Light-emitting device and display device

Abstract

The light-emitting device includes: a light source that emits laser light; a lens that collimates the laser light; and a light-reflecting part that is spaced apart in the direction of travel of the collimated light transmitted through the lens, having a plurality of reflecting surfaces that reflect the collimated light in a direction intersecting the direction of travel, wherein the beam diameter of the reflected light reflected by the plurality of reflecting surfaces is larger than the beam diameter of the collimated light.

Description

Technical Field

[0001] This disclosure relates to light-emitting devices and display devices. Background Technology

[0002] Light-emitting devices are used in display devices such as projectors. As light-emitting devices, there are known light-emitting devices equipped with laser light sources (for example, see Japanese Patent Application Publication No. 2019-36638). Summary of the Invention

[0003] The technical problem that the invention aims to solve

[0004] When a light-emitting device with a laser light source is used in a display device such as a projector, the low optical spread (low étendue) of lasers tends to decrease the angle of incidence of light from the optical components of the display device to the image generating element. Therefore, it is desirable to increase the angle of incidence of light from the optical components to the image generating element.

[0005] The subject of this disclosure is to provide a technique for outputting a laser beam with an expanded diameter in a light-emitting device having a light source that emits laser light.

[0006] Technical solutions for solving technical problems

[0007] A light-emitting device according to one aspect of this disclosure includes: a light source that emits laser light; a lens that collimates the laser light; and a light-reflecting part having a plurality of reflective surfaces, the plurality of reflective surfaces being spaced apart in the direction of travel of the collimated light transmitted through the lens, and reflecting the collimated light in a direction intersecting the direction of travel; the beam diameter of the reflected light after being reflected by the plurality of reflective surfaces is larger than the beam diameter of the collimated light.

[0008] Another aspect of the light-emitting device disclosed herein includes: a light source that emits laser light; a lens that collimates the laser light; and a light-reflecting part having a plurality of reflective surfaces, the plurality of reflective surfaces being arranged at intervals in the direction of travel of the collimated light transmitted through the lens, and reflecting the collimated light in a direction intersecting the direction of travel.

[0009] The length of the irradiation area of ​​the collimated light illuminating the plurality of reflective surfaces along the travel direction is longer than the length of the lens along the intersecting direction.

[0010] Invention Effects

[0011] According to this disclosure, in a light-emitting device equipped with a light source that emits laser light, it is possible to output laser light with an expanded beam diameter. Attached Figure Description

[0012] Figure 1This is a schematic top view of the light-emitting device and display device according to the first embodiment of the example.

[0013] Figure 2 This is a schematic top view of the incident angle of the example laser relative to the image generating element of the display device of the first embodiment.

[0014] Figure 3 This is a schematic cross-sectional view of the light-emitting device according to the example of the first embodiment.

[0015] Figure 4 This is a schematic cross-sectional view of the light-emitting device according to the example of the first embodiment.

[0016] Figure 5 This is a schematic perspective view of the illumination area of ​​collimated light illuminating the light reflecting section of the light-emitting device of the first embodiment.

[0017] Figure 6 This is a schematic top view of the light-emitting device and display device according to the second embodiment of the example.

[0018] Figure 7A This is a schematic cross-sectional view of the light-emitting device according to the second embodiment of the example.

[0019] Figure 7B yes Figure 7A A schematic enlarged side view of the light-reflecting part.

[0020] Figure 8 This is a schematic cross-sectional view of the light-emitting device according to the second embodiment of the example.

[0021] Figure 9 This is a schematic top view of the light-emitting device and display device according to the third embodiment of the example.

[0022] Figure 10 This is a schematic top view of the light-emitting device according to the third embodiment of the example.

[0023] Figure 11 It is along Figure 10 A schematic cross-sectional view of the 11X-11X line.

[0024] Figure 12 This is a schematic top view of a variation of the light-emitting device according to the third embodiment.

[0025] Figure 13 This is a schematic cross-sectional view of a light-emitting device illustrating other embodiments.

[0026] Figure 14 This is a schematic cross-sectional view of a light-emitting device illustrating other embodiments.

[0027] Figure 15This is a schematic cross-sectional view of a light-emitting device illustrating other embodiments. Detailed Implementation

[0028] Hereinafter, the methods for implementing this disclosure will be described based on the accompanying drawings. Elements indicated by the same reference numerals in the various drawings refer to the same or identical elements. Furthermore, in the embodiments described below, repeated descriptions and reference numerals are sometimes omitted. Additionally, the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown may not necessarily correspond to reality. Moreover, the dimensional relationships and ratios of the elements may not be consistent between the various drawings.

[0029] [First Implementation Method]

[0030] The light-emitting device 30 and the display device 20 of the first embodiment of this disclosure will be described.

[0031] (Display device 20)

[0032] First, the display device 20 will be described.

[0033] Figure 1 This is a schematic top view illustrating the light-emitting device 30 and the display device 20 of this embodiment. Figure 2 This is a schematic top view of the incident angle θ of the example laser relative to the image generating element 56 of the display device 20 in this embodiment.

[0034] 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 may be, for example, a projector, a head-up display, a head-mounted display, or a glasses-type wearable device.

[0035] like Figure 1 As shown, the display device 20 includes a light-emitting device 30, an optical system 50, an image generating element 56, and an imaging optical component 58.

[0036] The light-emitting device 30 is a device that outputs laser light (OL). The display device 20 of this embodiment includes multiple light-emitting devices 30 that output laser light (OL) with different wavelengths. Specifically, the display device 20 includes three light-emitting devices 30. These 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 structure except for the light source from which the laser light is emitted. Therefore, when describing the three light-emitting devices 30 individually, each structure will be labeled with R (red), G (green), and B (blue), representing the laser color. Furthermore, when describing the common structure of the three light-emitting devices 30, R, G, and B will not be labeled. Details regarding the light-emitting devices 30 will be described later.

[0037] The optical system 50 is an optical system that has the function of making the angular intensity distribution of the laser OL output from the light-emitting device 30 nearly uniform and the function of focusing the laser with a nearly uniform angular intensity distribution toward the image generating element 56. The optical system 50 of this embodiment includes a compound eye lens 52 and a condenser lens 54. In this embodiment, the laser OL output from the light-emitting device 30 passes through the optical system 50 and illuminates (injects) the image generating element 56. Specifically, the angular intensity distribution of the laser OL is nearly uniform in the compound eye lens 52, and it is focused onto the image generating element 56 in the condenser lens 54. Furthermore, hereinafter, the laser light focused by the condenser lens 54 and illuminating the image generating element 56 will be referred to as the illumination light IL. Figure 2 As shown, the incident angle θ of the illumination light IL relative to the image generating element 56 is in the range of 10 degrees to 30 degrees.

[0038] The optical system 50 of this embodiment includes a compound eye lens 52 that functions to make the angular intensity distribution of the laser OL nearly uniform. However, other optical components can be used instead of the compound eye lens 52 as long as the angular intensity distribution of the laser OL can be nearly uniform. Examples of other optical components include integrating bars and diffusers. In addition, any two or all of the compound eye lens 52, integrating bars, and diffusers can be used in combination as the optical system 50.

[0039] Image generating element 56 is an element into which laser light output from light-emitting device 30 is incident. Specifically, the laser light IL, which is focused by condenser lens 54, is incident onto image generating element 56. Image generating element 56 may include, for example, multiple optical switches. Image generating element 56 may include, for example, MEMS (Micro Electro Mechanical Systems) based elements. By incident the illumination light IL onto image generating element 56, light is obtained to generate an image to be displayed on object S.

[0040] Imaging optics 58 is a component that functions to image the light emitted from image generating element 56. Imaging optics 58 includes, for example, a projection lens. The light emitted from image generating element 56 passes through imaging optics 58 and images are formed on object S. Thus, an image is displayed on object S. Furthermore, in Figure 1 In the diagram, the symbol PL represents the light (projected light) projected from the imaging optical component 58 onto the object S.

[0041] (Light-emitting device 30)

[0042] Next, the details of the light-emitting device 30 will be explained.

[0043] Figure 3 and Figure 4 This is a schematic cross-sectional view illustrating the light-emitting device 30 of this embodiment. Furthermore, in Figure 4 The upper part of the paper illustrates the angular intensity distribution of the output laser OL. Figure 5 This is a schematic perspective view of the illumination area of ​​collimated light L2 illuminating the light reflecting part 38 of the light-emitting device 30 of this embodiment.

[0044] like Figure 3 and Figure 4 As shown, the light-emitting device 30 of this embodiment includes a light source 32, a first lens 34, and a light-reflecting part 38.

[0045] like Figure 4 As shown, light source 32 is a semiconductor laser that emits laser light L1. As an example, the light source 32 in this embodiment uses a facet-emitting semiconductor laser. Therefore, laser light L1 has an elliptical far-field pattern (hereinafter referred to as "FFP (Far Field Pattern)"). That is, laser light L1 is an elliptical beam, with the major axis of the ellipse lying on... Figure 4 The middle is along the longitudinal direction of the paper.

[0046] Furthermore, the light source 32R of the light-emitting device 30R emits a red laser L1 with a peak wavelength of 605 nm or more and 750 nm or less. The light source 32G of the light-emitting device 30G emits a green laser L1 with a peak wavelength of 495 nm or more and 570 nm or less. The light source 32B of the light-emitting device 30B emits a blue laser L1 with a peak wavelength of 420 nm or more and 494 nm or less.

[0047] like Figure 4As shown, the first lens 34 is a collimating lens that collimates the laser L1. Specifically, the first lens 34 collimates the elliptical laser L1 at least in the major axis direction. Furthermore, "collimating the laser" as described here may also include the convergence and divergence of the laser within an error range. The collimated laser (collimated light) includes, for example, lasers that converge or diverge within an error range of approximately ±3 degrees. Additionally, the first lens 34 may collimate the elliptical laser L1 in both the major and minor axes. The cross-sectional shape of the collimated light L2, after collimation by the first lens 34, is also elliptical, similar to that of the laser L1. Furthermore, the first lens 34 may, for example, be made of resin, glass, or quartz.

[0048] like Figure 4 As shown, 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. Additionally, as... Figure 5 As shown, the beam diameter BW1 of the collimated light L2 is its length along the major axis, i.e., its major diameter. Similarly, the beam diameter BW2 of the reflected light L3 is its length along the major axis, i.e., its major diameter.

[0049] like Figure 3 and Figure 4 As shown, the light reflecting unit 38 of this embodiment has a plurality of reflecting surfaces 36. The plurality of reflecting surfaces 36 are arranged at intervals in the direction of travel of the collimated light L2. Furthermore, the direction of travel of the collimated light L2 is... Figure 4 The middle arrow marks the direction indicated by AD.

[0050] Multiple reflecting surfaces 36 reflect the collimated light L2 in a direction intersecting the travel direction AD. In this embodiment, the multiple reflecting surfaces 36 reflect the collimated light L2 in a direction orthogonal to the travel direction AD. Furthermore, the travel direction of the reflected light L3 reflected by the multiple reflecting surfaces 36 is... Figure 4 The direction indicated by the middle arrow RD. In this embodiment, the direction of travel of the collimated light L2, AD, is orthogonal to the direction of travel of the reflected light L3, RD.

[0051] In this embodiment, the tilt angle α of the plurality of reflecting surfaces 36 relative to the direction of travel AD is the same. Furthermore, the term "same tilt angle" includes an error of approximately ±3 degrees. As an example, the tilt angle α is set to 45 degrees. By setting the tilt angle α to 45 degrees, the collimated light L2 can be reflected in a direction orthogonal to the direction of travel AD.

[0052] like Figure 5As shown, when the elliptical collimated beam L2 is reflected by multiple reflecting surfaces 36 spaced apart in the direction of travel AD, its major axis becomes longer. Therefore, the beam diameter BW2 of the reflected beam L3, which is the collimated beam reflected by the multiple reflecting surfaces 36, is larger than the beam diameter BW1 of the collimated beam L2.

[0053] In addition, as an example in this embodiment, such as Figure 4 As shown, the length D2 of the irradiation area of ​​the collimated light L2 incident on the multiple reflecting surfaces 36 along the travel direction AD is longer than the length D1 of the first lens 34 along the direction orthogonal to the travel direction AD. Here, the length D2 of the irradiation area of ​​the collimated light L2 refers to, as... Figure 4 and Figure 5 As shown, in the region illuminated by collimating light L2, the length measured along the travel direction AD from the earliest point of illumination to the latest point of illumination by collimating light L2. Additionally, the length D1 of the first lens 34 along a direction orthogonal to the travel direction AD is also shown. Figure 4 The length D1 refers to the length of the first lens 34 along the direction of travel of the reflected light L3. When the first lens 34 is a circular lens, the length D1 is the diameter of the first lens 34.

[0054] In addition, such as Figure 3 and Figure 4 As shown, the light reflecting portion 38 can also be configured as a reflecting member 40 having multiple reflecting surfaces 36. The reflecting member 40 has a connecting surface 42 that extends along the traveling direction AD and connects adjacent reflecting surfaces 36. Furthermore, the phrase "extending along the traveling direction" includes a direction inclined at approximately ±5 degrees relative to the traveling direction AD. In addition, the inclination angle of the connecting surface 42 relative to the traveling direction AD is preferably an angle that does not reflect the collimated light L2. The angle that does not reflect the collimated light L2 refers to an angle that is 0 degrees (parallel) or negative relative to the collimated light L2.

[0055] Furthermore, in this embodiment, the lengths of each connecting surface 42 along the travel direction AD are the same. In other words, the plurality of reflecting surfaces 36 are arranged at equal intervals relative to the travel direction AD. Moreover, this disclosure is not limited to the structure described above. For example, the lengths of adjacent connecting surfaces 42 along the travel direction AD may be different.

[0056] As an example, the reflective component 40 of this embodiment has four reflective surfaces 36 and three connecting surfaces 42.

[0057] The reflective component 40 may include, for example, resin, glass, or quartz. Additionally, the reflective surface 36 may also include a material with high reflectivity, such as metal.

[0058] like Figure 3 and Figure 4As shown, the light-emitting device 30 also includes a second lens 44 and a frame 46.

[0059] like Figure 4 As shown, the second lens 44 is a lens that outputs the reflected light L3 with a nearly uniform angular intensity distribution. For example, a lens with the structure disclosed in Japanese Patent Application Publication No. 2021-81701 can be used as the lens with the function of outputting light with a nearly uniform angular intensity distribution. Furthermore, the second lens 44 may, for example, contain resin, glass, or quartz. The reflected light L3 incident on the second lens 44 is output with a nearly uniform angular intensity distribution through the second lens 44. The output light from the second lens 44 becomes the laser OL output from the light-emitting device 30.

[0060] like Figure 3 As shown, the frame 46 internally houses the light source 32, the first lens 34, and the reflecting component 40. Specifically, the frame 46 includes a box 47 that is open on one side and a cover 48 that closes the open portion of the box 47. The box 47 includes a bottom 47A and a frame portion 47B. Furthermore, the box 47 and the cover 48 are constituent parts of the frame 46. In this embodiment, as an example, the bottom 47A and the frame portion 47B are formed of different materials. The bottom 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 addition, in this embodiment, the cover 48 is formed of a transparent material. Examples of transparent materials include resin, glass, or quartz. Furthermore, in this embodiment, the cover 48 only needs to be translucent in areas through which the laser L1 passes, and a light-shielding film may also be formed in areas through which the laser does not pass. The light-shielding film reduces the possibility of stray light other than the laser L1 generated inside the light-emitting device 30 leaking to the outside of the light-emitting device 30. The light-shielding film also reduces the likelihood of the reflected light from the laser OL emitted to the outside of the light-emitting device 30 reaching the light source 32. If the reflection of the reflected light can be reduced, damage to the light source 32 can be suppressed.

[0061] A light source 32, a first lens 34, and a reflective component 40 are fixed at the bottom 47A of the housing 47. Specifically, the light source 32 is fixed to the bottom 47A of the housing 47 via a secondary mounting component 33.

[0062] A second lens 44 is provided on the cover 48. Specifically, the second lens 44 is bonded to the cover 48. More specifically, the second lens 44 is bonded to the cover 48 via an adhesive layer 45 made of adhesive. The adhesive layer 45 is arranged to avoid the optical path of the reflected light L3. In addition, the cover 48 is assembled to the housing 47 in a way that seals the inside of the housing 47. Furthermore, this disclosure is not limited to the above structure, and the frame 46 may also be composed of a plate-shaped base and a cover covering the base. In this case, the light source 32, the first lens 34, and the reflecting component 40 are fixed on the base, and the second lens 44 is bonded to the cover, and the cover and the base are assembled in a way that seals the inside of the cover.

[0063] Additionally, the light-emitting device 30 is mounted on the substrate 90. The light source 32 is electrically connected to an electrode layer (not shown) on the substrate 90. Power is supplied through the electrode layer of the substrate 90, thereby causing the light source 32 to emit laser light L1. Furthermore, the light-emitting devices 30R, 30G, and 30B can be mounted on different substrates 90, or they can be mounted on a single substrate 90. Additionally, the light-emitting device 30 may also include the substrate 90.

[0064] Next, the effects of this embodiment will be explained.

[0065] like Figure 4 As shown, in the light-emitting device 30 of this embodiment, the laser L1 emitted from the light source 32 is collimated by the first lens 34. The collimated light L2, which passes through the first lens 34, is reflected by the plurality of reflecting 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 reflecting surfaces 36 is larger than the beam diameter BW1 of the collimated light L2. Specifically, when the collimated light L2 is reflected by the plurality of reflecting surfaces 36 arranged at intervals in the travel direction AD, the major axis becomes longer. That is, in the light-emitting device 30, by arranging the plurality of reflecting surfaces 36 at intervals in the travel direction AD, for example, compared to a structure where a single reflecting surface 36 is continuous, the length D2 of the irradiation area of ​​the collimated light L2 becomes longer, and therefore the beam diameter BW2 of the reflected light L3 becomes larger. Thus, in the light-emitting device 30, a laser OL with an enlarged beam diameter can be output. Even without internally provided beam-expanding optical components such as beam expanders, the display device 20 of this embodiment can output laser OL with an expanded beam diameter from the light-emitting device 30, thus suppressing the cost increase caused by the increase in the number of components that accompany the provision of beam-expanding optical components. Furthermore, the display device 20 can suppress the increase in size associated with the provision of beam-expanding optical components. In other words, the display device 20 does not have beam-expanding optical components, thereby achieving miniaturization.

[0066] 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 members can be suppressed compared to the case where reflective members with one reflective surface are arranged at intervals in the traveling direction AD. Additionally, high installation accuracy is required to arrange reflective members with one reflective surface with high precision at intervals in the traveling direction AD. In contrast, in the light-emitting device 30 of this embodiment, since one reflective member 40 has multiple reflective surfaces 36, the relative positions of each reflective surface 36 are determined, making it easy to arrange multiple reflective surfaces 36 at high precision at intervals in the traveling direction AD.

[0067] Furthermore, in the light-emitting device 30 of this embodiment, by increasing the length of the travel direction AD of the connecting surface 42, that is, by increasing the spacing between adjacent reflecting surfaces 36, the beam diameter BW2 of the reflected light L3 can be increased. Thus, in the light-emitting device 30, the size of the beam diameter BW2 of the reflected light L3 can be varied according to the length of the travel direction AD of the connecting surface 42, so that the desired beam diameter can be obtained with a simple structure.

[0068] Furthermore, in the light-emitting device 30 of this embodiment, the reflected light L3 reflected by the plurality of reflective surfaces 36 is output with a nearly uniform angular intensity distribution through the second lens 44. Thus, in the light-emitting device 30, the reflected light L3 passes through the second lens 44, thereby outputting laser OL with suppressed deviations in the angular intensity distribution. Therefore, the angular intensity distribution of the laser OL can be homogenized. By enabling the homogenization of the angular intensity distribution of the laser OL, in the display device 20, it is unnecessary to place an optical component for homogenizing the laser between the light-emitting device 30 and the optical system 50, which contributes to the miniaturization and cost reduction of the display device 20. Furthermore, the term "homogenization" here is not limited to a completely uniform state, but also includes a change in a manner close to "uniformity" compared to the original state.

[0069] Furthermore, in the light-emitting device 30 of this embodiment, the second lens 44 is joined to the cover 48 constituting the frame 46. Here, the cover 48 of this embodiment is formed of a glass material that can ensure the airtightness of the frame 46. On the other hand, the second lens 44 is formed of a glass material that functions as a lens. By joining the cover 48, which is formed of different glass materials, to the second lens 44, the light-emitting device 30 of this embodiment can achieve both the effect of ensuring the airtightness of the frame 46 and the effect of uniformizing the angular intensity distribution of the laser OL.

[0070] like Figure 1As shown, in the display device 20 of this embodiment, the beam diameter of the laser OL output from the light-emitting device 30 is increased, thus increasing the incident angle θ of the irradiating light IL towards the image generating element 56. By increasing the incident angle θ in this way, it is possible to suppress the generation of spots in the image displayed on the object S by the display device 20. Moreover, by setting the incident angle θ relative to the image generating element 56 within the range of 10 degrees to 30 degrees, it is possible to effectively suppress the spots generated in the image displayed on the object S. Furthermore, when the incident angle θ is less than 10 degrees, the effect of suppressing spots is insufficient. On the other hand, when the incident angle θ exceeds 30 degrees, it is necessary to reduce the F-value of the imaging optics 58, which raises concerns about increased costs. Therefore, it is preferable to set the incident angle θ within the range of 10 degrees to 30 degrees.

[0071] [Second Implementation]

[0072] The light-emitting device 130 and the display device 120 according to the second embodiment of this disclosure will be described. Furthermore, descriptions of structures identical to those of the light-emitting device 30 and the display device 20 of the first embodiment will be omitted.

[0073] (Display device 120)

[0074] First, the display device 120 will be described.

[0075] Figure 6 This is a schematic top view illustrating the light-emitting device 130 and the display device 120 of this embodiment.

[0076] The display device 120 of this embodiment includes a light-emitting device 130, an optical system 50, an image generating element 56, and an imaging optical component 58. The display device 120 of this embodiment has the same structure as the display device 20 of the first embodiment, except for the light-emitting device 130. Furthermore, the light-emitting device 130 is the same as the light-emitting device 30 of the first embodiment, and includes three light-emitting devices 130. 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 structure except for the light source that emits the laser light. Therefore, when describing the three light-emitting devices 130 individually, each structure is labeled with R (red), G (green), and B (blue), representing the laser color. Furthermore, when describing the common structure of the three light-emitting devices 130, R, G, and B are not labeled.

[0077] (Light-emitting device 130)

[0078] Next, the details of the light-emitting device 130 will be explained.

[0079] Figure 7AThis is a schematic cross-sectional view of the light-emitting device 130 of this embodiment. Figure 7B yes Figure 7A A schematic enlarged side view of the light-reflecting part. Figure 8 This is a schematic cross-sectional view illustrating the light-emitting device 130 of this embodiment. Furthermore, in Figure 8 The upper part of the paper illustrates the angular intensity distribution of the output laser OL.

[0080] like Figure 7A and Figure 8 As shown, the light-emitting device 130 of this embodiment includes a light source 32, a first lens 34, and a light-reflecting part 138. In addition, the light-emitting device 130 also includes a second lens 144 and a frame 146.

[0081] like Figure 8 As shown, the light reflecting part 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.

[0082] like Figure 7A As shown, the light reflecting unit 138 of this embodiment has a plurality of reflecting surfaces 136. The plurality of reflecting surfaces 136 are arranged at intervals along the travel direction AD of the collimated light L2.

[0083] Multiple reflecting surfaces 136 reflect the collimated light L2 in a direction intersecting the direction of travel AD. In this embodiment, the multiple reflecting surfaces 136 reflect the collimated light L2 in different directions. Furthermore, the direction of travel of the reflected light L3, reflected by the multiple reflecting surfaces 136, is... Figure 8 The direction indicated by the middle arrow RD. In this embodiment, the direction of travel of the collimated light L2, AD, is orthogonal to the direction of travel of the reflected light L3, RD.

[0084] like Figure 7B As shown, in this embodiment, the tilt angles α of the plurality of reflective surfaces 136 relative to the direction of travel AD are different angles. Furthermore, the phrase "different tilt angles" includes those different beyond a certain error range. For example, a difference of 3 degrees or more in angles means a difference of more than 3 degrees.

[0085] The tilt angle α of the plurality of reflective surfaces 136 increases sequentially from the side closest to the first lens 34 along the travel direction AD. In this embodiment, as an example, the light reflecting part 138 has five reflective surfaces 136. Figure 7BIn this embodiment, five reflecting surfaces 136 are designated by the symbols 136A, 136B, 136C, 136D, and 136E, respectively, starting from the side closest to the first lens 34. In this embodiment, when the tilt angle of reflecting surface 136A is α1, the tilt angle of reflecting surface 136B is α2, the tilt angle of reflecting surface 136C is α3, the tilt angle of reflecting surface 136D is α4, and the tilt angle of reflecting surface 136E is α5, the relationship α1 < α2 < α3 < α4 < α5 holds true.

[0086] like Figure 8 As shown, when the elliptical collimated beam L2 is reflected by a plurality of reflecting surfaces 136 spaced apart in the direction of travel AD, its major axis becomes longer. Therefore, the beam diameter BW2 of the reflected beam L3, which is the collimated beam reflected by the plurality of reflecting surfaces 136, is greater than the beam diameter BW1 of the collimated beam L2.

[0087] In addition, as an example in this embodiment, such as Figure 8 As shown, the length D2 of the irradiation area of ​​the collimated light L2 irradiating the multiple reflective surfaces 136 along the travel direction AD is longer than the length D1 of the first lens 34 along the direction orthogonal to the travel direction AD.

[0088] Alternatively, the light reflecting portion 138 may be configured as a reflecting member 140 having multiple reflecting surfaces 136. The reflecting member 140 has a connecting surface 142 that extends along the traveling direction AD and connects the reflecting surfaces 136 adjacent to each other.

[0089] Furthermore, in this embodiment, the length W of each connecting surface 142 along the travel direction AD is different. In other words, the plurality of reflecting surfaces 136 are arranged at different intervals relative to the travel direction AD. Specifically, the length W of each connecting surface 142 increases sequentially from the side closest to the first lens 34 along the travel direction AD. In this embodiment, as an example, the light reflecting part 138 has four connecting surfaces 142. The four connecting surfaces 142 are sequentially represented by the symbols 142A, 142B, 142C, and 142D from the side closest to the first lens 34. In this embodiment, when the length of connecting surface 142A is set to W1, the length of connecting surface 142B is set to W2, the length of connecting surface 142C is set to W3, and the length of connecting surface 142D is set to W4, the relationship W1 > W2 > W3 > W4 holds true.

[0090] The reflective component 140 may include, for example, resin, glass, or quartz. Additionally, the reflective surface 136 may also include a material with high reflectivity, such as metal.

[0091] The second lens 144 is a collimating lens that collimates the reflected light L3. The second lens 144 may include, 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. The output light output from the second lens 144 becomes the laser OL output from the light-emitting device 130.

[0092] The frame 146 internally houses the light source 32, the first lens 34, and the reflector 140. Additionally, the frame 146 includes a housing 47 and a cover 48 that closes the open portion of the housing 47. A second lens 144 is disposed on the cover 48. Specifically, the second lens 144 is bonded to the cover 48 via an adhesive layer 45 made of adhesive. The cover 48 is assembled to the housing 47 in a manner that seals the interior of the housing 47. Furthermore, this disclosure is not limited to the above structure; the frame 146 may also be constructed from a plate-like base and a cover that covers the base.

[0093] Additionally, the light-emitting device 130 is mounted on the substrate 90. The light source 32 is electrically connected to an electrode layer (not shown) on the substrate 90. Power is supplied through the electrode layer of the substrate 90, thereby causing the light source 32 to emit laser light L1. Furthermore, the light-emitting devices 130R, 130G, and 130B can be mounted on different substrates 90, or they can be mounted on a single substrate 90. Additionally, the light-emitting device 30 may also include the substrate 90.

[0094] Next, the effects of the light-emitting device 130 in this embodiment will be explained. Furthermore, the effects obtained using the same structure as in the first embodiment will be omitted from the explanation.

[0095] In the light-emitting device 130 of this embodiment, the collimated light L2 is reflected in different directions by multiple reflecting surfaces 136. Therefore, in the light-emitting device 130, compared to the case where the tilt angle α of the multiple reflecting surfaces is the same, even without a lens that makes the angular intensity distribution nearly uniform, the angular intensity distribution of the reflected light L3, i.e., the laser OL, transmitted through the second lens 144 can be nearly uniform. Therefore, as Figure 8 As shown in the upper angular intensity distribution, the intensity difference between the central portion and the end portion of the laser OL is within 20%. Furthermore, in the second lens 144, a range of 5% to 10% from the lens end corresponds to the aforementioned end portion, and a range including the center (80%) corresponds to the aforementioned central portion. In the light-emitting device 130, the laser OL with an intensity difference of less than 20% between the output end and the central portion in the angular intensity distribution effectively suppresses light spots generated when displaying images on the object S. Furthermore, because the light-emitting device 130 is included, the display device 120 does not need to include an optical system such as a compound eye lens to achieve uniform intensity distribution, enabling a reduction in the number of components and miniaturization.

[0096] [Third Implementation Method]

[0097] The light-emitting device 230 and the display device 220 according to the third embodiment of this disclosure will be described. Furthermore, descriptions of structures identical to those of the light-emitting device 30 and the display device 20 of the first embodiment will be omitted.

[0098] (Display device 220)

[0099] First, the display device 220 will be described.

[0100] Figure 9 This is a schematic top view illustrating the light-emitting device 230 and the display device 220 of this embodiment.

[0101] The display device 220 of this embodiment includes a light-emitting device 230, an optical system 50, an image generating element 56, and an imaging optical component 58. Except for the light-emitting device 230, the display device 220 of this embodiment has the same structure as the display device 20 of the first embodiment.

[0102] (Light-emitting device 230)

[0103] Next, the details of the light-emitting device 230 will be explained.

[0104] Figure 10 This is a schematic top view illustrating the light-emitting device 230 of this embodiment. Additionally, in Figure 10 The illustrations of the second lens 244 and cover 48 of the light-emitting device 230 are omitted. Figure 11 It is along Figure 10 A schematic cross-sectional view of the 11X-11X line. Additionally, in Figure 11 The diagram shows that in Figure 10 The second lens 244 and cover 48, etc., shown in the illustration are omitted.

[0105] like Figure 10 and Figure 11 As shown, the light-emitting device 230 includes multiple light sources 32, multiple first lenses 34, and multiple light reflectors 38. In addition, the light-emitting device 230 also includes multiple second lenses 244 and a frame 246.

[0106] like Figure 10 As shown, three light sources 32R, 32G, and 32B are respectively housed in the frame 246. The light sources 32R, 32G, and 32B are spaced apart within the frame 246 in a direction orthogonal to the emission direction of the laser L1.

[0107] Additionally, the frame 246 houses three first lenses 34R, 34G, and 34B. The first lenses 34R, 34G, and 34B are positioned corresponding to the light sources 32R, 32G, and 32B, respectively. That is, each first lens 34 is positioned at the point where the laser L1 emitted from each light source 32 enters.

[0108] In addition, the frame 246 houses three light reflecting parts 38R, 38G, and 38B. The light reflecting parts 38R, 38G, and 38B are positioned corresponding to the first lenses 34R, 34G, and 34B, respectively. That is, each light reflecting part 38 is positioned to reflect the collimated light L2 collimated by each of the first lenses 34.

[0109] The frame 246 includes a housing 47 and a cover 48 that closes the open portion of the housing 47. Three second lenses 244R, 244G, and 244B are disposed on the cover 48. In this embodiment, as an example, the three second lenses 244R, 244G, and 244B are integrally formed and bonded to the cover 48 via an adhesive layer 45 made of adhesive. This disclosure is not limited to this structure; each second lens 144 may also be formed separately and bonded to the cover 48 via the adhesive layer 45. The cover 48 is assembled to the housing 47 in a manner that seals the interior of the housing 47. Furthermore, this disclosure is not limited to the above structure; the frame 246 may also be composed of a plate-shaped base and a cover that covers the base.

[0110] Furthermore, the second lenses 244R, 244G, and 244B are positioned corresponding to the light reflecting parts 38R, 38G, and 38B, respectively. That is, each second lens 244 is positioned at the point where the reflected light L3, reflected by each light reflecting part 38, enters.

[0111] The light-emitting device 230 is mounted on the substrate 90. Light sources 32R, 32G, and 32B are electrically connected to an electrode layer (not shown) on 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. Alternatively, the light-emitting device 230 may also include the substrate 90.

[0112] Next, the effects of this embodiment will be explained. Furthermore, the effects obtained using the same structure as the first embodiment will be omitted from the explanation.

[0113] In the light-emitting device 230 of this embodiment, a plurality of light sources 32, a plurality of first lenses 34, and a plurality of light reflectors 38 are housed within a frame 246. Therefore, compared to a structure where a single light source is housed within a frame, the display device 220 can be miniaturized in the light-emitting device 230. In the light-emitting device 230, a plurality of second lenses 244 are joined to the cover 48 constituting the frame 246. Therefore, the light-emitting device 230 of this embodiment, like the light-emitting device 30 of the first embodiment, can achieve both ensuring the airtightness of the frame 246 and achieving uniform angular intensity distribution of the laser OL.

[0114] In the light-emitting device 230 of this embodiment, a plurality of light sources 32, a plurality of first lenses 34, and a plurality of light-reflecting parts 38 are housed in a frame 246. This structure can also be applied to other embodiments and modifications of this disclosure. For example, it can also be applied to the light-emitting device 130 of the second embodiment. In this case, a plurality of light sources 32, a plurality of first lenses 34, and a plurality of light-reflecting parts 138 are housed in a frame 246.

[0115] In the light-emitting device 230 of this embodiment, a plurality of light-reflecting portions 38 corresponding to a plurality of light sources 32 are provided, but this disclosure is not limited to this structure. For example, it may be as follows: Figure 12 As shown in the light-emitting device 330, it is configured such that a light-reflecting section 338 is provided for a plurality of light sources 32. The light-reflecting section 338 is formed by extending the lateral width of the light-reflecting section 38 in the first embodiment, and the structure of the reflecting surface is the same as that of the reflecting surface 36 of the light-reflecting section 38. In such a light-emitting device 330, the number of components can be reduced. Furthermore, the other structures of the light-emitting device 330 are the same as those of the light-emitting device 230 in the third embodiment.

[0116] [Other Implementation Methods]

[0117] In the light-emitting device 30 of the first embodiment, a second lens 44 is provided in the cover 48 of the frame 46, but this disclosure is not limited to this structure. For example, it may not be like this... Figure 13 As shown in the light-emitting device 430, a second lens 44 is provided on the cover 48. Specifically, the optical system 50 of the display device 20 has the function of making the angular intensity distribution of the laser OL nearly uniform, so the second lens 44 can be omitted as in the light-emitting device 430, depending on the performance requirements of the display device 20. When the second lens 44 is omitted, the reflected light L3 transmitted through the cover 48 becomes the laser OL as the output light. Furthermore, Figure 13The light-emitting device 430R includes a light source 32R, the light-emitting device 430G includes a light source 32G, and the light-emitting device 430B includes a light source 32B. The structure omitting the second lens 44 can also be applied to the third embodiment, variations, etc. of this disclosure. For example, in the case of the light-emitting device 230 applied to the third embodiment, the second lens 244 is omitted.

[0118] In the light-emitting devices 30, 130, 230, 330, and 430 described above, a surface-emitting semiconductor laser is used as the light source for the emitted laser L1. However, the present invention is not limited to this configuration. For example, alternative configurations may be used... Figure 14 As shown in the light-emitting device 530, a surface-emitting semiconductor laser is used as the light source 532. Additionally, Figure 14 This is a schematic cross-sectional view of the light-emitting device 530, illustrating other embodiments. Even when a surface-emitting semiconductor laser is used as the light source 532, as in the light-emitting device 530, it is possible to output laser OL with an expanded beam diameter, similar to the light-emitting device 30. Alternatively, a photonic crystal laser can be used instead of a surface-emitting semiconductor laser. When using a surface-emitting semiconductor laser or a photonic crystal laser as the light source 532, using... Figure 14 The auxiliary mounting bracket 533, as shown in the diagram, secures the light source 532 to the bottom of the housing 46. Furthermore, Figure 14 The light-emitting device 530R has a light source 532R, the light-emitting device 530G has a light source 532G, and the light-emitting device 530B has a light source 532B.

[0119] When using an end-emitting semiconductor laser or a photonic crystal laser as the source of the emitted laser L1, the beam divergence angle decreases. Therefore, it is also possible to... Figure 15 As shown in the light-emitting device 630, a first lens 34 is provided, and the laser L1 is not collimated. That is, when using an end-face-emitting semiconductor laser or a photonic crystal laser as the light source 632 emitting laser L1, the first lens 34 can be omitted. When the first lens 34 is omitted, laser L1 is reflected by the light-reflecting part 38 to become reflected light L3. In this case, the beam diameter BW2 of reflected light L3 is larger than the beam diameter BW1 of laser L1. Furthermore, Figure 15 This is a schematic cross-sectional view illustrating other embodiments of the light-emitting device. Additionally, Figure 15The light-emitting device 630R includes a light source 632R, the light-emitting device 630G includes a light source 632G, and the light-emitting device 630B includes a light source 632B. The structure of using an end-face-emitting semiconductor laser or a photonic crystal laser as the light source and omitting the first lens 34 can also be applied to the second embodiment, third embodiment, other embodiments, and variations of this disclosure.

[0120] In the light-emitting device 30 of the first embodiment, the second lens 44 is bonded to the cover 48 via an adhesive layer 45. However, this disclosure is not limited to this structure, and the cover 48 and the second lens 44 can also be integrally formed. That is, the cover 48 and the second lens 44 can also be integrally formed. In this case, the number of components in the light-emitting device 30 can be reduced. The structure of integrally forming the cover 48 and the second lens 44 can also be applied to the second embodiment, the third embodiment, other embodiments, and variations of this disclosure. For example, in the case of the light-emitting device 130 of the second embodiment, the cover 48 and the second lens 144 are integrally formed.

[0121] The display device 20 of the first embodiment includes a light-emitting device 30, an optical system 50, an image generating element 56, and an imaging optical component 58, but this disclosure is not limited to this structure. 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 refers to the function of the compound eye lens 52, and "all" of the functions of the optical system 50 refers to the functions of both the compound eye lens 52 and the condenser lens 54. In the display device 20, the structure that enables the light-emitting device 30 to have some or all of the functions of the optical system 50 may also be applied to the second embodiment, third embodiment, other embodiments, and modifications of this disclosure.

[0122] In the first embodiment, the light-emitting device 30 is used in the display device 20, but this disclosure is not limited to this structure. For example, the light-emitting device 30 can also be used in vehicle headlights, lighting, backlights of displays, etc. The light-emitting devices in the second, third, other embodiments, and modifications of this disclosure can also be used in the same way in vehicle headlights, lighting, backlights of displays, etc.

[0123] The above description illustrates embodiments of this disclosure, but these embodiments are merely examples and can be implemented with various modifications without departing from the spirit of the subject. Furthermore, the scope of this disclosure is not limited to these embodiments.

[0124] In addition to the above-described implementation methods, the following notes are also disclosed.

[0125] (Note 1)

[0126] A light-emitting device comprising: a light source that emits laser light; and a lens that collimates the laser light.

[0127] The light reflecting part has multiple reflecting surfaces, which are spaced apart in the direction of travel of the collimated light transmitted through the lens, and reflect the collimated light in a direction that intersects the direction of travel.

[0128] The diameter of the reflected light beam after being reflected by the plurality of reflective surfaces is larger than the diameter of the collimated light beam.

[0129] (Note 2)

[0130] A light-emitting device comprising: a light source that emits laser light; and a lens that collimates the laser light.

[0131] The light reflecting part has multiple reflecting surfaces, which are spaced apart in the direction of travel of collimated light transmitted through the lens, and reflect the collimated light in a direction that intersects the direction of travel.

[0132] The length of the irradiation area of ​​the collimated light illuminating the plurality of reflective surfaces along the travel direction is longer than the length of the lens along the intersecting direction.

[0133] (Note 3)

[0134] The light-emitting device described in Appendix 1 or 2, wherein the light-reflecting part includes a reflective component, and the reflective component has the plurality of reflective surfaces.

[0135] (Note 4)

[0136] According to the light-emitting device described in Appendix 3, the reflective component further has a connecting surface that extends along the direction of travel and connects the adjacent reflective surfaces.

[0137] (Note 5)

[0138] According to any one of Appendices 1 to 4, the light-emitting device wherein the plurality of reflecting surfaces have the same tilt angle relative to the direction of travel, and the light-emitting device comprises: a first lens serving as the lens; and a second lens that outputs the reflected light with an approximately uniform angular intensity distribution.

[0139] (Note 6)

[0140] According to any one of Appendices 1 to 4, the light-emitting device wherein the tilt angles of the plurality of reflective surfaces relative to the direction of travel are different.

[0141] (Note 7)

[0142] According to Appendix 6, the light-emitting device comprises: a first lens serving as the lens; and a second lens for collimating the reflected light, wherein the intensity difference between the central portion and the end portion in the angular intensity distribution of the output light transmitted through the second lens is within 20%.

[0143] (Note 8)

[0144] According to Appendix 5 or 7, the light-emitting device further includes a frame that houses the light source, the first lens, and the light-reflecting portion, wherein the second lens is engaged with one of the plurality of constituent parts constituting the frame.

[0145] (Note 9)

[0146] According to Appendix 5 or 7, the light-emitting device further comprises a frame that houses a plurality of light sources emitting lasers of different wavelengths, a plurality of first lenses corresponding to the plurality of light sources, and a plurality of light-reflecting parts corresponding to the plurality of first lenses.

[0147] Each of the second lenses corresponding to the plurality of light-reflecting portions is respectively engaged with one of the plurality of constituent parts constituting the frame.

[0148] (Postscript 10)

[0149] A display device comprising:

[0150] The light-emitting device described in any one of Appendix 1 to 9;

[0151] An image generating element, which receives light emitted from the light-emitting device;

[0152] An imaging optics component that enables the light emitted from the image generating element to be imaged.

[0153] (Postscript 11)

[0154] According to the display device described in Appendix 10, wherein,

[0155] The angle of incidence of the light emitted from the light-emitting device relative to the image generating element is in the range of 10 degrees to 30 degrees.

[0156] Explanation of reference numerals in the attached figures

[0157] 20: Display device

[0158] 30: Light-emitting device

[0159] 32: Light source

[0160] 33: Sub-installation component

[0161] 34: First lens (an example of a first lens)

[0162] 36: Reflective surface

[0163] 38: Light reflecting part

[0164] 40: Reflective component

[0165] 42: Connecting surface

[0166] 44: Second Lens (An example of a second lens)

[0167] 45: Adhesive layer

[0168] 46: Frame

[0169] 47: Box

[0170] 47A: Bottom

[0171] 47B: Frame

[0172] 48: Cover

[0173] 50: Optical System

[0174] 52: Compound eye lens

[0175] 54: Condensing Lens

[0176] 56: Image generating element

[0177] 58: Imaging optical components

[0178] 90: Substrate

[0179] 120: Display device

[0180] 130: Light-emitting device

[0181] 136: Reflecting surface

[0182] 138: Light reflecting part

[0183] 140: Reflective component

[0184] 142: Connecting surface

[0185] 144: Second Lens (An Example of a Second Lens)

[0186] 146: Frame

[0187] 220: Display device

[0188] 230: Light-emitting device

[0189] 244: Second Lens (An Example of a Second Lens)

[0190] 246: Frame

[0191] 330: Light-emitting device

[0192] 338: Light reflecting part

[0193] 430: Light-emitting device

[0194] 530: Light-emitting device

[0195] 532: Light Source

[0196] 533: Sub-mount component

[0197] 630: Light-emitting device

[0198] 632: Light source

[0199] α: Inclination angle

[0200] θ: Angle of incidence

[0201] AD: Direction of travel

[0202] RD: Direction of travel

[0203] BW1: Beam diameter

[0204] BW2: Beam diameter

[0205] L1: Laser

[0206] L2: Collimated light

[0207] L3: Reflected light

[0208] OL: Laser

[0209] IL: Irradiation light

[0210] PL: Projected light

[0211] S: Object

Claims

1. A light emitting device, characterized by, have: A light source that emits laser light; A lens that collimates the laser beam; The light reflecting part has multiple reflecting surfaces, which are spaced apart in the direction of travel of the collimated light transmitted through the lens, and reflect the collimated light in a direction that intersects the direction of travel. The diameter of the reflected light beam after being reflected by the plurality of reflective surfaces is larger than the diameter of the collimated light beam.

2. A light emitting device, characterized by have: A light source that emits laser light; A lens that collimates the laser beam; The light reflecting part has multiple reflecting surfaces, which are spaced apart in the direction of travel of the collimated light transmitted through the lens, and reflect the collimated light in a direction that intersects the direction of travel. The length of the irradiation area of ​​the collimated light illuminating the plurality of reflective surfaces along the travel direction is longer than the length of the lens along the intersecting direction.

3. The light-emitting device according to claim 1 or 2, characterized in that, The light reflecting part includes a reflecting component, and the reflecting component has the plurality of reflecting surfaces.

4. The light-emitting device according to claim 3, characterized in that, The reflective component also has a connecting surface that extends along the direction of travel and connects adjacent reflective surfaces.

5. The light-emitting device according to any one of claims 1 to 4, characterized in that, The plurality of reflective surfaces are tilted at the same angle relative to the direction of travel. The light-emitting device includes: a first lens serving as the lens; and a second lens that outputs the reflected light with a nearly uniform angular intensity distribution.

6. The light-emitting device according to any one of claims 1 to 4, characterized in that, The tilt angles of the plurality of reflective surfaces relative to the direction of travel are different.

7. The light-emitting device according to claim 6, characterized in that, It comprises: a first lens serving as the lens; and a second lens for collimating the reflected light. In the angular intensity distribution of the output light transmitted through the second lens, the intensity difference between the central part and the end part is within 20%.

8. The light-emitting device according to claim 5 or 7, characterized in that, It also includes a frame that houses the light source, the first lens, and the light reflector. The second lens is engaged with one of the constituent parts constituting the frame.

9. The light-emitting device according to claim 5 or 7, characterized in that, It also includes a frame that houses multiple light sources emitting lasers of different wavelengths, multiple first lenses corresponding to the multiple light sources, and multiple light-reflecting parts corresponding to the multiple first lenses. Each of the second lenses corresponding to the plurality of light-reflecting portions is respectively engaged with one of the plurality of constituent parts constituting the frame.

10. A display device, characterized by comprising: have: The light-emitting device according to any one of claims 1 to 9; An image generating element, which receives light emitted from the light-emitting device; An imaging optics component that enables the light emitted from the image generating element to be imaged.

11. The display device according to claim 10, characterized in that, The angle of incidence of the light emitted from the light-emitting device relative to the image generating element is in the range of 10 degrees to 30 degrees.

Images