Light-emitting device and display device

Abstract

This invention provides a technology for a light-emitting device equipped with a light source that emits laser light, which enables the output of laser light with an expanded beam diameter. [Solution] The light-emitting device comprises a light source that emits laser light, a lens that collimates the laser light, and a plurality of reflective surfaces arranged at intervals in the direction of propagation of the collimated light that has passed through the lens, which reflect the collimated light in a direction intersecting the direction of propagation, and in which the beam diameter of the reflected light reflected by the plurality of reflective surfaces is larger than the beam diameter of the collimated light.

Description

Technical Field

[0001] The present disclosure relates to a light-emitting device and a display device.

Background Art

[0002] A light-emitting device is used in a display device such as a projector. One with a laser light source is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003] [[ID=—]] [[ID=—]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=—]] When using a light-emitting device having a laser light source in a display device such as a projector, due to the low étendue peculiar to laser light, the incident angle of light from the optical member included in the display device to the image generation element tends to be small. Therefore, it is desirable to increase the incident angle of light from the optical member to the image generation element. [[ID=—]] [[ID=—]]

[0005] [[ID=—]] This disclosure aims to provide a technique capable of outputting laser light with an expanded beam diameter in a light-emitting device including a light source that emits laser light. [[ID=—]]

Means for Solving the Problems

[0006] [[ID=—]] A light-emitting device according to one aspect of the present disclosure includes: [[ID=—]] a light source that emits laser light; [[ID=—]] a lens that collimates the laser light; [[ID=—]] a light reflection unit that is arranged at an interval in the traveling direction of the collimated light transmitted through the lens and has a plurality of reflection surfaces that reflect the collimated light in a direction intersecting the traveling direction, and the beam diameter of the reflected light reflected by the plurality of reflection surfaces is larger than the beam diameter of the collimated light. It is equipped with.

[0007] Other embodiments of the light-emitting devices of this disclosure are: A light source that emits laser light, A lens for collimating the laser light, A light-reflecting portion having a plurality of reflective surfaces arranged at intervals in the direction of propagation of collimated light transmitted through the lens, which reflect the collimated light in a direction intersecting the direction of propagation, wherein the length of the illumination area of ​​the collimated light irradiated onto the plurality of reflective surfaces along the direction of propagation is longer than the length of the lens along the intersecting direction, It is equipped with. [Effects of the Invention]

[0008] According to this disclosure, a light-emitting device equipped with a light source that emits laser light can output laser light with an expanded beam diameter. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic plan view illustrating a light-emitting device and a display device according to the first embodiment. [Figure 2] Figure 2 is a schematic plan view illustrating the incident angle of laser light on the image generation element of the display device according to the first embodiment. [Figure 3] Figure 3 is a schematic cross-sectional view illustrating a light-emitting device according to the first embodiment. [Figure 4] Figure 4 is a schematic cross-sectional view illustrating a light-emitting device according to the first embodiment. [Figure 5] Figure 5 is a schematic perspective view illustrating the irradiation area of ​​collimated light irradiated onto the light-reflecting portion of the light-emitting device according to the first embodiment. [Figure 6] Figure 6 is a schematic plan view illustrating a light-emitting device and a display device according to the second embodiment. [Figure 7A] Figure 7A is a schematic cross-sectional view illustrating a light-emitting device according to the second embodiment. [Figure 7B]FIG. 7B is a schematic enlarged side view of the light reflecting portion in FIG. 7A. [Figure 8] FIG. 8 is a schematic cross-sectional view illustrating a light-emitting device according to the second embodiment. [Figure 9] FIG. 9 is a schematic plan view illustrating a light-emitting device and a display device according to the third embodiment. [Figure 10] FIG. 10 is a schematic plan view illustrating a light-emitting device according to the third embodiment. [Figure 11] FIG. 11 is a schematic cross-sectional view taken along the 11X-11X line in FIG. 10. [Figure 12] FIG. 12 is a schematic plan view illustrating a modified example of the light-emitting device according to the third embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view illustrating a light-emitting device according to other embodiments. [Figure 14] FIG. 14 is a schematic cross-sectional view illustrating a light-emitting device according to other embodiments. [Figure 15] FIG. 15 is a schematic cross-sectional view illustrating a light-emitting device according to other embodiments.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present disclosure will be described based on the drawings. Components denoted by the same reference numerals in the respective drawings mean the same or similar components. In the embodiments described below, redundant descriptions and reference numerals may be omitted. Further, the drawings used in the following description are all schematic, and the dimensional relationships between the respective elements shown in the drawings, the ratios of the respective elements, etc. do not necessarily match the actual ones. Also, the dimensional relationships between the respective elements, the ratios of the respective elements, etc. do not necessarily match even between the plurality of drawings.

[0011] [First Embodiment] The light-emitting device 30 and the display device 20 according to the first embodiment of the present disclosure will be described.

[0012] (Display Device 20) First, let me explain the display device 20. Figure 1 is a schematic plan view illustrating the light-emitting device 30 and display device 20 according to this embodiment. Figure 2 is a schematic plan view illustrating the incident angle θ of the laser beam to the image generation element 56 of the display device 20 according to this embodiment.

[0013] The display device 20 in this embodiment is a device that has the function of displaying an image on an object S. The display device 20 is, for example, a projector, a head-up display, a head-mounted display, or a glasses-type wearable device.

[0014] As shown in Figure 1, the display device 20 comprises a light-emitting device 30, an optical system 50, an image generation element 56, and an imaging optical member 58.

[0015] The light-emitting device 30 is a device that outputs laser light OL. The display device 20 of this embodiment is equipped with multiple light-emitting devices 30 that output laser light OL of different wavelengths. Specifically, the display device 20 is equipped with three light-emitting devices 30. The three light-emitting devices 30 are, for example, a light-emitting device 30R that outputs red laser light, a light-emitting device 30G that outputs green laser light, and a light-emitting device 30B that outputs blue laser light. The three light-emitting devices 30 have the same configuration except for the light source that emits the laser light. Therefore, when describing the three light-emitting devices 30 individually, each configuration will be described with R (red), G (green), and B (blue) to indicate the color of the laser light. When describing a configuration common to the three light-emitting devices 30, R, G, and B will not be used. Details of the light-emitting devices 30 will be described later.

[0016] The optical system 50 has the function of making the angular intensity distribution of the laser light OL output from the light-emitting device 30 as uniform as possible, and the function of focusing the laser light with a uniform angular intensity distribution toward the image generation element 56. The optical system 50 of this embodiment includes a fly-eye lens 52 and a focusing lens 54. In this embodiment, the laser light OL output from the light-emitting device 30 passes through the optical system 50 and is irradiated (incident) toward the image generation element 56. Specifically, the angular intensity distribution of the laser light OL is made as uniform as possible by the fly-eye lens 52, and then focused toward the image generation element 56 by the focusing lens 54. Hereinafter, the laser light that is focused by the focusing lens 54 and irradiated toward the image generation element 56 will be referred to as the irradiation light IL. As shown in Figure 2, the incident angle θ of the irradiation light IL toward the image generation element 56 is in the range of 10 to 30 degrees.

[0017] The optical system 50 of this embodiment includes a fly-eye lens 52 that has the function of making the angular intensity distribution of the laser beam OL closer to uniform. However, other optical components may be used instead of the fly-eye lens 52 as long as the angular intensity distribution of the laser beam OL can be made closer to uniform. Examples of other optical components include an integrating rod and a diffuser. Furthermore, the optical system 50 may be a combination of any two of the fly-eye lens 52, the integrating rod, and the diffuser, or all of them.

[0018] The image generation element 56 is an element into which laser light output from the light-emitting device 30 is incident. Specifically, the image generation element 56 is irradiated with irradiation light IL, which is laser light focused by the focusing lens 54. The image generation element 56 includes, for example, a plurality of optical switches. The image generation element 56 may also include, for example, an element based on MEMS (Micro Electro Mechanical Systems). When the irradiation light IL is irradiated onto the image generation element 56, light is obtained to generate the image to be displayed on the object S.

[0019] The imaging optical element 58 is a component that has the function of forming an image of the light emitted from the image generation element 56. The imaging optical element 58 includes, for example, a projection lens. The light emitted from the image generation element 56 is formed on the object S by the imaging optical element 58. As a result, an image is displayed on the object S. In Figure 1, the light projected from the imaging optical element 58 onto the object S (projected light) is indicated by the symbol PL.

[0020] (Light-emitting device 30) Next, the details of the light-emitting device 30 will be described. Figures 3 and 4 are schematic cross-sectional views illustrating the light-emitting device 30 according to this embodiment. The angular intensity distribution of the output laser light OL is shown at the top of Figure 4. Figure 5 is a schematic perspective view illustrating the irradiation area of ​​the collimated light L2 irradiated onto the light-reflecting section 38 of the light-emitting device 30 according to this embodiment.

[0021] As shown in Figures 3 and 4, the light-emitting device 30 of this embodiment comprises a light source 32, a first lens 34, and a light-reflecting section 38.

[0022] As shown in Figure 4, the light source 32 is a semiconductor laser that emits laser light L1. In this embodiment, as an example, an end-emitting semiconductor laser is used as the light source 32. Therefore, the laser light L1 has an elliptical far-field pattern (hereinafter referred to as "FFP (Far Field Pattern)"). That is, the laser light L1 is an elliptical beam, and the major axis of the ellipse is aligned with the vertical direction of the paper in Figure 4.

[0023] The light source 32R of the light-emitting device 30R emits red laser light L1 with a peak wavelength of 605 nm to 750 nm. The light source 32G of the light-emitting device 30G emits green laser light L1 with a peak wavelength of 495 nm to 570 nm. The light source 32B of the light-emitting device 30B emits blue laser light L1 with a peak wavelength of 420 nm to 494 nm.

[0024] As shown in Figure 4, the first lens 34 is a collimating lens that collimates the laser beam L1. Specifically, the first lens 34 collimates the elliptical laser beam L1 at least in the major axis direction. Note that "collimating the laser beam" here may include convergence and divergence of the laser beam within an error range. The collimated laser beam (collimated light) may, for example, converge and diverge within an error range of approximately ±3 degrees. Furthermore, the first lens 34 may collimate the elliptical laser beam L1 in both the major and minor axis directions. The cross-sectional shape of the collimated light L2 collimated by the first lens 34 is elliptical, similar to the laser beam L1. The first lens 34 may also include, for example, resin, glass, or quartz.

[0025] As shown in Figure 4, the light reflecting section 38 is a part of the light-emitting device 30 that has the function of making the beam diameter BW2 of the reflected light L3 larger than the beam diameter BW1 of the collimated light L2 by reflecting the collimated light L2 that has passed through the first lens 34. As shown in Figure 5, the beam diameter BW1 of the collimated light L2 is the length in the long axis direction, i.e., the major axis. Similarly, the beam diameter BW2 of the reflected light L3 is the length in the long axis direction, i.e., the major axis.

[0026] As shown in Figures 3 and 4, the light reflecting section 38 of this embodiment has a plurality of reflective surfaces 36. The plurality of reflective surfaces 36 are arranged at intervals in the direction of propagation of the collimated light L2. The direction of propagation of the collimated light L2 is indicated by the arrow AD in Figure 4.

[0027] The multiple reflective surfaces 36 reflect the collimated light L2 in a direction intersecting the direction of propagation AD. In this embodiment, the multiple reflective surfaces 36 reflect the collimated light L2 in a direction perpendicular to the direction of propagation AD. The direction of propagation of the reflected light L3 reflected by the multiple reflective surfaces 36 is indicated by the arrow RD in Figure 4. In this embodiment, the direction of propagation AD of the collimated light L2 and the direction of propagation RD of the reflected light L3 are perpendicular.

[0028] In this embodiment, the inclination angle α of the multiple reflective surfaces 36 with respect to the direction of travel AD is the same for each of them. Note that "same inclination angle" here includes an error of approximately ±3 degrees. Also, the inclination angle α is set to 45 degrees as an example. By setting the inclination angle α to 45 degrees, it becomes possible to reflect the collimated light L2 in a direction perpendicular to the direction of travel AD.

[0029] As shown in Figure 5, when the elliptical collimated light L2 is reflected by multiple reflective surfaces 36 arranged at intervals in the direction of propagation AD, its major axis becomes longer. As a result, the reflected light L3, which is the collimated light reflected by the multiple reflective surfaces 36, has a beam diameter BW2 that is larger than the beam diameter BW1 of the collimated light L2.

[0030] Furthermore, in this embodiment, as an example, as shown in Figure 4, the length D2 of the illumination area of ​​the collimating light L2 irradiated onto the multiple reflective surfaces 36 along the direction of travel AD is longer than the length D1 of the first lens 34 along the direction perpendicular to the direction of travel AD. Here, the length D2 of the illumination area of ​​the collimating light L2 is the length measured along the direction of travel AD from the point where the collimating light L2 was irradiated earliest to the point where it was irradiated latest, in the area irradiated by the collimating light L2, as shown in Figures 4 and 5. Also, the length D1 along the direction perpendicular to the direction of travel AD of the first lens 34 is the length along the direction of travel RD of the reflected light L3 from the first lens 34 in Figure 4. If the first lens 34 is a circular lens, the length D1 is the diameter of the first lens 34.

[0031] Furthermore, the light-reflecting portion 38 may be configured as a reflective member 40 having a plurality of reflective surfaces 36, as shown in Figures 3 and 4. The reflective member 40 includes a connecting surface 42 that extends in the direction of travel AD and connects adjacent reflective surfaces 36. Note that "extending in the direction of travel" here includes a direction inclined by approximately ±5 degrees with respect to the direction of travel AD. In addition, it is preferable that the inclination angle of the connecting surface 42 with respect to the direction of travel AD be an angle that does not reflect collimated light L2. An angle that does not reflect collimated light L2 means an angle that is 0 degrees (parallel) or negative with respect to the collimated light L2.

[0032] Furthermore, in this embodiment, the length of each connecting surface 42 along the direction of travel AD is the same. In other words, the multiple reflective surfaces 36 are arranged at equal intervals with respect to the direction of travel AD. However, this disclosure is not limited to the above configuration. For example, the lengths of adjacent connecting surfaces 42 along the direction of travel AD may be different.

[0033] In this embodiment, the reflective member 40, as an example, has four reflective surfaces 36 and three connecting surfaces 42.

[0034] The reflective member 40 may include, for example, resin, glass, or quartz. The reflective surface 36 may also include a highly reflective material such as metal.

[0035] As shown in Figures 3 and 4, the light-emitting device 30 further comprises a second lens 44 and a housing 46.

[0036] As shown in Figure 4, the second lens 44 is a lens that has the function of making the angular intensity distribution of reflected light L3 more uniform before outputting it. As a lens that has the function of making the angular intensity distribution of light more uniform before outputting it, for example, a lens with the structure disclosed in Japanese Patent Application Publication No. 2021-81701 may be used. The second lens 44 may also contain, for example, resin, glass, or quartz. The reflected light L3 incident on the second lens 44 is output with its angular intensity distribution made more uniform by the second lens 44. This output light from the second lens 44 becomes the laser light OL output from the light-emitting device 30.

[0037] As shown in Figure 3, the housing 46 houses the light source 32, the first lens 34, and the reflective member 40 inside. Specifically, the housing 46 comprises a box body 47 with one side open and a lid 48 that closes the open portion of the box body 47. The box body 47 includes a bottom portion 47A and a frame portion 47B. The box body 47 and the lid 48 are components of the housing 46. In this embodiment, as an example, the bottom portion 47A and the frame portion 47B are formed of different materials. The bottom portion 47A may be formed of a metallic material such as Cu or Al. The frame portion 47B may be formed of a ceramic material such as alumina (Al2O3) or AlN. In this embodiment, the lid 48 is formed of a transparent material. Examples of transparent materials include resin, glass, or quartz. In this embodiment, the lid 48 only needs to be translucent in a region that transmits the laser light OL, and a light-shielding film may be formed in the region that does not transmit the laser light. The light-shielding film reduces the possibility that stray light other than the laser light L generated inside the light-emitting device 30 will leak to the outside of the light-emitting device 30. The light-shielding film further reduces the possibility that the reflected light of the laser light OL emitted outside the light-emitting device 30 will reach the light source 32. If irradiation by reflected light can be reduced, damage to the light source 32 can be suppressed.

[0038] The light source 32, the first lens 34, and the reflector 40 are fixed to the bottom 47A of the box body 47. Specifically, the light source 32 is fixed to the bottom 47A of the box body 47 via a submount 33.

[0039] A second lens 44 is provided on the lid 48. Specifically, the second lens 44 is bonded to the lid 48. More specifically, the second lens 44 is bonded to the lid 48 via an adhesive layer 45 made of adhesive. The adhesive layer 45 is positioned to avoid the optical path of the reflected light L3. The lid 48 is assembled to the box body 47 so as to seal the inside of the box body 47. This disclosure is not limited to the above configuration, and the housing 46 may be composed of a plate-shaped base and a cover that covers this base. In this case, the light source 32, the first lens 34, and the reflective member 40 are fixed on the base, the second lens 44 is bonded to the cover, and the cover and base are assembled so as to seal the inside of the cover.

[0040] Furthermore, the light-emitting device 30 is mounted on the substrate 90. The light source 32 is electrically connected to an electrode layer (not shown) of the substrate 90. Power is supplied through the electrode layer of the substrate 90, causing the light source 32 to emit laser light L1. The light-emitting devices 30R, 30G, and 30B may be mounted on separate substrates 90, or on a single substrate 90. Note that the light-emitting device 30 may include the substrate 90.

[0041] Next, the effects and advantages of this embodiment will be described. As shown in Figure 4, in the light-emitting device 30 of this embodiment, the laser light L1 emitted from the light source 32 is collimated by the first lens 34. The collimated light L2 that has passed through the first lens 34 is reflected by a plurality of reflective surfaces 36 of the light-reflecting section 38. Here, in the light-emitting device 30, the beam diameter BW2 of the reflected light L3 reflected by the plurality of reflective surfaces 36 is larger than the beam diameter BW1 of the collimated light L2. Specifically, when the collimated light L2 is reflected by a plurality of reflective surfaces 36 arranged at intervals in the direction of travel AD, its major axis becomes longer. In other words, in the light-emitting device 30, by arranging the plurality of reflective surfaces 36 at intervals in the direction of travel AD, for example, the length D2 of the irradiation area of ​​the collimated light L2 becomes longer compared to a configuration in which there is one continuous reflective surface 36, and therefore the beam diameter BW2 of the reflected light L3 becomes larger. In this way, the light-emitting device 30 can output a laser light OL with an expanded beam diameter. In this embodiment, the display device 20 outputs a laser beam OL with an expanded beam diameter from the light-emitting device 30 without the need to include an expanding optical element such as an expander lens internally. Therefore, it is possible to suppress the cost increase due to the increase in the number of parts that would be incurred by providing an expanding optical element. Furthermore, the display device 20 can avoid becoming larger due to the inclusion of an expanding optical element. In other words, the display device 20 can be made smaller by not including an expanding optical element.

[0042] Furthermore, in the light-emitting device 30 of this embodiment, since one reflective member 40 has multiple reflective surfaces 36, the increase in the number of parts can be suppressed compared to the case where one reflective member having one reflective surface is arranged at intervals in the direction of travel A and D. Also, arranging one reflective member having one reflective surface at intervals in the direction of travel A and D with high precision requires high mounting precision. In contrast, in the light-emitting device 30 of this embodiment, since one reflective member 40 has multiple reflective surfaces 36, the relative position of each reflective surface 36 is determined, making it easy to arrange multiple reflective surfaces 36 at intervals in the direction of travel A and D with high precision.

[0043] Furthermore, in the light-emitting device 30 of this embodiment, the beam diameter BW2 of the reflected light L3 can be widened by increasing the length of the connecting surface 42 in the direction of travel AD, that is, by widening the distance between adjacent reflective surfaces 36. In this way, the light-emitting device 30 can change the size of the beam diameter BW2 of the reflected light L3 according to the length of the connecting surface 42 in the direction of travel AD, so that a desired beam diameter can be obtained with a simple structure.

[0044] Furthermore, in the light-emitting device 30 of this embodiment, the reflected light L3 reflected by the multiple reflective surfaces 36 is output after the angular intensity distribution is made more uniform by the second lens 44. In this way, the light-emitting device 30 outputs laser light OL with suppressed variations in angular intensity distribution as the reflected light L3 passes through the second lens 44. Therefore, the angular intensity distribution of the laser light OL can be made uniform. By making the angular intensity distribution of the laser light OL uniform, it is not necessary to place an optical element that uniformizes the laser light between the light-emitting device 30 and the optical system 50 in the display device 20, which contributes to miniaturization and cost reduction of the display device 20. Note that "uniformization" as used here is not limited to becoming completely uniform, but also includes changes that make the distribution closer to "uniform" compared to the original state.

[0045] Furthermore, in the light-emitting device 30 of this embodiment, the second lens 44 is joined to the lid 48 that constitutes the housing 46. Here, the lid 48 of this embodiment is made of a glass material that can ensure the airtightness of the housing 46. On the other hand, the second lens 44 is made of a glass material that performs its function as a lens. By joining the lid 48 and the second lens 44, which are made of such different glass materials, the light-emitting device 30 of this embodiment can achieve both the airtightness of the housing 46 and the effect of uniformizing the angular intensity distribution of the laser beam OL.

[0046] As shown in Figure 1, in the display device 20 of this embodiment, the beam diameter of the laser light OL output from the light-emitting device 30 is widened, which increases the incident angle θ of the light IL irradiating the image generation element 56. This increase in the incident angle θ suppresses the occurrence of speckle in the image displayed on the object S by the display device 20. By setting the incident angle θ for the image generation element 56 within the range of 10 to 30 degrees, the speckle generated in the image displayed on the object S can be effectively suppressed. If the incident angle θ is less than 10 degrees, the effect of suppressing speckle is insufficient. On the other hand, if the incident angle θ exceeds 30 degrees, it is necessary to reduce the F value of the imaging optical element 58, which raises concerns about increased costs. Therefore, it is preferable to set the incident angle θ within the range of 10 to 30 degrees.

[0047] [Second Embodiment] The light-emitting device 130 and display device 120 according to the second embodiment of this disclosure will now be described. Note that the same configuration as that of the light-emitting device 30 and display device 20 of the first embodiment will not be described.

[0048] (Display device 120) First, let me explain the display device 120. Figure 6 is a schematic plan view illustrating the light-emitting device 130 and display device 120 according to this embodiment.

[0049] The display device 120 of this embodiment comprises a light-emitting device 130, an optical system 50, an image generation element 56, and an imaging optical member 58. The display device 120 of this embodiment has the same configuration as the display device 20 of the first embodiment, except for the light-emitting device 130. The light-emitting device 130 comprises three light-emitting devices 130, similar to the light-emitting device 30 of the first embodiment. The three light-emitting devices 130 are, for example, a light-emitting device 130R that outputs red laser light, a light-emitting device 130G that outputs green laser light, and a light-emitting device 130B that outputs blue laser light. The three light-emitting devices 130 have the same configuration except for the light source that emits the laser light. Therefore, when describing the three light-emitting devices 130 individually, each configuration will be described with R (red), G (green), and B (blue) to indicate the color of the laser light. When describing a configuration common to the three light-emitting devices 130, R, G, and B will not be used.

[0050] (Light-emitting device 130) Next, we will describe the details of the light-emitting device 130. Figure 7A is a schematic cross-sectional view illustrating the light-emitting device 130 according to this embodiment. Figure 7B is a schematic enlarged side view of the light-reflecting portion in Figure 7A. Figure 8 is a schematic cross-sectional view illustrating the light-emitting device 130 according to this embodiment. The angular intensity distribution of the output laser light OL is shown at the top of the page in Figure 8.

[0051] As shown in Figures 7A and 8, the light-emitting device 130 of this embodiment comprises a light source 32, a first lens 34, and a light-reflecting section 138. The light-emitting device 130 further comprises a second lens 144 and a housing 146.

[0052] As shown in Figure 8, the light reflecting section 138 is a part of the light-emitting device 130 that has the function of making the beam diameter BW2 of the reflected light L3 larger than the beam diameter BW1 of the collimated light L2 by reflecting the collimated light L2 that has passed through the first lens 34.

[0053] As shown in Figure 7A, the light reflecting section 138 of this embodiment has a plurality of reflective surfaces 136. The plurality of reflective surfaces 136 are arranged at intervals in the direction AD of the propagation of the collimated light L2.

[0054] The multiple reflective surfaces 136 reflect the collimated light L2 in a direction intersecting the direction of propagation AD. In this embodiment, the multiple reflective surfaces 136 each reflect the collimated light L2 in a different direction. The direction of propagation of the reflected light L3 reflected by the multiple reflective surfaces 136 is indicated by the arrow RD in Figure 8. In this embodiment, the direction of propagation AD of the collimated light L2 and the direction of propagation RD of the reflected light L3 are perpendicular.

[0055] As shown in Figure 7B, in this embodiment, the inclination angles α of the multiple reflective surfaces 136 with respect to the direction of travel AD are all different angles. Note that "each inclination angle is different" includes differences exceeding the error range. A difference exceeding the error range means, for example, an angle difference of 3 degrees or more.

[0056] The inclination angles α of the multiple reflective surfaces 136 increase sequentially from the side closer to the first lens 34 along the direction of travel AD. In this embodiment, as an example, the light reflecting section 138 has five reflective surfaces 136. In Figure 7B, the five reflective surfaces 136 are indicated by the reference numerals 136A, 136B, 136C, 136D, and 136E in order from the side closest to the first lens 34. In this embodiment, when the inclination angle of reflective surface 136A is α1, the inclination angle of reflective surface 136B is α2, the inclination angle of reflective surface 136C is α3, the inclination angle of reflective surface 136D is α4, and the inclination angle of reflective surface 136E is α5, the relationship α1 < α2 < α3 < α4 < α5 holds.

[0057] As shown in Figure 8, when the elliptical collimated light L2 is reflected by multiple reflective surfaces 136 arranged at intervals in the direction of propagation AD, its major axis becomes longer. As a result, the reflected light L3, which is the collimated light reflected by the multiple reflective surfaces 136, has a beam diameter BW2 that is larger than the beam diameter BW1 of the collimated light L2.

[0058] Furthermore, in this embodiment, as an example, as shown in Figure 8, the length D2 of the irradiation area of ​​the collimated light L2 irradiated onto the multiple reflective surfaces 136 along the direction of propagation AD is longer than the length D1 along the direction perpendicular to the direction of propagation AD of the first lens 34.

[0059] The light-reflecting portion 138 may also be configured as a reflective member 140 having a plurality of reflective surfaces 136. The reflective member 140 includes connecting surfaces 142 that extend in the direction of travel AD and connect adjacent reflective surfaces 136.

[0060] Furthermore, in this embodiment, the lengths W of each connecting surface 142 along the direction of travel AD are different. In other words, the multiple reflective surfaces 136 are arranged at different intervals with respect to the direction of travel AD. Specifically, the length W of each connecting surface 142 increases in order from the side closer to the first lens 34 along the direction of travel AD. In this embodiment, as an example, the light reflecting section 138 has four connecting surfaces 142. The four connecting surfaces 142 are denoted by reference numerals 142A, 142B, 142C, and 142D in order from the side closest to the first lens 34. In this embodiment, when the length of connecting surface 142A is W1, the length of connecting surface 142B is W2, the length of connecting surface 142C is W3, and the length of connecting surface 142D is W4, the relationship W1>W2>W3>W4 holds.

[0061] The reflective member 140 may include, for example, resin, glass, or quartz. The reflective surface 136 may also include a highly reflective material such as metal.

[0062] The second lens 144 is a collimating lens that collimates the reflected light L3. The second lens 144 may contain, for example, resin, glass, or quartz. The reflected light L3 incident on the second lens 144 is collimated by the second lens 144 and output. This output light from the second lens 144 becomes the laser light OL output from the light-emitting device 130.

[0063] The housing 146 houses the light source 32, the first lens 34, and the reflective member 140. The housing 146 also comprises a box body 47 and a lid 48 that closes the open portion of the box body 47. A second lens 144 is provided on the lid 48. Specifically, the second lens 144 is bonded to the lid 48 via an adhesive layer 45 made of adhesive. The lid 48 is assembled to the box body 47 so as to seal the inside of the box body 47. This disclosure is not limited to the above configuration, and the housing 146 may be composed of a plate-shaped base and a cover that covers this base.

[0064] Furthermore, the light-emitting device 130 is mounted on the substrate 90. The light source 32 is electrically connected to an electrode layer (not shown) of the substrate 90. Power is supplied through the electrode layer of the substrate 90, causing the light source 32 to emit laser light L1. The light-emitting devices 130R, 130G, and 130B may be mounted on separate substrates 90, or on a single substrate 90. Note that the light-emitting device 30 may include the substrate 90.

[0065] Next, the effects and advantages of the light-emitting device 130 of this embodiment will be described. Note that the effects and advantages obtained by the same configuration as in the first embodiment will not be described.

[0066] In the light-emitting device 130 of this embodiment, the collimated light L2 is reflected in different directions by multiple reflective surfaces 136. Therefore, in the light-emitting device 130, the angular intensity distribution of the laser light OL, which is the reflected light L3 transmitted through the second lens 144, can be made more uniform compared to the case where the inclination angle α of the multiple reflective surfaces is the same, without the need to arrange a lens that makes the angular intensity distribution more uniform. As a result, as shown in the angular intensity distribution at the top of Figure 8, the difference in intensity between the center and the edges of the laser light OL is within 20%. Note that in the second lens 144, the range from 5% to 10% from the lens edge corresponds to the edge, and the range including the center, which is 80%, corresponds to the center. Since the light-emitting device 130 outputs laser light OL in which the difference in intensity between the edges and the center is within 20% in the angular intensity distribution, it is possible to effectively suppress speckle that occurs when displaying an image on the object S. Furthermore, because it is equipped with a light-emitting device 130, the display device 120 does not need to have an optical system that uniformizes the intensity distribution, such as a fly-eye lens, which makes it possible to reduce the number of parts and miniaturize the device.

[0067] [Third Embodiment] A light-emitting device 230 and a display device 220 according to the third embodiment of this disclosure will now be described. Note that the same configuration as that of the light-emitting device 30 and display device 20 of the first embodiment will not be described.

[0068] (Display device 220) First, let me explain the display device 220. Figure 9 is a schematic plan view illustrating the light-emitting device 230 and display device 220 according to this embodiment.

[0069] The display device 220 of this embodiment comprises a light-emitting device 230, an optical system 50, an image generation element 56, and an imaging optical member 58. The display device 220 of this embodiment has the same configuration as the display device 20 of the first embodiment, except for the light-emitting device 230.

[0070] (Light-emitting device 230) Next, we will describe the details of the light-emitting device 230. Figure 10 is a schematic plan view illustrating the light-emitting device 230 according to this embodiment. Note that the second lens 244 and the cover 48 of the light-emitting device 230 are omitted from the illustration in Figure 10. Figure 11 is a schematic cross-sectional view along the line 11X-11X in Figure 10. Note that the second lens 244 and the cover 48, etc., which were omitted from the illustration in Figure 10, are shown in Figure 11.

[0071] As shown in Figures 10 and 11, the light-emitting device 230 comprises a plurality of light sources 32, a plurality of first lenses 34, and a plurality of light reflecting parts 38. The light-emitting device 230 further comprises a plurality of second lenses 244 and a housing 246.

[0072] As shown in Figure 10, the housing 246 houses three light sources 32R, 32G, and 32B. The light sources 32R, 32G, and 32B are arranged within the housing 246 at intervals perpendicular to the direction of emission of the laser beam L1.

[0073] Furthermore, the housing 246 houses three first lenses 34R, 34G, and 34B. The first lenses 34R, 34G, and 34B are positioned to correspond to the light sources 32R, 32G, and 32B, respectively. That is, each first lens 34 is positioned to receive the laser light L1 emitted from each light source 32.

[0074] Furthermore, the housing 246 houses three light-reflecting sections 38R, 38G, and 38B. The light-reflecting sections 38R, 38G, and 38B are positioned to correspond to the first lenses 34R, 34G, and 34B, respectively. In other words, each light-reflecting section 38 is positioned to reflect the collimated light L2 collimated by each first lens 34.

[0075] The housing 246 comprises a box body 47 and a lid 48 that closes the open portion of the box body 47. The lid 48 is provided with three second lenses 244R, 244G, and 244B. In this embodiment, as an example, the three second lenses 244R, 244G, and 244B are integrally formed and bonded to the lid 48 via an adhesive layer 45 made of adhesive. The disclosure is not limited to this configuration, and each second lens 144 may be formed separately and bonded to the lid 48 via the adhesive layer 45. The lid 48 is assembled to the box body 47 to seal the inside of the box body 47. The disclosure is not limited to the above configuration, and the housing 246 may be composed of a plate-shaped base and a cover that covers this base.

[0076] Furthermore, the second lenses 244R, 244G, and 244B are positioned to correspond to the light-reflecting sections 38R, 38G, and 38B, respectively. In other words, each second lens 244 is positioned to receive the reflected light L3 reflected by each light-reflecting section 38.

[0077] The light-emitting device 230 is mounted on the substrate 90. The light sources 32R, 32G, and 32B are electrically connected to an electrode layer (not shown) of the substrate 90. Power is supplied through the electrode layer of the substrate 90, causing the light sources 32R, 32G, and 32B to emit laser light L1. The light-emitting device 230 may also include the substrate 90.

[0078] Next, the effects and advantages of this embodiment will be described. Note that the effects and advantages obtained by the same configuration as the first embodiment will not be described.

[0079] In the light-emitting device 230 of this embodiment, multiple light sources 32, multiple first lenses 34, and multiple light reflecting units 38 are housed in a single housing 246. Therefore, the light-emitting device 230 makes it possible to miniaturize the display device 220 compared to a configuration in which one light source is housed in a single housing. In the light-emitting device 230, multiple second lenses 244 are bonded to the lid 48 that constitutes the housing 246. Therefore, the light-emitting device 230 of this embodiment, like the light-emitting device 30 of the first embodiment, can achieve both the airtightness of the housing 246 and the effect of uniformizing the angular intensity distribution of the laser beam OL.

[0080] In the light-emitting device 230 of this embodiment, a single housing 246 houses a plurality of light sources 32, a plurality of first lenses 34, and a plurality of light-reflecting parts 38. This configuration may be applied to other embodiments and modifications of the present disclosure. For example, it may be applied to the light-emitting device 130 of the second embodiment. In this case, a single housing 246 houses a plurality of light sources 32, a plurality of first lenses 34, and a plurality of light-reflecting parts 138.

[0081] In the light-emitting device 230 of this embodiment, multiple light-reflecting sections 38 are provided corresponding to multiple light sources 32, but the disclosure is not limited to this configuration. For example, as shown in Figure 12, a single light-reflecting section 338 may be provided for multiple light sources 32. The light-reflecting section 338 is an extended version of the light-reflecting section 38 of the first embodiment, and the configuration of the reflective surface is the same as that of the reflective surface 36 of the light-reflecting section 38. Such a light-emitting device 330 can reduce the number of parts. The other configurations of the light-emitting device 330 are the same as those of the light-emitting device 230 of the third embodiment.

[0082] [Other embodiments] In the first embodiment of the light-emitting device 30, a second lens 44 is provided on the lid 48 of the housing 46, but this disclosure is not limited to this configuration. For example, the second lens 44 does not need to be provided on the lid 48, as in the light-emitting device 430 shown in Figure 13. Specifically, since the optical system 50 of the display device 20 has the function of making the angular intensity distribution of the laser light OL closer to uniform, the second lens 44 may be omitted, as in the light-emitting device 430, depending on the performance required of the display device 20. When the second lens 44 is omitted, the reflected light L3 that has passed through the lid 48 becomes the laser light OL as the output light. Note that in Figure 13, the light-emitting device 430R is equipped with a light source 32R, the light-emitting device 430G is equipped with a light source 32G, and the light-emitting device 430B is equipped with a light source 32B. The configuration of omitting the second lens 44 may be applied to the third embodiment and modifications of this disclosure. For example, when applied to the light-emitting device 230 of the third embodiment, the second lens 244 is omitted.

[0083] In the light-emitting devices 30, 130, 230, 330, and 430 of the embodiments described above, an end-face emitting semiconductor laser is used as the light source for emitting the laser light L1, but this disclosure is not limited to this configuration. For example, a surface emitting semiconductor laser may be used as the light source 532, as in the light-emitting device 530 shown in Figure 14. Figure 14 is a schematic cross-sectional view illustrating a light-emitting device 530 according to another embodiment. Even when a surface emitting semiconductor laser is used as the light source 532, as in the light-emitting device 530, a laser light OL with a widened beam diameter can be output, similar to the light-emitting device 30. Alternatively, the light source 532 may be a photonic crystal laser instead of a surface emitting semiconductor laser. When a surface emitting semiconductor laser or a photonic crystal laser is used as the light source 532, the light source 532 is fixed to the bottom of the housing 46 using a submount 533 having the shape shown in Figure 14. In Figure 14, the light-emitting device 530R is equipped with light source 532R, the light-emitting device 530G is equipped with light source 532G, and the light-emitting device 530B is equipped with light source 532B.

[0084] When an end-emitting semiconductor laser or a photonic crystal laser is used as the light source for emitting laser light L1, the beam divergence angle becomes smaller. Therefore, it is not necessary to provide a first lens 34 to collimate the laser light L1, as shown in the light-emitting device 630 in Figure 15. That is, when an end-emitting semiconductor laser or a photonic crystal laser is used as the light source 632 for emitting laser light L1, the first lens 34 may be omitted. When the first lens 34 is omitted, the laser light L1 is reflected by the light-reflecting section 38 and becomes reflected light L3. In this case, the beam diameter BW2 of the reflected light L3 becomes larger than the beam diameter BW1 of the laser light L1. Figure 15 is a schematic cross-sectional view illustrating a light-emitting device according to another embodiment. Also, in Figure 15, the light-emitting device 630R is equipped with a light source 632R, the light-emitting device 630G is equipped with a light source 632G, and the light-emitting device 630B is equipped with a light source 632B. The configuration in which the first lens 34 is omitted by using an end-emitting semiconductor laser or a photonic crystal laser as the light source may be applied to the second embodiment, third embodiment, other embodiments, and modifications of this disclosure.

[0085] In the first embodiment of the light-emitting device 30, the second lens 44 is bonded to the lid 48 via an adhesive layer 45. However, the present disclosure is not limited to this configuration, and the lid 48 and the second lens 44 may be integrally formed. That is, the lid 48 and the second lens 44 may be integrally molded products. In this case, the number of parts of the light-emitting device 30 can be reduced. The configuration in which the lid 48 and the second lens 44 are integrally formed may be applied to the second embodiment, third embodiment, other embodiments and modifications of the present disclosure. For example, when applied to the light-emitting device 130 of the second embodiment, the lid 48 and the second lens 144 are integrally formed.

[0086] The display device 20 of the first embodiment comprises a light-emitting device 30, an optical system 50, an image generation element 56, and an imaging optical member 58, but the disclosure is not limited to this configuration. For example, the light-emitting device 30 may have some or all of the functions of the optical system 50. Here, some of the functions of the optical system 50 is the function of the fly-eye lens 52, and all of the functions of the optical system 50 is the functions of both the fly-eye lens 52 and the condensing lens 54. The configuration in which the light-emitting device 30 has some or all of the functions of the optical system 50 in the display device 20 may be applied to the second embodiment, third embodiment, other embodiments and modifications of the disclosure.

[0087] In the first embodiment, the light-emitting device 30 is used in the display device 20, but the disclosure is not limited to this configuration. For example, the light-emitting device 30 may be used in vehicle headlights, lighting, display backlights, etc. Similarly, light-emitting devices in the second embodiment, third embodiment, other embodiments, and modifications of the disclosure may also be used in vehicle headlights, lighting, display backlights, etc.

[0088] Although embodiments of this disclosure have been described above with reference to examples, these embodiments are merely examples and can be modified in various ways without departing from the gist of the disclosure. Furthermore, it goes without saying that the scope of rights of this disclosure is not limited to these embodiments.

[0089] In addition to the embodiments described above, the following further notes are disclosed.

[0090] (Note 1) A light source that emits laser light, A lens for collimating the laser light, A light-reflecting section having a plurality of reflective surfaces arranged at intervals in the direction of propagation of the collimated light that has passed through the lens, and which reflect the collimated light in a direction intersecting the direction of propagation, wherein the beam diameter of the reflected light reflected by the plurality of reflective surfaces is larger than the beam diameter of the collimated light, A light-emitting device equipped with the following features.

[0091] (Note 2) A light source that emits laser light, A lens for collimating the laser light, A light-reflecting portion having a plurality of reflective surfaces arranged at intervals in the direction of propagation of collimated light transmitted through the lens, which reflect the collimated light in a direction intersecting the direction of propagation, wherein the length of the illumination area of ​​the collimated light irradiated onto the plurality of reflective surfaces along the direction of propagation is longer than the length of the lens along the intersecting direction, A light-emitting device equipped with the following features.

[0092] (Note 3) The light-emitting device according to Appendix 1 or Appendix 2, wherein the light-reflecting portion comprises a reflective member having the plurality of reflective surfaces.

[0093] (Note 4) The light-emitting device according to Appendix 3, wherein the reflective member further has connecting surfaces that extend in the direction of travel and connect adjacent reflective surfaces.

[0094] (Note 5) The plurality of reflective surfaces each have the same inclination angle with respect to the direction of travel. The first lens, as described above, A second lens that brings the angular intensity distribution of the reflected light closer to uniform and outputs it, A light-emitting device as described in any one of the appendices 1 to 4, having the following characteristics:

[0095] (Note 6) The light-emitting device according to any one of the appendices 1 to 4, wherein the plurality of reflective surfaces each have a different inclination angle with respect to the direction of travel.

[0096] (Note 7) The first lens, as described above, A second lens that collimates the reflected light, It has, The light-emitting device according to claim 7, wherein the difference in intensity between the central part and the edges of the angular intensity distribution of the output light transmitted through the second lens is within 20%.

[0097] (Note 8) The housing further comprises the light source, the first lens, and the light reflecting part, The second lens is joined to one of the multiple components that make up the housing. The light-emitting device described in Appendix 5 or Appendix 7.

[0098] (Note 9) The device further comprises a housing that houses a plurality of light sources that emit laser light of different wavelengths, a plurality of first lenses corresponding to each of the plurality of light sources, and a plurality of light reflecting parts corresponding to each of the plurality of first lenses, Each of the multiple second lenses, corresponding to each of the multiple light-reflecting portions, is joined to one of the multiple components that make up the housing. The light-emitting device described in Appendix 5 or Appendix 7.

[0099] (Note 10) A light-emitting device as described in any one of the appendices 1 to 9, An image generating element into which light emitted from the aforementioned light-emitting device is incident, An imaging optical member that forms an image of the light emitted from the image generation element, A display device equipped with the following features.

[0100] (Note 11) The display device according to Appendix 10, wherein the angle of incidence of the light emitted from the light-emitting device to the image generating element is within the range of 10 degrees to 30 degrees. [Explanation of Symbols]

[0101] 20 Display device 30 Light-emitting device 32 light source 33 Submount 34. First lens (an example of a first lens) 36 Reflective surface 38 Light reflecting part 40 Reflective material 42 Connection surface 44. Second lens (an example of a second lens) 45 Adhesive layer 46 cabinets 47 Box body 47A bottom 47B Frame 48 Lid 50 Optical system 52 Fly-eye lenses 54 Focusing lens 56 Image generation elements 58 Imaging optical components 90 circuit boards 120 Display device 130 Light-emitting device 136 Reflective surface 138 Light reflecting part 140 Reflective material 142 Connection surface 144 Second lens (an example of a second lens) 146 cabinets 220 Display device 230 Light-emitting devices 244 Second lens (an example of a second lens) 246 cabinets 330 Light-emitting device 338 Light reflection part 430 Light-emitting device 530 Light-emitting device 532 Light source 533 Submount 630 Light-emitting device 632 light source α Tilt angle θ angle of incidence AD direction of travel RD direction of travel BW1 Beam Diameter BW2 Beam Diameter L1 laser light L2 collimated light L3 reflected light OL laser light IL irradiation light PL projection light S Object

Claims

1. A light source that emits laser light, A lens for collimating the laser light, A light-reflecting section having a plurality of reflective surfaces arranged at intervals in the direction of propagation of the collimated light that has passed through the lens, and which reflect the collimated light in a direction intersecting the direction of propagation, wherein the beam diameter of the reflected light reflected by the plurality of reflective surfaces is larger than the beam diameter of the collimated light, A light-emitting device equipped with the following features.

2. A light source that emits laser light, A lens for collimating the laser light, A light-reflecting portion having a plurality of reflective surfaces arranged at intervals in the direction of propagation of collimated light transmitted through the lens, which reflect the collimated light in a direction intersecting the direction of propagation, wherein the length of the illumination area of ​​the collimated light irradiated onto the plurality of reflective surfaces along the direction of propagation is longer than the length of the lens along the intersecting direction, A light-emitting device equipped with the following features.

3. The light-emitting device according to claim 1, wherein the light-reflecting portion comprises a reflective member having the plurality of reflective surfaces.

4. The light-emitting device according to claim 3, wherein the reflective member further has connecting surfaces that extend in the direction of travel and connect adjacent reflective surfaces to each other.

5. The plurality of reflective surfaces each have the same inclination angle with respect to the direction of travel. The first lens, as described above, A second lens that brings the angular intensity distribution of the reflected light closer to uniform and outputs it, A light-emitting device according to claim 1, having the following features.

6. The light-emitting device according to claim 1, wherein the plurality of reflective surfaces each have a different inclination angle with respect to the direction of travel.

7. The first lens, as described above, A second lens that collimates the reflected light, It has, The light-emitting device according to claim 6, wherein the difference in intensity between the central part and the edges of the angular intensity distribution of the output light transmitted through the second lens is within 20%.

8. The housing further comprises the light source, the first lens, and the light reflecting part, The second lens is joined to one of the multiple components that make up the housing. The light-emitting device according to claim 5 or claim 7.

9. The device further comprises a housing that houses a plurality of light sources that emit laser light of different wavelengths, a plurality of first lenses corresponding to each of the plurality of light sources, and a plurality of light reflecting parts corresponding to each of the plurality of first lenses, Each of the multiple second lenses, corresponding to each of the multiple light-reflecting portions, is joined to one of the multiple components that make up the housing. The light-emitting device according to claim 5 or claim 7.

10. The light-emitting device according to claim 1, An image generation element into which light output from the aforementioned light-emitting device is incident, An imaging optical member that forms an image of the light emitted from the image generation element, A display device equipped with the following features.

11. The display device according to claim 10, wherein the angle of incidence of the light output from the light-emitting device to the image generating element is within the range of 10 degrees to 30 degrees.

Images