Light emitting device and projection system

Abstract

The invention discloses a light-emitting device and a projection system, and relates to the technical field of laser display. The light-emitting device comprises a light-emitting unit, a steering component and a collimating lens, and the collimating lens comprises a first area used for collimating laser light entering the first area; the second area is positioned on at least one side of the first area and is arranged along the first direction with the first area; and the light path adjusting unit is located in the second area and used for adjusting the light path of the laser entering the second area, so that the laser with the adjusted light path enters the first area and is collimated by the first area. Therefore, the light path adjusting unit is used for adjusting the light path of laser (namely stray light) entering the second area, the stray light with the light path adjusted is made to enter the first area, the first area collimates the part of stray light, the part of stray light is made to be utilized, and therefore the light energy utilization rate of the light-emitting device is improved; when the light-emitting device is applied to the projection system, the imaging quality and the contrast ratio can be improved, and the heat of the projection system can be reduced.

Description

Technical Field

[0001] The present application relates to the field of laser display technology, and in particular to a light emitting device and a projection system. Background Art

[0002] With the rapid development of laser technology, laser display technology has become the next generation of new display technology. Lasers as display light sources have become extremely important core display devices. With the upgrading of product demand, the miniaturization trend of lasers is obvious. As the size of products continues to decrease, the divergence angle of the light beam emitted by the light-emitting unit is still large. As a result, it is difficult to fully utilize the light beam emitted by the light-emitting unit, which makes the improvement and elimination of stray light of lasers a major problem.

[0003] If the stray light of the laser cannot be eliminated in time, the imaging quality and contrast of the system will be reduced in the projection system, and bright spots will easily appear in the imaging picture. The presence of stray light will also increase the overall heat in the system and increase the cooling cost. Summary of the invention

[0004] The present application provides a light emitting device and a projection system, which are used to solve the stray light problem of the light emitting device and improve the light energy utilization rate of the light emitting device. Applying the light emitting device to the projection system is beneficial to improving imaging quality and contrast, and is also beneficial to reducing the heat of the projection system.

[0005] In a first aspect, the present application provides a light emitting device, comprising:

[0006] A light emitting unit, configured to emit laser light in a first direction;

[0007] A deflection component, located at the light-emitting side of the light-emitting unit, and used to deflect the laser light emitted by the light-emitting unit to the light-emitting surface side of the light-emitting device;

[0008] A collimating lens, located on the light-emitting surface side, for receiving the laser light deflected by the steering component and collimating the received laser light;

[0009] The collimating lens comprises:

[0010] A first region, used for collimating laser light incident to the first region;

[0011] A second area, located on at least one side of the first area, and arranged along the first direction with the first area;

[0012] The optical path adjustment unit is located in the second area and is used to adjust the optical path of the laser incident to the second area, so that the laser after the optical path adjustment is incident to the first area and is collimated by the first area.

[0013] In a second aspect, the present application further provides a projection system, including any one of the above light-emitting devices.

[0014] The technical solution provided by the present application has the following advantages compared with the prior art:

[0015] In the technical solution provided by the present application, the collimating lens is improved. By providing an optical path adjustment unit in the second region of the collimating lens, the optical path of the laser (i.e., stray light) incident on the second region is adjusted by the optical path adjustment unit, so that the stray light after the optical path adjustment is incident on the first region, and the first region collimates this part of the stray light, making this part of the stray light utilized, thereby improving the light energy utilization rate of the light-emitting device; applying this light-emitting device to a projection system is beneficial to improving the imaging quality and contrast, and is also beneficial to reducing the heat of the projection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of a light-emitting device in the related art;

[0017] Figure 2 is Figure 1 an exploded view of the structure of the light-emitting device shown;

[0018] Figure 3 is a schematic diagram of the light processing process of a light-emitting device in the related art;

[0019] Figure 4 is a schematic diagram of the spot divergence process of a light-emitting unit in the related art;

[0020] Figure 5 is a schematic structural diagram of a collimating lens according to an exemplary embodiment of the present application;

[0021] Figure 6 is Figure 5 a schematic cross-sectional structure diagram of the collimating lens shown;

[0022] Figure 7 is a schematic diagram of the stray light processing process of a light-emitting device according to an exemplary embodiment of the present application;

[0023] Figure 8 is Figure 5 another schematic cross-sectional structure diagram of the collimating lens shown;

[0024] Fig. 9 is a cross-sectional schematic diagram of another collimating lens according to an exemplary embodiment of the present application;

[0025] Fig.10 is a schematic diagram of the stray light processing process of another light-emitting device according to an exemplary embodiment of the present application;

[0026] Fig.11 is a cross-sectional schematic diagram of another collimating lens according to an exemplary embodiment of the present application;

[0027] Fig.12 is a cross-sectional schematic diagram of another collimating lens according to an exemplary embodiment of the present application;

[0028] Fig.13 is a cross-sectional schematic diagram of another collimating lens according to an exemplary embodiment of the present application;

[0029] Fig.14 This is a schematic structural diagram of a diffraction unit according to an exemplary embodiment of the present application;

[0030] Fig.15 is a schematic structural diagram of another diffraction unit according to an exemplary embodiment of the present application;

[0031] Fig.16 This is a schematic structural diagram of another diffraction unit according to an exemplary embodiment of the present application;

[0032] Fig.17 This is a schematic structural diagram of a Fresnel structural surface according to an exemplary embodiment of the present application;

[0033] Fig.18 This is a schematic structural diagram of another collimating lens according to an exemplary embodiment of the present application;

[0034] Fig.19 for Fig.18 A schematic diagram of a cross-sectional structure of a collimating lens is shown;

[0035] Fig. 20 This is a schematic diagram of a stray light processing process of another light emitting device according to an exemplary embodiment of the present application;

[0036] Fig.21 This is a schematic structural diagram of another collimating lens according to an exemplary embodiment of the present application;

[0037] Fig. 22 This is a schematic diagram of a stray light processing process of another light emitting device according to an exemplary embodiment of the present application;

[0038] Fig.23 This is a schematic structural diagram of a light emitting device according to an exemplary embodiment of the present application;

[0039] Fig.24 It is a schematic structural diagram of another light emitting device according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the purpose and implementation method of the present application clearer, the exemplary implementation method of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0041] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0042] The terms "first", "second", "third", etc. in the specification and claims of this application and the above drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise noted. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances.

[0043] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0044] In related technologies, such as Figure 1-2 As shown, the light-emitting device includes: a base plate 5, a tube shell 4, a cover plate 6, a collimating lens 1, a light-emitting unit 2 and a steering component 3; wherein the base plate 5, the tube shell 4 and the cover plate 6 form a closed space, and the light-emitting unit 2 and the steering component 3 are located in the closed space; the light-emitting unit 2 is arranged in a line in the closed space, and the steering component 3 is located at the light-emitting side of the light-emitting unit, and is used to reflect the laser emitted by the light-emitting unit 2 to the cover plate 6, and the laser passes through the cover plate and is incident on the collimating lens 1, and is emitted after being collimated by the collimating lens 1.

[0045] like Figure 3 As shown in FIG. 1 , since the divergence angle of the light emitting unit 2 in the vertical direction (i.e., the fast axis direction) is large, as the laser propagation optical path increases, the diffused light spot size gradually increases. After the laser is reflected by the steering component 3 and passes through the cover plate 6, the size of the light spot is large, causing a part of the laser to exceed the collimation area of ​​the collimating lens 1. This part of the laser ( Figure 3 The laser in the area marked by the dotted ellipse is difficult to be collimated by the lens and eventually becomes stray light, which cannot be used by the back-end light source system and becomes an important factor affecting the optical system. Stray light in the optical system will affect the imaging quality of the system, especially for the projection system, where it will produce unnecessary bright spots in the beam and return to the mechanical components, which will increase the system heat.

[0046] like Figure 4As shown, the spot size (e.g., the major axis length of the elliptical spot) of the laser emitted by the light-emitting unit 2 at the reflection surface of the steering component 3 is L1, and the light beam at the reflection surface cannot be fully reflected and utilized; the spot size of L1 after reflection is L2, and the light beam that can be collimated and utilized by the collimating lens 1 in L2 is only L3, and the rest of the light beams are not utilized and become stray light. In the projection optical system, the stray light of the light-emitting device has a serious impact on the optical imaging quality. The presence of stray light will also reduce the optical imaging contrast, and bright spots are likely to appear on the imaging surface. Therefore, it is more important to suppress and eliminate this part of stray light for the entire optical system.

[0047] In order to solve the above technical problems, the embodiments of the present application provide a light-emitting device and a projection system, wherein the light-emitting device includes: a light-emitting unit, which is used to emit laser light along a first direction; a steering component, which is located on the light-emitting side of the light-emitting unit, and is used to deflect the laser light emitted by the light-emitting unit to the light-emitting surface side of the light-emitting device; a collimating lens, which is located on the light-emitting surface side and is used to receive the laser light deflected by the steering component and collimate the received laser light; the collimating lens includes: a first zone, which is used to collimate the laser light incident to the first zone; a second zone, which is located on at least one side of the first zone and is arranged along the first direction with the first zone; and an optical path adjustment unit, which is located in the second zone and is used to adjust the optical path of the laser light incident to the second zone, so that the laser light after the optical path is adjusted is incident to the first zone and is collimated by the first zone. In this way, by arranging an optical path adjustment unit in the second zone of the collimating lens, the optical path of the laser (i.e., stray light) incident on the second zone is adjusted by using the optical path adjustment unit, so that the stray light after the optical path adjustment is incident on the first zone, and the first zone performs collimation processing on this part of the stray light, so that this part of the stray light is utilized, thereby improving the light energy utilization rate of the light emitting device; applying the light emitting device to the projection system is beneficial to improving the imaging quality and contrast, and is also beneficial to reducing the heat of the projection system.

[0048] The light emitting device and the projection system provided in the embodiments of the present application are exemplarily described below in conjunction with the accompanying drawings.

[0049] In some embodiments, Figure 5-7 As shown in or 9-10, the light-emitting device includes: a light-emitting unit 2, a steering component 3 and a collimating lens 1; the light-emitting unit 2 is used to emit laser light along a first direction X; the steering component 3 is located on the light-emitting side of the light-emitting unit 2, and is used to deflect the laser light emitted by the light-emitting unit 2 to the light-emitting surface side of the light-emitting device 2; the collimating lens 1 is located on the light-emitting surface side of the light-emitting device, and is used to receive the laser light deflected by the steering component 3, and collimate the received laser light. Among them, the collimating lens 1 includes: a first area A1 and a second area A2 located on at least one side of the first area A1, and the first area A1 and the second area A2 are arranged along the first direction X. For example, the second area A2 can be located only on one side of the first area A1, or on both sides of the first area A1 (such as Figure 6 or as shown in 9).

[0050] For example, Figure 7 As shown in FIG. 10 , the light emitting unit 2 emits laser light along the first direction X. At this time, the fast axis direction of the laser light is in the vertical direction, which is perpendicular to the first direction X. The laser light emitted by the light emitting unit 2 is deflected by 90° by the steering component 3 and then incident on the collimating lens 1. With the deflection of the propagation direction of the light, the fast axis direction of the laser light also changes. At this time, the fast axis direction of the laser light is parallel to the first direction X. Figure 4 The first direction X is the long-axis direction of the elliptical spot formed by the laser at the collimating lens 1 , that is, the fast-axis direction of the laser incident on the collimating lens 1 .

[0051] The laser light emitted by the light emitting unit 2 has a certain divergence angle. The laser light with a smaller divergence angle will be incident on the first area A1 of the collimating lens 1 , while the laser light with a larger divergence angle will be incident on the second area A2 of the collimating lens 1 . For example, taking the divergence angle of the laser emitted by the light emitting unit 2 as 35°, the laser with a divergence angle less than 30° can be incident on the first area A1, and this part of the laser can be directly collimated by the first area A1 of the collimating lens to become collimated light that can be used by the back-end light source system; while the laser with a divergence angle of 30° to 35° is incident on the second area A2, and this part of the laser is the stray light that cannot be used in the related art. In the embodiment of the present application, an optical path adjustment unit 13 is arranged in the second area A2, and the optical path adjustment unit 13 is used to adjust the optical path of the laser incident on the second area A2, so that the laser after the optical path adjustment can be incident on the first area A1, and collimated by the first area A1, so that this part of the laser is reused and becomes collimated light that can be used by the back-end light source system, thereby improving the light energy utilization rate of the light emitting device; applying the light emitting device to the projection system is beneficial to improving the imaging quality and contrast, and is also beneficial to reducing the heat of the projection system. The way in which the optical path adjustment unit 13 adjusts the optical path includes but is not limited to reflection and scattering, and also includes all ways known to those skilled in the art, which are not limited here.

[0052] Among them, the light-emitting unit 2 includes a heat sink substrate 22 and a light-emitting chip 21, and the light-emitting chip 21 is welded on the heat sink substrate 22 by a eutectic process. The heat sink substrate 22 is made of a material with a high thermal conductivity, including but not limited to aluminum nitride (ALN) and silicon carbide (SiC). The optical path adjustment unit 13 has a high reflectivity and a low refractive index to the incident laser, and the reflectivity is greater than or equal to 80%. The optical path adjustment unit 13 includes a reflective surface or a scattering surface. Further, the optical path adjustment unit 13 is a total reflection surface.

[0053] It should be noted that the embodiment of the present application does not limit the surface shape of the first curved surface 12 located on the side of the first area A1 away from the light-emitting unit 2, and can be an aspherical surface or a free-form surface; the convex direction of the straight surface is not limited. Figure 5-10It is only exemplarily shown that the first curved surface 12 bulges in a direction away from the light emitting unit 2 , and the first curved surface 12 may also bulge in a direction close to the light emitting unit 2 .

[0054] In some embodiments, Figure 5 and 7 As shown, the light emitting device includes at least two light emitting units 2, and the first area A1 of the collimating lens 1 includes a first curved surface 12 corresponding to the light emitting units 2 one by one, and the arrangement direction of the first curved surface 12 is the same as the arrangement direction of the light emitting units 2, and both are arranged along the second direction Y, and the second direction Y is perpendicular to the first direction X. The first direction X is the fast axis direction of the laser incident on the collimating lens 1, and the second direction Y is the slow axis direction of the laser incident on the collimating lens 1.

[0055] Since the waveguide size of the light emitting unit 2 in the vertical direction is small, the beam quality of the emitted laser will produce a large divergence angle while approaching the diffraction limit, so this direction is defined as the fast axis, and the direction perpendicular to it is defined as the slow axis. The divergence angle of the light emitting unit 2 in the fast axis direction is greater than its divergence angle in the slow axis direction. For example, the divergence angle of the light emitting unit 2 in the fast axis direction is 40° to 60°, and the divergence angle of the light emitting unit 2 in the slow axis direction is 6° to 15°, and the size of the active area is generally 100μm to 500μm.

[0056] When the light emitting device includes a plurality of light emitting units 2, the light emitting units 2 are arranged in an array on the bottom plate 5, and the light emitting units 2 emit laser light along a first direction X, the first direction X is the column direction, and the second direction Y is the row direction. Figure 5 , the first direction X is the short side direction of the collimating lens 1, the second direction Y is the long side direction of the collimating lens 1, the first area A1 of the collimating lens 1 includes a first curved surface 12 corresponding to each light emitting unit 2, and the first curved surface 12 compresses and collimates the laser emitted by the corresponding light emitting unit 2 in the first direction X to reduce the divergence angle of the laser in the first direction X. The area where the first curved surface 12 is located is the first area A1, and along the first direction X, the second area A2 is located on at least one side of the first curved surface 12 (or the first area A1). The optical path adjustment unit 13 located in the second area A2 reflects the stray light of the light emitting unit 2 in the first direction X, and adjusts the optical path of this part of the stray light, so that the stray light after the optical path adjustment can be incident on the first area A1 and collimated by the first curved surface 12 located in the first area A1, and becomes collimated light that can be used by the back-end light source system, thereby improving the light energy utilization rate of the light emitting device.

[0057] In some embodiments, Figure 5-7As shown, the optical path adjustment unit 13 includes a first adjustment unit 131; the side of the collimating lens 1 facing the light-emitting unit 2 includes a groove, the bottom surface of the groove is the light incident surface 11, the light incident surface 11 is located in the first area A1, and the side wall of the groove is the first adjustment unit 131; wherein, the first adjustment unit 131 is used to adjust the optical path of the laser incident to the first adjustment unit 131, so that the laser after the optical path is adjusted can be incident to the light incident surface 11, enter the interior of the collimating lens 1 through the light incident surface 11, that is, enter the first area A1, and the first area collimates part of the laser.

[0058] In this embodiment, among the lasers emitted by the light-emitting unit 2, the lasers with a smaller divergence angle are directly incident on the light-entering surface 11. This part of the lasers enters the interior of the collimating lens 1 after passing through the light-entering surface 11, that is, it enters the first area A1, and is collimated by the first curved surface 12 located in the first area A1 and then emitted. The lasers with a larger divergence angle are incident on the first adjustment unit 131 located in the second area A2. The first adjustment unit 131 adjusts the optical path of this part of the lasers. The lasers after the optical path adjustment are incident on the light-entering surface 11, and enter the interior of the collimating lens 1 after passing through the light-entering surface 11, that is, it enters the first area A1, and is collimated by the first curved surface 12 located in the first area A1 to become collimated light, which can be used by the back-end light source system, thereby improving the light energy utilization rate of the light-emitting device.

[0059] Exemplarily, the first adjustment unit 131 is formed by coating a reflective film on the side wall of the groove, and the first adjustment unit 131 is an external reflective surface that reflects the laser incident to the first adjustment unit 131; or the first adjustment unit 131 is formed by providing a concave-convex microstructure on the side wall of the groove, and the laser incident to the first adjustment unit 131 is reflected and scattered. Exemplarily, as Figure 6 As shown, the collimating lens 1 is used to process the stray light in the optical path, wherein L1 represents the normal of the first adjustment unit 131, S1 represents the stray light, S2 represents the laser reflected by the first adjustment unit 131, S3 represents the collimated light, θ1 represents the incident angle, and θ2 represents the reflection angle. The first adjustment unit 131 is an external reflection surface, and the stray light S1 incident on the first adjustment unit 131 is reflected by the first adjustment unit 131; the reflected laser light S2 passes through the light incident surface 11 and is incident on the first curved surface 12, and becomes the collimated light S3 after passing through the first curved surface 12.

[0060] It should be noted that in order to clearly illustrate the optical path of stray light in the light emitting device, Figure 7 Only the stray light incident on the first adjustment unit 131 is shown, and the laser light directly incident on the light incident surface 11 is omitted. This does not mean that the collimating lens 1 does not collimate the laser light directly incident on the light incident surface 11 .

[0061] In some embodiments, Figure 6As shown in FIG8 , the included angle α between the first adjustment unit 131 and the light incident surface 11 satisfies: 110°≤α≤140°.

[0062] In this embodiment, the laser with a larger divergence angle will be incident on the first adjustment unit 131, and enter the collimating lens 1 after the optical path is adjusted by the first adjustment unit 131, and is collimated by the first curved surface 12 located in the first area A1. In order to ensure that all stray light can be incident on the first curved surface 12, the angle α between the first adjustment unit 131 and the light incident surface 11 is set in the range of [110°, 140°] (or the inclination angle of the adjustment unit is set between [40°, 70°]) so that the stray light can be completely reflected on the first curved surface 12 for collimation.

[0063] In some embodiments, Figure 8 As shown, along the direction in which the light emitting unit 2 points to the collimating lens, the depth H1 of the groove satisfies: 0.5 mm ≤ H1 ≤ 0.7 mm.

[0064] In this embodiment, the total thickness of the collimating lens 1 is between 1.5 mm and 2.5 mm. The collimating lens 1 needs to be grooved inwardly, and the groove depth H1 is set at 0.5 mm to 0.7 mm, which ensures that the laser emitted by the light-emitting unit 2 can be fully received, and the remaining thickness can ensure the overall strength of the collimating lens 1.

[0065] In some embodiments, Figure 7 As shown, the optical path distance D1 between the laser self-luminous unit 2 and the collimating lens 1 refers to the propagation distance between the light emitting side of the laser self-luminous unit 2 and the light incident surface 11 of the collimating lens 1, which must satisfy: 1.9mm≤D1≤2.2mm.

[0066] Since the laser is continuously diverging before passing through the collimating lens 1, that is, the spot size gradually increases with the increase of the light propagation distance, the width of the light incident surface 11 is related to the optical path distance of the laser. In order to ensure the miniaturization of the light emitting device, it is necessary to reduce the propagation distance of the laser (that is, the optical path distance D1) as much as possible, and the optical path distance D1 is set between 1.9mm and 2.2mm. Under this optical path, along the first direction X, the lateral width of the light incident surface 11 can be between 3.0mm and 3.4mm.

[0067] In some embodiments, Figure 8 As shown, the first curved surface 12 is arranged opposite to the light incident surface 11, and the width of the first curved surface 12 can be the same as the width of the light incident surface 11, that is, in the first direction X, the width W1 of the first curved surface 12 satisfies: 3.0mm≤W1≤3.4mm.

[0068] In the first direction X, the distance between the two end edges of the first curved surface 12 is the width W1 of the first curved surface 12 .

[0069] In some embodiments, the width of the first curved surface 12 is smaller than the width of the light incident surface 11. For example, the width of the light incident surface 11 is 3.2 mm, and the width of the first curved surface 12 is 3.0 mm. For another example, the width of the light incident surface 11 is 3.0 mm, and the width of the first curved surface 12 is 2.8 mm. For another example, the width of the light incident surface 11 is 3.6 mm, and the width of the first curved surface 12 is 3.4 mm.

[0070] In some embodiments, Figure 9-10 As shown, the optical path adjustment unit 13 includes a second adjustment unit 132, and the collimating lens 1 also includes: a light incident surface 11 located on the side of the collimating lens 1 facing the light-emitting unit; the laser emitted by the light-emitting unit enters the interior of the collimating lens 1 through the light incident surface, the laser incident on the first area A1 is collimated by the first area, and the laser incident on the second area A2 is incident on the first area A1 after the optical path is adjusted by the second adjustment unit 132, and this part of the laser is collimated by the first area A1.

[0071] Among them, the light incident surface 11 is distributed on the side of the first zone A1 and the second zone A2 facing the light-emitting unit 2, and is used to receive the laser emitted by the light-emitting unit 2 and allow the laser to enter the collimating lens 1. The second adjustment unit 132 adjusts the optical path of the laser incident to the second zone so that the laser after the adjusted optical path can be incident to the first zone A1 and collimated by the first zone A1.

[0072] Among the lasers emitted by the light-emitting unit 2, the lasers with a smaller divergence angle are directly incident on the light incident surface 11 located in the first area A1. After passing through the light incident surface 11, this part of the lasers enters the interior of the collimating lens 1 and is incident on the first curved surface 12. After being collimated by the first curved surface 12, it is emitted. The lasers with a larger divergence angle are incident on the light incident surface 11 located in the second area A2. After passing through the light incident surface 11, this part of the lasers enters the interior of the collimating lens 1 and is incident on the second adjustment unit 132. The second adjustment unit 132 adjusts the optical path of this part of the lasers. After the optical path is adjusted, the lasers are incident on the first curved surface 12 located in the first area A1. After passing through the first curved surface 12, they become collimated light, which can be used by the back-end light source system, thereby improving the light energy utilization rate of the light-emitting device.

[0073] For example, Fig. 9As shown, the collimating lens 1 is used to process the stray light in the optical path, wherein L2 represents the normal of the light incident surface 11, L3 represents the normal of the second adjustment unit 132, S4 represents stray light, S5 represents the laser light incident from the light incident surface, S6 represents the laser light reflected by the second adjustment unit 132, S7 represents collimated light, θ3 represents the incident angle of the stray light at the light incident surface, θ4 represents the refraction angle, θ5 represents the incident angle of the laser light at the second adjustment unit 132, and θ6 represents the reflection angle. The second adjustment unit 132 is an internal reflection surface, and the stray light S4 incident on the light incident surface 11 located in the second area A2 is refracted at the light incident surface 11 and enters the interior of the collimating lens 1, and the laser light S5 is incident on the second adjustment unit 132 and reflected. The reflected laser light S6 is incident on the first curved surface 12 located in the first area A1, and becomes the collimated light S7 after passing through the first curved surface 12.

[0074] It should be noted that in order to clearly illustrate the optical path of stray light in the light emitting device, Fig.10 Only the stray light incident on the light incident surface 11 located in the second area A2 is shown, and the laser directly incident on the light incident surface 11 located in the first area A1 is omitted, which does not mean that the collimating lens 1 does not collimate the laser incident on the light incident surface 11 located in the first area A1.

[0075] In some embodiments, Fig. 9 As shown in FIG. 11 , the angle β between the second adjustment unit 132 and the light incident surface 11 satisfies: 40°≤β≤50°

[0076] In this embodiment, the laser light with a larger divergence angle will be incident on the light incident surface 11 located in the second area A2 and enter the interior of the collimating lens 1. After the optical path of this part of the laser light is adjusted by the second adjustment unit 132, it will be incident on the first curved surface 12 and collimated by the first curved surface 12. In order to ensure that all stray light can be incident on the first curved surface 12, the angle β between the second adjustment unit 132 and the light incident surface 11 is set in the range of [40°, 50°], so that the stray light can be completely reflected on the first curved surface 12 for collimation.

[0077] In some embodiments, Fig.11 As shown, in this embodiment, when the light emitting unit 2 points to the direction of the collimating lens 1 (i.e. Fig.11 In the vertical direction in the image, the vertical distance between the light incident surface 11 and the vertex (i.e., the highest point) of the first curved surface 12 is the overall thickness H2 of the collimating lens 1, and the overall thickness H2 of the collimating lens 1 satisfies: 1.5mm≤H2≤2.0mm; the vertical distance between the vertex of the first curved surface 12 and the lowest point of the first curved surface 12 is the thickness H3 of the first curved surface, and the thickness H3 of the first curved surface 12 satisfies: 0.8mm≤H3≤1.1mm; the distance between the lowest point of the first curved surface 12 and the light incident surface 11 is H4, and H4 satisfies: 0.7mm≤H4≤0.9mm.

[0078] In some embodiments, Fig.10 As shown, the optical path distance D1 between the laser self-luminous unit 2 and the collimating lens 1 refers to the propagation distance between the light-emitting side of the laser self-luminous unit 2 and the light-entering surface 11 of the collimating lens 1, which must satisfy: 1.9mm≤D1≤2.2mm; in the direction perpendicular to the light-emitting unit 2 pointing to the collimating lens 1, the width W1 of the first curved surface 12 satisfies: 3.0mm≤W1≤3.4mm.

[0079] Since the laser is continuously diverging before passing through the collimating lens 1, that is, the spot size gradually increases with the increase of the light propagation distance, the width of the light incident surface 11 is related to the optical path distance of the laser. In order to ensure the miniaturization of the light-emitting device, it is necessary to reduce the propagation distance of the laser (that is, the optical path distance D1) as much as possible, and set the optical path distance D1 between 1.9mm and 2.2mm. In the first direction X, the distance between the two end edges of the first curved surface 12 is the width W1 of the first curved surface 12; within the above-mentioned optical path range, the width W1 of the first curved surface 12 can be between 3.0mm and 3.4mm. In this embodiment, the width of the light incident surface 11 is greater than the width of the first curved surface 12.

[0080] In some embodiments, Fig.12 As shown in FIG. 13 , the second area A2 includes a microstructure surface 14 . The microstructure surface 14 is located on a side of the second area A2 away from the light-emitting unit 2 and is used to collimate the laser incident on the microstructure surface 14 .

[0081] Due to the existence of manufacturing errors, the above parameters of the collimating lens 1 may exceed the design range, which may cause part of the stray light after the adjustment of the optical path to be incident on a position other than the first curved surface 12, such as the second area A2 on the other side of the first area A1. Therefore, a microstructure surface 14 is set on the side of the second area A2 away from the light-emitting unit (on the same side of the collimating lens 1 as the first curved surface 12), and the microstructure surface 14 is used to collimate this part of the stray light.

[0082] In one embodiment, Fig.12 As shown in FIG. 13 , in the first direction X, the width W2 of the microstructure surface 14 satisfies: 0.3 mm ≤ W1 ≤ 0.4 mm.

[0083] In some embodiments, Fig.14 As shown, the microstructure surface 14 includes diffraction units 141 .

[0084] The diffraction unit 141 has an uneven surface, and the surface morphology of the diffraction unit 141 can be set according to parameters such as the wavelength of the laser, the beam quality, and the near-field light intensity distribution. The diffraction unit 141 regulates the phase of the stray light. When the stray light passes through the diffraction unit 141, it can form a collimated beam at a certain distance. The processing effect of the diffraction unit 141 on the stray light is as follows: Fig.14 shown.

[0085] In some embodiments, Fig.15 As shown in FIG. 16 , a relief structure is provided on the surface of the diffraction unit 141 .

[0086] A relief may be formed on the side of the diffraction unit 141 away from the light incident surface 11 by etching, and the depth of the relief is at a sub-micron level.

[0087] It should be noted that Figure 14-15 The relief on the diffraction unit 141 is shown as a rectangular step, but does not limit the light emitting device provided in the embodiment of the present application. In other embodiments, the relief can also be set to other shapes, such as semicircular steps or triangular steps, which are not limited here.

[0088] In some embodiments, Fig.17 As shown, the microstructure surface 14 includes a Fresnel structure surface 142 .

[0089] In this embodiment, a Fresnel structure surface 142 is formed on the side of the second area A2 away from the light-emitting unit 2 by etching. The Fresnel structure surface 142 includes a series of sawtooth grooves, each of which has a different inclination angle, and each groove can be regarded as an independent small lens. When stray light with a divergent angle passes through the Fresnel structure surface 142, it can be corrected into parallel light. The Fresnel structure surface 142 actually uses the refraction principle of light to collimate the stray light, and forms contours with different angles as refraction surfaces in the second area A2 to achieve collimation of the stray light.

[0090] In some embodiments, Figure 18-22 As shown, the optical path adjustment unit 13 is not provided in the second area A2 of the collimating lens 1, but a second curved surface 15 is provided on the side of the second area A2 away from the light-emitting unit 2, and the second curved surface 15 collimates the stray light incident to the second area A2.

[0091] For example, Figure 20-21As shown, in the collimating lens 1, the second curved surface 15 is used to collimate the laser incident to the second area A2 of the collimating lens 1, so that this part of the laser can be used by the rear light source system, which is beneficial to improve the light energy utilization rate of the light emitting device. In this way, without increasing the size of the collimating lens 1, the second curved surface 15 is added on both sides of the first curved surface 12, and the second curved surface 15 can collimate the stray light not covered by the first curved surface 12, so as to collimate this part of the stray light into a usable light beam, thereby improving the light energy utilization rate of the light emitting device. The path of the second curved surface 15 is the same as the path of the first curved surface 12, the optical path of the laser does not change, and only the thickness parameter of the second curved surface 15 changes.

[0092] In some embodiments, the second curved surface 15 comprises a multifocal curved surface.

[0093] Among them, the second curved surface 15 is a single-focus curved surface, which can only collimate part of the stray light, and the stray light that does not pass through its focus still cannot be used and is diverged, and the collimation rate of the stray light is low. In this embodiment, the second curved surface 15 uses a multi-focus curved surface to collimate the stray light, which improves the collimation rate of the second curved surface 15 for the stray light, which is beneficial to improve the light energy utilization rate of the light-emitting device.

[0094] The embodiment of the present application does not limit the curvature radius of the multi-focal surface. The curvature radius of each surface may be the same or different, and is not limited here.

[0095] In some embodiments, the second curved surface 15 includes a multi-focal free surface, and the multi-focal free surface includes but is not limited to a diffraction surface and a Fresnel structure surface.

[0096] For example, Figure 18-20 As shown, the area where the first curved surface 12 is located is the first area A1, and along the first direction X, the second area A2 is located on both sides of the first curved surface 12 (or the first area A1); a second curved surface 15 is provided on the side of the second area A2 away from the light-emitting unit 2, and the second curved surface 15 is a Fresnel structure surface. The Fresnel structure surface collimates the incident stray light, so that this part of the stray light becomes collimated light that can be used by the back-end light source system, thereby improving the light energy utilization rate of the light-emitting device.

[0097] In some embodiments, Figure 21-24 As shown in any figure, the light emitting device further includes a base plate 5 , a tube shell 4 , a cover plate 6 and a turning component 3 .

[0098] The bottom plate 5 can be welded to the tube shell 4, and a circuit board can be printed inside the bottom plate 5 to realize the circuit interconnection function with the tube shell 4. The tube shell 4 and the bottom plate 5 can be welded and fixed by using tin-silver-copper alloy, and the welding method is not limited to reflow welding, and high-temperature pressure sintering silver paste (or copper paste) can also be used to achieve welding and fixing. The bottom plate 5 is made of metal materials such as oxygen-free copper and red copper.

[0099] The side wall 41 of the shell can be made of ceramic material or metal alloy material. The bottom of the shell is the patch area of ​​the light-emitting unit 2 and the steering component 3. Considering the patch accuracy and heat dissipation effect, the flatness of the bottom of the shell is relatively high, and materials with good heat dissipation such as oxygen-free copper and diamond are used. The bottom of the shell and the side wall 41 of the shell form the overall structure of the shell 4 through sintering. Both sides of the shell side wall 41 are stepped, and the steps 42 on both sides need to be plated with a metal film. The steps 42 on both sides can realize circuit conduction to the bottom of the shell, and finally interconnect with the bottom plate 5. The circular holes in the middle part of the steps 42 on both sides of the shell side wall 41 can be used as an identification area, and a global coordinate system is constructed through the circular holes on both sides. The middle rectangular part is a circuit isolation area, so that the electrical connections on both sides are independent of each other. An identification area can be set on one side of the shell side wall 41 for direction identification when used as a bottom plate.

[0100] In this embodiment, the laser emitted by the light emitting unit 2 needs to pass through the steering component 3, and the steering component 3 turns the light path back 90° to emit light. The steering component 3 is made of materials such as borosilicate glass, quartz and silicon, and the emitting surface of the steering component 3 is coated with an anti-reflection film to improve the reflectivity. Both the steering component 3 and the light emitting unit 2 can be fixed to the patch area at the bottom of the tube shell by low-temperature sintering of nano-metal slurry. After sintering, the thermal conductivity of the light emitting unit 2 and the mechanical reliability at high temperature are greatly improved.

[0101] The cover plate 6 is located at the top of the tube shell side wall 41, and is used to achieve the airtightness of the tube shell 4. The material of the cover plate 6 can be high-strength sapphire or glass. There needs to be a metal layer around the cover plate 6, and the rest is a light-transmitting area. The metal layer is combined with solder to achieve a high airtightness level. Alloy solder needs to be added to the metal layer around the cover plate 6 to achieve airtightness between the cover plate 6 and the tube shell 4. The thickness of the solder layer has a certain correlation with the processing flatness of the welding area of ​​the tube shell 4. After the alloy solder melts at a temperature above the melting point, it is used to fill the welding area. If the thickness of the alloy solder is less than the processing flatness of the welding area of ​​the tube shell 4, the solder cannot completely fill the welding area, resulting in poor airtightness.

[0102] The collimating lens 1 can be fixed by applying glue at the four corners, and the glue application positions need to avoid the optical effective area.

[0103] On the basis of the above implementation, the embodiment of the present application further provides a projection system, which includes: any one of the above-mentioned light-emitting devices, which has corresponding beneficial effects, and will not be described again here to avoid repeated description.

[0104] The projection system also includes all components known to those skilled in the art, such as a light valve modulation device and a projection lens, which are not limited here.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0106] For the convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A light emitting device, It is characterized in that include: A light emitting unit, configured to emit laser light in a first direction; A deflection component, located at the light-emitting side of the light-emitting unit, and used to deflect the laser light emitted by the light-emitting unit to the light-emitting surface side of the light-emitting device; A collimating lens, located on the light-emitting surface side, for receiving the laser light deflected by the steering component and collimating the received laser light; Wherein, the collimating lens comprises: A first region, used for collimating laser light incident to the first region; A second area, located on at least one side of the first area, and arranged along the first direction with the first area; The optical path adjustment unit is located in the second area and is used to adjust the optical path of the laser incident to the second area, so that the laser after the optical path adjustment is incident to the first area and is collimated by the first area.

2. The light emitting device according to claim 1, It is characterized in that The optical path adjustment unit includes a first adjustment unit; The collimating lens comprises a groove on one side facing the light emitting unit, the bottom surface of the groove is a light incident surface, the light incident surface is located in the first area, and the side wall of the groove is the first adjustment unit; The first adjustment unit is used to adjust the optical path of the laser incident on the first adjustment unit, so that the laser after the optical path is adjusted enters the collimating lens through the light incident surface and is collimated by the first area.

3. The light emitting device according to claim 2, It is characterized in that The included angle α between the first adjustment unit and the light incident surface satisfies: 110°≤α≤140°; and / or, The depth H1 of the groove satisfies: 0.5 mm ≤ H1 ≤ 0.7 mm.

4. The light emitting device according to claim 1, It is characterized in that The optical path adjustment unit includes a second adjustment unit; Wherein, the collimating lens further comprises: The light incident surface is located on the side of the collimating lens facing the light emitting unit; the laser emitted by the light emitting unit enters the interior of the collimating lens through the light incident surface, and the laser incident on the second area is incident on the first area after the optical path is adjusted by the second adjustment unit and is collimated by the first area.

5. The light emitting device according to claim 4, It is characterized in that The first zone includes: A first curved surface, located on a side of the collimating lens away from the light-emitting unit; Wherein, in the direction in which the light-emitting unit points to the collimating lens, the overall thickness H2 of the collimating lens satisfies: 1.5mm≤H2≤2.0mm; The thickness H3 of the first curved surface satisfies: 0.8mm≤H3≤1.1mm; A distance H4 between a side of the first curved surface close to the light incident surface and the light incident surface satisfies: 0.7 mm ≤ H4 ≤ 0.9 mm.

6. The light emitting device according to claim 4, It is characterized in that An included angle β between the second adjustment unit and the light incident surface satisfies: 40°≤β≤50°.

7. The light emitting device according to any one of claims 1 to 6, It is characterized in that The optical path distance D1 of the laser from the light emitting unit to the collimating lens satisfies: 1.9 mm ≤ D1 ≤ 2.2 mm; and / or, In the first direction, a width W1 of the first area satisfies: 3.0 mm≤W1≤3.4 mm.

8. The light emitting device according to any one of claims 1 to 6, It is characterized in that The second zone includes: The microstructure surface is located on a side of the collimating lens away from the light-emitting unit and is used to collimate the laser incident on the microstructure surface.

9. The light emitting device according to claim 8, It is characterized in that The microstructure surface includes a Fresnel structure surface and / or a diffraction unit.

10. A projection system, It is characterized in that include: A light-emitting device as claimed in any one of claims 1 to 9.

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