An assembling method and device of a multi-group lens group and an assembling method of a camera module

Abstract

The application provides an assembling method and device of a multi-group lens group and an assembling method of a camera module. The multi-group lens group comprises a first lens group, a second lens group and a third lens group. The assembling method of the multi-group lens group comprises the following steps: obtaining initial positions of the first lens group, the second lens group and the third lens group by means of an identification device; moving the first lens group, the second lens group and the third lens group to an assembling station by means of a taking device; pre-positioning the first lens group, the second lens group and the third lens group; and actively calibrating optical performance of the first lens group, the second lens group and the third lens group. The assembling method of the multi-group lens group makes the relative position relationship between the assembled optical lenses more reasonable, thereby ensuring that the continuous zoom system has good performance at each focal length position.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic devices, in particular, to an assembling method of a multi-group lens group, an equipment and an assembling method of a camera module. BACKGROUND

[0002] The vigorous development and popularity of smart phones make them one of the necessities in people's daily life. The use of smart phones covers all aspects of modern life, and the camera module of the smart phone is needed in social activities such as photography, consumption, work and entertainment. The camera module of the smart phone is designed at the initial stage only to meet the demand of users to complete the shooting on the phone, so that users can record some life scenes or landscapes, which is equivalent to a simplified and lightweight camera. However, in recent years, with the change of user demand and the development of hardware and software of the phone, the form of the camera module suitable for the phone has also changed dramatically.

[0003] The early camera module of the phone is a simple camera module with a simple focusing light path. The user needs to move the shooting position to find the clear point when shooting, and at the same time, the environmental light intensity also has a great influence on the shooting effect. The camera module in this design state has a simple light path, and the straight light path design is matched with a simple lens setting state. Although there are disadvantages such as troublesome operation and poor imaging effect, it can also meet the shooting needs of users to a certain extent. With the continuous upgrading of market demand, the related configurations of the phone also need to be continuously upgraded to maintain market competitiveness. As for the camera module, from low-pixel fixed-focus module to high-pixel fixed-focus module, fixed-focus module to zoom module, single-aperture module to multi-aperture (dynamic aperture), normal focal length to long focal length, planar image acquisition to stereoscopic image acquisition, straight light path to turning light path, etc. Among them, the change from straight light path to turning light path has a dramatic change on the form and function of the module, and the production process of the camera module has also changed.

[0004] With the appearance of the continuous zoom module, the continuous zoom module can bring users the fun of zoom shooting. Since the basic principle of the continuous zoom mechanism is to change the combined focal length of the optical system by moving two or more optical lens groups in the optical system, while keeping the image plane position unchanged, and the imaging quality remains good during zooming, it is necessary to have good optical performance quality of the optical lens at these focal lengths to shoot clear images at each distance from near to far. That is, unlike the general fixed-focus optical system, the continuous zoom system needs to ensure that the relative position relationship of two or more optical lens groups at each focal length is ideal to ensure that the overall optical system has good performance at each focal length.

[0005] In the existing multi-group optical lens assembly process, the step of assembling the multi-group optical lens to the camera module does not actively calibrate or actively calibrate the effect between adjacent optical lens groups, for example, there is a large eccentricity between each lens group, and the straightness of each lens group is poor when zooming. These cancellations will result in no perfect adaptation between the optical properties of the adjacent optical lens groups, resulting in poor imaging effect of the lens group during zooming, affecting the optical performance of the final camera module.

[0006] Therefore, there is a need for a multi-group lens assembly method, device and camera module assembly method, so that the relative position relationship between the assembled optical lenses is reasonable, and the continuous zoom system has good performance at each focal length position.

[0007] In the background section, the disclosed above information is only used to strengthen the understanding of the background of the present application, and therefore it can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0008] The present application aims to provide a multi-group lens assembly method, device and camera module assembly method, which can reduce the camera module assembly test time and ensure that the continuous zoom system has good performance at each focal length position.

[0009] The present application provides a multi-group lens assembly method, the multi-group lens assembly includes a first lens group, a second lens group and a third lens group, characterized in that the assembly method comprises: obtaining the initial positions of the first lens group, the second lens group and the third lens group through a recognition device; moving the first lens group, the second lens group and the third lens group to an assembly station through a taking device; pre-positioning the first lens group, the second lens group and the third lens group; actively calibrating the optical performance of the first lens group, the second lens group and the third lens group.

[0010] According to some embodiments, the pre-positioning of the first lens group, the second lens group and the third lens group comprises: capturing the first lens group, the second lens group and the third lens group through a depth camera to obtain the specific positions of the first lens group, the second lens group and the third lens group along the optical axis plane.

[0011] According to some embodiments, the pre-positioning of the first lens group, the second lens group and the third lens group further comprises: setting different depths of the depth camera, and measuring the three-axis directions of the first lens group, the second lens group and the third lens group respectively to obtain the specific positions of the first lens group, the second lens group and the third lens group along the optical axis plane.

[0012] According to some embodiments, the pre-positioning of the first lens group, the second lens group and the third lens group further comprises: leveling the first lens group, the second lens group and the third lens group according to the obtained specific positions along the optical axis plane.

[0013] According to some embodiments, the leveling is adjusting the inclination of the first lens group, the second lens group and the third lens group in the respective corresponding planes to 0.1-0.2 degrees respectively.

[0014] According to some embodiments, the pre-positioning of the first lens group, the second lens group and the third lens group further comprises: determining the initial spacing between the first lens group, the second lens group and the third lens group by camera shooting.

[0015] According to some embodiments, the pre-positioning of the first lens group, the second lens group and the third lens group further comprises: setting a preset distance between the first lens group, the second lens group and the third lens group, and adjusting the spacing to the preset spacing.

[0016] According to some embodiments, the active calibration of the optical performance of the first lens group, the second lens group and the third lens group comprises: measuring the optical performance of the first lens group, the second lens group and the third lens group before calibration to obtain an optical performance calibration amount; and calculating a position calibration amount required for the first lens group, the second lens group and the third lens group to reach the optical performance calibration amount according to the pre-positioning state of the first lens group, the second lens group and the third lens group.

[0017] According to some embodiments, the optical performance before calibration comprises imaging quality optical transfer function value, optical axis eccentricity, optical axis tilt angle and field curvature.

[0018] According to some embodiments, the position calibration amount comprises lens group spacing, optical axis eccentricity, optical axis tilt angle and field curvature sensitivity.

[0019] According to some embodiments, the intake device comprises a clamping jaw. According to some embodiments, the intake device further comprises a suction nozzle which sucks the multi-group lens group perpendicularly to the optical axis direction of the multi-group lens group.

[0020] The application also provides an assembly method of a camera module, comprising: the assembly method of the multi-group lens set according to any one of the preceding embodiments, wherein the first lens group and the second lens group are movable groups, and the third lens group is a fixed group; and adapting the first carrier to the first lens group after active calibration and adapting the second carrier to the second lens group after active calibration.

[0021] According to some embodiments, before the step of adapting the first carrier to the first lens group after active calibration and adapting the second carrier to the second lens group after active calibration, the method further comprises the step of: identifying specific position information of the first lens group and the second lens group after active calibration.

[0022] According to some embodiments, the specific position information comprises the interval, flatness and inclination of the first lens group and the second lens group.

[0023] According to some embodiments, the step of adapting the first carrier to the first lens group after active calibration and adapting the second carrier to the second lens group after active calibration comprises: adjusting the position state of the first carrier and the second carrier according to the specific position information, so as to adapt the first carrier to the first lens group after active calibration and adapt the second carrier to the second lens group after active calibration.

[0024] The application also provides an assembly device for assembling a multi-group lens set, wherein the multi-group lens set comprises a first lens group, a second lens group and a third lens group, and the assembly device comprises: a support; an identification device arranged on the support, wherein the identification device is used to obtain initial positions of the first lens group, the second lens group and the third lens group; and a taking device arranged on the support, wherein the taking device is used to move the first lens group, the second lens group and the third lens group to an assembly station.

[0025] According to some embodiments, the assembly device further comprises a depth camera arranged on the support, wherein the depth camera is used to shoot the first lens group, the second lens group and the third lens group, and obtain specific positions of the first lens group, the second lens group and the third lens group along an optical plane.

[0026] According to some embodiments, the assembly device further comprises a camera arranged on the support, wherein the camera is used to shoot to determine initial intervals between the first lens group, the second lens group and the third lens group.

[0027] According to some embodiments, the assembling device further comprises an active calibration device arranged on the support, the active calibration device being configured to actively calibrate optical performance of the first lens group, the second lens group and the third lens group.

[0028] It should be understood that the general description above and the detailed description below are only exemplary and are not restrictive of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0030] Figure 1 A flowchart of an assembling method of a multi-group lens assembly according to an example embodiment of the present application is shown.

[0031] Figure 2 A structural diagram of a multi-group lens assembly in an initial position according to an example embodiment of the present application is shown.

[0032] Figure 3 A structural diagram of a multi-group lens assembly after position adjustment according to an example embodiment of the present application is shown.

[0033] Figure 4 A flowchart of an assembling method of a camera module according to an example embodiment of the present application is shown.

[0034] Figure 5 A structural diagram of a camera module in a state of no calibration of lenses by a carrier according to an example embodiment of the present application is shown.

[0035] Figure 6 A structural diagram of a camera module after calibration of lenses by a carrier according to an example embodiment of the present application is shown.

[0036] Figure 7 A structural diagram of a camera module after assembly and molding according to an example embodiment of the present application is shown.

[0037] Figure 8 A structural diagram of a camera module assembly adjustment process according to some embodiments of the present application is shown.

[0038] Figure 9 A structural diagram of a light turning element assembly process according to some embodiments of the present application is shown.

[0039] Figure 10 A structural diagram of a material box according to some embodiments of the present application is shown.

[0040] Figure 11 A structural schematic diagram showing a periscopic camera module assembly process according to some embodiments of the present application.

[0041] Figure 12 A structural schematic diagram showing a multi-group lens assembly after assembly according to some embodiments of the present application.

[0042] Figure 13 A structural schematic diagram showing a periscopic camera module assembly process according to some embodiments of the present application.

[0043] Figure 14 A structural schematic diagram showing an assembly device according to an example embodiment of the present application. DETAILED DESCRIPTION

[0044] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views.

[0045] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the embodiments of the disclosure can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In some instances, well-known structures, methods, devices, implementations, materials, and operations are not shown or described in detail.

[0046] The flow diagrams shown in the Figures are merely examples and are not necessarily to be construed as having any prior or subsequent steps than those illustrated and are not necessarily performed in the order shown. For example, in some embodiments, steps can be performed in an order different than that shown, or can be performed concurrently. Further, in some embodiments, one or more steps can be omitted or combined, and additional steps can be performed.

[0047] The terms "first", "second", "third", etc., in the specification and claims of this application and in the above description of the drawings are used for distinguishing between similar objects and are not necessarily to be construed as describing a particular sequential or chronological order. Moreover, the terms "include", "have", and "contain" and variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a list of steps or elements is not necessarily limited to those steps or elements, but can include additional steps or elements not expressly listed or inherent to such process, method, system, product, or device.

[0048] The application provides an assembling method of a multi-group lens group, which is suitable for a periscopic camera module. Light from the object side to the photosensitive chip inside the module generally passes through the following components: a light inlet hole located at the outermost side, and a light path turning element. The light path turning element has a light turning surface (light reflecting surface) with a certain angle, which can make the incident light path turn by a certain angle. After the light path turning element, there is an optical lens group. The optical lens group adjusts the incident light to meet the subsequent imaging requirements. The optical lens group is a cooperation of two or more lens groups.

[0049] The optical lens group can further include a first lens group, a second lens group and a third lens group. The third lens group is a fixed group, and the first lens group and the second lens group are movable groups. In the application, the first lens group and the second lens group can be defined as mid-focus, close-focus and far-focus according to different shooting focal lengths. In the actual shooting process, the first lens group and the second lens group will move to different positions, and the distance between them will also be adjusted to adjust the focal length to the corresponding shooting distance. Further, the first lens group can be used as a zoom group in the actual use process, and the second lens group can be used as a focusing group in the actual use process. The first lens group and the second lens group can be matched in the movement process, so as to change the focal length of the optical lens group.

[0050] In the periscopic camera module, the total length of the light path has been increased several times compared with the traditional module after the light path of the periscopic camera module is turned several times. Relatively, the optical sensitivity of the periscopic camera module is higher, that is, a relatively small position change will have a greater impact on the function of the entire optical system. For example, a small deviation will cause image shooting deviation or failure to shoot the required image. Therefore, higher assembly precision control is required in the assembly process. In the traditional periscopic camera module assembly process, the assembly between the prism and the optical lens group is positioned into the module by machinery. After the assembly of the front components is completed, the imaging element is installed according to the light path structure formed by the front components. Since there are more than three optical lens groups in the multi-group lens group, it is more likely that the assembly error of the optical lens group will cause a large assembly deviation after the forming precision is superimposed. Therefore, in the periscopic camera module with a multi-group optical lens group, it is necessary to ensure the assembly precision between the multi-group lens groups, so as to ensure the imaging performance of the periscopic camera module.

[0051] More noteworthy, since the relative positions of the first lens group and the second lens group in the application will change due to the change of focal length during continuous zooming, the relative positional relationship between the first lens group and the second lens group, such as the inclination and offset between the groups, will cause the imaging of the module at this position to have poor image quality and unclear images during zooming. Therefore, only by ensuring that the first lens group and the second lens group maintain a good relative positional relationship at different focal lengths can a good image output be ensured at each focal length. In addition, since the optical lens groups are now moved by the motor carrier, that is, during the movement of the motor carrier, if the motor carrier itself has a relative position at different focal lengths, especially when assembling, in order to calibrate the gap between the first lens group and the second lens group, the first lens group and the second lens group are adjusted for assembly. Since there is no optical calibration between the motor carriers, only physical testing can be performed, so that at some focal lengths, the imaging effect of the first lens group and the second lens group assembled by the two motor carriers is high, but at other focal lengths, the two motor carriers cause errors in the imaging system composed of the first lens group, the second lens group, and the third lens group due to assembly or self-forming.

[0052] According to the technical concept of the application, the application improves the optical performance of the multi-group lens group at different focal lengths by position recognition, pre-positioning, and active calibration of the multi-group lens group, thereby ensuring that the continuous zoom system has good performance at each focal length. The application adapts the multi-group lens group after active calibration by the carrier, effectively reducing the assembly and testing time of the camera module while ensuring the optical performance of the camera module.

[0053] The assembly method, device, and assembly method of the camera module of the multi-group lens group according to the embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0054] Figure 1 The assembly method flowchart of the multi-group lens group according to the example embodiments of the application is shown.

[0055] Referring to Figure 1 At S101, the initial position of the multi-group lens group is identified.

[0056] The multi-group lens group includes a first lens group 11, a second lens group 13, and a third lens group 15. The initial positions of the first lens group 11, the second lens group 13, and the third lens group 15 are obtained by a recognition device, such as Figure 2As shown. Wherein, the initial position of the first lens group 11, the second lens group 13 and the third lens group 15 is identified by taking an image of the optical lens group and the environment, identifying the position of the first lens group 11, the second lens group 13 and the third lens group 15 in the image, thereby identifying the position of the first lens group 11, the second lens group 13 and the third lens group 15, and further ensuring that the position of the first lens group 11, the second lens group 13 and the third lens group 15 can be directly obtained.

[0057] In S103, the multi-group lens group is moved to the assembly station.

[0058] The first lens group 11, the second lens group 13 and the third lens group 15 are moved to the assembly station by the taking device. Wherein, the taking mechanism takes the first lens group 11, the second lens group 13 and the third lens group 15 respectively according to the position of the first lens group 11, the second lens group 13 and the third lens group 15.

[0059] According to some embodiments, the carrier can also be taken synchronously in this step, so that the required materials for subsequent production are ensured to be on the corresponding station, facilitating subsequent processing.

[0060] According to the embodiments of the present application, the taking device can be a gripper or a suction cup, and the number of grippers and suction cups in the taking device can be flexibly selected according to the arrangement space and the use scenario. For example, in some embodiments of the present application, 2 grippers and 1 suction cup are used for taking, and further, the first lens group 11 is gripped by a gripper, the second lens group 13 is sucked by a suction cup, and the third lens group 15 is gripped by a gripper. Wherein, in the present application, the second lens group 13 is preferably sucked by the suction cup perpendicular to the optical axis direction of the multi-group lens group, so that the subsequent second lens group 13 can be assembled into the carrier from top to bottom. In other embodiments, the first lens group 11, the second lens group 13 and the third lens group 15 can also be taken by using a gripper instead of a suction cup, or a suction cup instead of a gripper, as long as the number of taking devices meets the taking requirements of the embodiments of the present application.

[0061] In S105, the multi-group lens group is pre-positioned.

[0062] The first lens group 11, the second lens group 13 and the third lens group 15 are pre-positioned, as shown. Figure 3 The position of the first lens group 11, the second lens group 13 and the third lens group 15 taken by the taking device is obtained, so that the first lens group 11, the second lens group 13 and the third lens group 15 can be leveled along the optical axis direction of the multi-group lens group, to ensure that the inclination of the first lens group 11, the second lens group 13 and the third lens group 15 in the pre-positioning ensures the mutual levelness.

[0063] According to some embodiments of the present application, the specific positions of the first lens group 11, the second lens group 13 and the third lens group 15 along the optical axis plane are obtained by taking pictures of the first lens group 11, the second lens group 13 and the third lens group 15 through the depth camera. Further, the three-axis directions of the first lens group 11, the second lens group 13 and the third lens group 15 are measured respectively by setting the depth camera at different depths, and then the first lens group 11, the second lens group 13 and the third lens group 15 are leveled respectively by using the taking device. Furthermore, after the corresponding plane data is obtained, the taking mechanism can be adjusted accordingly, which includes leveling the corresponding lens groups on the XY plane, the XZ plane and the YZ plane. Further, the leveling includes adjusting the inclination of the first lens group 11, the second lens group 13 and the third lens group 15 on the corresponding plane to within 0.1-0.2 degrees, so as to ensure that the initial positions of the first lens group 11, the second lens group 13 and the third lens group 15 are relatively leveled, and to obtain higher imaging performance.

[0064] According to some embodiments of the present application, the distance between the first lens group 11, the second lens group 13 and the third lens group 15 is determined by the camera, which includes obtaining the initial distance between the first lens group 11, the second lens group 13 and the third lens group 15, and setting the preset distance between the first lens group 11, the second lens group 13 and the third lens group 15. The initial distance is adjusted to the preset distance to meet the requirements of the continuous zoom module at different focal lengths. For example, in a 3X-10X continuous zoom module, the 3X-10X focal lengths are different, which means that the distance between the optical lens groups of the first lens group 11, the second lens group 13 and the third lens group 15 will change.

[0065] In S107, the optical performance of the multi-group lens group is actively calibrated.

[0066] The optical performance of the first lens group 11, the second lens group 13 and the third lens group 15 before calibration is measured to obtain the optical performance calibration amount. Further, according to the predetermined position state of the first lens group 11, the second lens group 13 and the third lens group 15, the position calibration amount of the first lens group 11, the second lens group 13 and the third lens group 15 to reach the optical performance calibration amount is calculated, and active calibration is performed. The optical performance before calibration includes imaging quality optical transfer function value, optical axis eccentricity, optical axis inclination angle and field curvature, etc. The position calibration amount includes lens group distance, optical axis eccentricity, optical axis inclination angle and field curvature sensitivity, etc.

[0067] According to some embodiments of the present application, for the first lens group 11, the second lens group 13 and the third lens group 15, the predetermined position is only adjusted in terms of flatness and spacing on the lens shape, but the optical performance of the lens is not adjusted. In this step, the optical performance between the first lens group 11, the second lens group 13 and the third lens group 15 needs to be adjusted, so as to ensure that the optical system composed of the three lens groups has high performance. Further, the three groups are corrected in terms of optical performance, for example, in the present scheme, there is a gap between the first lens group 11 and the second lens group 13, and the gap is suitable for being adjusted in terms of the X, Y, Z, U, V, W six-axis directions of the camera module. Further, the first lens group 11 and the second lens group 13 are respectively pre-assembled with the carrier to preliminarily form the embryo of the camera module, and then the pre-assembled camera module is powered on to collect the image of the camera module.

[0068] In the present application, the imaging of the camera module is collected based on the shooting of the MTF (Modulation Transfer Function) test chart of the camera module. The imaging quality of the camera module is represented by the MTF value. The larger the MTF value is, the higher the imaging quality of the camera module is. After each collection of the image of the camera module, the MTF value of the corresponding image needs to be calculated to check whether the MTF value is greater than the standard requirement set in advance. In some embodiments of the present application, since the continuous zoom module has multiple focal lengths, for example, a continuous zoom module can have a different focal length range from 3X-10X, therefore, in the present scheme, the most sensitive focal length in the continuous zoom module is preferred to be assembled. The most sensitive focal length refers to the focal length with high sensitivity between the eccentricities of the first lens group 11, the second lens group 13 and the third lens group 15. The eccentricity can affect the field curvature and peak value of the optical system. Therefore, if the positions between the first lens group 11, the second lens group 13 and the third lens group 15 can be adjusted well, the high performance can also be guaranteed in other insensitive areas.

[0069] According to some embodiments of the present application, in the zoom distance of 3x-10x, the gap value between the lenses corresponding to the focal length with the highest eccentricity sensitivity between the first lens group 11, the second lens group 13 and the third lens group 15 is selected as the preset value. If the optical system can be calibrated at this focal length, the high imaging performance can also be guaranteed in other focal length ranges. During the process of collecting the image each time, the shooting environment parameters of the camera module are strictly controlled, including the distance between the MTF test chart and the camera module and the light source parameters, so as to ensure the accuracy and consistency of the image collection, and facilitate the subsequent calibration step. In the image collection process of the camera module, the MTF value is combined to further monitor the dirty point, distortion or dark corner characteristics of the camera module.

[0070] According to some embodiments of the present application, in this step, the software is used to calibrate the assembly position of the first lens group 11, the second lens group 13 and the third lens group 15. The software is used to calculate the calibration amount of the assembly position of the first lens group 11, the second lens group 13 and the third lens group 15 to be calibrated based on the study of the sensitivity of the lens optical design. The calculation method includes: (1) measuring the optical characteristics of the camera module before calibration, including MTF value, optical axis eccentricity, optical axis tilt angle and field curvature; and (2) calculating the required assembly position calibration amount of the first lens group 11, the second lens group 13 and the third lens group 15 to be calibrated according to the sensitivity of the optical axis eccentricity, the optical axis tilt angle and the field curvature of the assembly position of the optical system component to be calibrated.

[0071] In some embodiments of the present application, the gap between the first lens group 11 and the second lens group 13 can be adjusted to finally make the MTF value of the overall optical system within the threshold range, so that the performance of the optical system can meet the requirements.

[0072] In the step of positioning the first lens group 11, the second lens group 13 and the third lens group 15, the adjustment between the optical lens groups is in the adjustment of the distance between the lens barrels, the flatness and the like, but the overall imaging performance is still determined by the state between the first lens group 11, the second lens group 13 and the third lens group 15 and the forming precision of itself. Therefore, the assembly error of the lens group assembled into the lens barrel needs to be considered, such as the tilt of the lens group assembled into the lens barrel, or the deformation of the lens or the assembly eccentricity of the lens due to the tightness or looseness between the inner and outer diameters of the lens assembled into the lens barrel, thereby affecting the overall optical performance. Therefore, although the gap and flatness between the continuous zoom multiple lens barrels can be adjusted, the performance of the optical system composed of such assembly cannot be guaranteed to have a high level. Therefore, it is necessary to actively calibrate the optical performance of the first lens group 11, the second lens group 13 and the third lens group 15.

[0073] According to the technical concept of the present application, after the optical lens group at the first preset focal length is actively calibrated, the optical lens group at the second preset focal length is calibrated again. According to the optical characteristics at the second preset focal length, including MTF value, optical axis eccentricity, optical axis tilt angle and field curvature, it is determined whether the overall performance of the optical system at the second preset focal length meets the requirements. If the overall performance of the optical system at the second preset focal length does not meet the standard, the assembly of the optical lens group is cancelled, or the optical lens group is replaced for calibration again.

[0074] According to the embodiments of the present application, the barrel shape inclination and the gap of the first lens group 11, the second lens group 13 and the third lens group 15 are adjusted first, so that the first lens group 11, the second lens group 13 and the third lens group 15 have higher initial performance before detection. Since the first lens group 11, the second lens group 13 and the third lens group 15 are all part of the optical system, if the positions of the first lens group 11, the second lens group 13 and the third lens group 15 are not reasonably limited and initialized, it is difficult to obtain optical performance that can form a clear image, and it is also impossible to further calculate the MTF value from the image data. Therefore, the worse the initial performance is, the more time it will take to calibrate. The first lens group 11, the second lens group 13 and the third lens group 15 have higher consistency, the better the initial position is, and the clearer the image is, the more accurate the calculation of field curvature, aberration, etc. is. Because when calculating the defocus amount according to the clear focus, if the picture is relatively blurred, there will be a larger error in the calculated clear focus distance.

[0075] Figure 4 A flowchart of an assembly method of a camera module according to an example embodiment of the present application is shown.

[0076] Referring to Figure 4 In S201, a multi-group lens group is assembled.

[0077] The first lens group 11, the second lens group 13 and the third lens group 15 are sequentially subjected to initial position recognition, movement to an assembly station, pre-positioning and optical performance active calibration. The first lens group 11 and the second lens group 13 are movable groups, and the third lens group 15 is a fixed group.

[0078] In S203, the position information of the multi-group lens group after active calibration is recognized.

[0079] According to some embodiments of the present application, the position information of the first lens group 11, the second lens group 13 and the third lens group 15 is recognized, which includes recognizing the gap, flatness, inclination and other information between the first lens group 11, the second lens group 13 and the third lens group 15. In some embodiments, only the relative inclination and gap of the first lens group 11, the second lens group 13 and the third lens group 15 are known.

[0080] Wherein the positions of the first lens group 11, the second lens group 13 and the third lens group 15 are actively calibrated within a preset focal length, the directions of the six axes X, Y, Z, U, V, W between the first lens group 11, the second lens group 13 and the third lens group 15 are adjusted after the active calibration, so that the gap between the first lens group 11, the second lens group 13 and the third lens group 15 in different directions is adjusted due to the active calibration. During the assembly of the camera module, the first lens group 11, the second lens group 13 and the third lens group 15 need to be assembled to the corresponding motors respectively. Moreover, since the positional relationship between the first lens group 11, the second lens group 13 and the third lens group 15 is recognized by the recognition device, the equipment records the data, and the electric control module of the equipment can record the relative positional relationship of the corresponding first lens group 11, the second lens group 13 and the third lens group 15 after the active calibration, so as to obtain, for example, the gap, the inclination and the like between the first lens group 11, the second lens group 13 and the third lens group 15.

[0081] In S205, the carriers are respectively adapted to the calibrated lens groups.

[0082] The initial position state of the first carrier 21 and the second carrier 23 respectively adapted to the first lens group 11 and the second lens group 13 relative to the first lens group 11, the second lens group 13 and the third lens group 15 in the camera module is recognized, as shown in FIG. 2. Figure 5 According to the relative positional relationship between the first lens group 11, the second lens group 13 and the third lens group 15, the motor of the camera module is powered on so that the positions of the first carrier 21 and the second carrier 23 are respectively adapted to the positions of the first lens group 11 and the second lens group 13, and the positions between the first carrier 21 and the second carrier 23 are changed to adapt to the positions of the lens groups after the active calibration, as shown in FIG. 3. Figure 6 The first carrier 21 is adapted to the first lens group 11 after the active calibration, and the second carrier 23 is adapted to the second lens group 13 after the active calibration, as shown in FIG. 4. Figure 7

[0083] ​The change in the position between the first carrier 21 and the second carrier 23 of the motor includes energizing the motor, changing the relative position relationship between the first carrier 21 and the second carrier 23 of the motor, for example, adjusting the interval between the first carrier 21 and the second carrier 23 corresponding to the preset focal length according to the interval between the first lens group 11, the second lens group 13 and the third lens group 15, so that the interval between the first carrier 21 and the second carrier 23 of the motor corresponding to the focal length is consistent with the performance of the first lens group 11, the second lens group 13 itself. In the prior art, there is a scheme of assembling after active calibration of the carrier of the motor. However, since the position of the carrier of the motor is set according to the preset distance in the optical design, when the lens is actively calibrated, the lens group may be adjusted due to the relationship, and the interval between the lenses may be adjusted due to the active calibration, thereby affecting the position of the lens group after being assembled to the carrier. Therefore, in the actual situation, after the interval between the lenses is adjusted, the lens group may be actually assembled to the front end or the rear end of the carrier. At this time, since the carrier of the motor is still set as the interval between the carriers of the motor at the preset focal length, even if the optical system composed of the lens group has high optical performance at the preset focal length, after the motor switches to other focal lengths, the lens may collide with the carrier, the carrier may interfere, and the like. In addition, since the adjustment is only performed at the preset focal length, it is impossible to guarantee that the carrier of the motor can also have good performance at other focal lengths. For example, since the optical lens group has multiple focal length requirements, when different lenses are matched at different focal lengths to perform shooting at several preset focal lengths, after the carrier of the motor is used for shooting at the preset focal length by default, the optical lens may collide at other focal lengths.

[0084] Moreover, since the lens and the carrier have been fixedly connected at the preset focal length at this time, it is impossible to perform re-adjustment, and therefore this assembly method cannot realize high yield assembly. In addition, in some extreme cases, for example, the interval between the optical lens groups has different intervals at different focal lengths, so that the optical lens group has size difference at different focal lengths. Since it is considered that the lens group interval is large when the focal length is large, the lens group is assembled and calibrated at this time. If the lens is assembled to the carrier at this time, there is a certain deviation in the position of the lens, and the lens group interval is too small or too large at the focal length, and the deviation occurs.

[0085] The prior art described above, that is, keeping the fixing of the aforementioned multi-group lens group, the adjustable installation of the imaging element, that is, assembling the imaging element through the method of calibration (adjusting the X, Y, Z, U, V, W directions of the imaging element), compensating for the aforementioned installation error (or tolerance) through the subsequent position, angle, and rotation adjustment of the imaging element, but such a method can cause some problems, for example, when the installation error of the components before the imaging element is large, the subsequent position adjustment of the imaging element cannot compensate for the error, at this time, a poor module is generated, and because the installation error of the front components is large, the subsequent position adjustment process of the imaging element during assembly also requires a large amount of debugging time to constantly try to compensate for the previous error, which can affect the overall production efficiency. The technical concept of the present application is to improve the module quality and overall production efficiency by reducing the installation error at each step.

[0086] According to the technical concept of the present application, when the multi-group lens group and the camera module of the present application are adapted to the periscopic camera module, the FOV (field of view) deviation in the module assembly process is compensated by the directional position of the OIS (optical image stabilization) element inside the camera module, that is, the directional position of the OIS element compensates for the position deviation in the assembly process, thereby improving the installation accuracy of the entire module. Further, the present application realizes the process of running out of focus through the movement of the lens group with AF (auto focus) function, that is, during the adjustment process, the camera module is powered (generally, the camera module assembly is powered by the imaging element circuit board assembly, and the imaging element circuit board assembly moves under the control of the clamp to complete the function of running out of focus through the movement of the imaging element, which takes a long time, and the variation caused by the long-distance movement of the chip circuit board assembly is relatively large), in the present application, after the chip circuit board assembly is adjusted to the installation position, only the angle, inclination, rotation, and other variables need to be adjusted, as shown in Figure 8 .

[0087] Referring to Figure 8 , in the assembly process of the periscopic camera module, a reference object is first provided in the form of a mark plate, the mark plate is a transparent material with a specific pattern, and is arranged in a lamp box that can actively emit light. The lamp box can be regarded as a drawer-type component, the upper part of the drawer is a light source, and the lower part is a transparent bottom plate (generally glass) that carries the mark plate. The upper light source projects downward, and the mark plate forms a specific bright and dark clear image by being partially transparent, partially opaque, or having a low transmittance. The module captures this image information, and compares the captured image information with the preset standard to determine whether the quality of the module meets the standard.

[0088] In the production assembly process, first, a standard chip is arranged at a position where the imaging element is required to be installed, the standard chip is in an optimal state through multiple debugging in advance (which can be considered as the ideal position of the chip in the module assembly process), the position can be regarded as an inherent position, which remains unchanged in the subsequent production process, and the installation state of each component of the module is judged by the imaging effect of the chip, and the position of the component in the installation process is adjusted in real time to reach the preset standard. In the assembly and debugging process of the present application, as shown in Figure 8 The light turning element 1 shown in the figure can have an OIS function, and during assembly and testing, visual positioning is required for the module body and each component of the module, and the installation of components is carried out on the basis of visual positioning.

[0089] As shown in Figure 8 During assembly and debugging, the main body of the periscopic camera module is powered on and conducts electricity, that is, the driving elements and optical elements therein can work. During assembly, after the basic element assembly is completed, that is, after the light turning element, lens group, etc. are assembled, the module captures a standard plate image under the condition of using a standard chip and transmits the image information to a processor for processing. According to the processor processing and comparison with the preset data information, the position information of the components in the module is judged and adjusted in time.

[0090] During assembly, during assembly of the light turning element 1, the module body needs to be rotated by a certain angle (theoretically, it is generally rotated by 45°, so that the light turning element can have a horizontal plane for installation during installation), in the embodiment of the present application, the module body is controlled by a jig (or during installation into the jig, the module body is at an angle of 45° with the horizontal plane), so that the light reflecting surface of the light turning element can be adsorbed and adjusted in a horizontal state, reducing the assembly difficulty and assembly precision, as shown in Figure 9 .

[0091] As shown in Figure 9 The module body is controlled by the module jig to be at an angle of 45° with the XY plane, and the light turning element is adsorbed by the suction nozzle jig, that is, the reflecting surface 1 is adsorbed, so that the reflecting surface 1 participates in the assembly process in a horizontal state. In the present application, the light turning element is taken and placed by adsorption, the reflecting surface 1 is a smooth mirror, and vacuum negative pressure adsorption can well realize fixation and adjustment. During assembly of the light turning element, first, the position information of the light turning element is obtained by photographing through a visual positioning system, according to the position information, the suction nozzle moves above the light turning element and moves downward to finally adsorb the light turning element.

[0092] According to the embodiments of the present application, the light turning element can be placed in a specific material box, which has a downwardly recessed placing groove matching the outer contour of the light turning element. In this scheme, the groove matches the outer contour of the right angle of the light turning element 1. The schematic diagram of the material box is shown in Figure 10 .

[0093] Referring to Figure 10 , the material box of the light turning element 1 has a groove corresponding to the right angle contour of the light turning element. The bottom end of the groove is a right angle, and the right angle is symmetrically divided by a plane perpendicular to the horizontal plane, i.e., the angles on both sides of the normal are 45°. When the right angle end of the light turning element is placed in the groove, the reflecting surface of the light turning element is exactly in a horizontal state (the clamps in general mechanical equipment are usually vertically arranged. When taking and placing materials, it is most convenient and relatively best and most stable to take and place materials in a horizontal state). The suction nozzle is vertically arranged and moves from top to bottom to the reflecting surface and adsorbs the reflecting surface by negative pressure to realize the taking and placing and adjustment of the light turning element.

[0094] In the present application, the light turning element 1, the lens group, the light turning element 2, and the imaging element are sequentially assembled into the module main body, i.e., sequentially arranged along the light incident direction, i.e., arranged along the optical axis direction. The specific arrangement is shown in Figure 11 .

[0095] Referring to Figure 11 , first, the light turning element 1 is assembled. The position information of the light turning element 1 is obtained by visual positioning. The position information of the installation position of the light turning element 1 in the module main body is obtained by visual positioning. The light turning element is installed in the installation position through comparison of the position information. In this installation process, it is a preliminary mechanical positioning installation, i.e., corresponding to the installation groove or positioning structure (such as a groove, a boss, etc.) with a certain shape of the light turning element 1. After mechanical positioning is completed, the suction nozzle is photographed again. The installation state is judged by visual information. The light turning element 1 is adjusted according to the visual information, i.e., in the Figure 11 state, the suction nozzle adsorbs the reflecting surface of the light turning element and drives the light turning element to adjust. After the light turning element 1 is assembled, the module main body is controlled to return to the horizontal state. The lens group is assembled in the horizontal state. The horizontal state can be restored by controlling the jig to return the module main body to the horizontal state, or the module main body can be reinstalled (horizontally installed on the module jig).

[0096] Figure 12 The structure schematic diagram of the multi-group lens assembly after assembly according to some embodiments of the present application is shown.

[0097] Referring to Figure 12, the lens group body is accommodated in the lens group shell, in the present application, the lens group shell can have driving components inside, which drive the lens group body to move in the AF movement mode ①, that is, the shell is stationary, and the lens group body moves. Of course, in some other embodiments, the lens group body is accommodated in the lens group shell, and the lens group shell has corresponding driving devices such as guide rods, guide rails, etc. outside, which drive the lens group shell and the lens group body to move together to complete the AF movement. (During the lens group installation process, visual positioning, mechanical positioning, suction nozzle adsorption, etc. are also involved, which will not be described one by one)

[0098] After the multi-group lens group is assembled, the second light turning element is installed, which is mechanically installed in the posture as shown in Figure 5 , that is, the reflecting surface forms a 45° angle with the light path emitted from the lens group, that is, the reflecting surface is parallel to the Z axis. The light turning element has an adsorption surface adjacent to the reflecting surface and perpendicular to the reflecting surface. When the reflecting surface is parallel to the Z axis, the adsorption surface is parallel to the horizontal plane, that is, as shown in Figure 11 , the suction nozzle adsorbs the adsorption surface of the light turning element 2 and is installed into the module as a whole. At this stage, a standard chip is arranged on one side of the module body, that is, at the position of the imaging element as shown in Figure 11 . When the light turning element 2 is installed, the standard chip is powered on to draw a picture, and the module body is powered on (that is, the driving part of the light turning element 1, the lens group, and the light turning element 2 is powered on, if it has). When the light turning element 2 is assembled and cooperates with the standard chip, the module constitutes a complete module and can image. Therefore, during the assembly process of the light turning element 2, the picture is drawn, and the positional deviation of the light turning element 2 is obtained through image information and adjusted in real time.

[0099] At the same time, according to the image information, the positional deviation during the assembly process of the whole module is obtained. At this time, the module body is powered on, that is, the internal driving components such as OIS driving or AF driving are movable. At this time, according to the installation deviation of the whole module, the OIS driving in the module is controlled. The components in the module are controlled to deviate in direction to compensate for the installation error of the module, so as to improve the overall installation precision of the module. After adjustment, the components are fixed. After the module body part is installed, the imaging element is finally installed. The module body in which the light turning element and the lens group are installed is positioned through a ball center jig. The positioning ensures that the position of the motor assembly is relatively determined each time, and the consistency of the product is ensured.

[0100] Figure 13 The structure schematic diagram of the periscopic camera module and the imaging element assembly process according to some embodiments of the present application is shown.

[0101] Referring to Figure 13, after the periscopic camera module main body is assembled, the imaging element (assembly) is further assembled, the module main body is fed to a spherical center clamp, the spherical center clamp mechanically positions the module main body, the module main body is kept in a specific position and posture (that is, each module main body is basically in this state) through the limiting structure, and the light inlet of the module main body is in a vertical state, close to the actual shooting state, and the corresponding teleconverter below the mark plate has a teleconverter aspect, the acute angle between the teleconverter reflection surface and the horizontal plane is 45°, so that the light projected by the mark plate can be turned once and projected to the light inlet of the module main body. The module main body is fixed by the spherical center clamp, and the spherical center clamp is fixed on a six-axis adjustment platform, so the module main body can be adjusted by the six-axis adjustment.

[0102] The imaging element is clamped and fixed to the module main body by the six-axis adjustable clamp jaw and is fixed to the module main body by adhesive or other connection methods, and during the fixing process, the clamp and the clamp jaw can be spatially modulated according to the obtained image information, that is, the module as a whole and the imaging element are powered on and the image is taken. It is worth mentioning that during the adjustment process, the OIS device of the light conversion element of the module main body can realize OIS directional compensation deviation according to the deviation of the module (that is, control the OIS drive to move the light conversion element to a certain position), the AF drive device controls the AF component to realize AF movement to realize the module out-of-focus process without the imaging element moving greatly to realize the out-of-focus process. After the imaging element reaches the predetermined installation position, only the angle, inclination and other variables need to be fine-tuned.

[0103] Figure 14 A structural schematic diagram of an assembly device according to an example embodiment of the present application is shown.

[0104] Referring to Figure 14 The assembly device of the example embodiment is used for assembling a multi-group lens group, the multi-group lens group includes a first lens group 11, a second lens group 13 and a third lens group 15, and the assembly device includes a support 31, an identification device 32, a taking device 33, a depth camera 34, a camera 35 and an active calibration device 36.

[0105] As Figure 14As shown, the identification device 32 is arranged on the support 31, and is configured to obtain initial positions of the first lens group 11, the second lens group 13 and the third lens group 15; the taking device 33 is arranged on the support 31, and is configured to move the first lens group 11, the second lens group 13 and the third lens group 15 to an assembly station; the depth camera 34 is arranged on the support 31, and is configured to capture the first lens group 11, the second lens group 13 and the third lens group 15, and obtain specific positions of the first lens group 11, the second lens group 13 and the third lens group 15 along an optical axis plane; the camera 35 is arranged on the support 31, and is configured to capture to determine initial distances between the first lens group 11, the second lens group 13 and the third lens group 15; the active calibration device 36 is arranged on the support 31, and is configured to actively calibrate optical performance of the first lens group 11, the second lens group 13 and the third lens group 15.

[0106] The above detailed description and explanation of the embodiments of the present application. It should be clearly understood that the present application describes how to form and use specific examples, but the present application is not limited to any details of these examples. Instead, based on the teachings of the disclosure of the present application, these principles can be applied to many other embodiments.

[0107] Through the description of the example embodiments, those skilled in the art can easily understand that the technical solutions according to the embodiments of the present application have at least one or more of the following advantages.

[0108] According to the example embodiments of the present application, the assembly method of the multi-group lens group of the present application makes the relative position relationship between the assembled optical lenses more reasonable, and further ensures that the continuous zoom system has good performance at each focal length position.

[0109] According to the example embodiments of the present application, the present application improves the optical performance of the multi-group lens group at different focal lengths by position recognition, pre-positioning and active calibration of the multi-group lens group. Further, the present application adapts the multi-group lens group after active calibration by the carrier, which effectively reduces the assembly and test time of the camera module while ensuring the optical performance of the camera module.

[0110] The example embodiments of the present application are specifically shown and described above. It should be understood that the present application is not limited to the detailed structure, arrangement or implementation method described herein; on the contrary, the present application is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the appended claims.

Claims

1. A method for assembling a multi-lens group, wherein the multi-lens group comprises a first lens group, a second lens group, and a third lens group, characterized in that, The assembly method includes: The initial positions of the first lens group, the second lens group, and the third lens group are obtained through the recognition device; The first lens group, the second lens group, and the third lens group are moved to the assembly station using the acquisition device; The first lens group, the second lens group and the third lens group are pre-positioned, and the gap value between the lenses corresponding to the focal length with the highest eccentricity sensitivity among the first lens group, the second lens group and the third lens group is used as the preset value. Actively calibrate the optical performance of the first lens group, the second lens group, and the third lens group; The step of pre-positioning the first lens group, the second lens group, and the third lens group includes: The first lens group, the second lens group, and the third lens group are photographed by a depth camera to obtain the specific positions of the first lens group, the second lens group, and the third lens group along the optical axis plane. Based on the obtained specific positions along the optical axis plane, the first lens group, the second lens group, and the third lens group are leveled. The leveling process involves adjusting the tilt of the first lens group, the second lens group, and the third lens group to 0.1-0.2 degrees on their respective corresponding planes.

2. The assembly method of the multi-lens group according to claim 1, characterized in that, The step of pre-positioning the first lens group, the second lens group, and the third lens group further includes: Depth cameras at different depths are set up to measure the three-axis directions of the first lens group, the second lens group, and the third lens group respectively, so as to obtain the specific positions of the first lens group, the second lens group, and the third lens group along the optical axis plane.

3. The assembly method of the multi-lens group according to claim 1, characterized in that, The step of pre-positioning the first lens group, the second lens group, and the third lens group further includes: The initial spacing between the first lens group, the second lens group, and the third lens group is determined by taking pictures with the camera.

4. The assembly method of the multi-lens group according to claim 3, characterized in that, The step of pre-positioning the first lens group, the second lens group, and the third lens group further includes: Set a preset distance between the first lens group, the second lens group, and the third lens group, and adjust the spacing to the preset distance.

5. The assembly method of the multi-lens group according to claim 1, characterized in that, The active calibration of the optical performance of the first lens group, the second lens group, and the third lens group includes: The optical performance of the first lens group, the second lens group, and the third lens group before calibration is measured to obtain the optical performance calibration value; Based on the pre-positioned states of the first lens group, the second lens group, and the third lens group, calculate the position calibration amount required for the first lens group, the second lens group, and the third lens group to achieve the optical performance calibration amount.

6. The assembly method of the multi-lens group according to claim 5, characterized in that, The optical performance before calibration includes the image quality optical transfer function value, optical axis eccentricity, optical axis tilt angle, and field curvature.

7. The assembly method of the multi-lens group according to claim 5, characterized in that, The position calibration parameters include lens group spacing, optical axis eccentricity, optical axis tilt angle, and field curvature sensitivity.

8. The assembly method of the multi-lens group according to claim 1, characterized in that, The ingestion device includes grippers.

9. The assembly method of the multi-lens group according to claim 1, characterized in that, The acquisition device further includes a suction nozzle, which picks up the multi-lens group perpendicular to the optical axis of the multi-lens group.

10. A method for assembling a camera module, characterized in that, include: The assembly method of the multi-lens group as described in any one of claims 1 to 9, wherein the first lens group and the second lens group are movable groups, and the third lens group is a fixed group; The first carrier is adapted to the first lens group after active calibration, and the second carrier is adapted to the second lens group after active calibration.

11. The assembly method of the camera module according to claim 10, characterized in that, Before adapting the first carrier to the actively calibrated first lens group and the second carrier to the actively calibrated second lens group, the method further includes the following steps: The specific location information of the first lens group and the second lens group after active calibration is obtained.

12. The assembly method of the camera module according to claim 11, characterized in that, The specific location information includes the distance, flatness, and tilt of the first lens group and the second lens group.

13. The assembly method of the camera module according to claim 11, characterized in that, The process of adapting the first carrier to the actively calibrated first lens group and adapting the second carrier to the actively calibrated second lens group includes: Based on the specific location information, the positional states of the first carrier and the second carrier are adjusted so that the first carrier is adapted to the first lens group after active calibration, and the second carrier is adapted to the second lens group after active calibration.

14. An assembly apparatus for assembling the multi-lens group of claim 1, wherein the multi-lens group comprises a first lens group, a second lens group, and a third lens group, characterized in that, The assembly equipment includes: support; An identification device is mounted on the bracket, and the identification device is used to obtain the initial positions of the first lens group, the second lens group and the third lens group; An image capture device is disposed on the bracket, and the image capture device is used to move the first lens group, the second lens group and the third lens group to the assembly station.

15. The assembly equipment according to claim 14, characterized in that, Also includes: A depth camera is mounted on the bracket and is used to capture images of the first lens group, the second lens group, and the third lens group to obtain the specific positions of the first lens group, the second lens group, and the third lens group along the optical axis plane.

16. The assembly equipment according to claim 14, characterized in that, Also includes: A camera, mounted on the bracket, is used to capture images to determine the initial spacing between the first lens group, the second lens group, and the third lens group.

17. The assembly equipment according to claim 14, characterized in that, Also includes: An active calibration device is disposed on the bracket, and the active calibration device is used to actively calibrate the optical performance of the first lens group, the second lens group and the third lens group.

Images