embodiment includes a light source device unit 240A, a light source unit 250, and a prism 242. The light source device unit 240A is configured with light source units 240a and 240b and prism elements 241a and 241b extending across the light source units 240a and 240b. The light source unit 250 includes a light source element row 202g arranged along the Y direction. The prism 242 is arranged on the irradiation side of the light source device 240, spanning the light source device unit 240A and the light source unit 250.

[0099] 17 to 19 , the light source device unit 240A is shown to have a configuration similar to that of the light source device 210 according to the first embodiment described above, but the present disclosure is not limited thereto. The light source device unit 240A may have a configuration similar to that of the light source device 210 according to the first embodiment or the light source device 220 according to the second embodiment. Furthermore, the light source unit 250 is shown to have a configuration similar to that of the light source unit 220a according to the second embodiment described above, but the present disclosure is not limited thereto. The light source unit 250 may have a configuration similar to that of the light source units 210a and 210b according to the first embodiment, for example, and may include multiple light source element rows.

[0100] As shown in FIG. 18 , the light source element array 202g of the light source unit 250 is positioned away from the light source element arrays 202f1 and 202f2 of the light source unit 240b when viewed in the X direction, and is positioned so as not to intersect with the light source element arrays 202f1 and 202f2 when viewed in the Y direction. In this embodiment, for example, as shown in the figure, the upper end 202G of the light source element array 202g and the lower end 202F of the light source element arrays 202f1 and 202f2 can be positioned close to each other and generally adjacent to each other when viewed in the Y direction. Furthermore, although not limited thereto, in this embodiment, the light source element array 202g can be configured with light source elements 202m3 similar to the light source elements 202m1 and 202m2 of the light source units 210a and 210b of the light source device unit 240A. The light source element 202m3 has an arrangement direction different from that of the light source elements 202m1 and 202m2 and can include a collimating lens having a lens width m in the X direction.

[0101] In this embodiment, the prism 242 is used as a light-guiding optical system for the light emitted from the light source unit 250. The prism 242 is disposed opposite the light source element array 202g of the light source unit 250. The width T of the prism 242 in the X direction may be the same as or different from the width W of the prism elements 241a and 241b of the light source device unit 240A in the Y direction. In this embodiment, the width T of the prism 242 is substantially equal to the lens width m of the collimating lens of the light source element 202m3. This minimizes the gap between the light emitted from the light source element array 202g and the light emitted from the light source element arrays 202f1 and 202f2, thereby enabling the light emitted from the light source device 240 to be concentrated at a high density. Note that when the light source unit 250 includes multiple light source element arrays, the prism 242 may be composed of multiple prisms facing each of the light source element arrays of the light source unit 250, or may be composed of a single prism having a width covering the multiple light source element arrays.

[0102] The prism 242 can be configured similarly to the prism elements 241a and 241b. The light emitted from the light source element array 202g of the light source unit 250 enters the prism 242 and is guided by the prism 242 toward the light source device unit 240A, and can be emitted from the light source device 240 so as to overlap with the irradiation light from the light source device unit 240A when viewed from the X direction. The light emitted from the light source device unit 240A is emitted without passing through the prism 242.

[0103] 19 , in the XY plane, the light source element arrays 202e1 and 202e2 of the light source unit 240a are arranged in an area 246a, and the light source element arrays 202f1 and 202f2 of the light source unit 240b are arranged in an area 246b. The prism elements 241a and 241b cause the light source device unit 240A to emit irradiation light from a collective light-emitting area 247. The light source element array 202g of the light source unit 250 is arranged in an area 246c. The prism 242 guides the emitted light from the light source element array 202g from the area 246c to the vicinity of the area 247, as shown, so that the light can be emitted from the light-emitting area 246c1 that overlaps with the light-emitting area 247 of the light source device unit 240A when viewed from the X direction. At this time, at least some of the light source elements of the light source unit 250 can emit light from coordinate positions within the range of coordinate positions in the X direction where the light from the light source elements of the light source device unit 240A is emitted via the prism 242. In other words, the light emitted from the light source unit 250 and the light source device unit 240A is emitted from the light source device 240 so as to overlap when viewed from the X direction. Note that "emitted so as to overlap" here may mean that the light emitted from the light source device unit 240A and the light source unit 250 is emitted in a substantially completely overlapping manner or in a partially overlapping manner. This allows the light source device 240 to emit irradiation light from a light-emitting area 248 where the light emitted from the light source device unit 240A and the light source unit 250 is densely concentrated, thereby outputting high-brightness irradiation light. Note that, because the light source elements constituting the light source units 240a and 240b are arranged in different directions from those of the light source unit 250, the irradiation light emitted from the light-emitting area 248 may include light with different polarization directions.

[0104] The light source device 240 of this embodiment may include, for example, a light guide optical system including a reflective surface formed of a mirror, instead of the prism 242. The light guide optical system reflects the light emitted from the light source element array 202g of the light source unit 250 at the reflective surface, thereby guiding the light toward the light source device unit 240A, and the light can be emitted from the light source device 240 so as to overlap with the irradiation light from the light source device unit 240A when viewed from the X direction.

[0105] According to the fourth embodiment as described above, in a light source device having a plurality of light source units each including a light source element row in which a plurality of laser light source elements are arranged, the light emitted from each light source element row can be concentrated at a high density to output high-brightness irradiation light.

[0106] Although the light source device 240 of the fourth embodiment has been described as being configured by the light source device unit 240A and the light source unit 250, the present disclosure is not limited to this. For example, the light source device 240 of the fourth embodiment may be configured by two light source device units having a configuration similar to that of the light source device unit 240A but with light source elements arranged in different directions, instead of the light source unit 250. In this case, a prism having a configuration similar to the above-described prism 232 may be arranged as a light-guiding optical system across the two light source device units, or a light-guiding optical system including a reflective surface formed by a mirror may be arranged.

[0107] In the above-described embodiment, the light source unit has been described as including one or two light source element rows, but the present disclosure is not limited to this. The light source unit may include, for example, three or more light source element rows, and the light source device may include a light-guiding optical system corresponding to each of the light source element rows.

[0108] Furthermore, in the above-mentioned projection type image display device, the light source device emitting red light and the light source device emitting green light are described as including two light source units, but when it is required to output illumination light for the entire device, the light source device emitting blue light can also be configured to include multiple light source units, each including a light source element row in which multiple light source elements are arranged.

[0109] As described above, the above-described embodiments have been described as examples of the technology of the present disclosure. For this purpose, drawings and detailed descriptions are provided. Therefore, the components described in the drawings and detailed descriptions may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the above-described technology. Therefore, the fact that these non-essential components are described in the drawings or detailed descriptions should not be interpreted as immediately indicating that these non-essential components are essential.

[0110] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0111] The present disclosure is applicable to lighting devices used in projection-type image display devices.

[0112] REFERENCE SIGNS LIST 101 Rod integrator 102, 103 Relay lens 104, 208 Bending mirror 105 Field lens 106 Total reflection prism unit 107, 108 Prism 111 Color prism unit 113, 115, 116 Prism 117R, 117G, 117B Image display element, DMD 118 Projection optical system 200 Illumination device 202m, 202m1, 202m2, 202m3 Light source element 203 Substrate 204 Electrode 205, 206 Dichroic mirror 207, 209 Condenser lens 210R, 210G, 210B Light source device 210, 220, 230, 240 Light source device 210a, 210b, 220a, 220b Light source unit 230a, 230b, 230c, 230d Light source units 240a, 240b, 250 Light source units 230A, 230B, 240A Light source device, light source device unit 202a1, 202a2, 202b1, 202b2 Light source element array 211a, 211b, 221 Prism element 232, 242 Prism 212, 213, 214, 215 Prism surface 311 Support member W, T Prism width m Lens width

Claims

1. A light source device comprising: a first light source unit including a first light source element row formed by a plurality of light source elements arranged in a first direction and emitting a first laser beam; a second light source unit including a second light source element row formed by a plurality of light source elements arranged in the first direction, spaced apart from the first light source unit in the first direction, and emitting a second laser beam; and a light guiding optical system disposed opposite to the first light source element row and extending between the first light source unit and the second light source unit. The second light source unit includes at least two of the second light source element rows spaced apart from each other in a second direction orthogonal to the first direction. The first light source element row is disposed between two adjacent second light source element rows as viewed from the first direction. The first laser beam and the second laser beam are emitted in a third direction substantially orthogonal to the first direction and the second direction. The light guiding optical system includes: a first reflecting surface that reflects the incident first laser beam toward the second light source unit in the first direction; and a second reflecting surface that is parallel to the first reflecting surface, further reflects the first laser beam reflected by the first reflecting surface, and emits the reflected beam so as to overlap the second laser beam as viewed from the second direction.

2. The light source device according to claim 1, wherein the light guiding optical system is constituted by a prism element, and the prism element includes: a first prism surface on which the first laser beam is incident; a second prism surface that is the first reflecting surface; and a third prism surface that is the second reflecting surface.

3. The light source device according to claim 2, wherein the first light source unit includes: at least two of the first light source element rows spaced apart from each other in the second direction; and at least two of the prism elements disposed opposite to respective ones of the first light source element rows and extending between the first light source unit and the second light source unit. The first light source element row and the second light source element row are alternately arranged as viewed from the first direction. Each of the prism elements has a pair of fourth prism surfaces that are parallel to the third direction and extend along the first direction, and the second laser beam is emitted between the opposing fourth prism surfaces of adjacent prism elements.

4. The light source device according to claim 3, wherein the width between the pair of the fourth prism surfaces of the prism element is substantially equal to the distance between the adjacent side ends of two adjacent second light source element arrays.

5. The light source device according to claim 3 or 4, wherein the light source elements constituting the first light source element array include a semiconductor laser element and a collimating lens provided for the semiconductor laser element, and the collimating lens has a lens width that is substantially equal to the width between the pair of the fourth prism surfaces in the second direction.

6. The light source device according to claim 5, wherein the distance between the first prism surface and the collimating lens is not more than three times the lens width.

7. The light source device according to claim 2 or 3, further comprising a support member that supports the prism element, and the support member abuts against the first prism surface between the first light source unit and the second light source unit.

8. The light source device according to claim 1 or 2, comprising a first light source device that emits first irradiation light and is arranged at a first distance from each other in the first direction, a second light source device that emits second irradiation light, and a light guiding optical system arranged between the first light source device and the second light source device, wherein the light guiding optical system includes a third reflecting surface that reflects the incident second irradiation light toward the first light source device in the first direction, and a fourth reflecting surface that is parallel to the third reflecting surface, further reflects the second irradiation light reflected by the third reflecting surface, and emits the second irradiation light at a second distance smaller than the first distance from the first irradiation light in the first direction.

9. The light source device according to claim 8, wherein the light guiding optical system is constituted by a prism, and the prism includes a fifth prism surface on which the second irradiation light is incident, a sixth prism surface that is the third reflecting surface, and a seventh prism surface that is the fourth reflecting surface.

10. The light source device according to claim 1 or 2, comprising: a first light source device that emits first irradiation light; a third light source unit including a third light source element row formed by a plurality of light source elements arranged in the second direction, the third light source unit emitting third laser light in the third direction; and a light guide optical system disposed opposite to the third light source element row and extending between the third light source unit and the first light source device. The third light source element row is arranged away from the second light source element row when viewed in the first direction and does not intersect the second light source element row when viewed in the second direction. The light guide optical system includes: a fifth reflection surface that reflects the incident third laser light toward the first light source device in the second direction; and a sixth reflection surface that is parallel to the fifth reflection surface, further reflects the third laser light reflected by the fifth reflection surface, and emits the reflected light so as to overlap the first irradiation light when viewed in the first direction.

11. The light source device according to claim 10, wherein the light guide optical system is constituted by a prism, and the prism includes: an eighth prism surface on which the third laser light is incident; a ninth prism surface that is the fifth reflection surface; and a tenth prism surface that is the sixth reflection surface.

12. An illumination device including the light source device according to at least one of claims 1 or 2.

13. A projection type video display device, comprising: the illumination device according to claim 12; an image display element that modulates illumination light emitted from the illumination device and emits the modulated light as projection light; and a projection optical system that magnifies and projects the projection light to display an image.

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