Camera lens assembly method and camera lens

Abstract

Provided in the present application are a camera lens assembly method and a camera lens. In the camera lens assembly method, coarse positioning of a first group and a second group is performed on the basis of visual inspection and non-contact testing, and during the coarse positioning, the first group and the second group are relatively independent of each other, and are not in contact connection or adhesive connection, thereby simplifying the assembly steps of a camera lens; in addition, the method provides a basis for subsequent AA adjustment, and if the AA adjustment fails, one of the groups may be replaced in time and the AA adjustment may then be performed again, thereby improving the assembly yield and material utilization efficiency of camera lenses.

Description

A method for assembling a camera lens and the camera lens itself. Technical Field

[0001] This application relates to the field of camera module technology, specifically to a camera lens assembly method and a camera lens. Background Technology

[0002] A modular multi-group lens comprises a lens barrel assembly, external lens elements, and at least one internal lens element. In existing technologies, the lens elements and lens barrel need to be pre-assembled during lens assembly, followed by adjustments in at least one direction based on image quality. The drawbacks of this method are that pre-assembly adds an assembly step, and adhesive is applied to the groups before the two groups undergo AA (Active Alignment) adjustments. If the AA adjustment fails, both groups must be discarded, making it impossible to replace one group for reassembly and adjustment. Furthermore, the material utilization rate of the lens is low.

[0003] Therefore, it is necessary to provide a camera lens assembly method with a simple assembly process and high material utilization, as well as a camera lens. Summary of the Invention

[0004] The purpose of this application is to provide a camera lens assembly method and a camera lens, wherein the camera lens assembly method has a simple assembly process and high material utilization.

[0005] The technical solution of this application is as follows:

[0006] In a first aspect, this application provides a method for assembling a camera lens, which includes the following steps:

[0007] S1, coarse positioning of the first group and the second group is completed based on visual detection and non-contact height measurement respectively; the visual detection is used to determine the relative position between the first group and the second group, and the non-contact height measurement is used to detect the tilt angle and height position of the first group and the second group; the second group is located on the image side of the first group, the first group includes a lens barrel and a lens group housed in the lens barrel, and the second group includes an image-side lens;

[0008] S2, after coarse positioning in step S1, at least one degree of freedom of pose adjustment is performed on at least one of the first group and the second group to obtain qualified imaging performance. The relative pose parameters of the first group and the second group are measured and recorded based on the visual detection and the non-contact height measurement detection.

[0009] S3, after the processing in step S2, move the first group or the second group to the glue application station to apply glue;

[0010] S4, After applying glue, return the first group or the second group to the position recorded in step S2 according to the relative pose parameters;

[0011] S5, the first group and the second group processed in step S4 are solidified to connect the first group and the second group to obtain a camera lens.

[0012] Optionally, in step S1, the center deviation between the first group and the second group is within ±5µm, and the tilt deviation between the first group and the second group is within ±0.01°.

[0013] Optionally, the visual detection includes the steps of: using a first visual detection system and a second visual detection system to detect the positions of the first group and the second group respectively; and uniformly converting the point information of the first group and the second group detected by the first visual detection system and the second visual detection system to any one visual detection system to confirm the relative positional relationship between the first group and the second group.

[0014] Optionally, in the visual detection, the point information of the first group and the second group detected by the first visual detection system and the second visual detection system respectively is uniformly converted to the first visual detection system; the conversion formula is Equation 1: In Equation 1 A P is the coordinate of the first visual detection system in space. B P is the coordinate of the second visual detection system in space. Let be the rotation and translation matrix for coordinate transformation between the first visual detection system and the second visual detection system.

[0015] Optionally, the non-contact height measurement includes the following steps: using a non-contact height sensor to test the height of at least three points on a plane, and obtaining the height value of each point; calculating the tilt angle of the plane based on the measured height values ​​of each point and the relative distance between each point.

[0016] Optionally, the non-contact height measurement sensor includes a triangulation laser sensor or a white light confocal sensor. Optionally, in the non-contact height measurement detection, a white light confocal sensor is used; the number of position points is four, namely a first position point, a second position point, a third position point, and a fourth position point. The heights of each position point measured by the white light confocal sensor are h1, h2, h3, and h4, respectively. The first and third position points are positioned relative to each other along the y-axis, with a relative distance of d1. The second and fourth position points are positioned relative to each other along the x-axis, with a relative distance of d2. According to Equation 2:

[0017] Calculate the tilt angle around the x-axis according to Equation 3: Calculate the tilt angle around the y-axis.

[0018] Optionally, in step S2, the imaging performance includes one or more of MTF, SFR, or TV Line.

[0019] Optionally, when the adhesive used in step S4 is a UV adhesive; in step S5, the curing process includes UV curing or heat curing.

[0020] Secondly, this application provides a camera lens, which is assembled using the camera lens assembly method described above.

[0021] The beneficial effects of this application are as follows: The camera lens assembly method described in this application performs coarse positioning of the first group and the second group based on visual inspection and non-contact testing. During the coarse positioning process, the first group and the second group are relatively independent and there is no contact connection or glue connection, which simplifies the camera lens assembly steps; at the same time, it provides a basis for subsequent AA adjustment. If the AA adjustment fails, one of the groups can be replaced in time and the AA adjustment can be performed again, which improves the yield rate and material utilization rate of the camera lens assembly. Attached Figure Description

[0022] Figure 1 is a flowchart of the camera lens assembly method of this application.

[0023] Figure 2 is a schematic diagram of the distribution of the first and second groups in coarse localization.

[0024] Figure 3 is a schematic diagram of the visual inspection process.

[0025] Figure 4 is a schematic diagram of visual detection of the first group and the second group using the first visual detection system and the second visual detection system.

[0026] Figure 5 is a schematic diagram of the non-contact height measurement process.

[0027] Figure 6 is a schematic diagram of the distribution of location points during non-contact height measurement.

[0028] Figure 7 is a schematic diagram of the test structure for the MTF test on the backlight path.

[0029] Figure 8 shows the image plane tilt curves when the first group performs an x-axis scanning motion relative to the second group; (a) is the image tilt y curve, and (b) is the image tilt x curve.

[0030] Figure 9 is a schematic diagram showing the distribution of the curing light source along the camera lens during UV curing.

[0031] Among them, 1-first group, 11-lens barrel, 12-lens group, 2-second group, 21-image-side lens, 111-image-side surface of lens barrel, 112-object-side surface of lens barrel, 211-object-side surface of image-side lens, 212-image-side surface of image-side lens, 3-first vision inspection system, 4-second vision inspection system, 5-reticle assembly, 51-lifting drive, 52-reticle, 6-first group drive, 7-second group drive, 8-performance testing system, 9-curing light source, 10-camera lens, P1-first position information, P2-second position information, P3-first position point, P4-second position point, P5-third position point, P6-fourth position point. Detailed Implementation

[0032] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0033] In a first aspect, this application provides a method for assembling a camera lens, as shown in Figure 1, which includes the following steps:

[0034] S1, coarse positioning of the first group 1 and the second group 2 is completed based on visual detection and non-contact height measurement. The visual detection is used to determine the relative offset position between the first group 1 and the second group 2, and the non-contact height measurement is used to detect the tilt angle and height position of the first group 1 and the second group 2. Referring to Figure 2, the second group 2 is located on the image side of the first group 1. The first group 1 includes a lens barrel 11 and a lens group 12 housed within the lens barrel 11. The second group 2 includes an image-side lens 21. It should be noted that in this application, the x, y, and z directions are set parallel to the x-axis, y-axis, and z-axis in the spatial coordinate system, respectively. The three directions x, y, and z are set perpendicular to each other in space. Rx refers to rotation about the x-axis, and Ry refers to rotation about the y-axis. In this application, the coarse positioning of the first group 1 and the second group 2 mainly includes five degrees of freedom, namely x, y, z, Rx, and Ry. Specifically, in this application, the relative offset position between the first group 1 and the second group 2 refers to the relative offset between the first group 1 and the second group 2 along the x-axis and y-axis; the tilt angle between the first group 1 and the second group 2 refers to Rx and Ry; and the detection of the height position of the first group 1 and the second group 2 refers to the height of the first group 1 and the second group 2 along the z-axis.

[0035] S2, after coarse positioning in step S1, at least one degree of freedom of pose adjustment is performed on at least one of the first group 1 and the second group 2 to obtain qualified imaging performance. The relative pose parameters of the first group 1 and the second group 2 are measured and recorded based on the visual detection and the non-contact height measurement detection.

[0036] S3, after the processing of step S2, move the first group 1 or the second group 2 to the glue application station to apply glue;

[0037] S4, After applying glue, return the first group 1 or the second group 2 to the position recorded in step S2 according to the relative pose parameters;

[0038] S5, the first group 1 and the second group 2 processed in step S4 are solidified to connect the first group 1 and the second group 2 to obtain a camera lens.

[0039] The camera lens assembly method described in this application performs coarse positioning of the first group 1 and the second group 2 based on visual inspection and non-contact testing. During the coarse positioning process, the first group 1 and the second group 2 are relatively independent and there is no contact connection or glue connection between them, which simplifies the camera lens assembly steps. At the same time, it provides a basis for subsequent AA adjustment. If the AA adjustment fails, one of the groups can be replaced in time and the AA adjustment can be performed again, which improves the yield rate and material utilization rate of the camera lens assembly.

[0040] Optionally, in step S1, the center deviation between the first group 1 and the second group 2 is within ±5µm, and the tilt deviation between the first group 1 and the second group 2 is within ±0.01°.

[0041] Optionally, referring to Figure 3, the visual detection includes the following steps: using a first visual detection system 3 and a second visual detection system 4 to detect the positions of the first group 1 and the second group 2, respectively, obtaining first point information P1 and second point information P2; and uniformly converting the point information of the first group 1 and the second group 2 detected by the first visual detection system 3 and the second visual detection system to any one visual detection system to confirm the relative positional relationship between the first group 1 and the second group 2. A schematic diagram of the visual detection of the first group 1 and the second group 2 using the first visual detection system 3 and the second visual detection system 4 is shown in Figure 4.

[0042] Optionally, in the visual detection, the point information of the first group 1 and the second group 2 detected by the first visual detection system 3 and the second visual detection system 4 respectively is uniformly converted to the first visual detection system 3; the conversion formula is Equation 1: In Equation 1 A P is the coordinate of the first visual detection system 3 in space. B P is the coordinate of the second visual detection system 4 in space. It is the rotation and translation matrix for coordinate transformation between the first visual detection system 3 and the second visual detection system 4.

[0043] Both the first visual inspection system 3 and the second visual inspection system 4 include a visual camera, a camera lens, and a light source. In use, the camera lens is positioned facing the light source, the light source exposes the group to be inspected, and the visual camera acquires an image of the group to be inspected.

[0044] Optionally, referring to Figure 5, the non-contact height measurement detection includes the following steps: determining test location points on the same plane; using a non-contact height sensor to measure the height of at least three location points on a plane, obtaining the height value of each location point; and calculating the tilt angle of the plane based on the measured height values ​​of each location point and the relative distance between each location point. The plane detected by the non-contact height measurement detection includes the image-side surface 111 or the object-side surface 112 of the lens barrel, or the object-side surface 211 of the image-side lens or the image-side surface 212 of the lens barrel.

[0045] Optionally, the non-contact height measurement sensor includes a triangulation laser sensor or a white light confocal sensor.

[0046] Optionally, in the non-contact height measurement, the non-contact height sensor used is a white light confocal sensor; referring to Figure 6, the number of position points selected on the same plane is 4, namely, the first position point P3, the second position point P4, the third position point P5, and the fourth position point P6. The heights of each position point measured by the white light confocal sensor are h1, h2, h3, and h4, respectively. The first position point P3 and the third position point P5 are set relative to each other along the y-direction, and the relative distance between the first position point P3 and the third position point P5 is d1. The second position point P4 and the fourth position point P6 are set relative to each other along the x-direction, and the relative distance between the second position point P4 and the fourth position point P6 is d2; according to Equation 2: Calculate the tilt angle around the x-axis according to Equation 3: Calculate the tilt angle around the y-axis.

[0047] In step S2, the imaging performance includes one or more of MTF, SFR, or TV Line. MTF is an abbreviation for Modulation Transfer Function; SFR is an abbreviation for Spatial Frequency Response; and TV Line is an abbreviation for Television Line.

[0048] The preliminary lens imaging performance and the lens imaging performance after pose adjustment can be tested using either a backlight path or a frontlight path. Taking the MTF performance test using a backlight path as an example, the lens imaging performance test will be described. Referring to Figure 7, the backlight path testing device includes a reticle assembly 5 arranged along the z-direction, a first group drive member 6 and a second group drive member 7 located on both sides of the reticle assembly 5, and a performance testing system 4 located on top of the reticle assembly 5. The reticle assembly 5 includes a lifting drive member 51 and a reticle 52 driven by the lifting drive member 51. The first group drive member 6 and the second group drive member 7 are used to drive the first group 1 and the second group 2 to move, respectively. Specifically, the performance testing system 8 can be an MTF tester. The MTF performance test using the reverse light path method includes the following steps: the lifting drive component drives the reticle to move, thereby changing the lens image distance of the lens in the vision detection system, and simultaneously calculates the MTF at multiple field points, which can generate a set of defocus curves; based on the obtained defocus curves, the image plane tilt can be calculated; the calculation formula for the image plane tilt in the y-direction is shown in Equation 4, Equation 4: In Equation 4, shift is the field curvature and image high is the image height; correspondingly, the image tilt x value can be obtained.

[0049] Specifically, the second group 2 remains stationary, while the first group 1 performs a scanning motion in the X direction relative to the second group 2. Each time the movement reaches a new position, image tilt x and image tilt y are calculated, and fitted curves are plotted accordingly, as shown in Figure 8. The intersection of the fitted curves with the horizontal axis is the optimal position point of the first group 1 relative to the second group 2.

[0050] Optionally, when the adhesive used in step S4 is a UV adhesive; in step S5, the curing treatment includes UV curing or thermal curing. When using UV curing, the curing light sources 9 are evenly distributed around the circumference of the camera lens 10 to ensure the uniformity of the UV curing of the adhesive; specifically, as shown in Figure 9, four points of UV irradiation are used, and the number of curing light sources 9 is four. When using thermal curing, the temperature of the thermal curing treatment is 80±3℃; specifically, when using thermal curing, the camera lens is first UV cured, and then the UV-cured camera lens is thermally cured at 80±3℃.

[0051] Secondly, this application provides a camera lens, which is assembled using the camera lens assembly method described above.

[0052] The above description is merely an embodiment of this application. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this application, but these improvements all fall within the protection scope of this application.

Claims

1. A method for assembling a camera lens, characterized in that, Including the following steps: S1, coarse positioning of the first group and the second group is completed based on visual detection and non-contact height measurement respectively; the visual detection is used to determine the relative offset position between the first group and the second group, and the non-contact height measurement is used to detect the tilt angle and height position of the first group and the second group; the second group is located on the image side of the first group, the first group includes a lens barrel and a lens group housed in the lens barrel, and the second group includes an image-side lens. S2, after coarse positioning in step S1, at least one degree of freedom of pose adjustment is performed on at least one of the first group and the second group to obtain qualified imaging performance. The relative pose parameters of the first group and the second group are measured and recorded based on the visual detection and the non-contact height measurement detection. S3, after the processing in step S2, move the first group or the second group to the glue application station to apply glue; S4, After applying glue, return the first group or the second group to the position recorded in step S2 according to the relative pose parameters; S5, the first group and the second group processed in step S4 are solidified to connect the first group and the second group to obtain a camera lens.

2. The camera lens assembly method according to claim 1, characterized in that, In step S1, the center deviation between the first group and the second group is within ±5um, and the tilt deviation between the first group and the second group is within ±0.01°.

3. The camera lens assembly method according to claim 1, characterized in that, The visual detection includes the following steps: using a first visual detection system and a second visual detection system to detect the positions of the first group and the second group respectively; and uniformly converting the position information of the first group and the second group detected by the first visual detection system and the second visual detection system to any one visual detection system to confirm the relative positional relationship between the first group and the second group.

4. The camera lens assembly method according to claim 3, characterized in that, In the visual detection, the point information of the first group and the second group detected by the first visual detection system and the second visual detection system respectively is uniformly converted to the first visual detection system; The conversion formula is Equation 1: In Equation 1 A P is the coordinate of the first visual detection system in space. B P is the coordinate of the second visual detection system in space. Let be the rotation and translation matrix for coordinate transformation between the first visual detection system and the second visual detection system.

5. The camera lens assembly method according to claim 1, characterized in that, The non-contact height measurement includes the following steps: using a non-contact height sensor to measure the height of at least three points on a plane, and obtaining the height value of each point; calculating the tilt angle of the plane based on the measured height values ​​of each point and the relative distance between each point.

6. The camera lens assembly method according to claim 5, characterized in that, The non-contact height measurement sensor includes a triangulation laser sensor or a white light confocal sensor.

7. The camera lens assembly method according to claim 6, characterized in that, In the non-contact height measurement, a white light confocal sensor is used. There are four position points: a first position point, a second position point, a third position point, and a fourth position point. The heights of each position point measured by the white light confocal sensor are h1, h2, h3, and h4, respectively. The first and third position points are positioned relative to each other along the y-axis, with a relative distance of d1. Positions P2 and P4 are positioned relative to each other along the x-axis, with a relative distance of d2 between the second and fourth position points. According to Equation 2: Calculate the tilt angle around the x-axis according to Equation 3: Calculate the tilt angle around the y-axis.

8. The camera lens assembly method according to claim 1, characterized in that, In step S2, the imaging performance includes one or more of MTF, SFR, or TV Line.

9. The camera lens assembly method according to claim 1, characterized in that, When the adhesive used in step S4 is a UV adhesive; in step S5, the curing process includes UV curing or heat curing.

10. A camera lens, characterized in that, The camera lens is assembled using the camera lens assembly method as described in any one of claims 1-9.

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