CN207340018U - Camera module - Google Patents

Abstract

The utility model provides a camera module, which includes a first sub-lens and a second sub-assembly, wherein the second sub-assembly includes a second sub-lens and a photosensitive assembly fixed together; the first sub-lens is arranged on the second The optical axis of the sub-lens constitutes an imageable optical system; the first sub-lens and the second sub-lens are fixed together by a connection medium, and the connection medium is suitable for making the central axis of the first sub-lens It has an inclination angle relative to the central axis of the second sub-lens. The utility model can improve the resolution of the camera module; can improve the process capability index of the mass-produced camera module; can reduce the overall cost of the optical imaging lens and the module; can reduce the defect rate, reduce the production cost, and improve the imaging quality .

Description

camera module

technical field

The utility model relates to the field of optical technology, in particular, the utility model relates to a solution for a camera module.

Background technique

With the popularization of mobile electronic devices, related technologies of camera modules used in mobile electronic devices to help users acquire images (such as video or images) have developed rapidly and improved rapidly, and in recent years, camera modules Groups have been widely used in many fields such as medical treatment, security, industrial production and so on.

In order to meet more and more extensive market demands, high pixel, small size, and large aperture are irreversible development trends of existing camera modules. The market has put forward higher and higher demands on the imaging quality of camera modules. Factors affecting the resolution of a camera module with a given optical design include the quality of the optical imaging lens and manufacturing errors in the module packaging process.

Specifically, in the manufacturing process of optical imaging lenses, the factors that affect the resolution of the lens come from the error of each component and its assembly, the error of the thickness of the lens spacing element, the error of the assembly 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 errors such as the thickness of the optical surface of each lens monomer, the sagittal height of the optical surface of the lens, the shape of the optical surface, the radius of curvature, the eccentricity of the single surface of the lens and between surfaces, and the inclination of the optical surface of the lens. The size depends on the mold precision and molding precision control ability. The error of the thickness of the lens spacing element depends on the processing accuracy of the element. The error of the assembly fit of each lens depends on the dimensional tolerance of the assembled components and the assembly accuracy of the lens. The error introduced by the variation of the refractive index of the lens material depends on the stability of the material and the batch consistency.

The errors of the above-mentioned components affecting the resolution are accumulated and deteriorated, and this accumulated 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 the rotation of the lens to improve the resolution, but because the lens with high pixel and large aperture is more sensitive, the tolerance is strict, such as: some sensitive lenses 1um Lens eccentricity will cause 9′ image plane inclination, which makes lens processing and assembly more and more difficult. At the same time, due to the long feedback cycle in the assembly process, the process capability index (CPK) of lens assembly is low and fluctuates greatly, resulting in defective rate. high. And as mentioned above, because there are many factors that affect the resolution of the lens, they exist in multiple components, and the control of each factor has the limit of manufacturing accuracy. If the precision of each component is simply improved, the improvement capability is limited and the cost of improvement is high. Moreover, it cannot meet the increasing demands of the market for imaging quality.

On the other hand, during the processing of the camera module, the assembly process of various structural parts (such as photosensitive chip mounting, motor lens locking process, etc.) may cause the photosensitive chip to tilt, and the superposition of multiple tilts may cause the imaging module to The resolution cannot meet the established specifications, resulting in a low yield rate for module factories. In recent years, module factories have compensated for the inclination of the photosensitive chip through the Active Alignment process when assembling the imaging lens and the photosensitive module. However, the compensation capability of this process is limited. Since a variety of aberrations that affect the resolution come from the capabilities of the optical system itself, when the resolution of the optical imaging lens itself is insufficient, the existing active calibration process of the photosensitive module is difficult to compensate.

Utility model content

The present invention aims to provide a solution capable of overcoming at least one of the above-mentioned drawbacks of the prior art.

According to one aspect of the present invention, a camera module is provided, which is assembled by the following method:

Prepare a first sub-lens and a second sub-assembly; wherein the first sub-lens includes a first lens barrel and at least one first lens, and the second sub-assembly includes a second sub-lens and a photosensitive assembly fixed together, so The second sub-lens includes a second lens barrel and at least one second lens; the photosensitive component includes a photosensitive element;

arranging the first sub-lens on the optical axis of the second sub-lens to form an imageable optical system including the at least one first lens and the at least one second lens;

By adjusting the relative position of the first sub-lens relative to the second sub-lens, the measured resolution of the imaging of the optical system obtained by the photosensitive element is improved to a first threshold, and the photosensitive element is obtained The measured image plane tilt decreases up to a second threshold; and

The first sub-lens and the second sub-lens are connected so that the relative positions of the first sub-lens and the second sub-lens remain unchanged.

Wherein, in the step of adjusting the relative position of the first sub-lens relative to the second sub-lens, adjusting the relative position includes:

By moving the first sub-lens along the adjustment plane relative to the second sub-lens, the measured resolution of the imaging of the optical system is improved.

Wherein, in the step of adjusting the relative position of the first sub-lens relative to the second sub-lens, the moving along the adjustment plane includes translation and/or rotation on the adjustment plane.

Wherein, in the step of adjusting the relative position of the first sub-lens relative to the second sub-lens, adjusting the relative position includes: adjusting the axis of the first sub-lens relative to the second sub-lens The angle between the axes of the two sub-lenses.

Wherein, the step of adjusting the relative position of the first sub-lens relative to the second sub-lens includes the following sub-steps:

By moving the first sub-lens along the adjustment plane relative to the second sub-lens, the measured resolution of the optical system imaging obtained by the photosensitive element in the reference field of view is improved to a corresponding threshold; and

Adjusting the angle between the axis of the first sub-lens and the axis of the second sub-lens, so that the measured resolution of the optical system imaging obtained by the photosensitive element in the test field of view increases to a corresponding threshold, And the measured image plane inclination reduction obtained by the photosensitive element in the test field of view reaches the second threshold.

Wherein, the step of adjusting the relative position of the first sub-lens relative to the second sub-lens further includes:

By moving the first sub-lens relative to the second sub-lens in the z direction, the measured image plane obtained by the optical system through the photosensitive element is matched with the target plane, wherein the z direction is along the The direction of the optical axis.

Wherein, the adjustment plane is perpendicular to the z direction.

Among them, the methods for obtaining the measured image plane tilt include:

For the test field of view, a plurality of targets corresponding to different test positions of the test field of view are provided; and

A resolution defocus curve corresponding to each test position is obtained based on the image output by the photosensitive assembly.

Wherein, the reaching the second threshold is to reduce the positional deviation of the peak value of the resolution defocus curve in the direction of the optical axis corresponding to different test positions of the test field of view to reach the second threshold.

Wherein, reaching the second threshold is to reduce the position deviation of the peak value of the resolution defocus curve corresponding to different test positions of the test field of view in the direction of the optical axis to within +/-5 μm.

Wherein, the method for obtaining the measured resolution of the imaging of the optical system includes:

providing targets at a plurality of different test locations corresponding to the reference field of view and the test field of view; and

A resolution defocus curve corresponding to each test position is obtained based on the image output by the photosensitive assembly.

Wherein, in the sub-step of moving the first sub-lens relative to the second sub-lens along the adjustment plane, the reaching the corresponding threshold is: making the resolution of different test positions corresponding to the reference field of view be separated from The peak elevation of the focal curve reaches the corresponding threshold.

Wherein, in the sub-step of adjusting the angle between the axis of the first sub-lens and the axis of the second sub-lens, the reaching the corresponding threshold includes: making the The least one of the peaks of the plurality of resolution defocus curves increases to reach the corresponding threshold.

Wherein, the step of adjusting the relative position of the first sub-lens relative to the second sub-lens includes the following sub-steps:

By moving the first sub-lens relative to the second sub-lens within the first range along the adjustment plane, the measured resolution of the optical system imaging obtained through the photosensitive element in the reference field of view is improved by up to the corresponding threshold;

Then adjust the angle between the axis of the first sub-lens relative to the axis of the second sub-lens, so that the measured resolution of the optical system imaging obtained by the photosensitive element in the test field of view increases to a corresponding threshold , and the measured image plane inclination obtained by the photosensitive element in the test field of view is reduced, if the measured image plane inclination cannot reach the second threshold value, the readjustment step is further performed until the measured image plane inclination is reduced to reach said second threshold;

Wherein, the retuning step includes:

by moving the first sub-lens relative to the second sub-lens along the adjustment plane within a second range, wherein the second range is smaller than the first range; and

By adjusting the included angle between the central axis of the first sub-lens and the central axis of the second sub-lens, the inclination of the measured image plane obtained by the optical system through the photosensitive element is reduced.

Wherein, in the connecting step, the first sub-lens and the second sub-lens are connected by bonding or welding process.

Wherein, the welding process includes laser welding or ultrasonic welding.

Wherein, in the step of preparing the first sub-lens and the second sub-assembly, the second sub-lens and the photosensitive assembly are fixed by non-active calibration to form the second sub-assembly. Non-active calibration methods refer to methods other than active calibration, such as mechanical alignment and other alignment methods that do not need to light up the module chip. The English name of active alignment is ActiveAlignment, which can be abbreviated as AA.

According to another aspect of the present utility model, a camera module is also provided, including:

a first sub-lens including a first lens barrel and at least one first lens; and

The second subassembly includes a second sublens and a photosensitive assembly fixed together, the second sublens includes a second lens barrel and at least one second lens; the photosensitive assembly includes a photosensitive element;

Wherein, the first sub-lens is arranged on the optical axis of the second sub-lens to form an imageable optical system including the at least one first lens and the at least one second lens;

The first sub-lens and the second sub-lens are fixed together by a connection medium, and the connection medium is adapted to make the central axis of the first sub-lens have an inclination angle relative to the central axis of the second sub-lens .

Wherein, the connection medium is further adapted to make the central axis of the first sub-lens deviate from the central axis of the second sub-lens.

Wherein, the connecting medium is further adapted to provide a structural gap between the first sub-lens and the second sub-lens.

Wherein, the connection medium is a bonding medium or a welding medium.

Wherein, the central axis of the first sub-lens is offset from the central axis of the second sub-lens by 0-15 μm.

Wherein, the central axis of the first sub-lens has an inclination angle of less than 0.5 degrees relative to the central axis of the second sub-lens.

Wherein, the connection medium is also adapted to keep the relative position of the first sub-lens and the second sub-lens unchanged, and the relative position makes the actual measurement of the imaging of the optical system obtained by the photosensitive element The resolution is improved to reach a first threshold, and the measured image plane inclination of the optical system imaging obtained by the photosensitive element is reduced to a second threshold.

Wherein, the second sub-lens further includes a motor, the measured resolution is the measured resolution when the motor is turned on, and the measured image plane inclination is the measured image plane inclination when the motor is turned on.

Wherein, both the outer surfaces of the first sub-lens and the second sub-lens have contact surfaces that are convenient for ingestion.

There is a gap of 10-50 μm between the second sub-lens and the photosensitive component.

Compared with the prior art, the utility model has at least one of the following technical effects:

1. The utility model can improve the resolution of the camera module.

2. The utility model can improve the process capability index (CPK) of the mass-produced camera module.

3. The utility model reduces the overall cost of the optical imaging lens and the module by loosening the requirements on the precision and assembly precision of each component of the optical imaging lens and the module.

4. The utility model can adjust various aberrations of the camera module in real time during the assembly process, reduce the defect rate, reduce the production cost, and improve the imaging quality.

5. The utility model realizes one-time aberration adjustment of the whole module through the multi-degree-of-freedom relative position adjustment of the first sub-lens and the second sub-assembly, and further improves the imaging quality of the whole module.

6. The utility model can fix the photosensitive component and the second sub-lens through a non-active calibration method, thereby reducing costs and improving production efficiency.

Description of drawings

Exemplary embodiments are shown in the referenced drawings. The embodiments and drawings disclosed herein are to be regarded as illustrative rather than restrictive.

Fig. 1 shows the flowchart of the camera module assembly method of one embodiment of the present invention;

Fig. 2 shows a schematic diagram of the first sub-lens, the second sub-assembly and their initial arrangement positions in one embodiment of the present invention;

Fig. 3 has shown the relative position adjustment mode in one embodiment of the utility model;

Fig. 4 shows the rotation adjustment in another embodiment of the utility model;

Fig. 5 shows the relative position adjustment mode in which v and w direction adjustments are added in another embodiment of the present invention;

Fig. 6 shows the MTF defocus curve under the original state in one embodiment of the utility model;

FIG. 7 shows an example of the MTF defocus curve adjusted in step 310;

Fig. 8 shows the first sub-lens and the second sub-assembly adjusted in step 310 and their positional relationship in one embodiment of the present invention;

Fig. 9 shows the schematic diagram of image plane tilt;

Fig. 10 shows a comparative schematic diagram of images of the central position and the peripheral 1 and peripheral 1' positions;

Fig. 11 shows the MTF defocus curve adjusted by step 400 in one embodiment of the present invention;

FIG. 12 shows the relative positional relationship between the first sub-lens and the second sub-lens adjusted in step 320 in one embodiment of the present invention;

Fig. 13 shows the camera module formed after the connection is completed in one embodiment of the present invention;

Figure 14 shows an example of how targets are set up in one embodiment;

Fig. 15 shows the camera module in one embodiment of the present invention;

Figure 16 shows the assembled camera module with a motor and the motor is not turned on in one embodiment of the present invention;

Fig. 17 shows an assembled camera module with a motor and the motor turned on in an embodiment of the present invention.

Detailed ways

For a better understanding of the application, various aspects of the application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are descriptions of exemplary embodiments of the application only, and are not intended to limit the scope of the 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.

It should be noted that in this specification, expressions of first, second, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features. Accordingly, a first body discussed hereinafter may also be referred to as a second body without departing from the teachings of the present application.

In the drawings, the thickness, size and shape of objects have been slightly exaggerated for convenience of illustration. The drawings are examples only and are not strictly drawn to scale.

It should also be understood that the terms "comprises", "comprises", "has", "comprises" and/or "comprising", when used in this specification, means that there are stated features, integers, steps, operations , elements and/or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or combinations thereof. Furthermore, expressions such as "at least one of," when preceding a list of listed features, modify the entire listed feature and do not modify the individual elements of the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or illustration.

As used herein, the terms "substantially", "about", and similar terms are used as terms of approximation, not as terms of degree, and are intended to illustrate what would be recognized by one of ordinary skill in the art, measure Inherent bias in a value or calculated value.

Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted to have a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless It is expressly so defined herein.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

FIG. 1 shows a flow chart of a method for assembling a camera module according to an embodiment of the present invention. Referring to FIG. 1, the assembly method includes the following steps 100-400:

Step 100: Prepare the first sub-camera and the second sub-assembly. Fig. 2 shows a schematic diagram of the first sub-lens 1000, the second sub-assembly 6000 and their initial arrangement positions in one embodiment of the present invention. Referring to FIG. 2 , the first sub-lens 1000 includes a first lens barrel 1100 and at least one first lens 1200 . In this embodiment, there are two first lenses 1200 , but it is easy to understand that in other embodiments, there may be other numbers of first lenses 1200 , such as one, three or four.

The second subassembly 6000 includes a second sublens 2000 and a photosensitive assembly 3000 fixed together. The second sub-lens 2000 includes a second barrel 2100 and at least one second lens 2200 . In this embodiment, there are three second lenses 2200, but it is easy to understand that in other embodiments, there may be other numbers of second lenses 2200, such as one, two or four. In this embodiment, the second lens barrel 2100 of the second sub-lens 2000 includes an inner lens barrel 2110 and an outer lens barrel 2120 (sometimes the outer lens barrel 2120 is also a lens holder) nested together, and the inner lens barrel 2110 and the outer lens barrel 2110 The lens barrel 2120 is threaded. It should be noted that threaded connection is not the only way of connection between the inner lens barrel 2110 and the outer lens barrel 2120 . Of course, it is easy to understand that in other embodiments, the second lens barrel 2100 may also be an integrated lens barrel.

Still referring to FIG. 2 , in one embodiment, the photosensitive assembly 3000 includes a circuit board 3100 , a photosensitive element 3200 mounted on the circuit board 3100 , a cylindrical tube made on the circuit board 3100 and surrounding the photosensitive element 3200 A support body 3400 , and a color filter element 3300 installed on the support body 3400 . The cylindrical support body 3400 has an extension portion extending inward (directing toward the photosensitive element 3200 ) that can be used as a frame, and the color filter element 3300 is mounted on the extension portion. The cylindrical support 3400 also has an upper surface through which the photosensitive component can be connected with other components of the camera module (such as the second sub-lens 2000 ). Of course, it is easy to understand that in other embodiments, the photosensitive assembly 3000 can also have other structures, for example, the circuit board of the photosensitive assembly has a through hole, and the photosensitive element is installed in the through hole of the circuit board; another example is the support The part is formed around the photosensitive element by molding and extends inward and contacts the photosensitive element (for example, the support part covers at least a part of the non-photosensitive area located at the edge of the photosensitive element); for another example, the photosensitive component can also omit the filter color elements.

Further, in one embodiment, the second sub-lens 2000 and the photosensitive assembly 3000 are fixed by non-active calibration to form the second sub-assembly 6000 . The English name of active calibration is Active Alignment, which can be abbreviated as AA. The non-active calibration method refers to a method other than active calibration. For example, in one example, the second sub-lens 2000 and the photosensitive assembly 3000 may be fixed together by mechanical alignment to form the second sub-assembly 6000 .

Step 200 : Arranging the first sub-lens 1000 on the optical axis of the second sub-assembly 6000 to form an imageable optical system including the at least one first lens 1200 and the at least one second lens 2200 . In this step, arranging the first sub-lens 1000 on the optical axis of the second sub-assembly 6000 refers to preliminarily aligning the two to form an imageable optical system. That is to say, as long as the optical system including all the first mirrors 1200 and all the second mirrors 2200 can form images, it can be considered that the arrangement work in this step is completed. It should be noted that due to various manufacturing tolerances or other reasons in the manufacturing process of the sub-lens and the photosensitive assembly, after the arrangement is completed, the central axes of the first lens barrel 1100 and the second lens barrel 1200 do not necessarily overlap with the optical axis.

Step 300: By adjusting the relative position of the first sub-lens 1000 relative to the second sub-lens 2000, the measured resolution of the optical system imaging is maximized (the measured resolution is increased to a preset threshold, which can be regarded as The actual measured resolution is maximized), and the measured image plane inclination of the optical system imaging is minimized (the actual measured image plane inclination is reduced to a preset threshold, which can be regarded as the actual measured image plane inclination is minimized). Wherein, the adjustment of the relative position between the first sub-lens 1000 and the second sub-lens 2000 may include multiple degrees of freedom.

Fig. 3 shows the relative position adjustment method in one embodiment of the present invention. In this adjustment manner, the first sub-lens can move relative to the second sub-lens along x, y, 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.

Fig. 4 shows the rotation adjustment in another embodiment of the present invention. In this embodiment, in addition to the three degrees of freedom shown in FIG. 3 , the relative position adjustment also adds a rotational degree of freedom, that is, adjustment in the r direction. In this embodiment, the adjustment in the r direction is a rotation within the adjustment plane P, that is, a rotation around an axis perpendicular to the adjustment plane P.

Further, Fig. 5 shows a relative position adjustment mode in which v and w direction adjustments are added in another embodiment of the present invention. Wherein, 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 total tilt state. That is to say, by adjusting the v direction and the w direction, the inclination posture of the first sub-lens relative to the second sub-lens can be adjusted (that is, the optical axis of the first sub-lens is relative to the optical axis of the second sub-lens). slope).

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

Further, in one embodiment, the method for obtaining the measured resolution of the imaging of the optical system includes:

Step 301: Setting a plurality of targets corresponding to the reference field of view and/or the test field of view. For example, the central field of view may be selected as the reference field of view, and one or more fields of view corresponding to the region of interest may be selected as the test field of view (for example, 80% of the field of view).

Step 302: Obtain a resolution defocus curve corresponding to each target based on the image output by the photosensitive assembly. The measured resolution of the corresponding field of view can be obtained according to the resolution defocus curve.

In this embodiment, the resolution can be represented by MTF (Modulation Transfer Function). The higher the MTF value, the better the resolution. In this way, the imaging resolution of the optical system can be obtained in real time according to the MTF defocus curve obtained from the image output by the photosensitive component. According to the change of the MTF defocus curve, it can be judged whether the current state of maximizing the image power has been reached. Fig. 6 shows the MTF defocus curve in the original state in an embodiment of the present invention, which includes the MTF defocus curve of the central field of view and the sagittal direction and meridional direction of two target imaging located in the test field of view MTF defocus curve.

On the other hand, the imaging of the optical system often has the situation that the image plane is tilted. FIG. 9 shows a schematic diagram of image plane tilt. It can be seen that the object plane perpendicular to the optical axis in Fig. 9 forms an oblique image plane after being imaged by the lens. Among them, the incident light in the central field of view is focused at the central focal point after passing through the lens, and the incident light in the off-axis field of view 1 is focused at the peripheral focal point 1' after passing through the lens. There is an axial deviation D2 between this position and the central focal point, and the axis The incident light in the outer field of view 1' passes through the lens and is focused at the position of the peripheral focal point 1, which has an axial deviation D1 from the position of the central focal point. As a result, when the receiving surface of the photosensitive element is arranged perpendicular to the optical axis, the peripheral 1 and peripheral 1' positions cannot be clearly imaged. Figure 10 shows a schematic diagram of the comparison between the images at the central position and the peripheral 1 and peripheral 1' positions, and it can be seen that the images at the peripheral 1 and peripheral 1' positions are obviously blurred by the images at the central position. In the present invention, the above-mentioned inclination of the image plane can be compensated by adjusting the inclination angle between the first sub-lens and the second sub-lens.

In one embodiment, the method for obtaining the measured image plane tilt includes:

Step 303: For any test field of view (eg, 80% field of view), set a plurality of targets corresponding to different test positions of the test field of view. Figure 14 shows an example of how targets are set up in one embodiment. As shown in FIG. 14 , the test field of view is 80% of the field of view, and four targets are respectively set at the four corners of the standard plate.

Step 304: Obtain each resolution defocus curve corresponding to different positions of the same field of view based on the image output by the photosensitive component. When these resolving power defocus curves converge on the abscissa axis (coordinate axis representing the defocus amount along the optical axis), it means that the image plane tilt corresponding to the test field of view has been compensated, that is, on the test field of view The described minimization of the measured image plane tilt has been achieved. In one embodiment, the position deviation of the peak value of the resolution defocus curve corresponding to different test positions of the test field of view in the direction of the optical axis decreases to a corresponding threshold, indicating that the image plane tilt corresponding to the test field of view has been Get compensated.

Further, in one embodiment, the step 300 includes the following sub-steps:

Step 310: By moving the first sub-lens 1000 relative to the second sub-lens 2000 along the adjustment plane P, the measured resolution of the imaging of the optical system is increased to a corresponding threshold. The adjustment of the six degrees of freedom of x, y, z, r, v, and w is described above. Wherein, the translation in the x and y directions and the rotation in the r direction can be regarded as moving along the adjustment plane P in this step. In this step, a plurality of targets corresponding to the reference field of view and the test field of view are set, and then the resolution defocus curve corresponding to each target is obtained based on the image output by the photosensitive component. The first sub-lens 1000 is moved relative to the second sub-lens 2000 in x, y and r directions, so that the peak value of the resolution defocus curve corresponding to the target imaging of the reference field of view is raised to a corresponding threshold. The reference field of view may be the central field of view, but it should be noted that the reference field of view is not limited to the central field of view, and in some embodiments, other fields of view may also be selected as the reference field of view. In this step, reaching the corresponding threshold is: making the peak value of the resolution defocus curve of the target imaging corresponding to the reference field of view reach the corresponding threshold.

FIG. 7 shows an example of the MTF defocus curve adjusted in step 310 . It can be seen that after the adjustment, the MTF values of the sagittal and meridional directions of the two target imaging have been significantly improved. FIG. 8 shows the first sub-lens 1000 and the second sub-assembly 6000 adjusted in step 310 and their positional relationship in one embodiment of the present invention. It can be seen that the central axis of the first sub-lens 1000 is offset by Δx in the x direction relative to the central axis of the second sub-lens 2000 . It should be noted that Fig. 8 is only exemplary. Although the offset in the y direction is not shown in FIG. 8 , those skilled in the art can easily understand that the central axis of the first sub-lens 1000 can also have a value of Δy relative to the central axis of the second sub-lens 2000 in the y direction. offset.

Step 320: By tilting the axis of the first sub-lens 1000 relative to the axis of the second sub-lens 2000, the measured resolution of the imaging of the optical system in the test field of view is increased to a corresponding threshold, and the test field of view The measured inclination of the image plane imaged by the optical system of the field decreases to reach a corresponding threshold. Wherein, the rotation in the direction of v and w corresponds to the tilt adjustment in this step. The measured resolution reaching the corresponding threshold in this step includes: increasing the smallest one of the peaks of the resolution defocus curves corresponding to different test positions of the test field of view to reach the corresponding threshold. In other embodiments, the measured resolution reaching the corresponding threshold may also include: increasing the uniformity of the peak value of the resolution defocus curves of the multiple target imaging corresponding to different test positions of the test field of view to the corresponding threshold. The improvement of the uniformity includes: reducing the variance of the peak values of the resolution defocus curves of the plurality of target imaging corresponding to the test field of view to a corresponding threshold. Reducing the measured image plane inclination of the optical system imaging in the test field of view to reach the corresponding threshold includes: shifting the position of the peak value of the resolution defocus curve corresponding to different test positions of the test field of view in the direction of the optical axis decrease to reach the corresponding threshold.

FIG. 11 shows the MTF defocus curve adjusted in step 320 in one embodiment of the present invention. FIG. 12 shows the relative positional relationship between the first sub-lens and the second sub-lens adjusted in step 320 in an embodiment of the present invention. It can be seen that in FIG. 12 , on the basis that the central axis of the first sub-lens is offset by Δx in the x direction relative to the central axis of the second sub-lens, the central axis of the first sub-lens 1000 is also relative to the central axis of the second sub-lens. The central axis of the second sub-lens 2000 is tilted by Δv2. It should be noted that although the inclination in the w direction is not shown in FIG. 12 , those skilled in the art can easily understand that the axis of the photosensitive assembly 3000 may also have an inclination angle with respect to the central axis of the second sub-lens 2000 in the w direction.

Step 400: Connect the first sub-lens 1000 and the second sub-lens 2000 so that the relative positions of the first sub-lens 1000 and the second sub-lens 2000 remain unchanged. Fig. 13 shows the camera module formed after connection in one embodiment of the present invention.

The process of connecting the first sub-lens and the second sub-lens can be selected according to the situation. For example, in one embodiment, the first sub-lens and the second sub-lens are connected through a bonding process, as shown in FIG. 2000. In another embodiment, the first sub-lens and the second sub-lens may be connected by a laser welding process. In yet another embodiment, the first sub-lens and the second sub-lens may be connected by an ultrasonic welding process. In addition to the above processes, other welding processes are also available. It should be noted that in the present utility model, the term "connection" is not limited to direct connection. For example, in one embodiment, the first sub-lens and the second sub-lens can be connected through an intermediary (the intermediary can be a rigid intermediary), as long as the connection through the intermediary can make the first sub-lens and the second sub-lens The relative position (including relative distance and posture) between the two sub-lenses (between the photosensitive component and the second sub-lens) remains unchanged, so it is within the meaning of the word "connection".

The camera module assembly method of the above-mentioned embodiment can improve the resolution of the camera module; it can improve the process capability index (CPK) of the camera module produced in large quantities; it can make the accuracy of each component of the optical imaging lens and module and its The requirements for assembly accuracy become looser, which reduces the overall cost of optical imaging lenses and modules; various aberrations of the camera module can be adjusted in real time during the assembly process, thereby reducing the volatility of imaging quality, reducing the defective rate, and reducing Reduce production costs and improve imaging quality.

Further, in one of your embodiments, the step 300 may further include: making the optical system image by moving the first sub-lens relative to the second sub-lens in the direction of the optical axis The measured image plane matches the target plane. The adjustment of the six degrees of freedom of x, y, z, r, v, and w is described above. Wherein, the movement in the z direction can be regarded as the movement in the direction of the optical axis in this step.

For the assembled optical lens, there will be a desired imaging surface, which is referred to as the target surface in this paper. In some cases, the target surface is planar. For example, if the photosensitive surface of the photosensitive element of the camera module corresponding to the optical lens is a plane, then in order to achieve the best imaging quality, the desired imaging surface of the optical lens is also a plane, that is, the target surface is a plane at this time. . In other cases, the target surface may also be a convex or concave curved surface, or a wavy curved surface. For example, if the photosensitive surface of the photosensitive element of the camera module corresponding to the optical lens is a convex or concave curved surface, then in order to achieve the best imaging quality, the target surface should also be a convex or concave curved surface; if the optical lens The photosensitive surface of the photosensitive element of the corresponding camera module is a wavy curved surface, and the target surface should also be a wavy curved surface.

In one embodiment, it is identified according to the image output by the photosensitive element whether the measured image plane matches the target plane. In the step of matching the measured image surface with the target surface, matching the measured image surface with the target surface includes: obtaining the field curvature measured by the module through the image output by the photosensitive element, and making the field measured by the module Curves are within +/-5 μm. This embodiment can further improve the imaging quality of the camera module.

Further, in one embodiment, in the step 320, for the selected test field of view, targets are set in pairs. For example, a pair of first targets respectively located at two ends of the center position are arranged in the first direction, and a pair of second targets respectively located at both ends of the center position are arranged in the second direction. As shown in FIG. 14 , the test field of view is 80% of the field of view, and four targets are respectively set at the four corners of the standard plate. The two lower left and upper right targets can be used as a pair of first targets in the first direction, and the two upper left and lower right targets can be used as a pair of second targets in the second direction. According to the offset vector in the direction of the abscissa axis (that is, the direction of the optical axis) of the resolving power defocus curves of the pair of first targets, it is possible to identify the first position of the measured image plane imaged by the optical system. The tilt component in the direction, according to the offset vector in the direction of the abscissa axis of the resolving power defocus curve of the pair of second targets, can identify the measured image plane of the optical system imaging in the second direction , and then adjust the posture of the first sub-lens relative to the second sub-lens so that the included angle of the axis of the first sub-lens relative to the axis of the second sub-lens changes to compensate for the The tilt component in the first direction and the tilt component in the second direction.

Further, in one embodiment, in the step 310, the first sub-lens is moved relative to the second sub-lens along the adjustment plane within a first range;

In the step 320, if the measured image plane inclination cannot fall within the preset interval, further perform the readjustment step 330 until the measured image plane inclination falls within the preset interval;

Wherein, the retuning step 330 includes:

Step 331 : Move the first sub-lens relative to the second sub-lens within a second range along the adjustment plane. Wherein the second range is smaller than the first range, that is, relative to step 310, in step 331, the relative positions of the first sub-lens and the second sub-lens are adjusted on the adjustment plane within a small range. On the one hand, Due to the small adjustment range, the measured resolution achieved through the adjustment in step 310 can be basically maintained. On the other hand, the degree of image plane inclination can be reduced so that the image plane inclination can be compensated in step 332 .

Step 332: By adjusting the angle between the central axis of the first sub-lens and the central axis of the second sub-lens, the measured image plane inclination of the optical system imaging obtained by the photosensitive element is reduced to the corresponding threshold. If the measured image plane inclination cannot fall within the preset interval, the above steps 331 and 332 are executed in a loop until the measured image plane inclination falls within the preset interval.

According to an embodiment of the present invention, a camera module corresponding to the aforementioned camera module assembly method is also provided. Fig. 15 shows the camera module in this embodiment. Referring to FIG. 15 , the camera module includes: a first sub-lens 1000 and a second sub-assembly 6000. Wherein the first sub-lens 1000 includes a first lens barrel 1100 and at least one first lens 1200 . The second subassembly 6000 includes a second sublens 2000 and a photosensitive assembly 3000 fixed together, the second sublens 2000 includes a second lens barrel 2100 and at least one second lens 2200; the photosensitive assembly 3000 includes a photosensitive element 3300 .

Wherein, the first sub-lens 1000 is arranged on the optical axis of the second sub-lens 2000 to form an imageable optical system including the at least one first lens 1200 and the at least one second lens 2200;

The first sub-lens 1000 and the second sub-lens 2000 are fixed together by a connection medium 4000, and the connection medium 4000 is suitable for making the central axis of the first sub-lens 1000 relative to the second sub-lens The central axis of 2000 has an inclination of less than 0.5 degrees. The connection medium 4000 is also adapted to keep the relative position of the first sub-lens 1000 and the second sub-lens 2000 unchanged, and the relative position makes the optical system image obtained by the photosensitive element 3300 The measured resolution of the improved image reaches a first threshold, and the measured image plane inclination of the optical system imaging obtained by the photosensitive element 3300 decreases to a second threshold.

In one embodiment, the connection medium may be glue or a soldered sheet (eg, a metal sheet). The second connection medium can be adhesive material or welding sheet (such as metal sheet). The connection medium that connects the first sub-lens and the second sub-lens and fixes them together is neither a part of the first sub-lens nor a part of the second sub-lens.

In one embodiment, the connection medium is further adapted to make the central axis of the first sub-lens deviate from the central axis of the second sub-lens by 0-15 μm.

In one embodiment, the connection medium is further adapted to provide a structural gap between the first sub-lens and the second sub-lens. Both the first sub-lens 1000 and the second sub-lens 2000 have an optical surface and a structural surface. In the lens, the optical surface is the surface on the lens through which the effective light passes. The surface of the lens that is not an optical surface is a structural surface. The surfaces located in the lens barrel are structural surfaces. Structural gaps are gaps between structural faces.

Further, in one embodiment, the second sub-lens 2000 and the photosensitive assembly 3000 are assembled together by mechanical alignment to form the second sub-assembly 6000 . There is a gap 5000 suitable for mechanical alignment between the second sub-lens 2000 and the photosensitive assembly 3000 . In one example, the gap 5000 suitable for mechanical alignment is a gap of 10-50 μm.

In this paper, the central axis of the first sub-lens and the central axis of the second sub-lens are involved in many places. Referring to Fig. 16, for the convenience of measurement, the central axis of the first sub-lens 1000 can be understood as the central axis of the optical surface 1201 closest to the second sub-lens 2000 in the first sub-lens 1000; 2000 is the central axis defined by the structural surface 1202 of the closest first lens 1200; when the first lens 1200 of the first sub-lens 1000 and the first lens barrel 1100 are tightly fitted, the central axis of the first sub-lens 1000 can also be understood is the central axis defined by the inner surface of the first lens barrel.

Similarly, for the convenience of measurement, the central axis of the second sub-lens 2000 can be understood as the central axis of the optical surface 2201 closest to the first sub-lens 1000 in the second sub-lens 2000; The central axis defined by the structural surface 2202 of the closest second lens 2200; when the second lens 2200 of the second sub-lens 2000 and the second lens barrel 2100 are closely matched, the central axis of the second sub-lens 2000 can also be understood as The central axis defined by the inner surface of the second lens barrel.

The utility model is particularly suitable for a miniaturized camera module for an intelligent terminal with a lens diameter less than 10 mm. In one embodiment, both the outer surfaces of the first sub-lens and the second sub-lens have a sufficient contact surface, so that the mechanical arm (or other ingestion device) can ingest (for example, clamp or absorb) through the contact surface The first sub-lens and the second sub-lens realize accurate adjustment of the relative position between the first sub-lens and the second sub-lens. This precise adjustment can be an adjustment in six degrees of freedom. The adjustment step size can reach the micron level and below.

Further, in one embodiment, the second sub-lens 2000 may further include a motor, so as to realize automatic focusing of the mobile phone camera module. Fig. 16 shows an assembled camera module with a motor and the motor is not turned on in an embodiment of the present invention. Fig. 17 shows an assembled camera module with a motor and the motor turned on in an embodiment of the present invention. In this embodiment, the motor includes a motor base 2310 and a motor support 2320 mounted on the motor base 2310. The motor supporting body 2320 surrounds the second lens barrel 2100, and the driving mechanism of the motor (not shown in the figure) is mounted on the motor supporting body 2320. The motor support body 2320 is connected to the second lens barrel 2100 through a reed 2330 . When the driving mechanism is energized, the second sub-lens barrel moves along the optical axis, and the reed 2330 deforms (as shown in FIG. 17 ). In steps 310 and 320, the motor, the second lens barrel 2100 and the second lens 2200 installed in the second lens barrel 2100 move and adjust as a whole second sub-lens 2000 . In step 500 , the second sub-lens 2000 is connected to the photosensitive component 3000 by connecting the motor base 2310 to the photosensitive component 3000 . Further, in step 310, when adjusting the relative position of the first sub-lens and the second sub-lens, the motor is kept on (for example, the motor is powered on, which can be regarded as the motor is turned on), so that the obtained measured resolution is the same as when the motor is turned on. measured resolution. In step 320, when adjusting the inclination angle of the photosensitive assembly relative to the central axis of the second sub-lens, the motor is also kept turned on, so that the obtained measured image plane inclination is the measured image plane inclination when the motor is turned on. When the motor is turned on, the reed will deform accordingly. However, compared to the state where the motor is not turned on, the deformation of the reed caused by the motor turning on may cause an additional inclination of the central axis of the second sub-lens barrel relative to the central axis of the first sub-lens (refer to the inclination angle Δv4 in Figure 17) . The solution of this embodiment can make the extra tilt of the second lens barrel caused by turning on the motor be compensated in the adjustments of step 310 and step 320, so as to further improve the imaging quality of the auto-focus camera module.

The above description is only a preferred embodiment of the present application and an illustration of the applied technical principle. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solution formed by the specific combination of the above-mentioned technical features, and should also cover the above-mentioned utility models without departing from the concept of the utility model. Other technical solutions formed by any combination of technical features or equivalent features. For example, a technical solution formed by replacing the above-mentioned features with technical features with similar functions disclosed in (but not limited to) this application.

Claims (10)

1. A camera module, characterized in that, comprising: a first sub-lens including a first lens barrel and at least one first lens; and The second subassembly includes a second sublens and a photosensitive assembly fixed together, the second sublens includes a second lens barrel and at least one second lens; the photosensitive assembly includes a photosensitive element; Wherein, the first sub-lens is arranged on the optical axis of the second sub-lens to form an imageable optical system including the at least one first lens and the at least one second lens; The first sub-lens and the second sub-lens are fixed together by a connection medium, and the connection medium is adapted to make the central axis of the first sub-lens have an inclination angle relative to the central axis of the second sub-lens . 2 . The camera module according to claim 1 , wherein the connecting medium is further adapted to make the central axis of the first sub-lens deviate from the central axis of the second sub-lens. 3 . 3 . The camera module according to claim 1 , wherein the connection medium is further adapted to provide a structural gap between the first sub-lens and the second sub-lens. 4 . 4. The camera module according to claim 1, wherein the connecting medium is an adhesive medium or a welding medium. 5 . The camera module according to claim 1 , wherein the central axis of the first sub-lens is offset from the central axis of the second sub-lens by 0-15 μm. 6. The camera module according to claim 1, wherein the central axis of the first sub-lens has an inclination angle of less than 0.5 degrees relative to the central axis of the second sub-lens. 7. The camera module according to claim 1, wherein the connection medium is further adapted to keep the relative position of the first sub-lens and the second sub-lens unchanged, and the relative position The measured resolution of the optical system imaging obtained through the photosensitive element is increased to a first threshold, and the measured image plane inclination of the optical system imaging obtained through the photosensitive element is reduced to a second threshold. 8. The camera module according to claim 7, wherein the second sub-lens further includes a motor, the measured resolution is the measured resolution when the motor is turned on, and the measured image plane tilt is when the motor is turned on The measured image plane tilt below. 9. The camera module according to any one of claims 1-8, wherein the second sub-lens and the photosensitive component are fixed together in a non-active calibration manner. 10. The camera module according to any one of claims 1-8, wherein there is a gap of 10-50 μm between the second sub-lens and the photosensitive component.