Light source module, optical fiber scanning display device and projection display apparatus

Abstract

Disclosed in the present application are a light source module, an optical fiber scanning display device and a projection display apparatus. The light source module comprises: a light source; and a pigtail fiber, which is arranged on an emission optical path of the light source, wherein the pigtail fiber comprises an optical fiber, and an optical fiber coupling end face of the optical fiber is an inclined end face.

Description

Optical source module, optical fiber scanning display device and projection display device TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to an optical source module, an optical fiber scanning display device and a projection display device. BACKGROUND

[0002] The imaging principle of the optical fiber scanning imaging technology is that a light corresponding to each pixel point of a to-be-displayed image is modulated by an optical source, then a high-frequency movement of a scanning optical fiber is driven by a scanner to scan and output the light corresponding to each pixel point, so that the light corresponding to each pixel point of the to-be-displayed image is projected onto a projection screen one by one to form a projection picture. The laser light source has the advantages of good monochromaticity, high brightness and wide color gamut, and can be used as the light source of the optical fiber scanning imaging technology.

[0003] The partial abnormality of the displayed image in the optical fiber scanning imaging technology mainly comes from the non-steady-state driving (high-frequency modulation driving) of the laser light source itself, the echo of the rear-end link and the instability (optical fiber mode disturbance) of the transmission link. In the actual product research and development of researchers, it is found that the echo from the link has the greatest impact on the stability of the displayed image and the imaging quality, including but not limited to abnormal scattering of optical elements, one-time or multiple reflections of interfaces and backscattering of optical fibers. SUMMARY

[0004] Based on the above, the present application provides an optical source module, an optical fiber scanning display device and a projection display device to ensure the stability of the displayed image in the optical fiber scanning display technology and improve the image quality. It can also be used to solve the technical problems in the prior art that certain regular stripes, noise points and other abnormalities are formed on the image of the optical fiber scanning imaging, which deteriorates the picture quality.

[0005] In order to achieve the above-mentioned application purposes, based on one aspect of the present application, the present application provides an optical source module, which comprises:

[0006] an optical source;

[0007] a tail fiber arranged on an exit light path of the optical source;

[0008] The tail fiber comprises an optical fiber, and an optical fiber coupling end face of the optical fiber is an inclined end face.

[0009] Based on another aspect of the present application, the present application provides an optical source module applied to an optical fiber scanning display device, wherein the optical source module comprises:

[0010] an optical source;

[0011] a tail fiber arranged on an exit light path of the optical source; the tail fiber comprises an optical fiber fixing structure and an optical fiber; the optical fiber protrudes from an end face of the optical fiber fixing structure, and an optical fiber coupling end face is an inclined end face.

[0012] According to another aspect of the present application, an embodiment of the present application provides a light source module, which comprises:

[0013] a plurality of light sources;

[0014] an optical fiber pigtail arranged on an outgoing light path of the light source;

[0015] the optical fiber pigtail comprises an optical fiber, and an optical fiber coupling end face of the optical fiber is an inclined end face;

[0016] a housing, the housing comprising a frame, and an opening is arranged on a side of the frame;

[0017] a bearing plate for bearing the plurality of light sources, the bearing plate being embedded in the opening.

[0018] According to another aspect of the present application, an embodiment of the present application provides a light source module, which comprises:

[0019] a light source;

[0020] a coupling lens;

[0021] an optical fiber pigtail, the optical fiber pigtail comprising an optical fiber and an optical fiber clamping structure, an optical fiber coupling end face of the optical fiber is an inclined end face, and light emitted by the light source is coupled into the optical fiber through the coupling lens; the optical fiber pigtail is arranged separately from the coupling lens, and the optical fiber pigtail is arranged obliquely relative to the coupling lens, so that an optical axis of the optical fiber coincides with an optical axis of the coupling lens.

[0022] According to another aspect of the present application, an embodiment of the present application provides a light source module, which comprises:

[0023] a light source;

[0024] an optical fiber pigtail arranged on an outgoing light path of the light source, the optical fiber pigtail comprising an optical fiber fixing structure and an optical fiber, the optical fiber protruding from an end face of the optical fiber fixing structure, and an end portion of the optical fiber comprising a stripe-eliminating structure, the stripe-eliminating structure being capable of dispersing reflected light formed by the end portion of the optical fiber when light is incident on the stripe-eliminating structure.

[0025] According to another aspect of the present application, an embodiment of the present application provides a light source module, which comprises:

[0026] a laser light source;

[0027] a coupling lens arranged on an outgoing light path of the laser light source, an entrance side and / or an exit side of the coupling lens being provided with an aperture stop;

[0028] an optical fiber pigtail arranged on an outgoing light path of the coupling lens, light emitted by the laser light source being coupled into the optical fiber pigtail through the coupling lens;

[0029] the optical fiber pigtail comprises an optical fiber, and an optical fiber coupling end face of the optical fiber is an inclined end face.

[0030] Based on another aspect of the present application, the embodiment of the present application provides a light source module, the light source module comprises:

[0031] a laser light source;

[0032] a coupling lens arranged on an outgoing light path of the laser light source, an entrance side and / or an exit side of the coupling lens being provided with an aperture stop;

[0033] a pigtail arranged on an outgoing light path of the coupling lens, light emitted by the laser light source being coupled into the pigtail through the coupling lens;

[0034] the pigtail comprises an optical fiber, and an optical fiber coupling end face of the optical fiber is a flat end face.

[0035] Based on another aspect of the present application, the embodiment of the present application provides a fiber scanning display device, comprising:

[0036] the light source module of any one of the preceding items;

[0037] a fiber scanning module, light emitted by the light source module being scanned and output by the fiber scanning module as display image light;

[0038] the fiber scanning module comprises an actuator, and an optical fiber light emitting end in the light source module is fixed on the actuator, the optical fiber exceeding the actuator and forming an optical fiber cantilever, the optical fiber cantilever being driven by the actuator to scan in space.

[0039] Based on another aspect of the present application, the embodiment of the present application provides a projection display device, comprising:

[0040] the light source module of any one of the preceding items;

[0041] a light scanning module;

[0042] the optical fiber between the light source module and the light scanning module is at least provided with a few-mode optical fiber or a single-mode optical fiber.

[0043] In the scheme of the embodiment of the present application, the optical fiber protrudes from the end face of the optical fiber fixing structure, and the optical fiber coupling end face is an inclined end face, which can avoid stray light caused by coupling of light into the glue used for bonding the optical fiber, thereby weakening image stripes and noise caused by backward conduction of the stray light into the laser, and thus the technical problem of the existing art of picture quality defects is alleviated, and the technical effect of improving imaging picture quality is achieved. Other features and advantages of the present application will be described in the subsequent specification, and some of them will become apparent from the specification, or will be understood by implementing the technical scheme of the present application. The purpose and other advantages of the present application can be achieved and obtained by the structure and / or process specifically pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0044] Other features, objects, and advantages of the application will become more apparent from the following detailed description when read in conjunction with the accompanying drawings:

[0045] Fig. 1 is a structural schematic diagram of a pigtail fiber according to an embodiment of the present application;

[0046] Fig. 2A is a light path schematic diagram of a light source module according to an embodiment of the present application;

[0047] Fig. 2B is a schematic diagram of a pigtail fiber according to an embodiment of the present application;

[0048] Fig. 2C is a schematic diagram of a fiber protruding ferrule end face according to an embodiment of the present application;

[0049] Fig. 3A is a display effect diagram of a fiber protruding length being too short according to an embodiment of the present application;

[0050] Fig. 3B is a display effect diagram of a fiber protruding length being too short according to an embodiment of the present application;

[0051] Fig. 3C is a display effect diagram of a fiber protruding length being too short according to an embodiment of the present application;

[0052] Fig. 3D is a display effect diagram of a fiber protruding length being too short according to an embodiment of the present application;

[0053] Fig. 4A is a display effect diagram of a fiber protruding length being 0.05 mm according to an embodiment of the present application;

[0054] Fig. 4B is a display effect diagram of a fiber protruding length being 0.05 mm according to an embodiment of the present application;

[0055] Fig. 4C is a display effect diagram of a fiber protruding length being 0.05 mm according to an embodiment of the present application;

[0056] Fig. 5A is a display effect diagram of a fiber protruding length being 0.1 mm according to an embodiment of the present application;

[0057] Fig. 5B is a display effect diagram of a fiber protruding length being 0.1 mm according to an embodiment of the present application;

[0058] Fig. 6A is a schematic diagram of a fiber coupling end face being an inclined end face according to an embodiment of the present application;

[0059] Fig. 6B is a display effect diagram of a multi-mode fiber inclined end face having an inclination angle of 15° according to an embodiment of the present application;

[0060] Fig. 6C is a display effect diagram of a multi-mode fiber inclined end face having an inclination angle of 18° according to an embodiment of the present application;

[0061] FIG. 6D is a display effect diagram of a multi-mode optical fiber inclined end surface with an inclination angle of 20° according to an embodiment of the present application;

[0062] FIG. 6E is a display effect diagram of a multi-mode optical fiber inclined end surface with an inclination angle of 8° according to an embodiment of the present application;

[0063] FIG. 6F is a display effect diagram of a multi-mode optical fiber inclined end surface with an inclination angle of 10° according to an embodiment of the present application;

[0064] FIG. 6G is a display effect diagram of a multi-mode optical fiber inclined end surface with an inclination angle of 13° according to an embodiment of the present application;

[0065] FIG. 6H is a display effect diagram of a single-mode optical fiber inclined end surface with an inclination angle of 0° according to an embodiment of the present application;

[0066] FIG. 6I is a display effect diagram of a single-mode optical fiber inclined end surface with an inclination angle of 3° according to an embodiment of the present application;

[0067] FIG. 6J is a physical diagram of a fiber coupling end surface being flat according to an embodiment of the present application;

[0068] FIG. 7A is a schematic diagram of a fiber coupling end surface being arc-shaped according to an embodiment of the present application;

[0069] FIG. 7B is a display effect diagram of a fiber coupling end surface being flat according to an embodiment of the present application;

[0070] FIG. 7C is a display effect diagram of a fiber coupling end surface being arc-shaped according to an embodiment of the present application;

[0071] FIG. 7D is a display effect diagram of an arc-shaped cutting of a fiber coupling end surface of a single-mode optical fiber with an inclination angle of 3° according to an embodiment of the present application;

[0072] FIG. 7E is a display effect diagram of an arc-shaped cutting of a fiber coupling end surface of a few-mode optical fiber with an inclination angle of 3° according to an embodiment of the present application;

[0073] FIG. 7F is a physical diagram of a fiber coupling end surface being arc-shaped according to an embodiment of the present application;

[0074] FIG. 8 is a schematic diagram of a fiber coupling end surface being spherical according to an embodiment of the present application;

[0075] FIG. 9A is a schematic diagram of a fiber end portion provided with a spherical lens according to an embodiment of the present application;

[0076] FIG. 9B is a physical diagram of a fiber end portion provided with a spherical lens according to an embodiment of the present application;

[0077] FIG. 9C is a display effect diagram of a fiber end portion provided with a spherical lens according to an embodiment of the present application;

[0078] FIG. 10 is a structural schematic diagram of a light source module according to an embodiment of the present application;

[0079] FIG. 11 is a schematic diagram of an optical positioning plate according to an embodiment of the present application;

[0080] FIG. 12 is a schematic diagram of a groove according to an embodiment of the present application;

[0081] FIGS. 13 and 14 are schematic diagrams of a tooth-shaped splicing structure according to an embodiment of the present application.

[0082] FIG. 15 is a schematic diagram of the positional relationship between a pigtail component and a coupling lens according to an embodiment of the present application;

[0083] FIG. 16 is another structural schematic diagram of a light source module according to an embodiment of the present application;

[0084] FIG. 17 is a structural schematic diagram of a pigtail component according to an embodiment of the present application;

[0085] FIG. 18 is a structural schematic diagram of another possible light source module according to an embodiment of the present application;

[0086] FIG. 19 is a schematic diagram of a fiber scanning imaging system according to an embodiment of the present application;

[0087] FIG. 20 is a schematic diagram of the structure of a pigtail, a coupling lens and an aperture stop of a light source module according to an embodiment of the present application;

[0088] FIG. 21 is a light scanning display imaging target display diagram according to an embodiment of the present application;

[0089] FIG. 22 is a fiber scanning display imaging diagram of the fiber coupling end face of a single-mode fiber at different angles according to an embodiment of the present application;

[0090] FIG. 23 is a fiber scanning display imaging diagram of different inclination angles of the fiber coupling end face of a single-mode fiber and the reflectivity of a film according to an embodiment of the present application;

[0091] FIG. 24 is a fiber scanning display imaging diagram of the fiber coupling end face of a multi-mode fiber being a flat end face and the green light normal incidence reflectivity of the anti-reflection film being 1.5% according to an embodiment of the present application;

[0092] FIG. 25 is a fiber scanning display imaging diagram of the fiber coupling end face of a multi-mode fiber at different inclination angles according to an embodiment of the present application;

[0093] FIG. 26 is a fiber scanning display imaging diagram of the fiber coupling end face of a multi-mode fiber at different inclination angles and the normal incidence reflectivity of an anti-reflection film according to an embodiment of the present application;

[0094] FIG. 27 is a fiber scanning display imaging diagram of the fiber coupling end face of the multi-mode fiber at different tilt angles and normal incidence reflectivity of the anti-reflection film according to an embodiment of the present application;

[0095] FIG. 28 is a structure schematic diagram of the fiber coupling end face of the light source module according to an embodiment of the present application;

[0096] FIG. 29 is a fiber scanning display imaging diagram of the fiber coupling end face of the single-mode fiber at different anti-reflection films according to an embodiment of the present application;

[0097] FIG. 30 is a schematic diagram of a housing structure corresponding to the pigtail according to an embodiment of the present application;

[0098] FIG. 31 is a schematic diagram of another housing structure corresponding to the pigtail according to an embodiment of the present application;

[0099] FIG. 32 is a schematic diagram of still another housing structure corresponding to the pigtail according to an embodiment of the present application;

[0100] FIG. 33 is a schematic diagram of yet another housing structure corresponding to the pigtail according to an embodiment of the present application;

[0101] FIG. 34 is a light path schematic diagram of the optical module according to an embodiment of the present application;

[0102] FIG. 35A is a light path schematic diagram of the optical module in which the polarization beam combiner is placed obliquely according to an embodiment of the present application;

[0103] FIG. 35B is a schematic diagram of another polarization beam combiner according to an embodiment of the present application;

[0104] FIG. 36 is a light path schematic diagram of the optical module using a sheet polarization beam combiner according to an embodiment of the present application;

[0105] FIG. 37 is a structure schematic diagram of the sheet polarization beam combiner according to an embodiment of the present application;

[0106] FIG. 38 is a partial structure schematic diagram of the base and the semiconductor laser of the optical module according to an embodiment of the present application;

[0107] FIG. 39 is a structure schematic diagram of the projection display device according to an embodiment of the present application;

[0108] FIG. 40 is a fiber scanning display imaging diagram of the connector at different positions according to an embodiment of the present application.

[0109] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Embodiments of the present application

[0110] The application will be described in further detail below with reference to the drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application. It is also to be understood that, for the purpose of clarity, only related portions of the drawings are shown in the figures.

[0111] It should be noted that the terms "first", "second", and the like, in the description and in the claims of the present application as well as above-mentioned drawings mean for the purposes of distinguishing similar elements and are not necessarily used to describe a sequence or an order, unless otherwise specified. It will be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operating in other sequences than illustrated or otherwise described herein. Moreover, the terms "include", "have", and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, product or apparatus that comprises a list of steps or units are not necessarily limited to those steps or units that are expressly listed, but can include additional steps or units not expressly listed or inherent to such process, method, product or apparatus.

[0112] Referring to FIG. 1, FIG. 1 is a schematic diagram of a pigtail of a light source module according to an embodiment of the application. The light source module includes a light source (also referred to as a light module); a pigtail 24 disposed on an outgoing light path of the light source; the pigtail 24 includes an optical fiber, and a fiber coupling end face 240 of the optical fiber is an inclined end face, so that reflected light of the fiber coupling end face 240 deviates from the optical axis and is reflected, thereby reducing the proportion of reflected echoes generated at the fiber coupling end face 240 from entering a semiconductor laser of the laser light source, reducing the influence of the reflected echoes generated at the fiber coupling end face 240 on the semiconductor laser, and ensuring stable output of the semiconductor laser.

[0113] Referring to FIG. 2A and FIG. 2B, FIG. 2A is a schematic diagram of a light path of a light source module according to an embodiment of the application, and FIG. 2B is a schematic diagram of a pigtail according to an embodiment of the application. The light source module includes a light source 101; a pigtail disposed on an outgoing light path of the light source 101; the pigtail includes an optical fiber fixing structure 103 and an optical fiber 104; the optical fiber 104 protrudes from an end face 105 of the optical fiber fixing structure 103, and a fiber coupling end face 106 is an inclined end face. It should be understood that, in the embodiment of the application, light emitted by the light source 101 is coupled into the optical fiber 104 from the fiber coupling end face.

[0114] In the embodiment of the present application, the end face 105 of the optical fiber fixing structure 103 plays a role of directly fixing and limiting lateral displacement of the optical fiber 104. The optical fiber fixing structure 103 can be a ferrule, such as a ceramic ferrule or a ferrule made of other materials. The optical fiber fixing structure 103 can also be a fiber clamping structure, which includes a clamping structure main body and a through hole for the optical fiber 104 to pass through. The optical fiber fixing structure 103 can also be a flat plate structure, and the optical fiber 104 can be arranged on the surface of the flat plate structure and be bonded between the optical fiber 104 and the flat plate structure by curing glue. In the specific implementation process, the optical fiber fixing structure 103 can play a role of fixing the optical fiber 104, and the specific form of the optical fiber fixing structure 103 is not limited in the present application.

[0115] In the embodiment of the present application, in order to increase the stability between the optical fiber fixing structure 103 and the optical fiber 104, curing glue can be used to bond the optical fiber fixing structure 103 and the optical fiber 104. If the optical fiber 104 and the optical fiber fixing structure 103 are bonded by curing glue, at least a part of the side of the optical fiber 104 close to the optical fiber coupling end face 106 is not covered by the curing glue, in other words, at least a part of the side of the optical fiber 104 close to the optical fiber coupling end face 106 protrudes from the curing glue for fixing the optical fiber.

[0116] It should be noted that when the optical fiber 104 and the optical fiber fixing structure 103 are bonded by curing glue, in some cases, the length of the optical fiber 104 protruding from the end face 105 of the optical fiber fixing structure 103 can also refer to the length of the optical fiber 104 protruding from the curing glue, that is, the length of the side of the optical fiber 104 close to the optical fiber coupling end face 106 which is not covered by the curing glue. Specifically, when the end face 105 of the optical fiber fixing structure 103 is flush with the curing glue, the length of the optical fiber 104 protruding from the end face 105 of the optical fiber fixing structure 103 is the same as the length of the optical fiber 104 protruding from the curing glue. When the curing glue exceeds the end face of the optical fiber fixing structure 103, the length of the optical fiber 104 protruding from the end face 105 of the optical fiber fixing structure 103 can refer to the length of the optical fiber 104 protruding from the edge of the curing glue on the surface of the optical fiber 104.

[0117] In the embodiment of the present application, the optical fiber fixing structure 103 is taken as a ferrule for example for description. In order to eliminate the stripes, the optical fiber coupling end face 106 also needs to be processed on the basis of the optical fiber 104 protruding from the ferrule end face structure for the light source module. The following embodiments will respectively describe the processing methods of the optical fiber 104 protruding from the ferrule end face structure and the optical fiber coupling end face 106. It should be noted that in the embodiment of the present application, the verification of the stripe elimination effect is carried out under the premise of realizing high coupling efficiency (≥40%) and under the condition that the optical fiber 104 protruding from the ferrule end face structure and the optical fiber coupling end face 106 are inclined end faces.

[0118] As a possible implementation, referring to FIG. 2C, the fiber fixing structure 103 can be a ferrule 107, and the length of the fiber 104 protruding from the ferrule end face 108 is 0.05mm to 5mm, wherein the length of the fiber 104 protruding from the ferrule end face 108 is defined as follows: a point on the coupling end face of the fiber 104 extends along the fiber axis in the direction of the ferrule 107 until it is truncated by the ferrule end face, and the shortest distance in the line segment formed is the length of the fiber 104 protruding from the ferrule end face 108.

[0119] In the embodiments of the present application, when the length of the fiber 104 protruding from the ferrule end face 108 exceeds the above range, it will cause unexpected imaging quality problems and performance problems. Specifically, when the length of the fiber 104 protruding from the ferrule end face 108 is too short, the stray light formed after the laser output by the light source 101 is coupled into the fiber 104 and then reflected by the fiber coupling end face 106 presents obvious diffraction ring characteristics, as shown in FIG. 3A, and the cutting length of the fiber, i.e., the length of the fiber 104 protruding from the ferrule end face 108, is about 0.02mm. In this case, the “reflected” light is stray light with a large angle, which is difficult to eliminate, and is light that is strongly scattered and back-propagated, and this part of stray light will cause poor display effect, and the corresponding display stripe effect is shown in FIG. 3B. It should be noted that scattering refers to light scattered by the glue (i.e., cured glue) used to fix the fiber 104 in the ferrule, back-propagation refers to the back propagation of light away from the target direction after scattering by the glue, the target direction is the transmission of the coupled-in fiber 104 to the scanner, and scattering and back-propagation refer to the propagation of light scattered by the glue in the direction away from the light source. For a multi-mode fiber, when the length of the fiber 104 protruding from the ferrule end face 108 is too short, no matter how large the cutting angle of the coupling end face is, it is impossible to completely eliminate the display stripes while achieving high coupling efficiency, and the difference in coupling state will affect the distribution state of the stripes, and a typical comparison is shown in FIGS. 3B and 3D.

[0120] The above-mentioned reflected light is mainly from back scattering rather than reflection of the fiber coupling end face, because when fine adjustment of coupling is performed, it can be observed that another relatively concentrated uniform light spot moves according to the adjustment direction, and the above-mentioned ring is basically unchanged, as shown in FIG. 3C, and the obviously blurred part seen in FIG. 3A is a relatively concentrated uniform light spot superimposed in the ring. During the coupling adjustment process, the blurred light spot will move accordingly along the adjustment direction, which is the echo of the direct reflection of the fiber coupling end face, and during the coupling adjustment process, the distribution of the ring is always unchanged, which is that the image form corresponding to the back scattering light is different, and the stripe distribution state changes, as shown in FIG. 3D, because the adjustment process is accompanied by changes in coupling efficiency, mode matching and output power, so the stripe distribution state will be different.

[0121] When the protruding length of the optical fiber 104 is too long, the stability of the device is reduced, and the risk of accidental breakage of the optical fiber is increased. When the device encounters instantaneous acceleration impact, vibration, etc., the protruding part of the optical fiber may produce relative displacement, resulting in a rapid decrease in coupling efficiency.

[0122] When the protruding length becomes 0.05 mm, the circular ring distribution area formed by the backscattered light is obviously more concentrated, as shown in FIG. 4A. At this time, under fine adjustment, a relatively good display effect can be achieved, and the display effect diagram is shown in FIG. 4B. In the vicinity of the maximum coupling efficiency, a relatively good display effect can be achieved. When the coupling efficiency deviates by about 1%~2% (as shown in FIG. 4C), the image is obviously deteriorated. Therefore, in order to ensure the image quality, the coupling stability of the light source module needs to be high. It can be seen that under the protruding length of 0.05 mm, if the coupling efficiency during the device manufacturing is high and the stability is good, a relatively good display effect can still be achieved. It should be noted that under the protruding length of 0.05 mm, the coupling end face of the cut optical fiber with a larger angle is verified, and similar characteristics are exhibited. Therefore, in the embodiments of the present application, the length of the protruding ferrule end face 108 of the optical fiber 104 is 0.05 mm, which is a relatively extreme length parameter.

[0123] When the protruding length of the optical fiber is 0.1 mm, as shown in FIG. 5A, the light spot reflected by the optical fiber coupling end face is relatively uniform, and there is no obvious stray light characteristic. There is no circular ring, but a concentrated light spot. It can be seen that the effect of the protruding ferrule end face 108 of the optical fiber on the suppression of stray light is very obvious, and the imaging display effect is also good. The state of coupling adjustment is very low in sensitivity. As long as it is near the maximum coupling efficiency, there is no stripe, and the display effect is shown in FIG. 5B. Therefore, as a preferred embodiment in the present application, the length of the protruding ferrule end face 108 of the optical fiber 104 is 0.1 mm to 5 mm.

[0124] Next, the processing method of the optical fiber coupling end face is described. In the specific implementation process, the following processing methods are included but not limited to.

[0125] In a possible implementation, the fiber coupling end face is an inclined end face, and the end face is a plane, as shown in FIGS. 6A and 6J. For a multimode optical fiber, the inclination angle of the inclined end face is greater than or equal to 15°, and the display effects of different angles are shown in FIGS. 6B-6G. FIGS. 6B-6D respectively show the display effects of inclination angles of 15°, 18°, and 20°, and FIGS. 6E-6G respectively show the display effects of inclination angles of 8°, 10°, and 13°. For a single-mode optical fiber, the inclination angle of the inclined end face is greater than or equal to 3°, and the display effects of different angles are shown in FIGS. 6H and 6I. FIGS. 6H and 6I respectively show the display effects of 0° cutting and 3° cutting. It should be noted that the fiber coupling end face is an inclined end face, which means that the plane where the interface between the fiber coupling end face or the fiber core and the air is located is not perpendicular to the optical axis of the optical fiber, but is inclined to intersect. It should also be noted that, in the embodiments of the present application, the multimode optical fiber refers to a visible light multimode optical fiber. The commonly used single-mode optical fiber is for a communication waveband, and the conventional 9um communication optical fiber is single-mode for the communication waveband, but is multimode for visible light. The multimode refers to that the number of linearly polarized (LP) modes is greater than or equal to 3, and the single mode refers to that there is only one stable transmission mode. The few-mode optical fiber in the subsequent embodiments of the present application refers to an optical fiber containing two stable propagation modes.

[0126] In another possible implementation, the fiber coupling end face is an arc face, as shown in FIGS. 7A and 7F. For a multimode optical fiber, the inclination angle of the inclined end face is greater than or equal to 10°. Since the cutting surface is not a plane but an arc face with a certain curvature, the arc face can increase the effect of eliminating the stripes, as shown in FIGS. 7B and 7C, which are display effect comparison diagrams of the cutting surfaces being a plane and an arc face respectively under the same inclination angle. Specifically, FIGS. 7B and 7C show the display effects of an optical fiber with a fiber core of 9um under the same inclination angle (10°). Compared with the conventional plug-in core and the stripe elimination scheme of coating the fiber coupling end face (the inclination angle of the fiber coupling end face is not less than 13°), when the fiber coupling end face is an arc face, the required angle of the fiber coupling end face is smaller, and the tolerance is larger. The arc face makes the reflected light of the fiber coupling end face more dispersed, and thus less light enters the light source in the reverse direction. The effect is similar to that achieved by coating. It should be noted that when the angle of the fiber coupling end face is large, although the angle at which the end face reflected light deviates from the optical axis of the coupling lens is large, the end face reflected light still reflects back and forth inside the shell of the light source module to form stray light, causing a part of the end face reflected light to enter the light source.

[0127] As can be seen from FIGS. 7B and 7C, at the same cutting angle, the curved surface cutting is better than the flat surface cutting. In addition, the tolerance of the fiber coupling end face angle is higher when a fiber with a smaller core, a fiber with fewer modes or a single mode fiber is used. For example, for a single mode fiber, a good display effect can be achieved when the cutting angle reaches 3°. As shown in FIG. 7D, it is a display effect diagram of the curved surface cutting when the tilt angle of the fiber coupling end face of the single mode fiber is 3°. As shown in FIG. 7E, it is a display effect diagram of the curved surface cutting when the tilt angle of the fiber coupling end face of the few-mode fiber is 3° and the cutting length is 0.5 mm. Compared with the previous scheme of using a conventional tilt ferrule with a coating film, the curved surface cutting has a higher tolerance to the tilt angle, because the coating film can only reduce the echo caused by the reflection of the end face, while the curved surface cutting in the present case can make the end face reflection wave more dispersed, and greatly weaken the echo of the back scattering, so that the effect of eliminating the stripes is better.

[0128] In the embodiment in which the fiber coupling end face is a tilted end face or a curved surface, the light source module includes a coupling lens 102 arranged on the light path of the light source 101; the light emitted by the light source 101 is coupled into the fiber 104 through the coupling lens 102.

[0129] In another possible implementation, as shown in FIG. 8, the fiber coupling end face is a spherical surface. Forming the fiber coupling end face into a spherical surface through ablation or the like can bring additional benefits, especially for single mode fibers and few-mode fibers. The spherical fiber has a higher tolerance to echo, and the spherical surface symmetrical along the optical axis of the fiber can achieve a good stripe elimination effect. As a result, the fiber can be placed without tilting, reducing the difficulty of processing positioning and assembly production. Further, through matching of the spherical surface parameters, the external coupling lens can be omitted, saving cost, reducing the adjustment steps and reducing the volume.

[0130] In another possible implementation, as shown in FIGS. 9A and 9B, a spherical lens is arranged at the end of the fiber. As shown in FIG. 9C, it is a display effect diagram when a spherical lens is arranged at the end of the fiber. Generally speaking, the more the fiber modes (the larger the core size), the larger the cutting angle needs to be. The fewer the fiber modes, the greater the angle compatibility, and even a 0-degree combination of the spherical end face or the spherical lens can be used to achieve a good display effect.

[0131] In the embodiment of the present application, an anti-reflection film or a reflection elimination film can also be arranged at the fiber coupling end face to reduce the reflection of the fiber coupling end face.

[0132] In the embodiment of the present application, the fiber fixing structure can also adopt a tail handle of any angle (such as an inclined tail handle) as an auxiliary clamping structure of the optical fiber. The inclined tail handle is a structure in which the axial direction is not coincident with the optical axis of the coupling lens. When the fiber coupling end face is an inclined end face, the inclined tail handle structure can compensate for the deviation between the optical axis of the optical fiber and the optical axis of the coupling lens, thereby increasing the coupling efficiency of the optical fiber.

[0133] In the embodiment of the present application, researchers found that the displayed stripes are caused by stray light, and reflection and scattering can cause stray light. In the scheme of the embodiment of the present application, laser cutting is adopted to protrude the end face of the optical fiber, and the use of grinding is avoided, which can greatly improve the production capacity and reduce the cost. Further, the laser cutting can have a curvature. Compared with the case where the fiber coupling end face is flat, the scheme of arc surface cutting has good echo suppression effect and can save the cost of coating. The protruding ferrule of the optical fiber can also reduce the problem of glue scattering in the coupling of the initial section of the optical fiber, thereby reducing the echo and eliminating the display stripes.

[0134] When the fiber coupling end face of the protruding ferrule end face meets the corresponding angle, the echo directly reflected from the small-angle face type can be avoided from entering the laser light source, and the proportion of the echo returned by the corresponding angle backscattering is smaller, and the corresponding transmission mode can be better matched and excited.

[0135] The foregoing FIGS. 1-9C correspond to the embodiments of the tail fiber part of the light source module. Next, the shell structure of the light source module is described.

[0136] Please refer to FIG. 10, the embodiment of the present application provides a light source module, which includes a shell and a plurality of light sources; the shell includes a frame body 111, the side surface of the frame body 111 is provided with an opening; a bearing plate 112 is used for bearing a plurality of light sources, and the bearing plate 112 is embedded in the opening.

[0137] In the embodiment of the present application, the frame body 111 and the bearing plate 112 can adopt different materials. Generally, the materials adopted by the frame body 111 and the bearing plate 112 are required to have strong anti-external force interference ability. The frame body 111 as the main material is also required to have a relatively low price to reduce the cost. For the bearing plate 112, the thermal stability of the bearing plate 112 is better than that of the frame body 111, so as to ensure the stable performance of the light source and other devices mounted on the bearing plate 112.

[0138] In a possible implementation, in order to reduce the cost while taking into account the manufacturability, the shell is spliced, the frame 111 is made of aluminum alloy, the aluminum alloy has the advantages of high hardness, high strength, light weight, pressure casting, low mass production price, etc., at the same time, the aluminum alloy also has the problems of large thermal expansion coefficient, low reliability, not easy to weld for the light source, etc., therefore, in the embodiment of the present application, the material of the bearing plate 112 for bearing the light source is Kovar alloy or other reliable materials, such as alumina ceramic, nitride ceramic, zirconia ceramic, silicon carbide, quartz glass, diamond, nickel-iron-gallium alloy, etc., so that the module structure is simple, small in size, high in reliability, easy to process and low in cost.

[0139] Considering that the thermal expansion coefficient of the aluminum alloy is large, it is easy to be affected by temperature and deformed, resulting in changes in the relative positions of various elements on the optical link, in the embodiment of the present application, as shown in FIG. 11, a piece of material with good thermal stability is laid on the bottom of the aluminum alloy frame as an optical positioning plate 113, the optical positioning plate 113 can be selected from materials such as Kovar alloy, ceramic (such as alumina ceramic, zirconia ceramic, aluminum nitride ceramic, silicon carbide ceramic, etc.), glass, etc., considering the weight and cost, alumina ceramic is preferred, optical elements including lenses, PBS (polarization beam splitter prism), pigtail fibers, mirrors, etc., can be adjusted and fixed on the optical positioning plate 113, since the thermal expansion coefficient of the optical positioning plate 113 is small, the optical coupling efficiency can be ensured to be less affected by temperature.

[0140] It should be noted that in the embodiment of the present application, the optical fiber light emitting direction is taken as the forward direction, the direction of the light source module shown in FIG. 10 from right to left is the forward direction, the bearing plate 112 is located on the left side of the frame 111, and the optical positioning plate 113 is located at the bottom of the frame 111, the viewing angles of the various figures in the present application are all adopted in this position relationship for the purpose of illustrating the scheme, but it should be understood that those skilled in the art can also adjust the positions of various optical devices according to actual needs, which is not limited in the present application.

[0141] In the embodiment of the present application, in order to reduce the cost, the direct gluing method can be selected between the bottom of the frame 111 and the optical positioning plate 113, considering that the thermal mismatch between the optical positioning plate 113 with high thermal stability and the aluminum alloy is serious, the glue bonding surface may be peeled off due to thermal expansion and contraction in the interval of sharp temperature change, in order to alleviate the above problem, as shown in FIG. 12, some surface treatment can be performed on the aluminum alloy bonding surface, such as scoring some grooves, on the one hand, the grooves can be used as expansion joints to buffer the transverse (which can be considered as the direction parallel to the bonding surface) stress acting directly on the bonding surface, greatly reducing the possibility of glue peeling, on the other hand, the grooves can increase the infiltration of the glue and the aluminum alloy, produce the effect of grip, and make the bonding more firm.

[0142] In the embodiments of the present application, as shown in FIG. 13 and FIG. 14, the edges of the bearing plate 112 and the inner side of the opening of the frame are provided with intermatching and staggered tooth-shaped splicing structures, similar to mortise and tenon structures. Such structures can increase stability when the temperature changes. In other embodiments, mechanical reinforcement can also be used, such as screw fixation.

[0143] In a possible implementation, the frame 111 can also be made of ceramic materials, such as zirconia ceramic, alumina ceramic, aluminum nitride ceramic, etc. Taking alumina ceramic or toughened alumina ceramic as an example, the alumina ceramic or toughened alumina ceramic has the advantages of low cost, high hardness, high thermal stability, injection molding, low batch manufacturing cost, light weight, and similar thermal conductivity to Kovar alloy. The zirconia ceramic has the advantage of relatively good drop performance. The toughened alumina ceramic can greatly improve the drop reliability. After using ceramic design for the frame 111, the optical positioning plate can be removed, and the optical element can be directly arranged at the bottom of the shell. If the shell is made of aluminum nitride ceramic, the thermal conductivity can be further improved, which is especially suitable for AR application scenarios. Based on the above technical solutions, the requirements of high productivity, high reliability, and low weight can be met.

[0144] In the embodiments of the present application, considering the fragile characteristics of ceramic, protection design can be performed at key positions of the shell, such as internal reinforcing ribs and the like. On the outside of the shell, the corners are designed with rounded corners, and the structure of the edge and corner is wrapped, and the wrapping material can be selected from conventional aluminum alloy (good toughness), silicone, foam, and other conventional processing methods as a buffer.

[0145] In the embodiments of the present application, the light source can be a laser light source, such as a laser diode. The number of light sources in the drawings is only illustrative, and the embodiments of the present application do not limit the type and number of light sources.

[0146] Next, the setting method of the fiber tail part and the coupling lens will be described.

[0147] The present application finds that, in order to reduce the unique stripe phenomenon in fiber scanning imaging, it is required that the echoes formed by reflection and scattering of the device as little as possible enter the laser, and therefore, when the laser is coupled into the optical fiber, the central light is incident on the coupling end face of the optical fiber deviating from the vertical direction. The solution is to place the optical fiber obliquely or use an inclined end face. In the traditional scheme of assembling through the shaft cooperation of mechanical precision, in order to make the coupling efficiency as large as possible, the machining precision of the inclined tail handle used for clamping the optical fiber needs to be extremely high, especially for the large-angle inclined tail handle, the machining precision needs to be 1 um or even below, which leads to extremely high processing difficulty and cost. Therefore, in the scheme of the present application, a separate compensation adjustment scheme is used, which can greatly compress the cost.

[0148] Please refer to FIG. 15 and FIG. 16, the embodiment of the application provides a light source module, comprising a light source 121, a coupling lens 122 and a fiber tail component; the fiber tail component comprises an optical fiber 123 and an optical fiber clamping structure 124, the optical fiber coupling end face 125 of the optical fiber 123 is an inclined end face, the light emitted by the light source 121 is coupled into the optical fiber 123 from the optical fiber coupling end face 125 through the coupling lens 122; the fiber tail component is arranged separately from the coupling lens 122, and the fiber tail component is placed obliquely relative to the coupling lens 122, so that the optical axis of the optical fiber 123 and the optical axis of the coupling lens 122 coincide. It should be understood that the two dashed lines shown in FIG. 15 respectively represent the optical axis of the optical fiber 123 and the optical axis of the coupling lens 122, and the two optical axes are in a non-coincidence state, but the two optical axes can be made to coincide by adjusting the fiber tail component.

[0149] In the embodiment of the application, the way in which the optical fiber clamping structure 124 clamps and fixes the optical fiber 123 to form the fiber tail component can not only simplify the machining precision requirement of clamping the optical fiber inclined tail in the conventional light source assembly scheme, but also can realize the coincidence of the optical axes between the optical fiber 123 and the coupling lens 122 by separately adjusting the fiber tail component and the coupling lens 122, even if the end face of the optical fiber 123 is cut at an arbitrary angle according to actual needs; and the way of using the fiber tail component also simplifies the structure form, and the optical fiber clamping structure 124 can be compatible with the structure form of ordinary ceramic ferrule or no ceramic ferrule, which can effectively reduce the cost.

[0150] Specifically, in the above scheme, the overall angle of the fiber tail component is adjustable, and the positional relationship between the fiber tail component and the coupling lens 122 can be adjusted obliquely according to the cutting angle of the optical fiber, and the fiber tail component and the coupling lens 122 are placed at an inclined angle, so that the optical axis of the optical fiber 123 and the optical axis of the coupling lens 122 coincide, without eccentricity and defocus, and the light coupling efficiency is maximum. The optical axis alignment between the optical fiber 123 and the coupling lens 122 is realized by separate adjustment, which can ensure the coincidence of the optical axes without using machining precision, thereby avoiding the problems of great difficulty in machining and high cost.

[0151] In a possible implementation, as shown in FIG. 17, the fiber clamping structure 124 includes a clamping structure body 1241 and a through hole 1242 for the fiber 123 or the ferrule to pass through, the clamping structure body 1241 can be designed into a square, trapezoidal, irregular shape, etc. according to actual needs, which is not limited in the present application. The fiber end can be provided with a ferrule 126 including a through hole for the fiber to pass through, the fiber 123 can protrude from the end face of the ferrule 126, which can avoid stray light caused by the coupling of light into the glue used for bonding the fiber, thereby weakening the image stripes and noise caused by the backward conduction of stray light into the laser. The fiber end can also not be provided with a ferrule 126, but a fiber clamping structure 124 designed as needed is used to clamp and fix the fiber 123, forming a pigtail component. Similarly, in the case where no ferrule is provided, the fiber 123 can protrude from the end face of the fiber clamping structure 124, thereby avoiding stray light caused by the coupling of light into the glue of the fiber part.

[0152] In the embodiments of the present application, the end face of the ferrule 126 or the end face of the fiber clamping structure 124 can function as direct fixing and transverse displacement limiting for the fiber 123.

[0153] In the embodiments of the present application, the pigtail component and the coupling lens 122 can be positioned in height by an optical positioning plate, and the light path centering of the fiber 123 and the coupling lens 122 can be realized by the inclination of the pigtail component, thereby reducing the processing precision requirement of the pigtail positioning height, making it easier to realize production and processing, and exponentially reducing the production cost. In the embodiments of the present application, the optical positioning plate can be arranged between the fiber clamping structure 124 and the bottom of the housing 127, or between the coupling lens 122 and the bottom of the housing 127, or both, which is not limited in the present application.

[0154] The scheme in the embodiments of the present application also has the following advantages: the pigtail component is smaller in size and more compact; the device performance is more consistent; the tail sealing is easier and the reliability is higher.

[0155] In another possible implementation, as shown in FIG. 18, a through hole for the fiber 123 to pass through can be arranged on the housing 127, the housing 127 is used as a fiber clamping structure, and the pigtail is directly fixed on the housing 127, thereby saving the additional mechanical fiber clamping structure and saving cost. For the ferrule, a flat end ceramic ferrule with low cost and high precision can be used to clamp the fiber, the ceramic ferrule has high rigidity, is convenient to operate and easy to fix; for the pigtail, the pigtail is directly fixed on the housing 127, the structure of the entire pigtail component is compact, sealing is convenient, and the sealing method can be not limited to bonding, glass powder sintering, etc.; in the production process, the pigtail and the housing 127 can be assembled and then cut, thereby saving the step of adjusting the angle of the fiber rotation, making the production process more efficient.

[0156] In the embodiments of the present application, the light source can be a laser, such as a laser diode. The number of light sources in the drawings is only illustrative, and the embodiments of the present application do not limit the type and number of light sources.

[0157] It should be noted that the structure of the fiber protruding ferrule end face, the shell structure, the arrangement of the fiber tail component and the coupling lens in the above embodiments can be combined according to any embodiment to optimize the display effect of the scanning display device, and the present application does not limit this.

[0158] The embodiments of the present application also provide a scanning display device, which comprises the light source module and the optical fiber scanning module in the above embodiments. The light emitted by the light source module is scanned and output by the optical fiber scanning module and serves as display image light. The optical fiber scanning module comprises an actuator, and the optical fiber light emitting end in the light source module is fixed on the actuator. The optical fiber exceeds the actuator and forms an optical fiber cantilever. The optical fiber cantilever is driven by the actuator to scan in space. The scanning display device has the advantages of small size and easy installation, and is suitable for various projection devices and has a wide range of applications.

[0159] Please refer to FIG. 19, which is a schematic diagram of an optical fiber scanning imaging system provided by the embodiments of the present application. The optical fiber scanning imaging system mainly comprises a processor, a scanning driving circuit, a light source module, a light source modulation module, an optical fiber scanner 11, a light source beam combining module 12 and an optical fiber 13. The working principle of the optical fiber scanning imaging system is as follows: the processor drives the optical fiber scanner 11 by sending an electrical control signal to the scanning driving circuit, and at the same time, the processor controls the light emission of the light source module by sending an electrical control signal to the light source modulation module. The signal transmission between the processor, the scanning driving circuit and the light source modulation module can be performed through an electronic input / output device. The light source modulation module outputs a light source modulation signal according to the received control signal to modulate the light emitting units of multiple colors (such as lasers / LEDs, etc., and the RGB three-color lasers are shown in FIG. 19) in the light source module. The light generated by each color of light emitting unit in the light source module is combined by the light source beam combining module 12 to generate light corresponding to each pixel point in the image one by one. The light beam generated by the light source beam combining module 12 is introduced into the optical fiber scanner 11 through the optical fiber 13. At the same time, the scanning driving circuit outputs a scanning driving signal according to the received control signal to control the optical fiber 13 in the optical fiber scanner 11 to perform scanning motion in a predetermined two-dimensional scanning track (such as spiral scanning, grid scanning, Lissajous scanning). Then, the optical system amplifies and projects the light of each pixel point emitted by the optical fiber 13 onto a projection surface to form an image. The projection surface can be a projection screen, a wall, etc.

[0160] Semiconductor laser (LD) realizes specific wavelength output through resonant cavity. The structure characteristics and laser generation principle determine that the stability of LD output power is affected by temperature, internal refractive index distribution, injected current change and other factors. Meanwhile, the reverse transmission of external emission and stray light into the laser will greatly cause the instability of laser power, and even make the output light intensity and laser wavelength of the laser deviate from the target value.

[0161] When the laser is used as RGB LD for imaging display, especially in the laser imaging mode represented by fiber scanning and mainly pixel by pixel and internal modulation, the RGB lasers are accurately modulated by the injected current of the RGB laser. After passing through the optical system link, the RGB lasers can realize accurate color display and gray scale display with accurate proportioning. If the laser is affected by the injected stray light and back reflection as mentioned above, the deviation of the output wavelength and power of the laser will be very sensitive to the accuracy of the display image, causing inaccurate color display and abnormal brightness display. In addition, the characteristics of the time-varying energy utilization rate of the system link caused by the high-frequency scanning bending of the fiber, the lens mode matching and the intermodal dispersion of the fiber make the final imaging quality present serious color deviation, reduced color gamut and uneven brightness. These phenomena change over time, and the entire projection image looks "dirty" and unclear. In addition, the laser-based scanning projection technology also has many specific phenomena different from traditional displays, such as unstable gray scale display affecting the expressiveness and weak display anti-interference ability.

[0162] Therefore, to realize accurate and clean laser display image, the output of the laser itself needs to be more controllable and stable. This case proposes a suitable light source module scheme to solve this key problem and improve the display effect of fiber scanning imaging. The light source module will be described in detail in combination with the following embodiments.

[0163] Please refer to FIG. 1 and FIG. 20, which are structural schematic diagrams of a light source module provided by the embodiments of the present application. The light source structure includes a laser light source (also referred to as a light module); a coupling lens 21 arranged on the exit light path of the laser light source, the entrance side and / or the exit side of the coupling lens 21 being provided with an aperture stop 23; a pigtail 24 arranged on the exit light path of the coupling lens 21, the light emitted by the laser light source being coupled into the pigtail 24 through the coupling lens 21; the pigtail 24 including an optical fiber, the optical fiber coupling end face 240 of the optical fiber being an inclined end face, so that the reflected light of the optical fiber coupling end face 240 deviates from the optical axis, thereby reducing the proportion of the reflected back wave generated at the optical fiber coupling end face 240 entering the semiconductor laser of the laser light source, reducing the influence of the reflected back wave generated at the optical fiber coupling end face 240 on the semiconductor laser, and ensuring the stable output of the semiconductor laser.

[0164] In the scheme of the embodiment of the present application, since the fiber coupling end face 240 of the pigtail fiber 24 is inclined, the reflected light of the fiber coupling end face 240 can deviate from the optical axis, thereby reducing the reflected light returning to the receiving surface of the semiconductor laser along the optical axis; and the entrance side and / or the exit side of the fiber coupling lens 21 is provided with the aperture stop 23, which can intercept stray light in the light source system, thereby reducing the stray light returning to the receiving surface of the semiconductor laser resonant cavity through the fiber coupling lens 21. By tilting the fiber end face and cooperating with the aperture stop 23, the influence of echo and stray light on the semiconductor laser is reduced, so that the output of the semiconductor laser itself is more stable and controllable.

[0165] In order to further reduce the interference of the echo generated at the fiber coupling end face 240 on the semiconductor laser and ensure the image display quality, in some embodiments of the present specification, the pigtail fiber 24 is a single-mode fiber. Preferably, the single-mode fiber can be an RGB full-waveband single-mode fiber. Specifically, the visual perception of red light is relatively strong compared with blue light, and the sensitivity of a red semiconductor laser to reflected echo is stronger than that of a blue semiconductor laser or a green semiconductor laser. Therefore, the fiber used in the embodiment of the present specification is at least a single-mode fiber for red light wavelength.

[0166] Further, different inclination angles of the fiber coupling end face 240 of the pigtail fiber 24 can affect the reflection angle of the reflected echo generated at the fiber coupling end face 240, thereby changing the proportion of the reflected echo returning to the semiconductor laser along the original path, and further affecting the image display effect of the fiber scanning imaging. Specifically, the greater the inclination angle of the fiber coupling end face 240, the more the direction of the reflected echo deviates from the optical axis, the smaller the proportion of the reflected echo entering the semiconductor laser, and the better the image display effect of the fiber scanning imaging. It should be noted that in the embodiment of the present specification, the inclination angle θ of the fiber coupling end face 240 refers to the angle between the plane where the fiber coupling end face is located and the direction perpendicular to the main optical axis of the coupling lens. The display image quality of the fiber coupling end face at different inclination angles will be described in detail below.

[0167] FIG. 21 is a display image of fiber scanning, specifically a gray scale image horizontally distributed, which can be compared with the imaging images of different parameters (for example, inclination angle, normal incidence reflectivity) actually collected in the present specification, or can be compared with the target display image.

[0168] FIG. 22 is a display image of fiber scanning when the fiber coupling end face of a single-mode fiber has different inclination angles, and FIG. 22 (a), (b) and (c) are respectively display images of fiber scanning when the fiber coupling end face of a single-mode fiber has inclination angles of 8°, 9° and 11°, which are photos of images projected by a fiber scanning device on an imaging carrier (for example, a screen) through a camera.

[0169] As shown in FIG. 22, the local area of (a) has slight fish-scale-like speckle defects; the display screen of (b) with a larger tilt angle of the fiber coupling end face has relatively less defects than (a), and only noise-like defects can be seen; when the tilt angle is further increased to 11°, the display screen of (c) is pure and almost no display defects can be seen. Therefore, for display applications, no obvious difference can be seen when the tilt angle of the fiber coupling end face is greater than 8° (for example, 9°, 11°).

[0170] Based on the above, the tail fiber of the light source module provided by the embodiments of the present specification adopts a single-mode optical fiber, wherein when the tilt angle of the fiber coupling end face is greater than 8°, even if the fiber coupling end face is not coated, it can ensure high image quality when applied to the imaging of the optical fiber scanning display technology.

[0171] In some embodiments, the reflection echo generated at the fiber coupling end face can also be reduced by coating an anti-reflection film on the fiber coupling end face, so that the proportion of the reflection echo entering the semiconductor laser is small, thereby ensuring the image display effect of the optical fiber scanning imaging. Further, when the anti-reflection film is coated on the fiber coupling end face, the tilt angle of the fiber coupling end face can be relatively small. Based on this, the present specification also provides another light source module, which is mainly different from the light source module of FIG. 1, FIG. 20 and FIG. 22 and the corresponding contents thereof in that the tail fiber is a single-mode optical fiber, the tilt angle of the fiber coupling end face is not less than 5°, and the fiber coupling end face is coated with an anti-reflection film. The imaging effect will be described in detail below in combination with FIG. 23.

[0172] FIG. 23 is an optical fiber scanning display imaging diagram of different fiber coupling end faces. FIG. 23 (a) is an optical fiber scanning display imaging diagram of a red light normal incidence reflectivity of 1% when a single-mode optical fiber is used, the tilt angle of the fiber coupling end face is 5°, and an anti-reflection film is coated. FIG. 23 (b) is an optical fiber scanning display imaging diagram of a red light normal incidence reflectivity of 1.5% when a single-mode optical fiber is used, the tilt angle of the fiber coupling end face is 5°, and an anti-reflection film is coated. FIG. 23 (c) is an optical fiber scanning display imaging diagram of a red light normal incidence reflectivity of 1.5% when a single-mode optical fiber is used, the tilt angle of the fiber coupling end face is 3°, and an anti-reflection film is coated. It should be noted that the above imaging diagrams are photos of the images projected by the optical fiber scanning device on the imaging carrier (for example, a screen) through a camera. As shown in FIG. 23, the display screen of (a) is pure and almost no display defects can be seen; the display screen of (b) has a few local area defects, but they are not obvious; most of the area of (c) has a large number of densely packed defects, and even the low brightness area is relatively obvious. Therefore, the smaller the tilt angle of the fiber coupling end face, the greater the red light normal incidence reflectivity of the anti-reflection film, the greater the proportion of the reflection echo generated at the fiber coupling end face entering the semiconductor laser, and the more serious the corresponding image defects.

[0173] Based on the above, the optical source module provided by the embodiments of the present specification adopts a single-mode optical fiber for the pigtail, wherein the tilt angle of the optical fiber coupling end face is not less than 5°, and the red light normal incidence reflectivity of the anti-reflection film is not greater than 1.5%, and the blue light and green light normal incidence reflectivity of the anti-reflection film is not greater than 2%, so that the proportion of the reflected echo generated at the optical fiber coupling end face entering the semiconductor laser is small, and the imaging quality of the fiber scanning display technology is high. Further preferably, in order to further improve the imaging quality, the tilt angle of the optical fiber coupling end face is not less than 5°, and the red light normal incidence reflectivity of the anti-reflection film is not greater than 1%, and the blue light and green light normal incidence reflectivity of the anti-reflection film is not greater than 1.5%. The normal incidence in the embodiments of the present specification refers to the direction of the light entering the optical fiber coupling end face being perpendicular to the plane in which the optical fiber coupling end face lies.

[0174] It should be noted that, on the one hand, the visual sense of red light (wavelength near 635 nm) and green light (wavelength near 520 nm) is relatively strong compared with that of blue light (wavelength near 450 nm), and the embodiments provided by the present specification mainly take red light and green light as examples for display; on the other hand, the sensitivity of the red light semiconductor laser to the reflected echo is relatively higher than that of the green light and blue light semiconductor lasers, and it is more susceptible to the interference of the reflected echo. Based on this, when designing the anti-reflection film, it is necessary to consider reducing more reflected echoes of red light, and the red light normal incidence reflectivity of the anti-reflection film is required to be about 0.5% lower than the blue light and green light normal incidence reflectivity. In the embodiments of the present specification, red light or green light is taken as a specific example, and the normal incidence reflectivity of other colors of light of some anti-reflection films is not given, but it can be deduced accordingly, and the contents about normal incidence reflectivity in the specification will not be repeated.

[0175] In the embodiments corresponding to the above-mentioned FIG. 22 and FIG. 23, the pigtail adopts a single-mode optical fiber, and in some embodiments, the pigtail can also adopt a multi-mode optical fiber. The multi-mode optical fiber and the single-mode optical fiber involved in the present specification are all for visible light in the wavelength range of 400 nm-700 nm. Specifically, the multi-mode optical fiber in the present specification adopts a mature commercial communication optical fiber, i.e., a communication single-mode optical fiber, and the fiber core is 9 μm; the single-mode optical fiber is a special single-mode optical fiber designed for visible light (for example, S405-XP of Nufern). When the pigtail adopts a multi-mode optical fiber, the tilt angle of the optical fiber coupling end face, the normal incidence reflectivity of the anti-reflection film and other parameters will also be different from those when the pigtail is a single-mode optical fiber. Based on this, the embodiments of the present specification also provide another optical source module, which is mainly different from the optical source modules of FIG. 1, FIG. 20 and FIG. 22 and the corresponding contents in that the pigtail is a multi-mode optical fiber, and the tilt angle of the optical fiber coupling end face is not less than 13°. Preferably, the optical fiber coupling end face is coated with an anti-reflection film, and the red light normal incidence reflectivity of the anti-reflection film is not greater than 1%, and the blue light and green light normal incidence reflectivity of the anti-reflection film is not greater than 1.5%. The imaging effects will be specifically described below in combination with FIG. 24 to FIG. 27.

[0176] FIG. 24 to FIG. 27 are fiber scanning display imaging diagrams of different fiber coupling end faces. Specifically, FIG. 24 is a fiber scanning display imaging diagram of a green light normal incidence reflectivity of 1.5% when a flat end face of a fiber coupling end face is coated with an anti-reflection film and a multi-mode fiber is used. When the pigtail fiber uses a multi-mode fiber, the fiber coupling end face is a flat end face, and only the anti-reflection film with a green light normal incidence reflectivity of 1.5% is coated on the flat end face, the stripe defects in the collected imaging diagram are very obvious, and it is difficult to achieve a better display effect.

[0177] FIG. 25 (a) to (e) are fiber scanning display imaging diagrams when the tilt angle of the fiber coupling end face is 9°, 11°, 13°, 14° and 15° respectively and the anti-reflection film is not coated and a multi-mode fiber is used. Most of the area in (a) has obvious stripe defects; as the tilt angle of the fiber coupling end face increases, the stripe defects in the local area of (b) are reduced, and the stripe defects in (c) are not easy to be perceived. When the tilt angle of the fiber coupling end face is 13°, the pigtail fiber using a multi-mode fiber can be used for display. Further, referring to (d) and (e), when the tilt angle of the fiber coupling end face is 14° and 15° and the anti-reflection film is not coated on the fiber coupling end face, the corresponding imaging diagrams are relatively pure and no obvious stripe defects are seen. At the same time, when the tilt angle is greater than 13°, as the tilt angle of the fiber coupling end face continues to increase, the imaging effect does not show obvious differences. Therefore, when the pigtail fiber uses a multi-mode fiber, the tilt angle of the fiber coupling end face is not less than 13°, the proportion of the reflected echo generated at the fiber coupling end face entering the semiconductor laser is low, the influence on the semiconductor laser is small, and the fiber scanning display imaging can have a high quality.

[0178] In order to reduce the reflected echo generated at the fiber coupling end face, an anti-reflection film can also be coated on the fiber coupling end face of the multi-mode fiber. The following will be described in combination with examples of the anti-reflection film provided on the fiber coupling end faces with different tilt angles in FIG. 26 and FIG. 27. FIG. 26 (a) is a fiber scanning display imaging diagram when the tilt angle of the fiber coupling end face is 9° and the green light normal incidence reflectivity of the anti-reflection film is 1.5% and a multi-mode fiber is used. FIG. 26 (b) is a fiber scanning display imaging diagram when the tilt angle of the fiber coupling end face is 11° and the green light normal incidence reflectivity of the anti-reflection film is 1.5% and a multi-mode fiber is used. In combination with (a) of FIG. 25 and (a) of FIG. 26 and (b) of FIG. 25 and (b) of FIG. 26, when the tilt angles of the fiber coupling end faces are the same, the imaging effect of the green light normal incidence reflectivity of 1.5% of the anti-reflection film coated on the fiber coupling end face is improved compared with the imaging effect of the anti-reflection film not coated.

[0179] Fig. 27(a) is a fiber scanning display imaging diagram when the green light normal incidence reflectivity of the fiber coupling end face with a tilt angle of 13° and an anti-reflection film is 2%; Fig. 27(b) is a fiber scanning display imaging diagram when the green light normal incidence reflectivity of the fiber coupling end face with a tilt angle of 13° and an anti-reflection film is 1.5%. Referring to Fig. 27, when the tilt angle of the fiber coupling end face is a constant value, here taking the tilt angle of the fiber coupling end face as 13° as a specific example, the green light normal incidence reflectivity of the anti-reflection film of the fiber coupling end face will affect the proportion of the reflected echo generated at the fiber coupling end face and the echo returning to the semiconductor laser in the original way, and further affect the image quality of the fiber scanning display imaging. Specifically, the smaller the green light normal incidence reflectivity of the anti-reflection film of the fiber coupling end face, the higher the image quality of the fiber scanning display imaging. Preferably, when the fiber coupling end face adopts a multi-mode optical fiber, the tilt angle of the fiber coupling end face is not less than 13°, and the green light normal incidence reflectivity of the anti-reflection film of the fiber coupling end face is not greater than 1.5%, and correspondingly, the blue light normal incidence reflectivity is not greater than 1.5% and the green light normal incidence reflectivity is not greater than 1%.

[0180] In the foregoing light source module, the fiber coupling end face is a tilt face. In some embodiments, the fiber coupling end face can also be a flat end face. Based on this, another light source module is further provided in the embodiments of the present specification, as shown in Fig. 28, the main difference between which and Figs. 1, 20 and 22 and the corresponding contents thereof is that the pigtail is a single-mode optical fiber, the fiber coupling end face is a flat end face, the fiber coupling end face is coated with an anti-reflection film, and the red light normal incidence reflectivity of the anti-reflection film is not greater than 1% and the green light and blue light normal incidence reflectivity is not greater than 1.5%. It should be noted that here the fiber coupling end face is a flat end face, which means that the plane where the fiber coupling end face is located is perpendicular to the main optical axis of the coupling lens. The imaging effect will be specifically described below in combination with Figs. 29 and 30.

[0181] FIG. 29 is a fiber scanning display imaging diagram of different fiber coupling end faces, wherein FIG. 29(a) is a fiber scanning display imaging diagram of a single-mode fiber, a flat fiber coupling end face, and no anti-reflection film; FIG. 29(b) is a fiber scanning display imaging diagram of a single-mode fiber, a flat fiber coupling end face, and an anti-reflection film with a normal incidence reflectivity of 1%; specifically, a partial enlarged view of a white picture displayed in RGB three colors; FIG. 29(c) is a fiber scanning display imaging diagram of a single-mode fiber, a flat fiber coupling end face, and an anti-reflection film with a normal incidence reflectivity of 1% for red light; and FIG. 29(d) is a fiber scanning display imaging diagram of a single-mode fiber, a flat fiber coupling end face, and an anti-reflection film with a normal incidence reflectivity of 2% for red light. As shown in FIG. 29, in (a), there are many dense stripes, and even the low-luminance area is relatively obvious; the imaging diagrams of (b) and (c) have no defects in picture quality; and when the normal incidence reflectivity of the anti-reflection film in (d) is relatively large, the imaging effect is relatively close to that of no film, and the picture quality has obvious defects.

[0182] Based on the above, the tail fiber of the light source module provided in the embodiments of the present specification adopts a single-mode fiber, wherein the fiber coupling end face is a flat end face and the normal incidence reflectivity of the anti-reflection film is not greater than 1%, so that the proportion of the reflected echo generated by the fiber coupling end face entering the semiconductor laser is relatively low, thereby reducing the influence of the reflected echo on the semiconductor laser, and further improving the imaging quality of the fiber scanning display technology.

[0183] In the embodiments of the present specification, the aperture stop 23 arranged on the light-in side and / or the light-out side of the coupling lens 21 can be used to shield the reflected echo generated at the fiber coupling end face, so as to further reduce the influence of the reflected echo at the fiber coupling end face on the semiconductor laser. The aperture stop 23 arranged on the light-in side and / or the light-out side of the coupling lens 21 includes the following three possible schemes: first, the aperture stop is arranged on the light-in side of the coupling lens; second, the aperture stop is arranged on the light-out side of the coupling lens; and third, the aperture stop is arranged on the light-in side of the coupling lens, and at the same time, the aperture stop is arranged on the light-out side of the coupling lens.

[0184] Referring again to FIG. 20, in some embodiments of the present specification, the hole diameter of the aperture stop 231 can be greater than 1 mm and less than 2 mm. The hole diameter of the aperture stop is relatively small, which can satisfy the passing of light from the light-in side, while shielding the reflected echo generated at the fiber coupling end face. Further, the inner surface of the aperture stop can also be coated with light-absorbing paint, or the inner surface of the aperture stop can be black, so as to absorb the reflected echo generated at the fiber coupling end face.

[0185] In the embodiments of the present application, as shown in FIG. 1 and FIG. 20, the light source module includes a tail handle 26, the tail handle 26 has a through hole for the tail fiber 24 to pass through, and the tail handle 26 is sleeved outside the incident end of the tail fiber 24 passing through the through hole. In some embodiments, when the tail fiber with an inclined fiber coupling end face is used in the light source module, the axial direction of the tail handle 26 is not parallel to the main optical axis of the coupling lens 21, that is, the tail handle 26 is obliquely installed on the shell 28. The reason for this arrangement is that, compared with ordinary optical fibers, the use of an inclined fiber coupling end face will cause a certain angle deviation of the optical axis of the optical fiber, thereby causing a loss of optical energy. By arranging the axial direction of the tail handle 26 to be not parallel to the main optical axis of the coupling lens 21, the optical axis of the optical fiber is corrected so that the optical axis of the optical fiber and the optical axis of the coupling lens 21 are on the same straight line, thereby making the optical axis of the entire optical system coaxial. In addition, through the design of the inclined tail handle structure, the loss of optical power caused by the angle assembly deviation in the optical coupling is compensated, and the brightness of the display picture is improved. As shown in FIG. 28, in some embodiments, when the tail fiber with a flat fiber coupling end face and coated with an anti-reflection film is used in the light source module, the axial direction of the tail handle can be parallel to the main optical axis of the coupling lens.

[0186] In some embodiments, the stray light can also be eliminated by designing the shell corresponding to the tail fiber. The stray light elimination shell structure can have various implementation manners. Next, several examples are described below, and in the specific implementation process, the following several implementation manners are not limited.

[0187] In one possible implementation, please refer to FIG. 20 and FIG. 30, the light source module includes a shell 28, and a cavity 29 formed by the shell 28 between the coupling lens 21 and the fiber coupling end face 240; the inner surface of the shell 28 is provided with a spiral structure 281. Compared with a plane, the spiral structure 281 can increase the reflection times of the reflected light, thereby changing the energy distribution of the reflected light through multiple reflections, so as to attenuate the reflected light energy.

[0188] In another possible implementation, as shown in FIG. 31, the light source module includes a shell 28, and a cavity 29 formed by the shell 28 between the coupling lens 21 and the fiber coupling end face 240; the shell 28 is provided with a light transmission window 282, so that when the reflected light is incident on the light transmission window 282, the light transmission window 282 is shot out of the cavity 29. The light transmission window 282 can be a transparent piece provided on the shell 28, and the light transmission window 282 can be one or more local small areas carefully arranged, which can be rectangular, square, circular, etc.; the light transmission window 282 can also be a 360° annular light transmission band arranged along the circumference of the shell.

[0189] In some embodiments of the present disclosure, the entire housing 28 can also be in the form of a transparent piece, so that the reflected light is transmitted out of the cavity 29 from the housing 28 when the reflected light is incident on the housing 28. In a specific implementation, glass is also a feasible option for the encapsulated housing, considering that glass has a low thermal expansion coefficient and transparent properties.

[0190] In another possible implementation, as shown in FIG. 32, the light source module includes a housing 28, and a cavity 29 formed by the housing 28 between the coupling lens 21 and the fiber coupling end face 240; the light source module also includes an inner tube structure 30 located on the side close to the coupling lens 21, and a gap 301 is formed between the housing 28 and the inner tube structure 30, so that the reflected light of the fiber coupling end face 240 can be reflected multiple times in the gap 301.

[0191] In another possible implementation, as shown in FIG. 33, the light source module includes a housing 28, and a cavity 29 formed by the housing 28 between the coupling lens 21 and the fiber coupling end face 240; the inner surface 283 of the housing 28 is provided with light-absorbing paint.

[0192] It should be noted that the housing shown in FIGS. 30-33 can be applicable to the light source module described in FIGS. 1-29 of the present disclosure.

[0193] Please refer to FIG. 35A, which is a schematic diagram of a light module of a light source module provided in an embodiment of the present disclosure. The light module includes: an input light source, the input light source including an image light source, the image light source including two groups of light sources 161, 162, each group of light sources including at least R, G, and B light emitting units, and the polarizations of the light beams emitted by the two groups of light sources 161, 162 being different; two groups of wavelength combining devices 164, 165, respectively arranged on the light paths of the two groups of light sources 161, 162; a polarization combining device 167 arranged on the light path of the two groups of wavelength combining devices 164, 165; the light beams emitted by the two groups of light sources 161, 162 are combined into two image light beams by the corresponding wavelength combining devices; the polarization combining device 167 is coaxially arranged with one of the two groups of wavelength combining devices 164, 165, the light beam emitted by the coaxial wavelength combining device directly enters the polarization combining device 167, and the light beam emitted by the other wavelength combining device enters the polarization combining device 167 from the other side of the polarization combining device 167 after being reflected by a mirror 166, and after being turned by 90 degrees by the polarization combining device 167, the light beam is emitted in the same direction as the light beam directly entering the polarization combining device 167, so that the two image light beams are combined into one image light beam by the polarization combining device 167, and the combined image light beam is coupled into the aforementioned pigtail by the coupling lens 21.

[0194] Further preferably, the light module can further comprise at least one mirror located behind the polarization beam combiner for changing the exiting direction and transmission path of the image light beam to increase the distance between the inner cavity of the semiconductor laser LD and the fiber coupling end face, while most of the stray light reflected at the fiber coupling end face is blocked by the mirror to reduce the proportion of the echo entering the semiconductor laser LD, thereby reducing the influence of the stray light reflected at the fiber coupling end face on the inner cavity of the semiconductor laser LD. In the embodiments of the present application, two mirrors are arranged behind the polarization beam combiner as a specific example. With reference to FIG. 34, with respect to the light module of FIG. 35A, the light module can further comprise a first mirror 168 located behind the polarization beam combiner 167 and a second mirror 169 located at the side of the first mirror 168. The image light beam after the polarization beam combiner 167 is reflected by the first mirror 168 for the first time, the exiting direction of the image light beam after the first reflection is perpendicular to the exiting direction of the image light beam after the polarization beam combiner 167. The image light beam after the first reflection is reflected by the second mirror 169 for the second time, the exiting direction of the image light beam after the second reflection is parallel and opposite to the exiting direction of the image light beam after the polarization beam combiner 167. The image light beam after the second reflection is coupled into the aforementioned pigtail through the coupling lens 21. It should be noted that the number and arrangement of the mirrors are not limited to the arrangement of two mirrors shown in FIG. 33. In other embodiments, the number of mirrors can be one, for example, the mirror only comprises the first mirror 168. For example, the number of mirrors can be three, four or more, which can realize the increase of the transmission path of the image light beam, which is not limited herein.

[0195] In some embodiments, the input light source can further comprise a detection light source 163, which can be an infrared light source. Further, the light source module can further comprise a detection beam combining device 169. In some embodiments, the detection light source 163 can be located on the front side of the light source 162, and in other embodiments, the detection light source 163 can also be located on the light path between the polarization beam combiner 167 and the first mirror 168. The detection beam combining device is located on the side of the detection light source, and the exiting light beam of the detection light source is perpendicular to the exiting light beam of the polarization beam combiner. After the exiting light beam of the detection light source and the image light beams of the other two groups of light sources are combined into one beam, the combined beam is coupled into the pigtail through the coupling lens 28.

[0196] In the scheme of the embodiment of the present specification, the image light source includes two groups of light sources 161, 162, each group of light sources including R, G, and B light emitting units, and the polarization states of the light beams emitted by the two groups of light sources 161, 162 are different. Then, the light emitted by the two groups of image light sources and the detection light are combined into one light beam by the wavelength combining device 164, 165 and the polarization combining device 167, and then coupled into the pigtail, so as to improve the total power of the light source module and make it meet the brightness requirement of the fiber scanning imaging system in some high-brightness scenarios.

[0197] In some embodiments, the polarization combining device 167 is in the form of a cubic prism and is vertically placed in the light path corresponding to the two groups of light sources. In the fiber scanning imaging display technology, about 2% to 3% of the reflection echo will be generated when the light is normally incident to the interface, and a considerable part of the light will be reversed back to the semiconductor laser LD, resulting in a large defect in the image quality of the final image. Referring to FIGS. 35 and 36, based on the above problem, in the light source module suitable for the fiber scanning imaging display technology, the incident surface of the polarization combining device is offset from the light path by a specified angle, which is greater than 1°, and preferably, to ensure the coupling efficiency, the angle is less than 10°. It should be noted that the offset angle of the incident surface of the polarization combining device from the light path can be understood as the angle relative to the vertical of the light path and the incident surface of the polarization combining device. For example, in FIG. 34, the angle between the light path and the incident surface of the polarization combining device is 90°, and after the specified angle is offset, the angle between the light path and the incident surface of the polarization combining device in FIG. 35A can be less than 89°, and preferably greater than 80°. Similarly, the angle between the light beam emitted through the polarization splitting film and the exit surface of the polarization combining device 167 is greater than 80° and less than 89°.

[0198] It should be noted that the shape of the polarization beam combiner is not limited to the above-mentioned vertical prism, and can also be other shapes, such as cutting the vertical prism structure, which can satisfy the angle between the light beam and the incident surface deviating from the angle shown in FIG. 34 by more than 1° and less than 10°. Specifically, referring to FIG. 35B, the polarization beam combiner 167 shown by the dashed area in FIG. 35B is the vertical prism in the above-mentioned embodiment, and the polarization beam combiner 167 is cut to obtain the polarization beam combiner 167a, that is, the area shown by the solid line in FIG. 35B. Further, the incident surface of the polarization beam combiner 167a includes a first part 1671 and a second part 1672, the first part 1671 corresponds to the incident light beam (the light beam on the upper side and the right side in FIG. 35B), wherein the angle between the first part 1671 and the incident direction of the light beam is greater than 80° and less than 89°, and the incident direction of the light beam is perpendicular to the second part 1672. Similarly, the side surface opposite to the incident surface of the polarization beam combiner 167a can also include a first part and a second part, wherein the emergent light beam (the light beam on the left side of the polarization beam splitter film in FIG. 35B) after being combined by the polarization beam splitter film and a small part of light (the optical fiber on the lower side of the polarization beam splitter film in FIG. 35B) that transmits through the polarization beam splitter film correspond to the first part 1671. Wherein the angle between the first part 1671 and the emergent direction of the light beam is greater than 80° and less than 89°, and the emergent direction of the light beam is perpendicular to the second part 1672. It should be noted that the angle between the incident direction of the light beam and the incident surface of the polarization beam combiner and the angle between the emergent direction of the light beam and the emergent surface of the polarization beam combiner can be the same or different.

[0199] It should be noted that the description of "cutting" here is only relative to the structure of the polarization beam combiner based on the vertical prism, for the convenience of explanation and understanding of others, and the specific production process may not necessarily be based on the cutting of the vertical prism structure, but also other ways of production, such as through a mold corresponding to its shape. In addition, it can be considered that the polarization beam combiner 167 is cut to remove the structure similar to a triangular prism. In other embodiments, only the place where the light path enters or exits (such as the middle area of the side surface) can be processed, and the position close to the edge is not processed. The volume of the polarization beam combiner 167a is smaller than that of the polarization beam combiner with the vertical prism shape, which is convenient for miniaturization design of the overall light source module. Further, the incident surface and the emergent surface of the polarization beam combiner can be parallel or non-parallel. Preferably, in some embodiments, an anti-reflection film can also be coated on the incident surface and the emergent surface of the polarization beam combiner to further reduce the reflected light generated at the incident surface and the emergent surface of the polarization beam combiner, and reduce the influence of the echo on the semiconductor laser LD.

[0200] The embodiment of the present specification also provides another polarization beam combiner 167A for weakening the influence of the echo of the light path of the two groups of light sources when incident to the interface of the polarization beam combiner 167A. Referring to FIGS. 36 and 37, the polarization beam combiner includes two substrates 1671 and a polarization beam splitting film 1672 located between the two substrates 1671 for fixation. The polarization beam combiner 167A provided by the embodiment of the present specification has a smaller volume compared with the cubic prism form shown in FIGS. 35 and 36, and can facilitate the miniaturization design of the light source module as a whole. In addition, the plate-shaped structure is relatively light and thin, and in the specific assembly process, the incidence direction of the light beams corresponding to the two groups of light sources and the incidence surface can form a relatively large angle, for example, preferably 45°, so that the reflected light waves generated by the light beams corresponding to the two groups of light sources at the incidence surface of the polarization beam combiner 167A can return to the semiconductor laser LD as little as possible, thereby ensuring the final imaging quality.

[0201] In other alternative embodiments, the polarization beam combiner can include a substrate and a polarization beam splitting film attached to one side of the substrate.

[0202] In some embodiments, the semiconductor laser LD can adopt a DFB form to avoid external interference. In other embodiments, the semiconductor laser LD can also adopt an FP chip, and the base where the FP chip is located is provided with an external cavity to avoid the interference of external reflection echo, and further, the external cavity reflectivity is in the range of 5%-10%.

[0203] Referring to FIG. 38, in some embodiments, the light module includes a base 160 for mounting and fixing the above-mentioned light sources 161, 162, wavelength beam combiner, polarization beam combiner, etc., wherein the two groups of light sources 161, 162 are arranged on the base 30. Further, the inner surface of the bottom of the base 160 corresponding to the polarization beam combiner 167 is not a plane. In some embodiments, the inner surface of the bottom of the base 30 corresponding to the polarization beam combiner 167 is a bevel, and for the convenience of understanding, it needs to be explained that the bevel is relative to the image light beam after the polarization beam combiner beam combining, that is, the bevel has an included angle with the image light beam after the polarization beam combiner beam combining. In the embodiment of the present specification, by arranging the bevel, the reflected light on the bottom surface of the base after the reflection and projection of the polarization beam combiner 167 can be weakened, and the influence of the reflected light returning to the semiconductor laser LD in the reverse light path can be reduced. Further, in some embodiments, the inner surface of the base can also be provided with light-absorbing paint or the inner surface of the base can be black to absorb the reflected and transmitted light of the polarization beam combiner.

[0204] The embodiment of the present specification also provides a projection display device, comprising an R, G, and B three-color light source module and a light scanning module, light emitted by the R, G, and B three-color light source module is output after being scanned by the light scanning module, and serves as display image light; the R, G, and B three-color light source module comprises the light source module in any one of the above embodiments, the light scanning module comprises an actuator, the exit end of the pigtail is fixed on the actuator, the pigtail exceeds the actuator and forms a fiber cantilever, and the fiber cantilever is driven by the scanning actuator to scan in a three-dimensional space.

[0205] In some embodiments, the R pigtail laser light source, the G pigtail laser light source, and the B pigtail laser light source can be independent light source modules, then the light is combined into one optical fiber through an RGB optical fiber combiner, and then the light is output through the light scanning module to form a scanning image.

[0206] In another possible implementation, the R, G, and B three-color light source module can be a combined light source, that is, the light emitted by the R, G, and B laser combined pigtail light source is directly coupled into an optical fiber, and then the light is output through the light scanning module to form a scanning image. For example, the R laser light source, the G laser light source, and the B laser light source are combined through a dichroic filter, and then the light is directly coupled into a pigtail.

[0207] In order to reduce the production difficulty of the projection display device, reduce the cost, and achieve a better image display effect, in some embodiments, a few-mode or single-mode optical fiber can be connected / fused between the light scanning module and the light source module. Specifically, the instability of the light source can cause the energy to be distributed unstably between modes when transmitted in the multi-mode optical fiber, and the image changes. At this time, after passing through the few-mode optical fiber jumper, the mode filtering is performed, the stability is achieved, the light field distribution reaching the light scanning module is relatively stable, and the image display effect is ensured. It should be noted that the few-mode optical fiber in the embodiment of the present specification is for visible light, and the size of the few-mode optical fiber is between the size of the single-mode optical fiber and the size of the multi-mode optical fiber.

[0208] In other alternative embodiments, the light source module adopts an optical fiber with fewer modes to output, and then the light is conducted to an optical fiber with more modes to output, or even the few-mode / single-mode optical fiber is used in the whole link of the projection display device to achieve the maximum anti-interference capability.

[0209] In some specific application scenarios, the projection display device provided by the embodiments of the present application has a long optical fiber link, such as in a vehicle-mounted scenario. In order to facilitate installation, the projection display device includes a light source module 210, a connector 220, and a light scanning module (not shown in the figure), wherein the connector 220 is located between the light source module 210 and the light scanning module. A certain echo will be generated at the position of the connector 220, similar to the reverse reflection light generated at the coupling end face of the optical fiber as described above. The distance of the connector 220 relative to the light module will affect the image quality of the projection display device. In order to reduce its influence, in some embodiments, the distance between the connection position of the first connector 220 at the rear end of the light source module and the light module 211 is not less than 50 cm. It should be noted that the connector 220 has two optical fiber end faces inside, and the distance between the two optical fiber end faces is extremely small and can be ignored. In the embodiments of the present application, any one of the two optical fiber end faces is taken as the connection position of the connector 220. The distance between the connection position of the connector 220 and the light module 211 refers to the distance from the connection position to the semiconductor laser LD closest to the coupling lens of the light module. For details, see FIG. 40 and the related description thereof.

[0210] (a), (b), and (c) in FIG. 40 are imaging effects of the joint position and the module housing distance. As can be seen from (a), (b), and (c) in FIG. 40, when the joint is at 10 cm and 20 cm, the defects of the overall image are relatively obvious, and when the joint is at 50 cm, the image defects mainly concentrate in the dark area with extremely low brightness, and the influence on the display effect is already small.

[0211] The expressions “first”, “second”, “third”, or “fourth” used in various embodiments of the present disclosure can modify various components regardless of order and / or importance, but these expressions do not limit the corresponding components. The above expressions are only configured for the purpose of distinguishing elements from other elements.

[0212] The above description is merely preferred embodiments of the present application and a description of the principles of the technology used. It should be understood by those skilled in the art that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and also covers other technical solutions formed by any combination of the above technical features or equivalent features without departing from the above inventive concept. For example, the above features are replaced with technical features disclosed in the present application (but not limited to) having similar functions to form technical solutions.

Claims

1. A light source module, wherein, The light source module comprises: a light source; a pigtail arranged on an outgoing light path of the light source; the pigtail comprises an optical fiber; and an optical fiber coupling end face of the optical fiber is an inclined end face.

2. The light source module of claim 1, wherein, The optical fiber is configured as: a multi-mode optical fiber, the inclined end face is a plane, and an inclination angle of the plane is greater than or equal to 15°; or a single-mode optical fiber, the inclined end face is a plane, and an inclination angle of the plane is greater than or equal to 3°; or a multi-mode optical fiber, the inclined end face is a curved surface, and an inclination angle of the curved surface is greater than or equal to 10°.

3. The light source module of claim 1, wherein, The optical fiber coupling end face is provided with an anti-reflection film or a reflection elimination film.

4. A light source module for use in a fiber scanning display device, wherein, The light source module comprises: a light source; a pigtail arranged on an outgoing light path of the light source; the pigtail comprises an optical fiber fixing structure and an optical fiber; the optical fiber protrudes from an end face of the optical fiber fixing structure, and an optical fiber coupling end face is an inclined end face.

5. The light source module of claim 4, wherein, The optical fiber fixing structure comprises a ferrule, the ferrule is provided with a through hole for the optical fiber to pass through; the optical fiber is arranged in the through hole, and the optical fiber protrudes from an end face of the ferrule.

6. The light source module of claim 4, wherein, The optical fiber fixing structure comprises a clamping structure main body, and a through hole for the optical fiber to pass through; the optical fiber is arranged in the through hole, and the optical fiber protrudes from an end face of the clamping structure main body.

7. The light source module of claim 4, wherein, The optical fiber is arranged on a surface of the optical fiber fixing structure; the optical fiber and the optical fiber fixing structure are bonded by a cured adhesive.

8. The light source module of claim 4, wherein, The optical fiber and the optical fiber fixing structure are bonded by a cured adhesive; at least a section of a side of the optical fiber close to the optical fiber coupling end face is not covered by the cured adhesive.

9. The light source module according to claim 4 or 8, wherein A length of the optical fiber protruding from the end face of the optical fiber fixing structure is 0.05mm to 5mm.

10. The light source module of claim 9, wherein, A length of the optical fiber protruding from the end face of the optical fiber fixing structure is 0.1mm to 5mm.

11. The light source module of claim 4, wherein, The optical fiber is a multi-mode optical fiber, the inclined end face is a plane, and an inclination angle of the plane is greater than or equal to 15°.

12. The light source module of claim 4, wherein, The optical fiber is a single-mode optical fiber, the inclined end face is a plane, and an inclination angle of the plane is greater than or equal to 3°.

13. The light source module of claim 4, wherein, The optical fiber is a multi-mode optical fiber, the inclined end face is a curved surface, and an inclination angle of the curved surface is greater than or equal to 10°.

14. The light source module of claim 4, wherein, The light source module comprises a coupling lens arranged on an outgoing light path of the light source; light emitted by the light source is coupled into the optical fiber through the coupling lens.

15. The light source module of claim 4, wherein, The optical fiber coupling end face is provided with an anti-reflection film or a reflection elimination film.

16. A light source module, wherein, The light source module comprises: a plurality of light sources; a pigtail arranged on an outgoing light path of the light source; the pigtail comprises an optical fiber; and an optical fiber coupling end face of the optical fiber is an inclined end face; a housing, the housing comprises a frame, and an opening is arranged on a side of the frame; a bearing plate for bearing the plurality of light sources, the bearing plate is embedded in the opening.

17. The light source module of claim 16, wherein, The frame and the bearing plate are made of different materials.

18. The light source module of claim 16, wherein, The bearing plate is any one of Kovar alloy, ceramic, glass, diamond, and nickel-iron-gallium alloy; and the frame is an aluminum alloy.

19. The light source module of claim 16, wherein, The light source module comprises a plurality of optical elements for light source beam combination, arranged at a bottom of the frame; an optical positioning plate is arranged between the optical elements and the bottom of the frame; and a thermal stability of the optical positioning plate is greater than a thermal stability of the frame.

20. The light source module of claim 19, wherein, A viscous adhesive layer is arranged between the bottom of the frame and the optical positioning plate.

21. The light source module of claim 19, wherein, The bonding surface of the bottom of the frame body is provided with a plurality of grooves.

22. The light source module of claim 16, wherein, The carrier plate is Kovar alloy, and the frame body is ceramic.

23. The light source module of claim 16, wherein, The edge of the carrier plate and the inner side of the opening of the frame body are provided with interlocking and staggered tooth-shaped splicing structures.

24. A light source module, wherein, The light source module comprises: a light source; a coupling lens; a tail fiber; the tail fiber comprises an optical fiber and an optical fiber clamping structure, an optical fiber coupling end face is an inclined end face, and light emitted by the light source is coupled into the optical fiber through the coupling lens; the tail fiber is arranged separately from the coupling lens, and the tail fiber is arranged obliquely relative to the coupling lens, so that an optical axis of the optical fiber and an optical axis of the coupling lens coincide.

25. The light source module of claim 24, wherein, The optical fiber clamping structure comprises a clamping structure main body and a through hole through which the optical fiber or a ferrule passes.

26. The light source module of claim 25, wherein, The optical fiber end is provided with a ferrule, and the ferrule comprises a through hole through which the optical fiber passes.

27. The light source module of claim 26, wherein, The optical fiber protrudes from an end face of the ferrule.

28. The light source module of claim 24, wherein, The optical fiber clamping structure is a shell of the light source module, and the shell is provided with a through hole through which the optical fiber passes.

29. The light source module of claim 28, wherein, The optical fiber end is provided with a ferrule, and the ferrule comprises a through hole through which the optical fiber passes, and an end face of the ferrule is a flat end face.

30. The light source module of claim 28, wherein, An optical positioning plate is arranged between the optical fiber clamping structure and the bottom of the shell, and / or an optical positioning plate is arranged between the coupling lens and the bottom of the shell.

31. A light source module, wherein, The light source module comprises: a light source; a tail fiber arranged on an outgoing light path of the light source; the tail fiber comprises an optical fiber fixing structure and an optical fiber; the optical fiber protrudes from an end face of the optical fiber fixing structure; and the optical fiber end comprises a stripe-eliminating structure capable of dispersing reflected light formed by the optical fiber end when light is incident on the stripe-eliminating structure.

32. The light source module of claim 31, wherein, The stripe-eliminating structure comprises an optical fiber coupling end face, and the optical fiber coupling end face is a spherical surface.

33. The light source module of claim 32, wherein, The spherical surface is arranged symmetrically relative to an optical axis of the optical fiber.

34. The light source module of claim 31, wherein, The stripe-eliminating structure comprises a ball lens arranged at the optical fiber end.

35. The light source module of claim 31, wherein, The optical fiber is a single-mode optical fiber.

36. The light source module of claim 31, wherein, The optical fiber is a few-mode optical fiber.

37. A light source module, wherein, The light source module comprises: a laser light source; a coupling lens arranged on an outgoing light path of the laser light source, and an aperture stop is arranged on an incident side and / or an outgoing side of the coupling lens; a tail fiber arranged on an outgoing light path of the coupling lens, and light emitted by the laser light source is coupled into the tail fiber through the coupling lens; The tail fiber comprises an optical fiber; and an optical fiber coupling end face of the optical fiber is an inclined end face.

38. The light source module of claim 37, wherein, The optical fiber is a single-mode optical fiber, and an inclination angle of the inclined end face is greater than 8°.

39. The light source module of claim 37, wherein, The optical fiber is a single-mode optical fiber, the inclined end face is coated with an anti-reflection film, an inclination angle of the inclined end face is not less than 5°, and red light normal incidence reflectivity of the anti-reflection film is not greater than 1.5%, and blue light and green light normal incidence reflectivity of the anti-reflection film is not greater than 2%.

40. The light source module of claim 37, wherein, The optical fiber is a multi-mode optical fiber, and an inclination angle of the inclined end face is not less than 13°.

41. The light source module of claim 40, wherein, The inclined end face is coated with an anti-reflection film, red light normal incidence reflectivity of the anti-reflection film is not greater than 1%, and blue light and green light normal incidence reflectivity of the anti-reflection film is not greater than 1.5%.

42. The light source module of claim 37, wherein, A hole diameter of the aperture stop is greater than 1 mm and less than 2 mm.

43. The light source module of claim 37, wherein, The laser light source comprises an image light source, the image light source comprises two groups of light sources, each group of light sources comprises at least R, G and B light emitting units, and the polarization states of light beams emitted by the two groups of light sources are different; Two sets of wavelength combining devices are arranged on the light paths of the two groups of light sources; the light beams emitted by the two groups of light sources are combined into two image light beams by the corresponding wavelength combining devices; A polarization combining device is coaxially arranged with one of the two sets of wavelength combining devices, the light beam emitted by the coaxial wavelength combining device directly enters the polarization combining device, the light beam emitted by the other set of wavelength combining devices is reflected by a reflecting mirror and then enters the polarization combining device from the other side of the polarization combining device, and the two image light beams are combined into one image light beam by the polarization combining device; A first reflecting mirror is located behind the polarization combining device, a second reflecting mirror is located on the side of the first reflecting mirror, and the image light beam combined by the polarization combining device is reflected by the first reflecting mirror and the second reflecting mirror, the emission direction of the reflected image light beam is parallel to and opposite to the emission direction of the image light beam combined by the polarization combining device, and the reflected image light beam is coupled into the pigtail fiber through the coupling lens.

44. The light source module of claim 43, wherein, The polarization combining device is a cubic prism, and the included angle between the light beam emitted to the polarization combining device and the incident surface of the polarization combining device is in the range of 80°-89°.

45. The light source module of claim 44, wherein, The polarization combining device comprises a polarization splitting film, and the included angle between the light beam passing through the polarization splitting film and the exit surface of the polarization combining device is in the range of 80°-89°.

46. The light source module of claim 43, wherein, The incident surface of the polarization combining device comprises a first part and a second part, the first part corresponds to the incident light beam, the included angle between the first part and the incident direction of the light beam is in the range of 80°-89°, and the second part is perpendicular to the incident direction of the light beam.

47. The light source module of claim 46, wherein, The surface opposite to the incident surface in the polarization combining device comprises a first part and a second part, the included angle between the first part and the light beam passing through the polarization splitting film of the polarization combining device is in the range of 80°-89°, and the second part is perpendicular to the light beam passing through the polarization splitting film.

48. The light source module of claim 43, wherein, The polarization combining device comprises a substrate and a polarization splitting film, and the polarization splitting film is attached to one side of the substrate.

49. The light source module of claim 43, wherein, The polarization combining device comprises a first substrate, a second substrate and a polarization splitting film, and the polarization splitting film is located between the first substrate and the second substrate.

50. The light source module of claim 43, wherein, The light source module comprises a base configured to carry the light source, the wavelength combining device and the polarization combining device, and the inner surface of the base corresponding to the polarization combining device has an included angle with the image light beam after being combined by the polarization combining device.

51. The light source module of claim 50, wherein, The inner surface of the base is provided with a light-absorbing coating.

52. A light source module, wherein, The light source module comprises: a laser light source; a coupling lens arranged on the light path of the laser light source, and an aperture stop is arranged on the light entrance side and / or the light exit side of the coupling lens; a pigtail fiber arranged on the light path of the coupling lens, and the light emitted by the laser light source is coupled into the pigtail fiber through the coupling lens; The tail fiber comprises an optical fiber; and a fiber coupling end face of the optical fiber is a flat end face.

53. The light source module of claim 52, wherein, The flat end face is coated with an anti-reflection film, and the red light normal incidence reflectivity of the anti-reflection film is not greater than 1%, and the blue light and green light normal incidence reflectivity is not greater than 1.5%.

54. The light source module of claim 52, wherein, The aperture diameter of the aperture stop is greater than 1mm and less than 2mm.

55. The light source module of claim 52, wherein, The laser light source comprises an image light source, the image light source comprises two groups of light sources, each group of light sources comprises at least R, G and B three kinds of light emitting units, and the polarization states of the light beams emitted by the two groups of light sources are different; Two sets of wavelength combining devices are respectively arranged on the light paths of the two groups of light sources; the light beams emitted by the two groups of light sources are combined into two image light beams by the corresponding wavelength combining devices; A polarization combining device is coaxially arranged with one of the two sets of wavelength combining devices, the light beam emitted by the coaxial wavelength combining device directly enters the polarization combining device, the light beam emitted by the other set of wavelength combining device is reflected by a reflecting mirror and then enters the polarization combining device from the other side of the polarization combining device, and the two image light beams are combined into one image light beam by the polarization combining device; A first reflecting mirror is located behind the polarization combining device, and a second reflecting mirror is located on the side of the first reflecting mirror, the image light beam after being combined by the polarization combining device is reflected by the first reflecting mirror and the second reflecting mirror, the emission direction of the reflected image light beam is parallel to and opposite to the emission direction of the image light beam after being combined by the polarization combining device, and the reflected image light beam is coupled into the tail fiber through the coupling lens.

56. The light source module of claim 55, wherein, The polarization combining device is a cubic prism, and the included angle between the light beam emitted to the polarization combining device and the incident face of the polarization combining device is in the range of 80°-89°.

57. The light source module of claim 56, wherein, The polarization combining device comprises a polarization splitting film, and the included angle between the light beam passing through the polarization splitting film and the exit face of the polarization combining device is in the range of 80°-89°.

58. The light source module of claim 55, wherein, The incident face of the polarization combining device comprises a first part and a second part, the first part corresponds to the incident light beam, the included angle between the first part and the incident direction of the light beam is in the range of 80°-89°, and the second part is perpendicular to the incident direction of the light beam.

59. The light source module of claim 58, wherein, The face opposite to the incident face in the polarization combining device comprises a first part and a second part, the included angle between the first part and the light beam passing through the polarization splitting film of the polarization combining device is in the range of 80°-89°, and the second part is perpendicular to the light beam passing through the polarization splitting film.

60. The light source module of claim 55, wherein, The polarization combining device comprises a substrate and a polarization splitting film, and the polarization splitting film is attached to one side of the substrate.

61. The light source module of claim 55, wherein, The polarization combining device comprises a first substrate, a second substrate and a polarization splitting film, and the polarization splitting film is located between the first substrate and the second substrate.

62. The light source module of claim 55, wherein, The light source module comprises a base configured to carry the light source, the wavelength combining device and the polarization combining device, and the inner surface of the base corresponding to the polarization combining device has an included angle with the image light beam after being combined by the polarization combining device.

63. The light source module of claim 62, wherein, The inner surface of the base is provided with a light-absorbing coating.

64. An optical fiber scanning display device, wherein, Comprise: The light source module as claimed in any one of claims 1-3, 4-15, 16-23, 24-30, 31-36, 37-51 or 52-63; The optical fiber scanning module, the light emitted by the light source module is scanned and output by the optical fiber scanning module as display image light; The optical fiber scanning module comprises an actuator, the optical fiber light emitting end in the light source module is fixed on the actuator, the optical fiber exceeds the actuator and forms an optical fiber cantilever, the optical fiber cantilever is driven by the actuator to scan in space.

65. A projection display device, wherein, Comprise: The light source module as claimed in any one of claims 1-3, 4-15, 16-23, 24-30, 31-36, 37-51 or 52-63; The light scanning module; The optical fiber between the light source module and the light scanning module is provided with at least one section of few-mode optical fiber or single-mode optical fiber.

66. The projection display device of claim 65, wherein, The optical fiber of the light scanning module and the light source module is connected through a connector, the distance between the connection position of the connector and the laser light source of the light source module is not less than 50 cm.

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