CN212571686U

CN212571686U - Active alignment system

Info

Publication number: CN212571686U
Application number: CN202021180583.8U
Authority: CN
Inventors: 程章金
Original assignee: Barzini Capital Pte Ltd
Current assignee: Chaoying Optical Technology Pte. Ltd.
Priority date: 2020-06-23
Filing date: 2020-06-23
Publication date: 2021-02-19
Anticipated expiration: 2030-06-23

Abstract

The utility model provides an active alignment system for the equipment laser module, this laser module include optical lens piece and produce laser beam's laser unit. The active alignment system comprises a positioning unit, a sensing unit and a control unit electrically connected between the positioning unit and the sensing unit, wherein the positioning unit is used for moving the optical lens; the sensing unit is used for sensing the laser beam passing through the optical lens to obtain a detected pattern; the control unit is used for driving the positioning unit to move the optical lens according to the detected pattern until the detected pattern meets a detection standard. The utility model has the advantages of improve the manufacturing accuracy of laser module and reduce manufacturing cost, and be applicable to bulk production.

Description

Active alignment system

Technical Field

The utility model belongs to the technical field of optics and specifically relates to an active alignment system.

Background

Since the laser light source has a relatively high photoelectric conversion efficiency, and the laser beam output by the laser light source has optical characteristics of high energy, uniform wavelength, single frequency and good collimation, the laser light source is gradually widely used. Referring to fig. 1 and 2, fig. 1 is a schematic cross-sectional view of a portion of a conventional laser module, and fig. 2 is an exploded perspective view of the portion of the laser module shown in fig. 1. The conventional laser module 1 includes an outer housing 10, an inner housing 11, a substrate 12, a laser unit 13, a reflective optical element 15, a collimating optical element 16, a Diffractive Optical Element (DOE) 17 and a ceramic plate 14, wherein the substrate 12 is used for carrying the laser unit 13, the ceramic plate 14, the outer housing 10 and the inner housing 11, and the laser unit 13 is disposed on the ceramic plate 14 to be electrically connected to the substrate 12; the inner housing 11 is disposed in the accommodating space of the outer housing 10, and the collimating optical element 16 and the diffractive optical element 17 are respectively fixed on the inner housing 11 and the outer housing 10, such that the collimating optical element 16 is located between the substrate 12 and the diffractive optical element 17 in the vertical direction.

Furthermore, after the laser unit 13 receives power, the laser unit 13 can provide a plurality of laser beams L1, and the laser beams L1 travel toward the reflective optical element 15, and are reflected by the reflective optical element 15 after being projected onto the reflective optical element 15 and travel toward the collimating optical element 16 and the diffractive optical element 17. The collimating optical element 16 is used for collimating the laser beam L1 reflected by the reflecting optical element 15, so that the laser beam L1 passing through the collimating optical element 16 enters the diffractive optical element 17 in a preferred incident direction, and the diffractive optical element 17 is used for beam shaping the laser beam L1 passing through the collimating optical element 16, so that the laser beam L1 forms structured light and projects the structured light outwards.

Particularly, the laser module 1 has more components, which not only increases the assembly complexity, but also becomes a barrier for improving the assembly precision; for example, in the process of assembling the laser module 1, positioning deviation may occur when the collimating optical element 16 is fixed above the reflecting optical element 15, and positioning deviation may also occur when the diffractive optical element 17 is fixed above the collimating optical element 16, and obviously, the stacking composition of the elements will result in continuous expansion of the overall deviation, and the precision thereof only slightly falls on the order of micrometers, so that the structured light projected by the laser module 1 cannot meet the actual use requirements.

The conventional calibration means is to cut the bottom (i.e., the connection point with the substrate 12) of the carrier (i.e., the inner housing 11) carrying the collimating optical element 16 by mechanical cutting through micro-machining (micro-machining) so as to position the collimating optical element 16 at the in-focus position and posture, and to cut the bottom (i.e., the connection point with the substrate 12) of the carrier (i.e., the outer housing 10) carrying the diffractive optical element 17 by mechanical cutting through micro-machining (micro-machining) so as to position the diffractive optical element 17 at the in-focus position and posture. However, the precision that can be improved by the above-mentioned micro machining (mechanical cutting) method is still limited, and it is about in the order of micron, and it needs to be performed by an extremely expensive precision processing machine, and it is not suitable for mass production.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, to the above-mentioned not enough that prior art exists, provide an active alignment system for assembling laser module, borrow this and improve laser module's manufacturing accuracy and reduce manufacturing cost, and be applicable to bulk production.

The utility model provides a technical scheme that its technical problem adopted provides an active alignment system for assemble a laser module, this laser module includes an at least optical lens piece and a laser unit, and the produced laser beam of this laser unit outwards throws behind through this at least optical lens piece, and wherein, this active alignment system includes: a positioning unit for moving the at least one optical lens; a first sensing unit for sensing the laser beam passing through the at least one optical lens to obtain a detected pattern; and a control unit electrically connected between the positioning unit and the first sensing unit for driving the positioning unit to move the at least one optical lens according to the detected pattern until the detected pattern meets a detection standard.

Preferably, the laser module further comprises a reflective optical element, and the laser unit is an edge-emitting laser unit; the reflective optical element is used for reflecting the laser beam generated by the edge-emitting laser unit so that the laser beam travels towards the direction of the at least one optical lens.

Preferably, the Laser unit is a Vertical Cavity Surface Emitting Laser (VCSEL), and the Laser beam generated by the VCSEL travels toward the at least one optical lens.

Preferably, the positioning unit is a six-axis positioning unit.

Preferably, the at least one optical lens includes a collimating optical element, and the collimating optical element is configured to collimate the laser beam passing through the collimating optical element.

Preferably, the detection criteria include a spot size detection criterion, a spot shape detection criterion, and/or a spot position detection criterion.

Preferably, the first sensing unit is a beam profiler (beam profiler).

Preferably, the laser module further comprises an inner housing, and the inner housing is used for the collimating optical element to be arranged thereon; wherein the positioning unit moves the collimating optical element by moving the inner housing.

Preferably, the active alignment system further comprises a second sensing unit electrically connected to the control unit and configured to capture the collimated optical element; the control unit is further used for driving the positioning unit to move the collimating optical element according to a shooting result of the second sensing unit, so that the collimating optical element is positioned at a standard position which takes the position of the laser unit as a positioning reference and is in a standard posture.

Preferably, the collimating optical element is moved by the positioning unit to be located at a predetermined position with a system-defined reference standard as a positioning reference and at a predetermined attitude, and then is placed on the inner housing by the positioning unit.

Preferably, the second sensing unit includes at least three cameras, and the at least three cameras are respectively located at different directions of the collimating optical element.

Preferably, the at least one optical lens includes a Diffractive Optical Element (DOE) for beam shaping the laser beam passing therethrough so that the laser beam forms a structured light.

Preferably, the detection criteria include a feature point number (dot count) detection criterion, a contrast (contrast) detection criterion, a field of illumination (field of illumination) detection criterion, a hot spot (hot spot) detection criterion, a pattern angle (pattern angle) detection criterion, a zero order beam (zero order) detection criterion, an energy uniformity (power uniformity) detection criterion, and/or a geometric and pattern center of gravity (geometric & pattern center) detection criterion.

Preferably, the first sensing unit includes a projected surface and a camera module, and the projected surface is disposed between the diffractive optical element and the camera module; the camera module is used for shooting when the structured light is projected to the projected surface so as to obtain the detected pattern.

Preferably, the laser module further comprises an outer casing, and the outer casing is used for arranging the diffractive optical element thereon; wherein the positioning unit moves the diffractive optical element by moving the outer housing.

Preferably, the active alignment system further comprises a second sensing unit electrically connected to the control unit and configured to capture the image of the diffractive optical element; the control unit is further used for driving the positioning unit to move the diffractive optical element according to a shooting result of the second sensing unit, so that the diffractive optical element is located at a standard position and is in a standard posture.

Preferably, the at least one optical lens further includes a collimating optical element located below the diffractive optical element, and the laser module further includes an inner housing for the collimating optical element to be disposed thereon; the control unit is used for driving the positioning unit to move the diffractive optical element according to the shooting result of the second sensing unit, so that the diffractive optical element is positioned at the standard position which takes the position of the inner shell and/or the collimation optical element as a positioning reference and is positioned at the standard posture.

Preferably, the second sensing unit includes at least three cameras, and the at least three cameras are respectively located in different directions of the diffractive optical element.

Preferably, the second sensing unit photographs the outer shell for subsequent shell surface analysis.

Preferably, the active alignment system further comprises at least one mirror element disposed adjacent to the outer shell; the second sensing unit photographs the outer shell and/or the at least one mirror element for subsequent shell surface analysis.

Preferably, the diffractive optical element is moved by the positioning unit to be located at a predetermined position with a system-defined reference standard as a positioning reference and at a predetermined attitude, and then is placed on the outer housing by the positioning unit.

The utility model discloses active alignment system can fix a position and rectify the position and the gesture of optical lens in the in-process of equipment laser module to improve the equipment precision of laser module and reduce the equipment cost by a wide margin, be fit for bulk production.

Drawings

FIG. 1: is a schematic cross-sectional view of a part of the structure of a conventional laser module.

FIG. 2: is a schematic perspective exploded view of a part of the structure of the laser module shown in fig. 1.

FIG. 3: for applying the present invention, the active alignment system is assembled to a laser module according to a cross-sectional concept of a partial structure of a preferred embodiment.

FIG. 4: is a schematic perspective exploded view of a part of the structure of the laser module shown in fig. 3.

FIG. 5: a schematic block concept diagram of a preferred embodiment of the active alignment system of the present invention is shown.

FIG. 6A: the concept of the first stage of assembling the collimating optical element to the inner housing using the active alignment system of FIG. 5 is illustrated.

FIG. 6B: the concept of the second stage of assembling the collimating optical element to the inner housing using the active alignment system of FIG. 5 is illustrated.

FIG. 7A: a preferred conceptual illustration of a coarse positioning of a collimating optical element using the active alignment system of figure 5 is shown.

FIG. 7B: a conceptual diagram of a preferred embodiment of fine-tuning the alignment optics and assembling them into a laser module using the active alignment system of fig. 5 is shown.

FIG. 8A: a conceptual diagram of the measured pattern when the collimating optics is in a non-collimated position and posture is shown.

FIG. 8B: a conceptual diagram of the measured pattern when the collimating optical element is in the in-focus position and posture is shown.

FIG. 9A: the conceptual diagram of the first stage of assembling the diffractive optical element to the outer housing using the active alignment system of FIG. 5 is shown.

FIG. 9B: the conceptual diagram of the second stage of assembling the diffractive optical element to the outer housing using the active alignment system of FIG. 5 is shown.

FIG. 10A: a preferred conceptual illustration of a coarse positioning of a diffractive optical element using the active alignment system of figure 5 is shown.

FIG. 10B: a conceptual diagram of a preferred embodiment of fine-tuning the positioning of the diffractive optical element and assembling it into a laser module using the active alignment system of fig. 5 is shown.

FIG. 11: a preferred conceptual diagram of the measured pattern when the diffractive optical element is in the in-focus position and attitude is shown.

FIG. 12: a preferred block flow diagram of the active alignment method is shown.

FIG. 13A: a preferred block flow diagram of the active alignment method is shown.

FIG. 13B: a preferred block flow diagram of the active alignment method is shown.

FIG. 14: the relative relationship between the positioning tolerance and the assembly cost of the optical positioning and the mechanical positioning is shown schematically.

FIG. 15: for applying the present invention, the active alignment system is assembled to a laser module according to a cross-sectional concept of a partial structure of a preferred embodiment.

Detailed Description

Embodiments of the present invention will be further explained by referring to the following drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts. In the drawings, the shape and thickness may be exaggerated for simplicity and convenience. It is to be understood that elements not specifically shown in the drawings or described in the specification are in a form known to those of ordinary skill in the art. Various changes and modifications may be made by one of ordinary skill in the art in light of the teachings of the present invention.

First, a laser module assembled by using the Active Alignment system (Active Alignment Sysem) of the present invention will be described. Referring to fig. 3 and 4, fig. 3 is a schematic cross-sectional view of a partial structure of a laser module assembled by using the active alignment system of the present invention, and fig. 4 is a schematic perspective exploded view of the partial structure of the laser module shown in fig. 3. The laser module 2 includes an outer housing 20, an inner housing 21, a substrate 22, a laser unit 23, a ceramic plate 24, a reflective optical element 25, a collimating optical element 26, and a Diffractive Optical Element (DOE) 27, wherein the substrate 22 is used for carrying the laser unit 23, the ceramic plate 24, the outer housing 20, and the inner housing 21, and the laser unit 23 is disposed on the ceramic plate 24 to be electrically connected to the substrate 22; the inner housing 21 is disposed in the accommodating space of the outer housing 20, and the collimating optical element 26 and the diffractive optical element 27 are respectively fixed on the inner housing 21 and the outer housing 20, such that the collimating optical element 26 is located between the substrate 22 and the diffractive optical element 27 in the vertical direction.

Furthermore, in the preferred embodiment, the laser unit 23 is an edge-emitting laser unit, and when the laser unit 23 receives power, the laser unit 23 can provide a plurality of laser beams L2, and the laser beams L2 travel toward the reflective optical element 25, and are reflected by the reflective optical element 25 after being projected onto the reflective optical element 25 and travel toward the collimating optical element 26 and the diffractive optical element 27. The collimating optical element 26 collimates the laser beam L2 reflected by the reflecting optical element 25, so that the laser beam L2 passing through the collimating optical element 26 enters the diffractive optical element 27 in a preferred incident direction, and the diffractive optical element 27 performs beam shaping on the laser beam L2 passing through the collimating optical element 26, so that the laser beam L2 forms structured light and projects the structured light outward.

The active alignment system of the present invention is described next. Please refer to fig. 5, which is a block diagram illustrating an active alignment system according to a preferred embodiment of the present invention. The active alignment system 3 includes a first sensing unit 31, a second sensing unit 32, a positioning unit 33 and a control unit 34, and the control unit 34 is electrically connected between the first sensing unit 31, the second sensing unit 32 and the positioning unit 33, wherein the positioning unit 33 is used for moving the optical lens (such as the collimating optical element 26 or the diffractive optical element 27), the first sensing unit 31 is used for sensing the laser beam passing through the optical lens to obtain a detected pattern, and the second sensing unit 32 is used for photographing the optical lens.

Furthermore, in the process of assembling the laser module 2, the control unit 34 drives the positioning unit 33 to move the optical lens according to the shooting result of the second sensing unit 32, so that the optical lens is located at a standard position and at a standard posture to complete the preliminary coarse positioning, and then drives the positioning unit 33 to move the optical lens according to the detected pattern obtained by the first sensing unit 31 until the detected pattern meets a detection standard, thereby completing the fine positioning for the subsequent fixing procedure.

The assembly process of the laser module 2 is described in detail below. Referring to fig. 6A and 6B, fig. 6A is a conceptual diagram illustrating a first stage of assembling the collimating optical element onto the inner housing by using the active alignment system shown in fig. 5, and fig. 6B is a conceptual diagram illustrating a second stage of assembling the collimating optical element onto the inner housing by using the active alignment system shown in fig. 5. In the preferred embodiment, the second sensing unit 32 includes three cameras 325, and the positioning unit 33 includes a six-axis positioning unit 334 capable of six-axis movement with respect to the straight optical element 26. However, the implementation and number of the second sensing units 32 and the positioning units 33 are not limited to the above.

Fig. 6A illustrates that in the first stage of assembling the collimating optical element 26 on the inner housing 21 by the active alignment system 3, the six-axis positioning unit 334 first moves the collimating optical element 26 to the three cameras 325, so that the three cameras 325 are respectively located at the lower vicinity, the rear vicinity and the lateral vicinity of the collimating optical element 26, then the cameras 325 respectively take pictures of the collimating optical element 26, and the pictures taken by the cameras 325 are transmitted back to the control unit 34, so that the control unit 34 obtains relevant control feedback, and drives the six-axis positioning unit 334 to move the collimating optical element 26 until the collimating optical element 26 is located at a predetermined position (e.g. an angular position) with a system-defined reference standard as a positioning reference. In the preferred embodiment, the lower camera 325 is used to confirm the position of the collimating optic 26 in the XY plane, and the rear and side cameras 325 are used to confirm the parallelism (flatness) of the collimating optic 26.

Fig. 6B illustrates that in the second stage of assembling the collimating optical element 26 onto the inner housing 21 by the active alignment system 3, the camera 326 disposed above the collimating optical element 26 is used to align the collimating optical element 26 and the inner housing 21 for shooting, and the shooting result of the camera 326 is transmitted back to the control unit 34, so that the control unit 34 obtains relevant control feedback, and accordingly drives the six-axis positioning unit 334 to move the collimating optical element 26 until the collimating optical element 26 aligns with the inner housing 21 and the collimating optical element 26 is disposed on the inner housing 21.

Before the active alignment system 3 shown in fig. 6A and 6B positions the collimating optical element 26 on the inner housing 21, a glue is applied to the collimating optical element 26 or the inner housing 21 to make the collimating optical element 26 or the inner housing 21 have a glue thereon, and after the active alignment system 3 shown in fig. 6A and 6B positions the collimating optical element 26 on the inner housing 21, the glue is cured (e.g., uv curing) to fix the collimating optical element 26 on the inner housing 21.

Referring to fig. 7A and 7B, fig. 7A is a schematic diagram of a preferred embodiment of a coarse alignment of the collimating optical element by the active alignment system of fig. 5, and fig. 7B is a schematic diagram of a preferred embodiment of a fine alignment of the collimating optical element by the active alignment system of fig. 5 and the collimating optical element assembled to the laser module. In the preferred embodiment, the first sensing unit 31 includes a beam analyzer (beam profiler)311, the second sensing unit 32 includes three cameras 321, and the positioning unit 33 includes a six-axis positioning unit 331 capable of performing six-axis movement with respect to the straight optical element 26. Since the collimating optical element 26 is assembled to the inner housing 21, in the preferred embodiment, the six-axis positioning unit 331 moves the collimating optical element 26 by moving the inner housing 21. However, the implementation and number of the first sensing unit 31, the second sensing unit 32 and the positioning unit 33 are not limited to the above.

Fig. 7A illustrates that in the course of the active alignment system 3 performing coarse positioning on the straight optical element 26, the six-axis positioning unit 331 first moves the inner housing 21 and the collimating optical element 26 fixed thereon to the three cameras 321, so that the three cameras 321 are respectively located above, behind, and beside the collimating optical element 26, then the cameras 321 respectively take pictures of the inner housing 21 and the collimating optical element 26 fixed thereon, and the pictures taken by the cameras 321 are returned to the control unit 34, so that the control unit 34 obtains relevant control feedback, and drives the six-axis positioning unit 331 to move the inner housing 21 and the collimating optical element 26 fixed thereon until the inner housing 21 and the collimating optical element 26 fixed thereon are located at a standard position with the position of the laser unit 23 as a positioning reference and at a standard posture (e.g. an angular posture), the coarse positioning procedure is completed. In the preferred embodiment, the top camera 321 is used to confirm the position of the inner housing 21 and the collimating optical element 26 fixed thereon on the XY plane, and the rear and side cameras 321 are used to confirm the parallelism (flatness) of the inner housing 21 and the collimating optical element 26 fixed thereon.

Fig. 7B shows that in the process of fine-tuning and positioning the alignment optical element 26 by the active alignment system 3, the beam analyzer 311 is disposed above and adjacent to the laser module 2, the control unit 34 drives the power unit 35 electrically connected to the control unit to provide power to the laser module 2, so that the laser unit 23 provides the laser beam L2, and after the laser beam L2 is reflected by the reflective optical element 25 and travels toward the alignment optical element 26 and passes through the alignment optical element 26, the beam analyzer 311 above the alignment optical element 26 senses the laser beam L2 passing through the alignment optical element 26 to obtain the detected pattern I1, and the control unit 34 drives the six-axis positioning unit 331 to move the inner housing 21 and the alignment optical element 26 fixed thereon according to the detected pattern I1 until the detected pattern I1 obtained by the beam analyzer 311 meets the detection standard, when the detected pattern I1 meets the detection standard, it represents that the collimating optical element 26 is located at the in-focus position and posture, and the subsequent procedure of fixing the inner housing 21 can be prepared.

Further, before the active alignment system 3 shown in fig. 7A and 7B positions the inner housing 21 and the collimating optical element 26 thereon to the laser module 2, a glue is applied to the inner housing 21 or the substrate 22 to make the inner housing 21 or the substrate 22 have a glue thereon, and after the active alignment system 3 shown in fig. 7A and 7B positions the inner housing 21 and the collimating optical element 26 thereon to the laser module 2, the glue is cured (e.g., uv curing) to make the inner housing 21 fixed on the laser module 2.

In addition, the above-described test criteria for positioning measured pattern I2 of collimating optics 26 are further described below. Referring to fig. 8A and 8B, fig. 8A is a schematic diagram of a preferred concept of the measured pattern when the collimating optical element is in a non-in-focus position and posture, and fig. 8B is a schematic diagram of a preferred concept of the measured pattern when the collimating optical element is in an in-focus position and posture. As shown in fig. 8A and 8B, the size, shape and position of the light spot in the measured pattern I1 are changed according to the position and posture of the collimating optical element 26, so that in the preferred embodiment, the detection criteria include a light spot size detection criterion, a light spot shape detection criterion and/or a light spot position detection criterion, and the detection of the size, shape and/or position of the light spot in the measured pattern I1 can be used as a basis for determining whether the collimating optical element 26 is located at the in-focus position and posture. However, the design of the test standard is not limited to the above, and those skilled in the art can make any equivalent design changes according to the actual application requirements.

Referring to fig. 9A and 9B, fig. 9A is a conceptual diagram of a first stage of assembling the diffractive optical element on the outer housing by using the active alignment system shown in fig. 5, and fig. 9B is a conceptual diagram of a second stage of assembling the diffractive optical element on the outer housing by using the active alignment system shown in fig. 5. In the preferred embodiment, the second sensing unit 32 includes three cameras 322, and the positioning unit 33 includes a six-axis positioning unit 332 capable of six-axis movement of the diffractive optical element 27. However, the implementation and number of the second sensing units 32 and the positioning units 33 are not limited to the above.

Fig. 9A illustrates that in the first stage of assembling the diffractive optical element 27 on the outer housing 20 by the active alignment system 3, the six-axis positioning unit 332 first moves the diffractive optical element 27 to the three cameras 322, so that the three cameras 322 are respectively located at the lower vicinity, the rear vicinity and the lateral vicinity of the diffractive optical element 27, then the cameras 322 respectively take pictures of the diffractive optical element 27, and the pictures taken by the cameras 322 are transmitted back to the control unit 34, so that the control unit 34 obtains relevant control feedback, and drives the six-axis positioning unit 332 to move the diffractive optical element 27 until the diffractive optical element 27 is located at a predetermined position (e.g., an angular position) with a system-defined reference standard as a positioning reference and is located at a predetermined position. In the preferred embodiment, the lower camera 322 is used to confirm the position of the diffractive optical element 27 on the XY plane, and the rear and side cameras 322 are used to confirm the parallelism (flatness) of the diffractive optical element 27.

Fig. 9B illustrates that in the second stage of assembling the diffractive optical element 27 onto the outer housing 20 by the active alignment system 3, the camera 323 disposed above the diffractive optical element 27 is used to capture images of the diffractive optical element 27 and the outer housing 20, and the captured result of the camera 323 is transmitted back to the control unit 34, so that the control unit 34 obtains relevant control feedback, and accordingly drives the six-axis positioning unit 332 to move the diffractive optical element 27 until the diffractive optical element 27 aligns with the outer housing 20 and the diffractive optical element 27 is disposed on the outer housing 20.

Before the active alignment system 3 shown in fig. 9A and 9B positions the diffractive optical element 27 on the outer housing 20, a glue is applied to the diffractive optical element 27 or the outer housing 20 to make the diffractive optical element 27 or the outer housing 20 have a glue thereon, and after the active alignment system 3 shown in fig. 9A and 9B positions the diffractive optical element 27 on the outer housing 20, the glue is cured (e.g., uv cured) to fix the diffractive optical element 27 on the outer housing 20.

Referring to FIGS. 10A and 10B, FIG. 10A is a schematic diagram of a preferred embodiment of a coarse positioning of a diffractive optical element using the active alignment system of FIG. 5, and FIG. 10B is a schematic diagram of a preferred embodiment of a fine positioning of a diffractive optical element using the active alignment system of FIG. 5 and assembled into a laser module. In the preferred embodiment, the first sensing unit 31 includes the camera module 312 and the projected surface 313, the second sensing unit 32 includes three cameras 324, and the positioning unit 33 includes a six-axis positioning unit 333 capable of six-axis movement of the diffractive optical element 27; since the diffractive optical element 27 is assembled to the outer housing 20, the six-axis positioning unit 333 moves the diffractive optical element 27 by moving the outer housing 20 in the preferred embodiment. However, the implementation and number of the first sensing unit 31, the second sensing unit 32 and the positioning unit 33 are not limited to the above.

Fig. 10A illustrates that in the course of coarse positioning of the diffractive optical element 27 by the active alignment system 3, the six-axis positioning unit 333 first moves the outer housing 20 and the diffractive optical element 27 fixed thereon to the three cameras 324, so that the three cameras 324 are respectively located above, behind, and beside the diffractive optical element 27, then the cameras 324 respectively take pictures of the outer housing 20 and the diffractive optical element 27 fixed thereon, and the pictures taken by the cameras 324 are returned to the control unit 34, so that the control unit 34 obtains related control feedback, and accordingly drives the six-axis positioning unit 333 to move the outer housing 20 and the diffractive optical element 27 fixed thereon until the outer housing 20 and the diffractive optical element 27 fixed thereon are located at a standard position (such as an angular position) with the position of the inner housing 21 and/or the collimating optical element 26 as a positioning reference and are in a standard posture, the coarse positioning procedure is completed. In the preferred embodiment, the upper camera 324 is used to confirm the position of the outer housing 20 and the diffractive optical element 27 fixed thereon on the XY plane, and the rear and side cameras 324 are used to confirm the parallelism (flatness) of the outer housing 20 and the diffractive optical element 27 fixed thereon.

Preferably, but not limited thereto, the active alignment system 3 further includes one or more mirror elements 36 located adjacent to the outer shell 20 and used for imaging at least a part of the outer shell 20, and when the cameras 324 capture images of the outer shell 20 and the mirror elements 36 adjacent to the outer shell 20, the control unit 34 can further perform shell surface analysis on the outer shell 20 according to the capturing results of the cameras 324, so as to determine whether the outer shell 20 is scratched or damaged.

Fig. 10B shows that in the fine adjustment and positioning process of the active alignment system 3 on the diffractive optical element 27, the image pickup module 312 and the projected surface 313 are disposed above and adjacent to the laser module 2, the projected surface 313 is located between the diffractive optical element 27 and the image pickup module 312, the control unit 34 drives the power unit 35 electrically connected to the control unit to provide power to the laser module 2, so that the laser unit 23 provides the laser beam L2, and after the laser beam L2 is reflected by the reflective optical element 25 to travel in the direction of the collimating optical element 26 and the diffractive optical element 27 and sequentially passes through the collimating optical element 26 and the diffractive optical element 27 to form structured light, the image pickup module 312 above the projected surface 313 picks up the structured light projected to the projected surface 313 to obtain the measured pattern I2, the control unit 34 drives the six-axis positioning unit 333 to move the outer housing 20 and the diffractive optical element 27 fixed thereon according to the measured pattern I2, until the detected pattern I2 obtained by the camera module 312 meets the detection standard, wherein when the detected pattern I2 meets the detection standard, it represents that the diffractive optical element 27 is in the in-focus position and posture, and the subsequent procedure of fixing the outer shell 20 can be prepared.

Further, before the active alignment system 3 shown in fig. 10A and 10B positions the outer housing 20 and the diffractive optical element 27 thereon to the laser module 2, a glue is applied to the outer housing 20 or the substrate 22 to form a glue on the outer housing 20 or the substrate 22, and after the active alignment system 3 shown in fig. 10A and 10B positions the outer housing 20 and the diffractive optical element 27 thereon to the laser module 2, the glue is cured (e.g., uv cured) to fix the outer housing 20 to the laser module 2.

In addition, the detection criteria described above with respect to the detected pattern I2 for positioning the diffractive optical element 27 are further described below. Please refer to fig. 11, which is a schematic diagram illustrating a preferred concept of the measured pattern when the diffractive optical element is in the in-focus position and posture. Wherein the contrast (contrast), the illumination field (field of illumination), the hot spot (hot spot), the pattern angle (pattern angle), the energy uniformity (power uniformity), the geometric and pattern center of gravity (geometric & pattern center), the zero order (zero order) of the light beam and the number of the feature points (dot count) of the pattern I2 are varied according to the position and the posture of the diffractive optical element 27, so that, in the preferred embodiment, the detection criteria include the number detection criteria, the contrast detection criteria, the illumination field detection criteria, the hot spot detection criteria, the pattern angle detection criteria, the zero order light beam detection criteria, the energy uniformity detection criteria and/or the geometric and pattern center of gravity detection criteria, and the contrast, the illumination field, the hot spot, the pattern angle, the energy uniformity, the geometric and pattern center of gravity in the pattern I2, the illumination field, the hot spot, the pattern angle, the energy uniformity, the geometric and the pattern center of gravity are varied, The representation of the zeroth order beam and/or the detection of the number of the characteristic points can be used as a basis for determining whether the diffractive optical element 27 is located at the in-focus position and the attitude. However, the design of the test standard is not limited to the above, and those skilled in the art can make any equivalent design changes according to the actual application requirements.

In summary, an Active Alignment Method (Active Alignment Method) for assembling the laser module is shown in fig. 12. The active alignment method comprises the following steps: step S11, sensing the laser beam passing through the optical lens to obtain a detected pattern; and step S12, moving the optical lens according to the detected pattern until the detected pattern meets the detection standard.

In the preferred embodiment, an active alignment method for assembling the laser module 2 is further illustrated in fig. 13A and 13B. The active alignment method comprises the following steps:

step S201, shooting the collimating optical element 26 by at least three cameras 325, and the cameras 325 are respectively located in different directions of the collimating optical element 26;

step S202, moving the collimating optical element 26 by using the six-axis positioning unit 334 according to the shooting result of step S201 until the collimating optical element 26 is located at a predetermined position with a system-customized reference standard as a positioning reference and is in a predetermined posture;

step S203, shooting the collimating optical element 26 and the inner housing 21 with the camera 326;

step S204, moving the collimating optical element 26 according to the shooting result of step S203, so that the collimating optical element 26 is aligned with the inner housing 21 and is placed on the inner housing 21;

step S205, using at least three cameras 321 to photograph the inner housing 21 and the collimating optical element 26 fixed thereon, wherein the cameras 321 are respectively located in different directions of the collimating optical element 26;

step S206, moving the inner housing 21 and the collimating optical element 26 fixed thereon by using the six-axis positioning unit 331 according to the shooting result of the step S205 until the inner housing 21 and the collimating optical element 26 fixed thereon are located at a standard position with the location of the laser unit 23 as a positioning reference and are in a standard posture;

step S207, sensing the laser beam L2 passing through the collimating optical element 26 by the beam analyzer 311 to obtain a detected pattern I1;

step S208, moving inner housing 21 and collimating optical element 26 fixed thereon according to the detected pattern I1 obtained in step S207 until the detected pattern I1 meets the detection criteria for positioning collimating optical element 26;

step S209 of photographing the diffractive optical element 27 with at least three cameras 322, the cameras 322 being respectively located in different directions of the diffractive optical element 27;

step S210 of moving the diffractive optical element 27 by using the six-axis positioning unit 332 according to the shooting result of the step S209 until the diffractive optical element 27 is located at a predetermined position with a system-customized reference standard as a positioning reference and is in a predetermined posture;

step S211 of imaging the diffractive optical element 27 and the outer housing 20 with the camera 323;

step S212, moving the diffractive optical element 27 according to the shooting result of step S211, aligning the diffractive optical element 27 with the outer casing 20 and placing the diffractive optical element on the outer casing 20;

step S213, using at least three cameras 324 to photograph the outer casing 20 and the diffractive optical element 27 fixed thereon, wherein the cameras 324 are respectively located in different directions of the diffractive optical element 27;

step S214, moving the outer shell 20 and the diffractive optical element 27 fixed thereon by using the six-axis positioning unit 333 according to the shooting result of step S213 until the outer shell 20 and the diffractive optical element 27 fixed thereon are located at a standard position with the position of the inner shell 21 and/or the collimating optical element 26 as a positioning reference and are in a standard posture;

step S215, when the laser beam L2 passes through the diffractive optical element 27 to form a structured light and is projected onto the projected surface 313, the image is captured by the image capturing module 312 to obtain a detected pattern I2; and

in step S216, the outer housing 20 and the diffractive optical element 27 fixed thereon are moved according to the test pattern I2 obtained in step S215 until the test pattern I2 meets the detection criteria for positioning the diffractive optical element 27.

What has been particularly described is that, compare in the background art, the utility model discloses utilize the active alignment system of optics formula to fix a position and rectify optical lens's position and gesture in the in-process of equipment laser module, can improve equipment precision to nanometer grade and reduce the equipment cost by a wide margin, be fit for bulk production. Further, please refer to fig. 14, which is a diagram illustrating a relative relationship between the positioning tolerance and the assembly cost of the optical positioning and the mechanical positioning. Fig. 14 illustrates that the cost required for optical positioning is more than 10 percent less than the cost required for mechanical positioning at positioning tolerances below 0.025 mm.

In addition, although the above description has been made by taking a laser module having an edge-emitting laser unit, a reflective optical element, a collimating optical element and a diffractive optical element as an example, the laser module assembled by applying the active alignment system of the present invention is not limited to the above description, and those skilled in the art can apply the laser module of various embodiments to be assembled according to the actual situation through the teachings obtained by the above embodiments.

For example, please refer to fig. 15, which is a schematic cross-sectional view of a laser module assembled by an active alignment system according to a preferred embodiment of the present invention. The Laser module 4 includes a Laser unit 41, a projection structure 42 and a diffractive optical element 43, wherein the Laser unit 41 is a Vertical Cavity Surface Emitting Laser (VCSEL), and the projection structure 42 is disposed between the Laser unit 41 and the diffractive optical element 43 and has at least one optical lens (not shown), wherein after the Laser unit 41 receives power, the Laser unit 41 can provide a plurality of Laser beams L3, and the Laser beams L3 travel toward the projection structure 42, then travel toward the diffractive optical element 43 through the guidance of the optical lens, and finally form a structured light after passing through the diffractive optical element 43 and project the structured light outward.

Similarly, in the process of assembling the laser module 4, the projection structure 42 and/or the optical lens therein can be aligned with the laser unit 41 by the active alignment system of the present invention, and the diffractive optical element 45 can be aligned with the projection structure 42 and/or the optical lens therein by the active alignment system of the present invention, so that the assembling accuracy of the laser module 4 can be greatly improved and the assembling cost can be reduced.

The above description is only for the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims, therefore, all other equivalent changes and modifications that do not depart from the spirit of the present invention should be included in the scope of the claims.

Claims

1. An active alignment system for assembling a laser module, the laser module including at least one optical lens and a laser unit, and a laser beam generated by the laser unit projecting outwards after passing through the at least one optical lens, the active alignment system comprising:

a positioning unit for moving the at least one optical lens;

a first sensing unit for sensing the laser beam passing through the at least one optical lens to obtain a detected pattern; and

and the control unit is electrically connected between the positioning unit and the first sensing unit and used for driving the positioning unit to move the at least one optical lens according to the detected pattern until the detected pattern meets a detection standard.

2. The active alignment system of claim 1, wherein the laser module further comprises a reflective optical element, and the laser unit is an edge-emitting laser unit, wherein the reflective optical element is configured to reflect the laser beam generated by the edge-emitting laser unit such that the laser beam travels in a direction of the at least one optical lens; or, the laser unit is a vertical cavity surface emitting laser unit, and the laser beam generated by the vertical cavity surface emitting laser unit travels towards the direction of the at least one optical lens.

3. The active alignment system of claim 1, wherein the positioning unit is a six-axis positioning unit.

4. The active alignment system of claim 1, wherein the at least one optical lens includes a collimating optical element, and the collimating optical element is configured to collimate the laser beam passing through the collimating optical element.

5. The active alignment system of claim 4, wherein the detection criteria include a spot size detection criteria, a spot shape detection criteria, and/or a spot position detection criteria.

6. The active alignment system of claim 4, wherein the first sensing unit is a beam analyzer.

7. The active alignment system of claim 4, wherein the laser module further comprises an inner housing, and the inner housing is configured for the collimating optics to be disposed thereon; wherein the positioning unit moves the collimating optical element by moving the inner housing.

8. The active alignment system of claim 4, further comprising a second sensing unit electrically connected to the control unit for capturing the image of the collimating optical element; the control unit is further used for driving the positioning unit to move the collimating optical element according to a shooting result of the second sensing unit, so that the collimating optical element is positioned at a standard position which takes the position of the laser unit as a positioning reference and is in a standard posture.

9. The active alignment system of claim 8, wherein the laser module further comprises an inner housing, the inner housing being configured to mount the collimating optics thereon; wherein the positioning unit moves the collimating optical element by moving the inner housing.

10. The active alignment system of claim 9, wherein the collimating optical element is moved by the positioning unit to a predetermined position and in a predetermined attitude with a system-defined reference standard as a positioning reference, and then is placed on the inner housing by the positioning unit.

11. The active alignment system of claim 8, wherein the second sensing unit comprises at least three cameras, and the at least three cameras are respectively located at different directions of the collimating optical element.

12. The active alignment system of claim 1, wherein the at least one optical lens includes a diffractive optical element for beam shaping the laser beam passing therethrough to form the laser beam into a structured light.

13. The active alignment system of claim 12, wherein the detection criteria include a feature number detection criteria, a contrast detection criteria, an illumination field of view detection criteria, a hot spot detection criteria, a pattern angle detection criteria, a zeroth order beam detection criteria, an energy uniformity detection criteria, and/or a geometric and pattern centroid position detection criteria.

14. The active alignment system of claim 12, wherein the first sensing unit comprises a projected surface and a camera module, and the projected surface is disposed between the diffractive optical element and the camera module; the camera module is used for shooting when the structured light is projected to the projected surface so as to obtain the detected pattern.

15. The active alignment system of claim 12, wherein the laser module further comprises an outer housing, and the outer housing is configured for the diffractive optical element to be disposed thereon; wherein the positioning unit moves the diffractive optical element by moving the outer housing.

16. The active alignment system of claim 12, further comprising a second sensing unit electrically connected to the control unit for photographing the diffractive optical element; the control unit is further used for driving the positioning unit to move the diffractive optical element according to a shooting result of the second sensing unit, so that the diffractive optical element is located at a standard position and is in a standard posture.

17. The active alignment system of claim 16, wherein the at least one optical lens further comprises a collimating optical element disposed below the diffractive optical element, and the laser module further comprises an inner housing for disposing the collimating optical element thereon; the control unit is used for driving the positioning unit to move the diffractive optical element according to the shooting result of the second sensing unit, so that the diffractive optical element is positioned at the standard position which takes the position of the inner shell and/or the collimation optical element as a positioning reference and is positioned at the standard posture.

18. The active alignment system of claim 16, wherein the second sensing unit comprises at least three cameras, and the at least three cameras are respectively located at different directions of the diffractive optical element.

19. The active alignment system of claim 16, wherein the laser module further comprises an outer housing, and the outer housing is configured for the diffractive optical element to be disposed thereon; wherein the positioning unit moves the diffractive optical element by moving the outer housing.

20. The active alignment system of claim 19, wherein the second sensing unit photographs the outer housing for subsequent analysis of a housing surface.

21. The active alignment system of claim 19, further comprising at least one mirror element disposed adjacent to the outer shell; the second sensing unit photographs the outer shell and/or the at least one mirror element for subsequent shell surface analysis.

22. The active alignment system of claim 19, wherein the diffractive optical element is moved by the positioning unit to a predetermined position and a predetermined attitude with a system-defined reference standard as a positioning reference, and then is placed on the housing by the positioning unit.