Camera lens assembly method and camera lens

Abstract

The present invention provides a camera lens assembly method and a camera lens; the camera lens assembly method performs rough positioning of the first group and the second group based on visual detection and non-contact testing; during the rough positioning process, the first group and the second group are relatively independent and do not have contact connection or glue connection, thereby simplifying the camera lens assembly steps; and at the same time, a basis is provided for subsequent AA adjustment; if the AA adjustment fails, one of the groups can be replaced in time and then the AA adjustment can be performed again, thereby improving the assembly yield rate and material utilization rate of the camera lens.

Description

Technical Field

[0001] The present invention relates to the technical field of camera modules, and in particular to a camera lens assembly method and a camera lens. Background Art

[0002] The split multi-group lens includes a lens barrel component, an external lens, and at least one internal lens. In the prior art, the lens and the lens barrel need to be pre-assembled during the lens assembly process, and then adjusted in at least one direction according to the image quality. The drawback of this method is that the pre-assembly increases the assembly process, and the glue is applied to the groups before the two groups AA adjustment (Active Alignment, active alignment detection and assembly). If the AA adjustment fails, the two groups can only be scrapped, and it is impossible to replace one of the groups for reassembly and adjustment, and the material utilization rate of the lens is low.

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

[0004] The object of the present invention is to provide a camera lens assembly method and a camera lens, wherein the camera lens assembly method has simple assembly procedures and high material utilization rate.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a camera lens assembly method, comprising the steps of:

[0007] S1, based on visual detection and non-contact height measurement detection, respectively, the first group and the second group are roughly positioned; the visual detection is used to determine the relative position between the first group and the second group, and the non-contact height measurement detection is used to detect the inclination 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 accommodated in the lens barrel, and the second group includes an image side lens;

[0008] S2, after the rough positioning in step S1, adjusting the posture of at least one of the first group and the second group by at least one degree of freedom to obtain qualified imaging performance, and measuring and recording the relative posture parameters of the first group and the second group based on the visual detection and the non-contact height measurement detection;

[0009] S3, after being processed in step S2, moving the first group or the second group to a gluing station to apply glue;

[0010] S4, after gluing, returning the first group or the second group to the position recorded in step S2 according to the relative posture parameter;

[0011] S5, performing a solidification process on the first group and the second group processed in step S4, so as to connect the first group and the second group to obtain a camera lens.

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

[0013] Optionally, the visual detection includes the steps of: respectively using a first visual detection system and a second visual detection system to detect the positions of the first group and the second group; 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 position relationship between the first group and the second group.

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

[0015] Optionally, the non-contact height measurement detection includes the steps of: using a non-contact height measurement sensor to test the height of at least three points on a plane to obtain the height value of each point; and calculating the inclination angle of the plane based on the measured height value of each point and the relative distance value 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, the non-contact height measurement sensor used is a white light confocal sensor; the number of the position points is 4, and the position points are respectively the first position point, the second position point, the third position point and the fourth position point, and the heights of the position points measured by the white light confocal sensor are respectively h1, h2, h3 and h4, the first position point and the third position point are relatively arranged along the y direction, and the relative distance between the first position point and the third position point is d1, the second position point and the fourth position point are relatively arranged along the x direction, and the relative distance between the second position point and the fourth position point is d2; according to Formula 2: Calculate the tilt angle around the x-axis according to formula 3: Calculates the tilt angle about the y-axis.

[0017] Optionally, in step S2, the imaging performance includes one or more of MTF, SFR or TV Line.

[0018] Optionally, when the glue used in step S4 is UV glue; in step S5, the curing treatment includes UV curing treatment or thermal curing treatment.

[0019] In a second aspect, the present invention provides a camera lens, wherein the camera lens is assembled using the camera lens assembly method as described above.

[0020] The beneficial effects of the present invention are as follows: the assembly method of the camera lens of the present invention performs rough positioning of the first group and the second group based on visual detection and non-contact testing. During the rough positioning process, the first group and the second group are relatively independent and there is no contact connection or glue connection, which simplifies the assembly steps of the camera lens; 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 then AA adjustment can be performed again, which improves the assembly yield and material utilization rate of the camera lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of the camera lens assembly method.

[0022] Figure 2 This is a schematic diagram of the distribution of the first group and the second group in rough positioning.

[0023] Figure 3 Schematic diagram of the visual inspection process.

[0024] Figure 4 It is a schematic diagram of using the first visual inspection system and the second visual inspection system to perform visual inspection on the first group and the second group.

[0025] Figure 5 This is a schematic diagram of the process of non-contact height measurement.

[0026] Figure 6 Schematic diagram of the distribution of position points during non-contact height measurement.

[0027] Figure 7 Schematic diagram of the test structure for the reverse light path MTF test.

[0028] Figure 8 Graphs showing image tilt when the first group performs x-direction scanning motion relative to the second group; (a) is a graph showing image tilt y, and (b) is a graph showing image tilt x.

[0029] Fig. 9 Schematic diagram of the distribution of the curing light source along the camera lens during UV curing treatment.

[0030] Among them, 1-first group, 11-lens barrel, 12-lens group, 2-second group, 21-image side lens, 111-image side surface of the lens barrel, 112-object side surface of the lens barrel, 211-object side surface of the image side lens, 212-image side surface of the image side lens, 3-first visual detection system, 4-second visual detection system, 5-graticule assembly, 51-lifting drive member, 52-graticule, 6-first group drive member, 7-second group drive member, 8-performance test system, 9-curing light source, 10-camera lens, P1-first point information, P2-second point information, P3-first position point, P4-second position point, P5-third position point, P6-fourth position point. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0032] In a first aspect, the present invention provides a camera lens assembly method, referring to Figure 1 As shown, it includes the steps of:

[0033] S1, based on visual detection and non-contact height measurement detection, respectively complete the rough positioning of the first group 1 and the second group 2; 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 detection is used to detect the inclination angle and height position of the first group 1 and the second group 2; see Figure 2As shown, 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 accommodated in the lens barrel 11, and the second group 2 includes an image side lens 21; it should be noted that in the present invention, the x direction, y direction and z direction are respectively arranged parallel to the x axis, y axis and z axis in the space coordinate system, the three directions of the x direction, y direction and z direction are arranged perpendicular to each other in space, Rx refers to the rotation around the x direction, and Ry refers to the rotation around the y direction. In the present invention, the rough positioning of the first group 1 and the second group 2 mainly includes five degrees of freedom, including x, y, z, Rx and Ry. Specifically, in the present invention, the relative offset position between the first group 1 and the second group 2 refers to the relative offset of the first group 1 and the second group 2 along the x axis and the y axis; the inclination angles of the first group 1 and the second group 2 refer to Rx and Ry; 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.

[0034] S2, after the rough positioning in step S1, adjusting the posture of at least one of the first group 1 and the second group 2 by at least one degree of freedom to obtain qualified imaging performance, and measuring and recording the relative posture parameters of the first group 1 and the second group 2 based on the visual detection and the non-contact height measurement detection;

[0035] S3, after being processed in step S2, moving the first group 1 or the second group 2 to a gluing station to apply glue;

[0036] S4, after gluing, returning the first group 1 or the second group 2 to the position recorded in step S2 according to the relative posture parameters;

[0037] S5, performing a curing process on the first group 1 and the second group 2 processed in step S4, so as to connect the first group 1 and the second group 2 to obtain a camera lens.

[0038] The camera lens assembly method of the present invention performs rough positioning of the first group 1 and the second group 2 based on visual detection and non-contact testing. During the rough positioning process, the first group 1 and the second group 2 are relatively independent and do not have 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 then the AA adjustment can be performed again, which improves the assembly yield and material utilization rate of the camera lens.

[0039] Optionally, in step S1, a center deviation between the first group 1 and the second group 2 is within ±5 um, and a tilt deviation between the first group 1 and the second group 2 is within ±0.01°.

[0040] Optional, see Figure 3 As shown, the visual inspection includes the steps of: respectively using the first visual inspection system 3 and the second visual inspection system 4 to detect the positions of the first group 1 and the second group 2, respectively obtaining the first point information P1 and the 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 inspection system 3 and the second visual inspection system to any visual inspection system to confirm the relative position relationship between the first group 1 and the second group 2. See the schematic diagram of the visual inspection of the first group 1 and the second group 2 using the first visual inspection system 3 and the second visual inspection system 4. Figure 4 shown.

[0041] Optionally, in the visual inspection, the point information of the first group 1 and the second group 2 respectively detected by the first visual inspection system 3 and the second visual inspection system 4 are uniformly converted to the first visual inspection system 3; the conversion formula used is Formula 1: In formula 1 A P is the coordinate of the first visual detection system 3 in space, B P is the coordinate of the second visual inspection system 4 in space, is the rotation and translation matrix of the coordinate transformation between the first visual inspection system 3 and the second visual inspection system 4.

[0042] The first visual inspection system 3 and the second visual inspection system 4 both include a visual camera, a camera lens and a light source. When in use, the camera lens is arranged toward the light source, the light source exposes the group to be inspected, and the visual camera collects images of the group to be inspected.

[0043] Optional, see Figure 5 As shown, the non-contact height measurement detection includes the steps of: determining a test position point on the same plane; using a non-contact height measurement sensor to test the height of at least three positions on a plane to obtain the height value of each position point; and calculating the inclination angle of the plane according to the measured height value of each position point and the relative distance value between each position point. The plane detected by the non-contact height measurement detection includes the image side surface 111 of the lens barrel 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.

[0044] Optionally, the non-contact height measurement sensor includes a triangulation laser sensor or a white light confocal sensor.

[0045] Optionally, in the non-contact height measurement detection, the non-contact height measurement sensor used is a white light confocal sensor; see Figure 6 As shown, the number of position points selected on the same plane is 4, and the position points are respectively a first position point P3, a second position point P4, a third position point P5 and a fourth position point P6, and the heights of the position points measured by the white light confocal sensor are respectively h1, h2, h3 and h4, the first position point P3 and the third position point P5 are relatively arranged 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 relatively arranged along the x direction, and the relative distance between the second position point P4 and the fourth position point P6 is d2; according to Formula 2: Calculate the tilt angle around the x-axis according to formula 3: Calculates the tilt angle about the y-axis.

[0046] In step S2, the imaging performance includes one or more of MTF, SFR or TV Line. Among them, MTF is the abbreviation of Modulation Transfer Function, which is translated into Chinese as Modulation Transfer Function; SFR is the abbreviation of Spatial Frequency Response, which is translated into Chinese as Spatial Frequency Response; TV Line is the abbreviation of Television Line, which is translated into Chinese as TV Line or TV Line.

[0047] The preliminary lens imaging performance and the lens imaging performance after the posture adjustment can be performed in a reverse light path or a forward light path. Taking the MTF performance in a reverse light path as an example, the lens imaging performance test is described; wherein, see Figure 7As shown, the reverse light path test device includes a graticule assembly 5 arranged along the z direction, a first group driver 6 and a second group driver 7 arranged on both sides of the graticule assembly 5, and a performance test system 4 arranged on the top of the graticule assembly 5; the graticule assembly 5 includes a lifting driver 51 and a graticule 52 driven by the lifting driver 51, the first group driver 6 and the second group driver 7 are used to drive the first group 1 and the second group 2 to move respectively, and the specific performance test system 8 can be an MTF tester. The MTF performance test using the reverse light path includes the steps of: the lifting driver drives the graticule to move, thereby changing the lens image distance of the lens in the visual inspection system, and calculating the MTF of multiple field of view points at the same time, so that a set of defocus curves can be drawn; the image plane tilt can be calculated based on the obtained defocus curve; the calculation formula of the image plane tilt in the y direction is shown in Formula 4, Formula 4: In formula 4, shift is the field curvature, image high is the image height; correspondingly, the image tilt x value can be obtained.

[0048] Specifically, the second group 2 is fixed, and the first group 1 performs scanning motion in the X direction relative to the second group 2. Image tilt x and image tilt y are calculated once for each position moved, and fitting curves are drawn respectively. Figure 8 As shown, the intersection of the fitting calculation curve and the abscissa is the optimal position point of the first group 1 relative to the second group 2.

[0049] Optionally, when the glue used in step S4 is UV glue; in step S5, the curing process includes UV curing process or thermal curing process. When the UV curing process is used, the curing light source 9 is evenly distributed along the circumference of the camera lens 10 to ensure the uniformity of the UV curing process of the glue; for details, see Fig. 9 As shown, 4-point UV irradiation is adopted, and the number of the curing light sources 9 is 4. When the thermal curing treatment is adopted, the temperature of the thermal curing treatment is 80±3°C; specifically, when the thermal curing treatment is adopted, the camera lens is first subjected to UV curing treatment, and then the camera lens after UV curing treatment is subjected to thermal curing treatment at 80±3°C.

[0050] In a second aspect, the present invention provides a camera lens, wherein the camera lens is assembled using the camera lens assembly method as described above.

[0051] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A camera lens assembly method, characterized in that: Includes steps: S1, based on visual detection and non-contact height measurement detection, respectively, the first group and the second group are roughly positioned; 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 detection is used to detect the inclination 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 accommodated in the lens barrel, and the second group includes an image side lens; S2, after the rough positioning in step S1, adjusting the posture of at least one of the first group and the second group by at least one degree of freedom to obtain qualified imaging performance, and measuring and recording the relative posture parameters of the first group and the second group based on the visual detection and the non-contact height measurement detection; S3, after being processed in step S2, moving the first group or the second group to a gluing station to apply glue; S4, after gluing, returning the first group or the second group to the position recorded in step S2 according to the relative posture parameter; S5, performing a solidification process on the first group and the second group processed in step S4, so as 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 ±5 um, 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 inspection includes the steps of: respectively using a first visual inspection system and a second visual inspection system to inspect the positions of the first group and the second group; uniformly converting the point information of the first group and the second group detected by the first visual inspection system and the second visual inspection system to any one of the visual inspection systems to confirm the relative position 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 inspection, the point information of the first group and the second group respectively detected by the first visual inspection system and the second visual inspection system are uniformly converted to the first visual inspection system; The conversion formula used is formula 1: In formula 1 A P is the coordinate of the first visual inspection system in space, B P is the coordinate of the second visual inspection system in space, is the rotation and translation matrix for coordinate transformation between the first vision inspection system and the second vision inspection system.

5. The camera lens assembly method according to claim 1, characterized in that: The non-contact height measurement detection includes the steps of: using a non-contact height measurement sensor to test the height of at least three positions on a plane to obtain the height value of each position point; and calculating the inclination angle of the plane according to the measured height value of each position point and the relative distance value between each position 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 detection, the non-contact height measurement sensor used is a white light confocal sensor; the number of the position points is 4, and the position points are respectively the first position point, the second position point, the third position point and the fourth position point, and the heights of the position points measured by the white light confocal sensor are respectively h1, h2, h3 and h4, the first position point and the third position point are relatively arranged along the y direction, and the relative distance between the first position point and the third position point is d1, P2 and P4 are relatively arranged along the x direction, and the relative distance between the second position point and the fourth position point is d2; according to Formula 2: Calculate the tilt angle around the x-axis according to formula 3: Calculates the tilt angle about 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 glue used in step S4 is UV glue; in step S5, the curing process includes UV curing process or thermal curing process.

10. A camera lens, characterized in that: The camera lens is assembled using the camera lens assembly method according to any one of claims 1 to 9.

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