Optical lens, camera module and assembly method thereof

Abstract

The present invention provides an optical lens, comprising: a first lens component, which includes a first lens barrel and a first lens installed in the first lens barrel; a second lens component, which includes a second lens barrel and a second lens installed in the second lens barrel, the second lens and the first lens together constitute an imageable optical system, and the material of the first lens barrel is different from that of the second lens barrel; and a first adhesive material, which is located in a first gap between the first lens component and the second lens component, and is suitable for supporting and fixing the first and second lens components after curing, wherein the axis of the first lens component and the axis of the second lens component have a non-zero angle. The present invention also provides a corresponding camera module and an assembly method. The present invention can reduce the difference between the state of the optical system after the first adhesive material is cured and the state of the optical system determined by active calibration by reducing the variation of the first lens component, thereby ensuring the imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to an optical lens, a camera module and an assembly method thereof. Background Art

[0002] With the popularization of mobile electronic devices, the relevant technologies of camera modules used in mobile electronic devices to help users obtain images (such as videos or images) have been rapidly developed and improved, and in recent years, camera modules have been widely used in many fields such as medical treatment, security, industrial production, etc.

[0003] In order to meet the increasingly broad market demand, high pixel, small size and large aperture are the irreversible development trend of existing camera modules. However, it is very difficult to achieve the three requirements of high pixel, small size and large aperture in the same camera module. For example, the compact development of mobile phones and the increase in the screen-to-body ratio of mobile phones have made the space inside the mobile phone for the front camera module smaller and smaller, while the market has put forward higher and higher requirements on the imaging quality of camera modules.

[0004] In the field of compact camera modules (such as camera modules for mobile phones), it is often necessary to consider the quality of optical imaging lenses and manufacturing errors in the module packaging process. Specifically, in the manufacturing process of optical imaging lenses, the factors affecting the lens resolution come from the errors of each component and its assembly, the error of the thickness of the lens spacing element, the error of the assembly and matching of each lens, and the change of the refractive index of the lens material. Among them, the errors of each component and its assembly include the optical surface thickness of each lens monomer, the lens optical surface sag, the optical surface surface shape, the radius of curvature, the single-sided and inter-face eccentricity of the lens, the tilt of the optical surface of the lens, etc. The size of these errors depends on the mold accuracy and molding accuracy control capabilities. The error of the thickness of the lens spacing element depends on the processing accuracy of the component. The error of the assembly and matching of each lens depends on the dimensional tolerance of the assembled component and the assembly accuracy of the lens. The error introduced by the change of the refractive index of the lens material depends on the stability of the material and the batch consistency. There is a phenomenon of cumulative deterioration in the errors of the above-mentioned components affecting the resolution, and this cumulative error will continue to increase with the increase in the number of lenses. The existing resolution solution is to control the tolerance of the size of each relatively sensitive component and compensate for the lens rotation to improve the resolution. However, since high-pixel and large-aperture lenses are more sensitive, strict tolerances are required. For example, 1um lens eccentricity of some sensitive lenses will cause 9' image plane tilt, which makes lens processing and assembly more and more difficult. At the same time, due to the long feedback cycle during the assembly process, the process capability index (CPK) of lens assembly is low and fluctuates greatly, resulting in a high defect rate. And as mentioned above, because there are many factors that affect the resolution of the lens, which exist in multiple components, the control of each factor has the limit of manufacturing precision. If the precision of each component is simply improved, the improvement capacity is limited, the improvement cost is high, and it cannot meet the market's increasing demand for imaging quality.

[0005] The applicant has proposed an assembly method for manufacturing a complete optical lens or camera module by adjusting and determining the relative positions of the upper and lower sub-lenses based on an active calibration process, and then bonding the upper and lower sub-lenses together according to the determined relative positions. This solution can improve the process capability index (CPK) of mass-produced optical lenses or camera modules; it can relax the requirements for the accuracy of each component of the material (such as the sub-lens or photosensitive components used to assemble the optical lens or camera module) and its assembly accuracy, thereby reducing the overall cost of the optical imaging lens and the camera module; it can adjust the various aberrations of the camera module in real time during the assembly process, reduce the defect rate, reduce production costs, and improve imaging quality.

[0006] However, active calibration of the optical system of the lens itself is a new production process. Actual mass production needs to consider many factors such as the reliability, drop resistance, weather resistance and production cost of the optical lens and camera module, and sometimes it is necessary to face the yield reduction caused by various unpredictable factors. For example, in one process scheme, a glue is filled between the first lens component and the second lens component to keep the first lens component and the second lens component in the relative position determined by the active calibration. However, the actual trial production found that the imaging quality of the optical lens and the camera module is often degraded compared to the imaging quality obtained in the active calibration stage, and this degradation sometimes exceeds the tolerance range, resulting in defective products. The applicant's research found that after the active calibration process is introduced in the assembly of the optical lens or camera module, the variation of the glue, lens barrel or lens and other unknown factors may be the cause of the above problems. There is an urgent need for solutions that can overcome the above problems in order to improve product yield. Summary of the invention

[0007] The present invention aims to provide a solution that overcomes at least one of the drawbacks of the prior art.

[0008] According to one aspect of the present invention, there is provided an optical lens, comprising: a first lens component, comprising a first lens barrel and at least one first lens installed in the first lens barrel; a second lens component, comprising a second lens barrel and at least one second lens installed in the second lens barrel, the at least one second lens and the first lens together forming an imageable optical system, and the material of the first lens barrel is different from that of the second lens barrel; and a first adhesive material, which is located in a first gap between the first lens component and the second lens component, the first adhesive material being suitable for supporting and fixing the first lens component and the second lens component after curing, wherein the axis of the first lens component and the axis of the second lens component have a non-zero angle between them.

[0009] In one embodiment, the first adhesive material is suitable for supporting and fixing the first lens component and the second lens component, so that the relative position of the first lens component and the second lens component is maintained at a relative position determined by active calibration.

[0010] In one embodiment, a difference between a thermal expansion coefficient of the first lens barrel and a thermal expansion coefficient of the first lens is less than a first threshold.

[0011] In one embodiment, the moisture absorption rate of the material of the first lens barrel is lower than the moisture absorption rate of the material of the second lens barrel.

[0012] In one embodiment, the first lens is a glass lens, and the first lens barrel is a metal lens barrel.

[0013] In one embodiment, the first lens is a high borosilicate glass lens, and the first lens barrel is an oxygen-free copper lens barrel.

[0014] In one embodiment, the elastic modulus of the material of the first lens barrel is smaller than that of the material of the first lens, so as to buffer the force exerted by an external photographing mechanism on the first lens.

[0015] In one embodiment, the material of the first lens barrel has a density of 0.920-0.940 g / cm 3 The first lens is made of polyethylene material, and the material of the first lens is polymethyl methacrylate material.

[0016] In one embodiment, the material of the first lens barrel is a first plastic, the material of the first lens is a second plastic, and the difference in thermal expansion coefficient between the first plastic and the second plastic is within 4×10 -5 / ℃ or less.

[0017] In one embodiment, the number of the first lenses is smaller than the number of the second lenses, and the second lenses are closer to the photosensitive chip than the first lenses.

[0018] In one embodiment, the number of the first lenses is one, and the outer diameter of the first lens is larger than the second lens having the smallest outer diameter.

[0019] In one embodiment, the second lens barrel is made of polycarbonate.

[0020] In one embodiment, the first adhesive material is located between the first lens and the second lens barrel, and there is no filler between the first lens barrel and the second lens barrel.

[0021] According to another aspect of the present invention, there is further provided a camera module, comprising: the optical lens as described in any one of the embodiments described above.

[0022] According to another aspect of the present invention, there is also provided an optical lens assembly method, comprising: preparing a first lens component and a second lens component to be separated from each other, wherein the first lens component comprises a first lens barrel and at least one first lens installed in the first lens barrel, and the second lens component comprises a second lens barrel and at least one second lens installed in the second lens barrel, wherein the first lens barrel is made of a material different from that of the second lens barrel; pre-positioning the first lens component and the second lens component so that the at least one first lens and the at least one second lens together constitute an imageable optical system; actively calibrating according to the measured imaging result of the optical system to determine the relative position of the first lens component and the second lens component; and bonding the first lens component and the second lens component to support and fix the relative position of the first lens component and the second lens component.

[0023] In one embodiment, the active calibration includes: capturing and moving the first lens component by a capturing mechanism to adjust and determine the relative position of the first lens and the second lens component.

[0024] In one embodiment, the active calibration further includes: moving the first lens component along an adjustment plane, and determining the relative position between the first lens component and the second lens component on the adjustment plane according to a measured resolution based on an actual imaging result of the optical system; the relative position on the adjustment plane includes the relative position in a translation direction and / or a rotation direction on the adjustment plane.

[0025] In one embodiment, the active calibration further comprises: adjusting and determining an angle between the axis of the first lens component and the axis of the second lens component according to a measured resolution based on an actual imaging result of the optical system.

[0026] In one embodiment, the active calibration further includes: moving the first lens component along a direction perpendicular to the adjustment plane, and determining the relative position between the first lens component and the second lens component in the direction perpendicular to the plane according to a measured resolution based on an actual imaging result of the optical system.

[0027] According to another aspect of the present invention, a camera module assembly method is also provided, comprising: assembling an optical lens using the optical lens assembly method described above; and manufacturing a camera module based on the assembled optical lens.

[0028] Compared with the prior art, the present invention has at least one of the following technical effects:

[0029] 1. The present invention can reduce the difference between the state of the optical system after the first adhesive is cured and the state of the optical system determined by active calibration by reducing the variation of the first lens component, thereby ensuring the imaging quality of the lens or module.

[0030] 2. In some embodiments of the present invention, the expansion amount of the inner side surface of the first lens barrel from the outside to the inside and the expansion amount of the outer side surface of the first lens from the inside to the outside can be mutually offset (or eliminated) by selecting the material of the first lens barrel, thereby reducing the deformation of the first lens component caused by heat (such as baking), thereby ensuring the imaging quality of the lens or module.

[0031] 3. Some embodiments of the present invention can reduce the difference between the optical system state after the first adhesive is cured and the optical system state determined by active calibration by reducing the shape variation or position displacement of the first lens barrel caused by moisture accumulation, thereby ensuring the imaging quality of the lens or module.

[0032] 4. Some embodiments of the present invention can suppress the deformation of the optical surface of the first lens due to the clamping of the external capturing mechanism, which helps to reduce the difference between the state of the optical system after the first adhesive is cured and the state of the optical system determined by active calibration, thereby ensuring the imaging quality of the lens or module. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Exemplary embodiments are shown in the referenced drawings. The embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.

[0034] Figure 1 A cross-sectional schematic diagram of an optical lens according to an embodiment of the present invention is shown;

[0035] Figure 2 A cross-sectional schematic diagram of an optical lens according to another embodiment of the present invention is shown;

[0036] Figure 3 A cross-sectional schematic diagram of an optical lens according to another embodiment of the present invention is shown;

[0037] FIG. 4A to FIG. 4G An optical lens assembly method in one embodiment of the present invention is shown;

[0038] FIG. 5A to FIG. 5F An optical lens assembly method in another embodiment of the present invention is shown;

[0039] Fig. 6A The relative position adjustment method in active calibration in one embodiment of the present invention is shown;

[0040] Figure 6B shows the rotation adjustment in active calibration of another embodiment of the present invention;

[0041] Figure 6C A relative position adjustment method with added v and w direction adjustments in active calibration of yet another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0042] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0043] It should be noted that in this specification, the expressions of first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Therefore, without departing from the teaching of this application, the first subject discussed below can also be referred to as the second subject.

[0044] In the drawings, the thickness, size and shape of objects have been slightly exaggerated for ease of explanation. The drawings are only examples and are not drawn strictly to scale.

[0045] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, wholes, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, parts and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0046] As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation, not degree, and are intended to account for the inherent variations in measurements or calculations that would be recognized by those of ordinary skill in the art.

[0047] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0048] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] Figure 1A schematic cross-sectional view of an optical lens of an embodiment of the present invention is shown. The cross-section is a cross-section passing through the optical axis of the optical lens. In this embodiment, the optical lens includes a first lens component 100, a second lens component 200 and a first adhesive material 300. The first lens component 100 includes a first lens barrel 102 and a first lens installed in the first lens barrel 102, and the first lens barrel 102 and the first lens 101 are optionally connected using an adhesive 103; the second lens component 200 includes a second lens barrel 202 and four second lenses 201 installed in the second lens barrel 202, and the four second lenses 201 and the first lens 101 together constitute an imageable optical system, and the first lens barrel 102 is made of a material different from the second lens barrel 202; and the first adhesive material 300 is located in a first gap 400 between the first lens component 100 and the second lens component 200, and the first adhesive material 300 is suitable for supporting and fixing the first lens 101 and the second lens component 200 after curing. In this embodiment, the first lens barrel 102 and the second lens barrel 202 are optionally connected by the first adhesive material 300 to realize the connection between the first lens component 100 and the second lens component 200. The first adhesive material 300 can be suitable for supporting and fixing the first lens 101 and the second lens component 200, so that the relative position of the first lens 101 and the second lens component 200 is maintained at the relative position determined by the active calibration. The difference between the thermal expansion coefficient of the first lens barrel 102 and the thermal expansion coefficient of the first lens 101 can be less than the first threshold value. In this embodiment, the material of the first lens barrel 102 is different from that of the second lens barrel 202, and the difference between the thermal expansion coefficient and the thermal expansion coefficient of the first lens 101 is less than the first threshold value. This technical solution makes the thermal expansion coefficient between the first lens barrel 102 and the first lens 101 basically consistent, thereby helping to reduce the difference between the optical system state after the first adhesive material 300 is cured and the optical system state determined by the active calibration, thereby ensuring the imaging quality of the lens or module. In this embodiment, the first lens 101 and the first lens barrel 102 have approximately the same variation conditions, and thus have the same degree of variation under the same conditions, thereby reducing the change in relative position, reducing the relative stress of the first lens 101 and the first lens barrel 102, and avoiding the weakening of the structural strength. At the same time, when variation occurs, the first lens 101 and the first lens barrel 102 may have the same or similar variation, which can also reduce the degradation of the optical system caused by the variation. Exemplarily, since the first lens barrel 102 is annular, when the first lens barrel 102 is heated and expanded, its inner side will expand from the outside to the inside. At the same time, the outer side of the first lens 101 is heated and expands from the inside to the outside.Since the thermal expansion coefficient of the first lens barrel 102 is close to that of the first lens 101 (the difference between the two is controlled within a first threshold), the expansion amount of the inner side of the first lens barrel 102 from the outside to the inside is close to the expansion amount of the outer side of the first lens 101 from the inside to the outside, so these two expansion amounts can offset (or eliminate) each other, thereby reducing the deformation of the first lens component caused by heat (such as baking), helping to reduce the difference between the optical system state after the first adhesive 300 is cured and the optical system state determined by active calibration, thereby ensuring the imaging quality of the lens or module.

[0050] In another embodiment, the first lens barrel 102 is made of a material with a moisture absorption rate less than that of the second lens barrel 202. Herein, the moisture absorption rate can also be understood as water absorption rate. In this embodiment, the moisture absorption rate of the material of the first lens barrel 102 can be less than the corresponding threshold value, so that the shape variation or position offset of the first lens barrel 102 caused by moisture accumulation can be reduced, thereby helping to reduce the difference between the optical system state after the first glue material 300 is cured and the optical system state determined by active calibration, and then guaranteeing the imaging quality of the lens or module. The material of the second lens barrel 202 is still made of traditional materials, such as polycarbonate (PC) material. In this way, the second lens component can still be made using traditional technology, which helps to improve product yield.

[0051] Furthermore, in one embodiment, the first lens 101 may be a glass lens. Since the glass lens has a high refractive index, it helps to reduce the height of the optical lens or camera module. For example, the first lens 101 made of glass material reduces the height of the optical lens, which is in line with the current trend of thinner mobile phones.

[0052] Further, in one embodiment, the first lens barrel 102 is elastic to buffer the force of the external capturing mechanism on the first lens 101. Here, the elasticity of the first lens barrel 102 can be understood as the elastic modulus of the material of the first lens barrel is smaller than the elastic modulus of the material of the first lens. The smaller the elastic modulus of the material, the more elastic the material is. In other words, the lower the elastic modulus, the greater the deformation of the material under the same stress conditions, and the better the flexibility of the material to be easily deformed.

[0053] Further, in a preferred embodiment, the difference between the thermal expansion coefficient of the first lens barrel 102 and the thermal expansion coefficient of the first lens 101 is smaller than a first threshold, and the moisture absorption rate of the first lens barrel 102 is smaller than that of the second lens barrel 202 .

[0054] Further, in a preferred embodiment, the difference between the thermal expansion coefficient of the first lens barrel 102 and the thermal expansion coefficient of the first lens 101 is less than a first threshold, and the moisture absorption rate of the first lens barrel 102 is less than the moisture absorption rate of the second lens barrel 202, and the material of the first lens barrel 102 also has elasticity for buffering the force of the external pickup mechanism on the first lens 101. In this embodiment, the elastic first lens barrel 102 is located between the first lens 101 and the external pickup mechanism, and can play a buffering role when the external pickup mechanism moves the first lens 101, thereby suppressing the deformation of the optical surface of the first lens 101 due to the clamping of the external pickup mechanism.

[0055] On the basis of the above embodiment, further, the number of the first lenses 101 can be less than the number of the second lenses 201, and the second lenses 201 are closer to the photosensitive chip than the first lenses 101. Further, in one embodiment, the number of the first lenses 101 is one, and the outer diameter of the first lens 101 is greater than the outer diameter of the second lens 201 with the smallest outer diameter. In this embodiment, the outer diameter of the first lens 101 is greater than the outer diameter of the smallest second lens 201. The reason for adopting this technical solution is that the first lens barrel 102 uses unconventional materials, which may introduce additional tolerances. Therefore, the assembly tolerance is reduced by reducing the number of first lenses 101, designing a larger first lens 101, etc. (because generally speaking, the smaller and more compact, the more difficult it is to control the tolerance), and the active calibration technology is used to compensate for the above assembly tolerance, so as to ensure the overall imaging quality of the optical lens or module.

[0056] Furthermore, in some embodiments, the second lens barrel 202 can be made of conventional materials, such as polycarbonate (PC) material. In this way, the second lens component can still be made using conventional processes, which helps to improve product yield and production efficiency.

[0057] Further, Figure 2 FIG. 2 is a cross-sectional schematic diagram of an optical lens of another embodiment of the present invention. The cross-section is a cross-section passing through the optical axis of the optical lens. In this embodiment, the first adhesive material 300 is located between the first lens 101 and the second lens barrel 202, and there is no filler between the first lens barrel 102 and the second lens barrel 202. Figure 1The first adhesive material 300 is not located between the first lens barrel 102 and the second lens barrel 202, but between the first lens 101 and the second lens barrel 202. This embodiment can help the optical system state of the finished optical lens (or camera module) to be closer to the state determined in the active calibration stage, for the following reasons: in the active calibration stage, the external fixture captures and moves the first lens component 100 by clamping the first lens barrel 102, and the elastic first lens barrel 102 can buffer the force of the fixture on the first lens 101, prevent the first lens 101 from deforming, and thus prevent the optical system state in the active calibration stage (when the first lens component 100 is clamped by the fixture) and the stage after the first adhesive material 300 is cured (when the first lens component 100 is not clamped by the fixture) from being inconsistent. Further, the deformation of the elastic first lens barrel 102 itself may affect the state of the optical system, and the connection between the first lens 101 and the second lens barrel 202 through the first adhesive material 300 can effectively avoid this defect.

[0058] Further, Figure 3 A schematic cross-sectional view of an optical lens of another embodiment of the present invention is shown. The cross-section is a cross-section passing through the optical axis of the optical lens. This embodiment is substantially the same as the embodiment of FIG. 1 , except that the first adhesive material 300 is located between the first lens barrel 102 and the second lens barrel 202 and between the first lens 101 and the second lens barrel 202.

[0059] Furthermore, in another embodiment of the present invention, a camera module based on the above-mentioned optical lens is also provided. The camera module includes an optical lens and a photosensitive component. The optical lens may be the optical lens in any of the aforementioned embodiments. This embodiment can reduce the secondary variation of the optical system of the camera module after the active calibration is completed, thereby ensuring the imaging quality of the camera module and improving the yield in mass production. In some embodiments, the camera module may also include a motor (or other types of optical actuators), the optical lens may be installed in a cylindrical carrier of the motor, and the base of the motor may be installed on the top surface of the photosensitive component. The photosensitive component may, for example, include a circuit board, a photosensitive chip installed on the surface of the circuit board, an annular support body formed or installed on the surface of the circuit board and surrounding the photosensitive chip, and a color filter. The annular support body may form a step, and the color filter is installed on the step of the annular support body. The base of the motor is installed on the top surface of the annular support body.

[0060] According to one embodiment of the present invention, there is also provided an optical lens assembly method, comprising:

[0061] Step S10, preparation step. Prepare a first lens component 100 and a second lens component 200 that are separated from each other. The first lens component 100 includes a first lens barrel 102 and a first lens 101 installed in the first lens barrel 102; the second lens component 200 includes a second lens barrel 202 and four second lenses 201 installed in the second lens barrel 202, the four second lenses 201 and the first lens 101 together constitute an imageable optical system, and the first lens barrel 102 is made of a material different from that of the second lens barrel 202.

[0062] Step S20 is a pre-positioning step. The first lens component 100 and the second lens component 200 are pre-positioned so that the first lens 101 and the at least one second lens 201 together form an optical system capable of forming an image.

[0063] Step S30 is an active calibration step. The relative positions of the first lens component 100 and the second lens component 200 are adjusted and determined based on active calibration.

[0064] Step S40, bonding step. The first lens component 100 and the second lens component 200 are bonded by a first adhesive material 300. The first adhesive material 300 is located in the gap between the first lens component 100 and the second lens component 200. After the first adhesive material 300 is cured, the first lens component 100 and the second lens component 200 are fixed and maintained at the relative position determined by the active calibration.

[0065] In this embodiment, the first lens 101 can be protected by selecting an appropriate material of the first lens barrel 102 to reduce the secondary variation of the shape and position of the first lens 101 after the active calibration is completed. Specifically, the secondary variation refers to the change of the optical system after baking and curing relative to the optical system determined by the active calibration.

[0066] Furthermore, the active calibration described in the present application can adjust the relative position of the first lens component 100 and the second lens component 200 in multiple degrees of freedom. Fig. 6A The relative position adjustment method in active calibration in one embodiment of the present invention is shown. In this adjustment method, the first lens component 100 (or the first lens 101) can move relative to the second lens component 200 along the x, y, and z directions (that is, the relative position adjustment in this embodiment has three degrees of freedom). The z direction is the direction along the optical axis, and the x and y directions are the directions perpendicular to the optical axis. The x and y directions are both in an adjustment plane P, and the translation in the adjustment plane P can be decomposed into two components in the x and y directions.

[0067] Figure 6BFIG. 2 shows the rotation adjustment in active calibration of another embodiment of the present invention. In this embodiment, the relative position adjustment has Fig. 6A In addition to the three degrees of freedom, a rotational degree of freedom, i.e., adjustment in the r direction, is added. In this embodiment, the adjustment in the r direction is a rotation within the adjustment plane P, i.e., a rotation around an axis perpendicular to the adjustment plane P.

[0068] Further, Figure 6C The figure shows a relative position adjustment method with v and w direction adjustments added in the active calibration of another embodiment of the present invention. The v direction represents the rotation angle of the xoz plane, the w direction represents the rotation angle of the yoz plane, and the rotation angles of the v direction and the w direction can be synthesized into a vector angle, which represents the overall tilt state. In other words, by adjusting the v direction and the w direction, the tilt posture of the first lens component 100 relative to the second lens component 200 (that is, the tilt of the optical axis of the first lens component 100 relative to the optical axis of the second lens component 200) can be adjusted.

[0069] The adjustment of the six degrees of freedom of x, y, z, r, v, and w may affect the imaging quality of the optical system (for example, the resolution). In other embodiments of the present invention, the relative position adjustment method may be to adjust only any one of the six degrees of freedom, or a combination of any two or more thereof.

[0070] Furthermore, in one embodiment, in the active calibration step, the movement also includes translation on the adjustment plane, ie, movement in the x and y directions.

[0071] Furthermore, in one embodiment, the active calibration further comprises: adjusting and determining the angle between the axis of the first lens component 100 and the axis of the second lens component 200 according to the measured resolution of the optical system, that is, adjustment in the w and v directions. In the assembled optical lens or camera module, the axis of the first lens component 100 and the axis of the second lens component 200 may have a non-zero angle.

[0072] Furthermore, in one embodiment, the active calibration also includes: moving the first lens component 100 along a direction perpendicular to the adjustment plane (i.e., adjustment in the z direction), and determining the relative position between the first lens component 100 and the second lens component 200 in the direction perpendicular to the adjustment plane according to the measured resolution of the optical system.

[0073] Furthermore, in one embodiment, in the pre-positioning step, a gap is provided between the bottom surface of the first lens component 100 and the top surface of the second lens component 200; and in the bonding step, the adhesive is arranged in the gap.

[0074] In one embodiment, in the active calibration step, the second lens component 200 may be fixed, the first lens component 100 may be clamped by a fixture, and the first lens component 100 may be moved under the drive of a six-axis motion mechanism connected to the fixture, thereby realizing the relative movement of the first lens component 100 and the second lens component 200 in the above six degrees of freedom. The fixture may be supported or partially supported on the side of the first lens component 100, thereby clamping the first lens component 100.

[0075] Further, FIG. 4A to FIG. 4G An optical lens assembly method in one embodiment of the present invention is shown. Figure 4A The first lens component 100 and the second lens component 200 are shown in a separated state, and the direction indicated by the arrow shows the moving direction of the first lens component 100. FIG4B shows a schematic diagram of pre-positioning and actively calibrating the first lens component 100 and the second lens component 200. Specifically, the first lens component 100 and the second lens component 200 are pre-positioned so that the first lens 101 and the four second lenses 201 together constitute an imageable optical system, and the six-axis coordinates of the first lens component 100 are adjusted through an external capture mechanism so that the measured imaging quality meets the standard (for example, the measured resolution reaches a threshold value), and then the six-axis coordinate position of the first lens component 100 that meets the imaging quality standard is recorded. Figure 4C The schematic diagram of applying glue on the top surface of the second lens barrel 202 after active calibration is shown. Specifically, after the active calibration is completed, the first lens component 100 is removed, and then the first glue material 300 is applied on the top surface of the second lens barrel 202 of the second lens component 200 for connection between the first lens component 100 and the second lens component 200. The arrow in the figure indicates that the first lens component 100 is removed. Figure 4D It shows that after the first adhesive 300 is painted on the top surface of the second lens barrel 202 of the second lens component 200, the external capturing mechanism restores the first lens component 100 to the calibration position according to the six-axis coordinate position determined by the active calibration (ie the recorded six-axis coordinate position). Figure 4E Specifically, after the first lens component 100 is moved to the calibration position, the first adhesive material 300 is exposed to pre-cure the first adhesive material 300. During the exposure process, the external pickup mechanism keeps the first lens component 100 at the calibration position. Figure 4E The arrow in FIG. 1 is used for the light for exposing the first adhesive material 300 . Figure 4FThe first adhesive material 300 is shown in a cured state. After exposure, the external pickup mechanism is removed, and the first lens component 100 is maintained in the calibration position by the support and fixation of the pre-cured first adhesive material 300 . Figure 4G The state after permanent curing is shown. The optical lens after pre-curing of the first adhesive material 300 is baked to achieve permanent curing. Figure 4G In the embodiment, the first adhesive material 300 is baked to permanently connect the first lens component 100 and the second lens component 200, and is kept at Figure 4B Active calibration position shown.

[0076] In this embodiment, the first adhesive material 300 is painted between the top surface of the second lens barrel 202 and the bottom surface of the first lens barrel 102, wherein a gap is maintained between the first lens 101 and the second lens barrel 202; optionally, the first adhesive material 300 may also be painted between the bottom surface of the first lens 101 and the top surface of the second lens barrel 202, wherein a gap is maintained between the first lens barrel 102 and the second lens barrel 202; optionally, the first adhesive material 300 may also be painted between the first lens barrel 102 and the top surface of the second lens barrel 202, and between the bottom surface of the first lens 101 and the top surface of the second lens barrel 202.

[0077] Further, FIG. 5A to FIG. 5F An optical lens assembly method in another embodiment of the present invention is shown. Figure 5A The schematic diagram shows that the top surface of the second lens barrel 202 of the second lens component 200 has the first adhesive material 300 , wherein the first adhesive material 300 is painted on the top surface of the second lens barrel 202 of the second lens component 200 for connection between the first lens component 100 and the second lens component 200 . Figure 5B A schematic diagram of clamping and moving the first lens component 100 for pre-positioning is shown, wherein after the first adhesive material 300 is painted on the top surface of the second lens barrel 202 of the second lens component 200, active calibration is used to pre-position the first lens component 100 and the second lens component 200, so that the first lens 101 and the at least one second lens 201 together constitute an imageable optical system, and the six-axis coordinates of the first lens component 100 are adjusted through an external capture mechanism so that the measured imaging quality meets the standard (for example, the measured resolution reaches a threshold value), so that the first lens component 100 is moved to the six-axis coordinate position that meets the imaging quality standard, and the direction indicated by the arrow shows the moving direction of the first lens component 100. Figure 5C A schematic diagram is shown after the first lens component 100 is moved to the calibration position by using active calibration. In this schematic diagram, the first lens component 100 and the second lens component 200 contain a first adhesive material 300 and are held in the calibration position by an external pickup mechanism. Figure 5DA schematic diagram of exposing the first adhesive material 300 for pre-curing is shown, wherein after the first lens component 100 is moved to the first adhesive material 300 painted on the top surface of the second lens barrel 202 of the second lens component 200, it is kept at the calibration position, and then the first adhesive material 300 is exposed and pre-cured, thereby keeping the first lens component 100 at the calibration position. Figure 5E The first adhesive material 300 is shown in a cured state. After the first adhesive material 300 is exposed, the external capturing mechanism is moved away, and the first lens component 100 is kept in the calibration position. Fig. 5F The state after permanent curing is shown. The optical lens pre-cured with the first adhesive 300 is baked to achieve permanent curing. Fig. 5F In the embodiment, the first adhesive material 300 is baked to permanently connect the first lens component 100 and the second lens component 200, and is kept at Figure 5C Active calibration position shown.

[0078] In this embodiment, the first adhesive material 300 is painted between the top surface of the second lens barrel 202 and the bottom surface of the first lens barrel 102, wherein a gap is maintained between the first lens 101 and the second lens barrel 202; optionally, the first adhesive material 300 may also be painted between the bottom surface of the first lens 101 and the top surface of the second lens barrel 202, wherein a gap is maintained between the first lens barrel 102 and the second lens barrel 202; optionally, the first adhesive material 300 may also be painted between the first lens barrel 102 and the top surface of the second lens barrel 202, and between the bottom surface of the first lens 101 and the top surface of the second lens barrel 202.

[0079] Furthermore, according to an embodiment of the present invention, a camera module assembly method is also provided, comprising: assembling an optical lens using the optical lens assembly method of any of the aforementioned embodiments, and then using the assembled optical lens to manufacture a camera module.

[0080] Furthermore, the applicant has further analyzed the thermal expansion coefficient, moisture absorption rate and elastic modulus of various materials, and obtained a series of preferred embodiments based on the analysis.

[0081] Among them, moisture absorption rate can also be called water absorption rate, which indicates the ability of a material to absorb water under standard atmospheric pressure. Table 1 gives the water absorption rates of some plastic materials.

[0082] Table 1

[0083]

[0084] With reference to Table 1, in some embodiments of the present invention, the first lens barrel can be made of a material with a water absorption rate of less than 0.3%, such as LCP, FR-PET, PI, PBT, PE, PP, PPO, PEI or AS. In addition, since the water absorption rate of metal materials is usually less than 0.3%, the first lens barrel can also be made of metal materials. The use of a material with a water absorption rate of less than 0.3% to make the first lens barrel can reduce the shape variation or position offset of the first lens barrel caused by moisture accumulation, thereby helping to reduce the difference between the optical system state after the first glue is cured and the optical system state determined by active calibration, thereby ensuring the imaging quality of the lens or module. The material of the second lens barrel 202 is still made of traditional materials, such as PC materials. In this way, the second lens component can still be made using traditional processes, which helps to improve product yield and improve production efficiency.

[0085] In this article, the polymer materials and metal materials involved are isotropic in three-dimensional directions, so the thermal expansion coefficients are all linear expansion coefficients.

[0086] In one embodiment of the present invention, the first lens may be made of glass material, and the first lens barrel may be made of metal material.

[0087] Generally speaking, the thermal expansion coefficient of glass materials is: (5.8~150)×10 -7 / ℃.

[0088] The thermal expansion coefficients of some common industrial metal materials are as follows:

[0089] Copper: 1.7×10 -5 / ℃,

[0090] Aluminum: 2.3×10 -5 / ℃,

[0091] Iron: 1.2×10 -5 / ℃,

[0092] General carbon steel: 1.3×10 -5 / ℃.

[0093] Glass has a smaller coefficient of thermal expansion than plastic, and metal lens barrels generally also have a smaller coefficient of thermal expansion than plastic. Therefore, the combination of glass lenses and metal lens barrels can help reduce deformation of the first lens component caused by heat (such as baking). In addition, since the metal lens barrel has a lower water absorption rate, it can also reduce shape variation or position displacement of the first lens barrel caused by moisture accumulation.

[0094] Furthermore, in a preferred embodiment of the present invention, oxygen-free copper can be used as the material of the first lens barrel. The thermal expansion coefficient of oxygen-free copper is: 1.86×10 -7 / ℃, and high borosilicate glass is used as the first lens material. The thermal expansion coefficient of high borosilicate glass is: (3.3±0.1)× 10 -6 / ℃. The thermal expansion coefficients of these two materials are close, which can reduce the deformation of the first lens component caused by heat (such as baking), and because the water absorption rate of oxygen-free copper is very small, this embodiment can also reduce the shape variation or position displacement of the first lens barrel caused by moisture accumulation. Therefore, the solution of this embodiment is very helpful to reduce the difference between the optical system state after the first adhesive is cured and the optical system state determined by active calibration, thereby ensuring the imaging quality of the lens or module.

[0095] In another embodiment of the present invention, the first lens and the first lens barrel are both made of plastic material. The first lens barrel can be made of a first plastic, and the first lens can be made of a second plastic. The difference in thermal expansion coefficient between the first plastic and the second plastic is within 4×10 -5 / ℃ or less.

[0096] Commonly used plastic lens materials include: PC or PMMA (polymethyl methacrylate), PMMA is commonly known as plexiglass or acrylic.

[0097] Among them, the thermal expansion coefficient of PMMA is: 7×10 -5 / ℃,

[0098] The thermal expansion coefficient of PC is: (6.5~6.6)×10 -5 / ℃.

[0099] Sometimes, lenses can also be made of resin materials, such as CR-39 (propylene glycol carbonate, also known as Columbia resin or ADC resin), which has a thermal expansion coefficient of 9 to 10 × 10 -5 / ℃.

[0100] Table 2 further shows the thermal expansion coefficients of some plastics.

[0101] Table 2

[0102] Material Name Linear expansion coefficient (℃^-1) PE(medium density) 10×10^-5 PC (5～7)×10＾-5 PBT 110^-5 PE(high density) 22×10^-5； PPO(NORYL) 0.7×10＾-5 PP Polypropylene (5.8～10.2)10＾-5 PEI 5.6×10＾-5

[0103] In Table 2, the symbol “^” represents a power, for example, “10^-5” represents “10 -5 ”.

[0104] Furthermore, in some embodiments of the present invention, the material of the first lens barrel can be selected so that the elasticity of the first lens barrel is greater than the elasticity of the first lens, so as to buffer the clamping force of the external clamp when the first lens barrel is clamped, thereby reducing the force indirectly acting on the first lens. At the same time, the good elasticity of the lens barrel can make the first lens barrel easy to return to its original shape after the clamp is released. Table 3 shows the elastic modulus of some lens barrel materials. Table 4 shows the elastic modulus of some lens materials.

[0105] Table 3

[0106] Material Name Elastic modulus(GPa) PE(medium / low density) 0.172 FR-PET 1.5-2 POLIYIMSE 1.07 AS(ASN) 1.93 PC 2.4-2.6 PBT 2.8 PE(high density) 2.914 PPO(NORYL) 2.32 PP Polypropylene 4 PEI 10 LCP 11.7

[0107] Table 4

[0108]

[0109] In a preferred embodiment, a first lens made of PMMA material and a first lens barrel made of medium-low density PE material (the medium-low density PE material may have a density of 0.920-0.940 g / cm 3 In this way, the first lens barrel not only has better elasticity than the first lens, but also has a very small water absorption rate. At the same time, the difference in thermal expansion coefficient between the first lens barrel and the second lens barrel is within 4×10 -5 / ℃ or less. The solution of this embodiment can reduce the deformation of the first lens component caused by heat (such as baking), can reduce the shape variation or position displacement of the first lens barrel caused by moisture accumulation, and can buffer the force of the external capture mechanism on the first lens through the elasticity of the first lens barrel, which is very helpful to reduce the difference between the optical system state after the first glue is cured and the optical system state determined by active calibration, thereby ensuring the imaging quality of the lens or module. In this embodiment, the second lens barrel can be made of traditional lens barrel materials (such as PC materials), so that the second lens component can still be made using traditional processes, which helps to improve product yield and production efficiency. In the case of large-scale mass production (such as mass production of mobile phone camera modules), the production volume of the same type of camera modules (or corresponding optical lenses) may reach the order of tens of millions or even hundreds of millions, so the product yield and production efficiency cannot be ignored.

[0110] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. An optical lens, characterized in that: include: A first lens assembly includes a first lens barrel and at least one first lens installed in the first lens barrel; A second lens component includes a second lens barrel and at least one second lens installed in the second lens barrel, wherein the at least one second lens and the first lens together form an imageable optical system, and the material of the first lens barrel is different from that of the second lens barrel; as well as A first adhesive material is located in a first gap between the first lens component and the second lens component, the first adhesive material is suitable for supporting and fixing the first lens component and the second lens component after curing, wherein the axis of the first lens component and the axis of the second lens component have a non-zero angle, the material elastic modulus of the first lens barrel is smaller than the material elastic modulus of the first lens to buffer the force exerted by an external pickup mechanism on the first lens, the first adhesive material is located between the first lens and the second lens barrel, and there is no filler between the first lens barrel and the second lens barrel.

2. The optical lens according to claim 1, characterized in that: The first adhesive material is suitable for supporting and fixing the first lens component and the second lens component, so that the relative position of the first lens component and the second lens component is maintained at a relative position determined by active calibration.

3. The optical lens according to claim 1, characterized in that: A difference between a thermal expansion coefficient of the first lens barrel and a thermal expansion coefficient of the first lens is smaller than a first threshold.

4. The optical lens according to claim 1, characterized in that: The moisture absorption rate of the material of the first lens barrel is lower than the moisture absorption rate of the material of the second lens barrel.

5. The optical lens according to any one of claims 1 to 4, characterized in that: The first lens is a glass lens, and the first lens barrel is a metal lens barrel.

6. The optical lens according to claim 5, characterized in that: The first lens is a high borosilicate glass lens, and the first lens barrel is an oxygen-free copper lens barrel.

7. The optical lens according to claim 1, characterized in that: The material of the first lens barrel has a density of 0.920-0.940 g / cm 3 The first lens is made of polyethylene material, and the material of the first lens is polymethyl methacrylate material.

8. The optical lens according to claim 7, characterized in that: The number of the first lenses is smaller than the number of the second lenses, and the second lenses are closer to the photosensitive chip than the first lenses.

9. The optical lens according to claim 8, characterized in that: The number of the first lenses is one, and the outer diameter of the first lens is larger than the second lens having the smallest outer diameter.

10. The optical lens according to any one of claims 7 to 9, characterized in that: The second lens barrel is made of polycarbonate material.

11. The optical lens according to any one of claims 1 to 4, wherein the first lens barrel is made of a first plastic, the first lens is made of a second plastic, and the difference in thermal expansion coefficient between the first plastic and the second plastic is within 4×10 -5 / ℃ or less.

12. A camera module, characterized in that: include: An optical lens as claimed in any one of claims 1 to 11.

13. An optical lens assembly method, characterized in that: include: A first lens component and a second lens component are prepared to be separated from each other, wherein the first lens component comprises a first lens barrel and at least one first lens installed in the first lens barrel, and the second lens component comprises a second lens barrel and at least one second lens installed in the second lens barrel, wherein the first lens barrel is made of a material different from that of the second lens barrel, and the elastic modulus of the material of the first lens barrel is smaller than the elastic modulus of the material of the first lens; Pre-positioning the first lens component and the second lens component so that the at least one first lens and the at least one second lens together form an imageable optical system; According to the measured imaging result of the optical system, the first lens component is captured and moved by a capturing mechanism for active calibration, so as to adjust and determine the relative position of the first lens component and the second lens component; as well as The first lens component and the second lens component are bonded by a first adhesive material to support and fix the relative position of the first lens component and the second lens component. The first adhesive material is located between the first lens and the second lens barrel, and there is no filler between the first lens barrel and the second lens barrel.

14. The optical lens assembly method according to claim 13, characterized in that: The active calibration also includes: moving the first lens component along the adjustment plane, and determining the relative position between the first lens component and the second lens component on the adjustment plane according to the measured resolution based on the actual imaging result of the optical system; the relative position on the adjustment plane includes the relative position in the translation direction and / or rotation direction on the adjustment plane.

15. The optical lens assembly method according to claim 13, characterized in that: The active calibration further includes: adjusting and determining the angle between the axis of the first lens component and the axis of the second lens component according to the measured resolution based on the actual imaging result of the optical system.

16. The optical lens assembly method according to claim 13, characterized in that: The active calibration also includes: moving the first lens component along a direction perpendicular to the adjustment plane, and determining the relative position between the first lens component and the second lens component in the direction perpendicular to the plane according to the measured resolution based on the actual imaging result of the optical system.

17. A camera module assembly method, characterized in that: include: Assembling an optical lens using the optical lens assembly method described in any one of claims 13 to 16; And manufacturing camera modules based on the assembled optical lenses.

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